- Email: [email protected]
Enhancing antimicrobial properties of dyed and finished cotton fabrics
Carbohydrate Polymers 78 (2009) 502–510
Contents lists available at ScienceDirect
Carbohydrate Polymers journal homepage: www.elsevier.com/locate/carbpol
Enhancing antimicrobial properties of dyed and finished cotton fabrics Mohamed Hashem a, Nabil A. Ibrahim a,*, Wfaa A. El-Sayed b, Shereef El-Husseiny b, Elham El-Enany b a b
Textile Division, National Research Centre, Dokki, Cairo, Egypt Faculty of Girls, Ain-Shams University, Cairo, Egypt
a r t i c l e
i n f o
Article history: Received 6 April 2009 Received in revised form 8 May 2009 Accepted 11 May 2009 Available online 18 May 2009 Keywords: 1,2,3-Benzothiazole-7-thiocarboxylic acidS-methylester Antimicrobial Biocides Cotton fabric Finishing
a b s t r a c t 1,2,3-Benzothiazole-7-thiocarboxylic acid-S-methylester (commercially known as ActigardÒ AM-87) was utilized to impart cotton fabric durable antimicrobial properties. Finishing treatment was carried out under a variety of conditions. The latter were included, effect of pH, concentration of antibacterial agents, curing temperature and curing time. The effect of fabric construction, mercerization, and dyeing with different dyestuff were also investigated. The study was also extended to investigate the technical feasibility of combining antimicrobial finishing treatment in question with other finishing treatment generally carried out on cotton fabric, like soft finishing and crease recovery finishing. The treated fabrics were monitored for antimicrobial properties before and after washing. The treated fabrics were also evaluated for the physio-mechanical properties like fabric tensile strength, elongation at break (or bursting strength for knitted fabric), wettability, crease recovery angle, whiteness index and roughness. Results obtained show that, the most appropriate conditions for treatment cotton fabric with ActigardÒ are: padding the cotton fabric in aqueous solution containing 6% ActigardÒ at pH 5 (adjusted using formic acid) then squeezed to wet pick up of 100%, dried at 80 °C for 5 min then cured at 100 °C for 150 s. The untreated cotton fabric did not show any antimicrobial activity towards Staphylococcus aureus or Escherichia coli. Treatment of cotton fabric with ActigardÒ improves its antimicrobial properties towards S. aureus or E. coli. It is also observed that, treatment of cotton fabric with ActigardÒ marginally decreases fabric tensile strength, elongation at break, roughness and WI, whereas; both wettability and crease recovery angle remain practically intact. This was observed whether the fabric was pre-mercerized or not. Ó 2009 Elsevier Ltd. All rights reserved.
1. Introduction In industrial practices, each decade brings into focus new technologies as a marketing strategy to boost the sale both in domestic and export markets. Textile industry is no exception to this. One of the themes which are dominating the present decade in the textile industry is the ‘‘medical textile”. Microbial damage to raw cotton is a common problem, because cotton fabrics have poor resistance to microorganisms and thus the possibility of harming the human body due to the close contact between skin and textile after only short wearing times they are crowded by microorganisms. Additionally, the environmental conditions on textiles are similarly favorable as on the skin and thus support the bacteria growth (Allen, Auer, & Pailthorpe, 2005; Böhringer, Rupp, & Yonenaga, 2000). Antimicrobial finishes prevent the growth of microorganisms on fabrics used in wide variety of apparel, home furnishing, commercial and industrial products. Fabrics for tents, tarpaulins, and auto fabrics will have a longer life when treated with some type of antimicrobial finish that reduces or prevents damage from rot and mildew (Joseph & Marjory, 1998). * Corresponding author. E-mail address: [email protected] (N.A. Ibrahim). 0144-8617/$ - see front matter Ó 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.carbpol.2009.05.007
The purpose of an antimicrobial finish is to (Böhringer et al., 2000; Rouette, 2001): – Prevent the transmission and spreading of pathogenic (disease causing) microbes. – Inhibit odor development resulting from microbial degradation. – Avoid losses of textile performance properties. Antimicrobial finishes should have the following requirements (Holme, 2007; Payne, 1997; Schatz, 2001; Sun & Xu, 1998, 1999). – – – – – –
Durability of activity to laundering dry cleaning. Selective activity towards undesirable micro organisms. Acceptable moisture transport properties. Compatibility with other finishing agents and easy to apply. Absence of toxic effects for both the manufacturer and consumer. Applicable with no adverse effect on the fabric properties including wear comfort. – Should be low cost. – Resistant to body fluids and to disinfections (sterilization). Graft polymerization of cellulosic textiles with poly(2-methyl-5vinylpyridine) followed by treatment with potassium iodide solution imparts antibacterial and antifungal activity (Holme,
503
M. Hashem et al. / Carbohydrate Polymers 78 (2009) 502–510
2007; Payne, 1997; Schatz, 2001; Sun & Xu, 1998, 1999). One of the most durable type of antimicrobial products is based on a diphenyl ether (bis-phenyl) derivative like 2,4,40 -trichloro0 -2-hydroxy diphenyl ether or 5-chloro-2-(2-dichloro-phenoxyl) phenol (Chung, Lee, & Kim, 1998; Sekar, 2001; Washino, 1993; Wenming, Peixin, Wei, & Oing, 2002). Quaternary ammonium compounds, biguanide, amines and glucoprotamine show polycationic, porous and absorbent properties. Fibres finished with these substances bind microorganisms to their cell membrane resulting in the breakdown of the cell (Ha, Jung, Lee, Kim, & Kim, 1998; Lee & Jeong, 2005; Schindler & Hauser, 2004). Complexing metallic compounds based on metals like cadmium, silver, copper and mercury cause inhibition of the active enzyme center (inhibition of metabolism). Amongst these, the silver compounds are very popular and already been used in the preparation of antimicrobial drinking water (Ha et al., 1998; Lee & Jeong, 2005; Schindler & Hauser, 2004; Seo, Mitsuhashi, & Tanibe, 1992). Chitosan is an effective natural antimicrobial agent derived from chitin, a major component in crustacean shells. Coatings of chitosan on conventional fibres appear to be the more realistic prospect since; they do not provoke an immunological response. A fibre made from chitosan is also available in the market place (Ha et al., 1998; Lee & Jeong, 2005; Schindler & Hauser, 2004; Seo et al., 1992). The work presented in this paper aimed essentially at imparting cotton fabric an antimicrobial properties using 1,2,3-benzothiadiazole-7-thiocarboxylic acid-S-methyl ester (commercially known as ActigardÒ 87). The study was also extended to investigate the technical feasibility of combination between the antimicrobial treatment with other finishing treatment of cotton fabrics like easy care finishing, softener finishing and dyeing. 2. Experimental
2.2. Microorganisms used Both Staphylococcus aureus (S. aureus) (gram positive) and Escherichia coli (E. coli) (gram negative) were used for determination the antimicrobial properties of the treated samples according to AATCC standard test method (Rowe, 1978). 2.3. Dyes Table 2 summarizes the commercial name and colour index as well as the manufacture of dyes used. 2.4. Treatment of 100% cotton fabric with ActigardÒ 100% cotton fabric were padded to a wet pick up of 100% using laboratory padding machine in an aqueous solution containing ActigardÒ (0–9%), at pH (2.5–9). Acidic pH was adjusted using 1% formic acid whereas alkaline pH was adjusted using 1% aqueous NaOH. The fabric was then dried at 80 °C for 5 min then cured at (100–150 °C) for (60–210 s) in laboratory oven. The treated samples were then evaluated to antimicrobial activity before and after washing.
Table 2 Name, color index and the manufacture of the dyes used in our study.
2.1. Materials and chemicals Fabrics used and its specification are set out in Table 1. The fabrics were pre washed using an aqueous solution containing Na2CO3, (10 g/L), wetting agent (2 g/L) at 95 °C for 30 min, followed by washed several times with hot water then with cold water and dried at ambient conditions. ActigardÒ AM-87 was kindly supplied by Clariant international Ltd. (It is based on 1,2,3-benzothiadiazole-7-thiocarboxylic acid-Smethyl ester – shown by structure I): O
Silicon softener under commercial name of SiligenÒ SIA, cationic softener under commercial name of LeomineÒ NI and FixapretÒ Eco, were of technical grade chemicals kindly supplied by BASF International Ltd. MgCl26H2O, citric acid, sodium hypophosphite, gluteraldehyde, zinc sulphate, formic acid, sodium carbonate, sodium sulphate, sodium hydrosulphite, peptone, beef extract, agar, and sodium chloride, were of laboratory grade chemicals.
C
SCH3 S N
1,2,3-benzothiazole-7-thiocarboxylic acid-s-methylester (Actigard ®87)
Commercial name of dye
CI
Company
SunfixÒ Supra REd S3B SPE 150%
Reactive red 195
Alwan Misr Co., Egypt
Cibanon Navy Blue-01 Cibanon Scarlet BNIE 200% Cibacron Red FNR 0.05%
Vat Blue 20 Vat 89 Reactive Mix
Ciba Specialty Chemicals
Remazol plus Remazol Remazol Plus Remazol Remazol
Brilliant Blue R. Spec
Reactive blue 19
Dyestar
Brilliant Red 3BS Brilliant Yellow 4GL
Reactive Reactive 160 Reactive Reactive
Brilliant Red B.B. Turquoise Blue G plus
Reactive black B plus Reactive black HFGR plus Reactive red ME 4 BL
red 195 yellow red 21 blue 220
Reactive black 5 Reactive Mix Reactive red 195
Dyes and Intermediates Ltd.
Table 3 Dyeing recipes and conditions.
Table 1 Specification of the used substrates.
Dye
Shade (%)
[Salt] (g/L)
[Na2CO3] (g/L)
Temp. (°C)
Subs. No.
Fabrics specification
20
60
100% woven cotton fabric (Gabardine), bleached, not mercerized (229 g/m2), weave construction 1/3 carded yarn 100% woven cotton fabric (Popline), bleached, not mercerized (189 g/ m2), weave construction 1/1 carded yarn 100% woven cotton fabric (Gabardine), bleached, mercerized (229 g/ m2), weave construction 1/3 carded yarn 100% woven cotton fabric (Popline), bleached, mercerized (189 g/m2), weave construction 1/1 carded yarn 100% cotton, simple weave, (73/m2), weave construction 1/1 carded yarn 100% knitted cotton fabric, Single jersey (58 g/m2)
3.90 3.36 0.65
40
Subs (1)
Reactive black B plus Reactive black HFGR plus Reactive Red ME4BL Remazol Turquoise Blue G plus Remazol Brilliant Yellow 4 GL plus Remazol Brilliant Red BB
2.60
40
20
60
2.40
40
20
60
0.23 0.05
40
20
60
Subs. (2) Subs (3) Subs. (4) Subs. (5) Subs. (6)
Remazol Brilliant Blue R Spec. plus Remazol Brilliant Red 3BS Cibacron Red FNR 0.05%
0.25 0.014
504
M. Hashem et al. / Carbohydrate Polymers 78 (2009) 502–510
2.5. Pilot-scale experiment
E. coli Before
The antimicrobial activity of the treated samples against S. aureus and E. coli were determined using agar diffusion method. The experimental technique was adopted as follows: known diameter of a swatch treated fabric put in the center of an agar plate. The plates were incubated at 37 °C for 24 h, a growth free ‘‘zone of inhibition” around the fabric appears as the antibacterial agent migrates from the fabric onto the agar, and diffuses outward. Diameters of inhibition zones were determined according to AATCC test method 100–1999 (Fig. 1). Tensile strength and elongation at break of woven fabrics were determined according to ASTM standard test method D-168294 (1994). Bursting strength of the knitted fabrics was determined according to ASTM standard test method D-3786-01 (2002). Crease recovery angle of the fabric was determined according to AATCC test method 66-1972. Surface Roughness was measured according to JIS 94 Standard using measuring instrument SE 1700a made in Japan. Wettability was assessed in terms of drop disappearance, AATCC standard test method, D-79-1968. The degree of whiteness of the fabric sample expressed as whiteness index was measured using Colour EyeÒ 3100 spectrophotometer supplied with SDL international according to reported method (Rowe, 1978). The colour strength (K/S) of dyed fabric was assessed using Kubeka-Munk equation (Convert, Schacher, & Viallier, 1999):
Inhibition zone (mm)
2.6. Testing and analysis
Staph. Before
Staph. After
25
20
15
10
5
0 2.5
5
7
9
pH Fig. 2. Effect of pH on the antimicrobial properties of treated cotton fabric. Conditions used: bleached cotton fabric padded in aqueous solution containing 6% ActigardÒ, acidic pH was adjusted using 1% formic acid solution whereas alkaline pH was adjusted using 1% NaOH aqueous solution, wet pick up 100%, drying at 80 °C for 5 min, fixation at 120 °C for 90 s. (For interpretation of color mentioned in this figure legend the reader is referred to the web version of the article.)
E. coli Before
E. coli After
Staph. Before
Staph. After
30
Inhibition zone (mm)
Ten meters from each kind of cotton fabric (plain weave mercerized, twill weave and knitted cotton fabric) were dyed in winch machine (Barazoly). Dyeing recipes and conditions are set out in Table 3.
E. coli After
25 20 15 10 5 0 0
1
2
3
6
9
Actigard Concentration (% owb)
K=S ¼ ð1 RÞ2 =2R where K, S, and R are the absorption coefficient, scattering coefficient, and reflectance, respectively. 3. Results and discussion
Fig. 3. Effect of ActigardÒ concentration on the antimicrobial properties of the treated cotton fabric. Conditions used: bleached cotton fabric padded in aqueous solution containing ActigardÒ, pH was adjusted at 5 using 1% diluted formic acid, wet pick up, 100%, drying at 80 °C for 5 min, fixation at 120 °C for 90 s. (For interpretation of color mentioned in this figure legend the reader is referred to the web version of the article.)
3.1. Effect of pH 100% cotton fabric was treated with an aqueous solution containing 1,2,3-benzothiazol-7-thiocarboxylic acid-S-methyl-ester (commercially known ActigardÒ AM-87) at different pH’s as ex-
plained in the experimental part. The treated fabric samples were evaluated for antimicrobial properties against S. aureus and E. coli before and after washing. Results obtained are set out in Fig. 2. It is seen from Fig. 2 that the inhibition zone observed with treated
Fig. 1. Photograph showing inhibition zone technique.
M. Hashem et al. / Carbohydrate Polymers 78 (2009) 502–510
E. coli Before
E. coli After
Staph. Before
Staph. After
30
505
3.3. Effect of curing temperature
15
Fig. 4 shows the effect of curing temperature on antimicrobial properties of ActigardÒ treated cotton fabric before and after washing. It is seen from Fig. 4 that increasing curing temperature from 100 to 150 °C exerts no effect on the antimicrobial properties of the treated fabric. Therefore, curing at 100 °C was selected as optimum curing temperature.
10
3.4. Fixation time
25 20
5 0 100
110
120
130
140
150
Curing Temperature ( °C) Fig. 4. Effect of curing temperature on the antimicrobial properties of the treated cotton fabric. Conditions used: bleached cotton fabric was padded in aqueous solution containing 6% ActigardÒ, pH was adjusted at 5 using formic acid, wet pick up 100%, drying at 80 °C for 5 min, fixation time 90 s. (For interpretation of color mentioned in this figure legend the reader is referred to the web version of the article.)
samples before washing increases as pH of the treated bath increases from 2.5 to 5. Further increase in pH to 9 decreases the inhibition zone. The observed inhibition zone is higher with S. aureus than that with E. coli at the same pH. After washing the inhibition zone remain practically intact with E. coli whereas marginally decrease with S. aureus. Result of Fig. 2 show that optimum pH for treated 100% cotton fabric with ActigardÒ is 5. 3.2. Effect of ActigardÒ concentration Fig. 3 shows the effect of ActigardÒ concentration on the antimicrobial properties of treated cotton fabric before and after washing. Zero ActigardÒ concentration represents the untreated samples. It is seen from Fig. 3 that the inhibition zone increases as the concentration of ActigardÒ increased from 1% to 9%. This is observed before and after washing. Results of Fig. 3 show also that, the inhibition zone observed with S. aureus is higher than that observed with E. coli.
E. coli Before
E. coli After
Staph. Before
Staph. After
25
Inhibition zone (mm)
20
15
10
5
0 60
90
120
150
180
210
Fixationtime (sec.) Fig. 5. Effect of fixation time on the antimicrobial properties of the treated cotton fabric. Conditions used: bleached cotton fabric was padded in aqueous solution containing 6% ActigardÒ, pH was adjusted at 5 using formic acid, wet pick up 100%, drying at 80 °C for 5 min, fixation at 100 °C. (For interpretation of color mentioned in this figure legend the reader is referred to the web version of the article.)
Fig. 5 shows the effect of fixation time on the antimicrobial properties of the treated 100% cotton fabric. The treated samples were evaluated for antimicrobial properties against S. aureus and E. coli before and after washing. It is seen from Fig. 5 that the inhibition zone increase as the fixation time increases from 150 to 180 s. Further increase in the reaction time decreases the inhibition zone. 3.5. Mechanism of antimicrobial activity of Actigard Antimicrobial finishes inhibit or preferably kill microorganisms by a number of different mechanisms that act around the cell wall of the microorganism. Thus cell wall damage, alteration of cytoplasm membrane permeability, alteration of the physical or chemical state of proteins and nucleic acids, inhibition of enzyme action, or inhibition of protein or nucleic acids, inhibition of enzyme action, or inhibition of protein or nucleic acid synthesis are all chemical approaches that can be utilized by antimicrobial finishes to inhibit or kill the microorganism (Anand, Kennedy, Miraftab, & Rajendran, 2006; Parkih et al., 2005; Rastogi et al., 2003). 3.6. Effect of type of substrate Releasing ActigardÒ leached from the treated cotton fabric and its interaction with E. coli or S. aureus would account for the antimicrobial activity of the fabrics. It can be feasible that, for the same ActigardÒ concentration, fabric construction and surface area may have a rule in alteration the antimicrobial properties of the fabric. In order to investigate the effect of fabric construction and fabric state, different bleached cotton fabric having different construction with and without premercerization, were subjected to antimicrobial treatment with ActigardÒ. Optimum conditions obtained previously (Figs. 1–5) were used to carry out the treatments. The fabrics were monitored for strength properties, wettability, roughness, crease recovery angle, whiteness index and antimicrobial properties before and after treatment. It should be noted here that, strength properties of the treated woven fabric was expressed as tensile strength and elongation at break, whereas for knitted fabric was expressed as bursting coefficient. Different fabric construction include, twill, plain and simple weave as knitted fabric. Results obtained for untreated and treated fabrics are set-out in Table 4. Results obtained for untreated and treated fabrics reveal that: i. For the same fabric construction, both tensile strength and crease recovery angle are higher for mercerized compared with unmercerized cotton fabric whereas elongation at break, wettability are comparable. Moreover, the WI is marginally lower for mercerized fabric than unmercerized one. ii. Treatment of cotton fabric with ActigardÒ marginally decrease tensile strength elongation at break, roughness and WI whereas, both wettability and crease recovery angle remain practically intact. This was observed irrespective to whether, the fabric pre-mercerized or not.
506
M. Hashem et al. / Carbohydrate Polymers 78 (2009) 502–510
Table 4 Effect of cotton fabric construction and mercerization on the antimicrobial properties of ActigardÒ treated fabric. TS (Kgf)a (BC)
State of the fabric
El (%)
Wett (s)
Rous (lm)
CRA (deg)
WI
Inhibition zone (mm) Before washing
After washing
S. aureus
E. coli
S. aureus
E. coli
Bleached twill weave
Mercerized Unmercerized
139 (144) 103 (109)
13 (15) 8 (14)
2 (2) 2 (2)
10.80 (14) 10.31 (17.31)
113 (114) 163 (184)
109.82 (114.1) 95.13 (99.44)
20 (0) 20 (0)
24 (0) 22 (0)
15 (0) 15 (0)
18 (0) 16 (0)
Bleached plain weave
Mercerized Unmercerized
85.5 (88) 72.5 (76)
6 (7.5) 8 (8.5)
2 (2) 2 (2)
16.39 (19.85) 13.79 (19.44)
163 (191) 145 (155)
107.72 (112) 103.81 (109.37)
18 (0) 19 (0)
23 (0) 24 (0)
14 (0) 15 (0)
16 (0) 16 (0)
Simple weave cotton fabric
22 (30.5)
9 (9.5)
2 (2)
23 (24.95)
185 (259)
83.4 (98.28)
25 (0)
25 (0)
20 (0)
19 (0)
Knitted cotton fabric
8.9 (8.55)
– (–)
5.5 (72)
13 (21.02)
– (–)
100.62 (104.98)
19 (0)
22 (0)
15 (0)
18 (0)
TS, tensile strength; BC, bursting coefficient. El, elongation at break; Wett, wettability; Rou, roughness; CRA, crease recovery angle; WI, whiteness index; IZ, inhibition zone. ActigardÒ (6% owb), pH was adjusted at 5 using 1% formic acid, wet pick up 100% and drying at 80 °C for 5 min, fixation at 100 °C for 150 s. Bursting coefficient was measured for Knitted fabric. Values in parentheses represent those obtained with untreated fabrics.
iii. Untreated twill weave cotton fabric did not show any antimicrobial activity towards S. aureus or E. coli. This was evidenced by zero inhibition zone observed with mercerized and unmercerized fabrics. Treatment of twill weave cotton fabric with ActigardÒ improves its antimicrobial properties and the inhibition zone increased to 20 mm and 24 mm towards S. aureus and E. coli, respectively, before washing and increased to 15 mm and 18 mm, respectively, after washing. Similar results are obtained with plain weave, simple weave and knitted fabrics. iv. For given fabric construction, pre-mercerization did not improve the antimicrobial properties of Actigard treated samples.
3.7. Combined easy care and antimicrobial finishing One stage process for antimicrobial treatment and low formaldehyde finishing was undertaken using ActigardÒ as antimicrobial agent whereas FixapretÒ. Eco was selected as low formaldehyde finishing agent. The treated fabrics were evaluated for antimicrobial and easy care properties. Results obtained are set-out in Table 5. It is seen from Table 5 that: i. Treatment of cotton fabric with ActigardÒ only did not improve easy care properties of cotton fabric whereas whiteness index slightly decrease. This was observed irrespective to the weaving structure. ii. Cotton samples treated with antimicrobial and easy care finishing in one-step process exhibit higher crease recovery angle compared with the untreated or treated with ActigardÒ only, the crease recovery angle increase from 113°
It could be emphasized from results of Table 4 that, the antimicrobial properties of ActigardÒ treated cotton fabric did not rely on fabric construction or pre-mercerization.
Table 5 Properties of cotton fabric treated with ActigardÒ and FixapretÒ Eco in one step. Types of cotton fabric
Treatment
TS (Kgf)
El. (%)
Wett (s)
CRA
WI
IZ (mm) before washing S. aureus
E. coli
Twill weave bleached mercerized
Untreated I II
144 139 117
15 13 16
2 2 3
114 113 286
114.1 109.82 86.35
0 20 30
0 24 32
Twill weave bleached not mercerized
Untreated I II
109 103 87
14 8 12
2 2 3
184 163 270
99.44 95.13 85.96
0 20 30
0 22 34
Plain weave bleached mercerized
Untreated I II
88 85.5 83
7.5 6 6.5
2 2 3
191 163 291
112 107.72 86.65
0 18 31
0 23 35
Plain weave bleached not mercerized
Untreated I II
76 72.5 63
8.5 8 8.5
2 2 3
155 145 268
109.37 103.81 87.1
0 19 31
0 24 34
Simple weave lawn
Untreated I II
30.5 22 19
9.5 9 7
2 2 3
259 185 262
98.28 83.4 78.61
0 25 32
0 25 38
Wett (s)
WI
Types of cotton fabric
Knitted fabric
Treatment
Untreated I II
BC (Kgf/cm2)
6.90 8.90 6.15
7.2 5.5 4.5
104.98 100.62 94.4
IZ (mm) before washing S. aureus
E. coli
0 19 30
0 22 31
TS, tensile strength; El, elongation at break; Wett, wettability; CRA, crease recovery angle; WI, whiteness index; IZ, inhibition zone; BC, bursting coefficient. Cotton fabric was treated with an aqueous solution containing ActigardÒ, 6%, FixapretÒ-Eco, 6%, and MgCl2, 2%. pH was adjusted at 5 using 1% formic acid, wet pick up 100%, curing at 80 °C for 5 min, fixation at 160 °C for 150 s. Treatment I: cotton fabric treated with ActigardÒ; treatment II: one-step process for ActigardÒ and FixapretÒ-Eco treatments.
507
M. Hashem et al. / Carbohydrate Polymers 78 (2009) 502–510 Table 6 Properties of cotton fabric treated with ActigardÒ and citric acid in one step. Types of cotton fabric
Treatment
TS (Kgf)
El. (%)
Wett (s)
CRA
WI
IZ (mm) before washing S. aureus
E. coli
Twill weave bleached mercerized
Untreated I II
144 139 145
15 13 14
2 2 3
114 113 278
114.1 109.8 86.6
0 20 24
0 24 25
Twill weave bleached not mercerized
Untreated I II
109 103 108
14 8 10.5
2 2 3
184 163 273
99.44 95.13 82.54
0 20 27
0 22 24
Plain weave bleached mercerized
Untreated I II
88 85.5 86
7.5 6.0 6.5
2 2 3
191 163 286
112 107.7 91.2
0 18 32
0 23 24
Plain weave bleached not mercerized
Untreated I II
76 72.5 76.5
8.5 8 7.5
2 2 3
155 145 273
109.37 103.8 92.93
0 19 33
0 24 25
Simple weave lawn
Untreated I II
30.5 22 25.5
9.5 9 5.5
2 2 3
259 185 261
98.28 83.4 72.03
0 25 33
0 25 26
Types of cotton fabric
Knitted fabric
Treatment
Untreated I II
BC (Kgf/cm2)
Wett (s)
8.55 8.9 7.7
72 5.5 3
WI
IZ (mm) before washing
104.98 100.62 88.34
S. aureus
E. coli
0 19 31
0 22 24
TS, tensile strength; El, elongation at break; Wett, wettability; CRA, crease recovery angle; WI, whiteness index; IZ, inhibition zone; BC, bursting coefficient. Cotton fabric was treated with an aqueous solution containing ActigardÒ, 6%, citric acid, 7%, and sodium hypophosphate, 3%, pH was adjusted at 5 using 1% formic acid, wet pick up 100%, drying at 80 °C for 5 min, fixation at 170 °C for 120 s. Treatment I: cotton fabric treated with ActigardÒ; treatment II: one-step process for ActigardÒ and citric acid finishing treatments.
and 163° to 286° and 270° for mercerized and unmercerized twill weave cotton fabric, respectively. Similar results were obtained for plain weave and simple weave fabric. iii. The salient feature observed in Table 5 is the higher antimicrobial properties of cotton fabric treated with ActigardÒ and DMDHEU (FixapretÒ Eco.) in one bath. The inhibition zone
increased significantly in the presence than in the absence of Fixapret Eco. This was observed with all kind of cotton fabric under investigation, whether mercerized or not. Results of Table 5 demonstrate that, combination between antimicrobial finishing with ActigardÒ and easy care finishing treatment
Table 7 Properties of cotton fabric treated with ActigardÒ and gluteraldehyde in one step. Types of cotton fabric
Treatment
TS (Kgf)
El. (%)
Wett (s)
CRA
WI
IZ (mm) before washing S. aureus
E .coli
Twill weave bleached mercerized
Untreated I II
144 139 157
15 13 15
2 2 3
114 113 276
114.1 109.8 90.4
0 20 41
0 24 30
Twill weave bleached not mercerized
Untreated I II
109 103 101
14 8 9
2 2 3
184 163 270
99.44 95.13 74
0 20 42
0 22 30
Plain weave bleached mercerized
Untreated I II
88 85.5 89
7.5 6 7
2 2 3
191 163 285
112 107.7 94
0 18 40
0 23 28
Plain weave bleached not mercerized
Untreated I II
76 72.5 95
8.5 8 7.5
2 2 3
155 145 270
109.37 103.8 91.18
0 19 40
0 24 27
Simple weave lawn
Untreated I II
30.5 22 32
9.5 9 7.5
2 2 3
259 185 260
98.28 83.4 52.27
0 25 36
0 25 33
Types of cotton fabric
Treatment
BC (Kgf/cm2)
Wett (s)
WI
Knitted fabric
Untreated I II
8.55 8.9 7.4
72 5.5 40
104.98 100.62 77.59
IZ (mm) before washing S. aureus
E. coli
0 19 37
0 22 24
TS, tensile strength; El, elongation at break; Wett, wettability; CRA, crease recovery angle; WI, whiteness index; IZ, inhibition zone; BC, brusting coefficient. Cotton fabrics treated with an aqueous solution containing, ActigardÒ, 6%, gluteraldhyde, 5%, and Zn sulphate, 2%. pH was adjusted at 5 using 1% formic acid, wet pick up 100%, drying at 80 °C for 5 min, fixation at 160 °C for 150 s. Treatment I: cotton fabric treated with ActigardÒ; treatment II: one-step process for ActigardÒ and gluteraldehyde.
508
M. Hashem et al. / Carbohydrate Polymers 78 (2009) 502–510
with FixapretÒ Eco can be carried out successfully and the fabrics show improved antimicrobial properties towards S. aureus and E. coli. Similar results are obtained when antimicrobial finishing treatment is combined with anti-crease finishing using citric acid and gluteraldehyde. Results obtained are set in Tables 6 and 7, respectively. Results of Tables 6 and 7 are similar to that obtained in Table 5 and could be explained on similar basis.
3.8. One-step process for antimicrobial and soft finishing of cotton fabric In this regards, bleached cotton fabric was treated separately with two kind of softening agent, namely SiligenÒ SIA Co. (silicon based softener) and LeargineÒ NIA (cationic based softener) in absence and presence of ActigardÒ as antimicrobial finishing agent.
Table 8 Properties of cotton fabric treated with ActigardÒ and silicon softener in one step. Types of cotton fabric
Treatment
TS (Kgf)
El. (%)
Wett (s)
Rou (lm)
WI
IZ (mm) before washing S. aureus
E. coli
Twill weave bleached mercerized
Untreated I II
144 139 118
15 13 12
2 2 5
14 10.80 10.45
114.1 109.8 104
0 20 39
0 24 29
Twill weave bleached not mercerized
Untreated I II
109 103 84
14 8 15
2 2 5
17.31 10.31 10.15
99.44 95.13 90.65
0 20 37
0 22 31
Plain weave bleached mercerized
Untreated I II
8.8 85.5 64
10 7.5 8
2 2 5
19.85 16.39 15.89
112 107.7 105.1
0 18 39
0 23 30
Plain weave bleached not mercerized
Untreated I II
76 72.5 68
8.5 8 9
2 2 5
19.44 13.79 13.59
109.37 104 103.21
0 19 38
0 24 31
Simple weave lawn
Untreated I II
30.5 22 20.5
9.5 9 10
2 2 5
24.95 23 22.31
98.28 83.4 82.81
0 25 39
0 25 30
Types of cotton fabric
Treatment
BC (Kgf/cm2)
Wett (s)
Rou (lm)
WI
IZ (mm) before washing S. aureus
E. coli
Knitted fabric
Untreated I II
8.55 8.9 8.2
72 5.5 90
21.02 13 12
104.98 100.62 98.18
0 19 34
0 22 33
TS, tensile strength; El, elongation at break; Wett, wettability; Rou, roughness; WI, whiteness index; IZ, inhibition zone; BC, bursting coefficient. Cotton fabric was treated with an aqueous solution containing ActigardÒ, 6%, silicon softener (SiligenÒ SIA), 30 g/L. pH was adjusted at 5 using 1% formic acid, wet pick up 100%, drying at 80 °C for 5 min, fixation at 100 °C for 150 s. Treatment I: cotton fabric treated with ActigardÒ; treatment II: one-step process for ActigardÒ and silicon softener.
Table 9 Properties of cotton fabric treated with ActigardÒ and cationic softener in one step. Types of cotton fabric
Treatment
TS (Kg)
El. (%)
Wett (s)
Rou (lm)
WI
IZ (mm) before washing S. aureus
E. coli
Twill weave bleached mercerized
Untreated I II
144 139 130
15 13 12
2 2 5
14 10.80 10.8
114.1 109.9 108
0 20 27
0 24 33
Twill weave bleached not mercerized
Untreated I II
109 103 93
14 8 12
2 2 5
17.31 10.31 9
99.44 95.13 90.67
0 20 25
0 22 31
Plain weave bleached mercerized
Untreated I II
88 85.5 84
7.5 6 7
2 2 5
19.85 16.39 14.39
112 107.8 106.8
0 18 28
0 23 33
Plain weave bleached not mercerized
Untreated I II
76 72.5 71
8.5 8 10.5
2 2 5
19.44 13.79 12.79
109.37 103.8 101.74
0 19 26
0 24 32
Simple weave lawn
Untreated I II
30.5 22 21
9.5 9 10
2 2 5
24.95 23 18.49
98.28 83.4 82.1
0 25 28
0 25 35
Types of cotton fabric
Treatment
B. C (Kgf/cm2)
Wet (s)
Rou (lm)
WI
IZ (mm) before washing S. aureus
E. coli
Knitted fabric
Untreated I II
8.55 8.9 8.4
72 5.5 37
21.02 13.76 13.0
104.98 100.62 98.23
0 19 27
0 22 29
TS, tensile strength; El, elongation at break; Wett, wettability; Rou, roughness; WI, whiteness index; IZ, inhibition zone; BC, bursting coefficient. Cotton fabric was treated with an aqueous solution containing ActigardÒ 6%, and cationic softener (LeargineÒ NIA), 30 g/L. pH was adjusted at 5 using 1% formic acid, wet pick up 100%, drying at 80 °C for 5 min, fixation at 100 °C for 150 sec. Treatment I: cotton fabric treated with ActigardÒ; treatment II: ActigardÒ and cationic softener.
509
M. Hashem et al. / Carbohydrate Polymers 78 (2009) 502–510
It is seen from Table 8 that, the antimicrobial properties of cotton fabric treated with ActigardÒ and silicon softener in one bath is much higher than those treated with ActigardÒ only. This was observed irrespective of type of cotton fabric. Higher antimicrobial properties of cotton fabric treated with ActigardÒ in presence of silicon softener may be attributed to the protective coating action of silicon softener to the surface of fabric. This in turn prevents the microorganism to reach the surface of fabric and create unsuitable condition for bacterial growth. This was confirmed by decrease in the wettability of cotton fabric treated with Silicon softener and ActigardÒ in one bath, from 2 s to 5 s. It is also seen from results in Table 8 that the decrease in fabric roughness follows the decreasing order: II > I > untreated regardless the used substrate. Similar trend was obtained by using LeargineÒ NIA (cationic softener) in combination with ActigardÒ. Results obtained are set-out in Table 9. Results of Table 9 are similar to that of Table 8 and could be explained on similar basis. It could be emphasized from results of Tables 8 and 9 that, incorporating ActigardÒ in soft finishing formulation enhance the antimicrobial properties of the cotton fabric compared with those treated with ActigardÒ alone whereas other physical properties are comparable.
3.9. Effect of reactive dyeing sequence In order to investigate the effect of reactive dying sequence on the antimicrobial properties of ActigardÒ treated cotton fabric, bleached unmercerized plain weave cotton fabric was treated with ActigardÒ then dyed. For other set of samples, reactive dyeing was carried out before the treatment with ActigardÒ, the reactive dye used in our study is SunfixÒ supra red and the dyeing conditions were taken from the manufactures. The treated samples were evaluated for K/S, wettability and antimicrobial properties. Results obtained are set-out in Table 10. Results of Table 10 depict the following: i. Cotton fabric treated with ActigardÒ followed by reactive dyeing loses its antimicrobial properties. This was evidenced by zero inhibition zone either with S. aureus or E. coli. At the same time, the K/S was slightly lower than that obtained with untreated and dyed samples. Losing the antimicrobial properties of ActigardÒ treated samples, and then reactive dyeing is attributed to the solubility and removability of ActigardÒ under the effect of reactive dyeing conditions (higher temp. and alkali).
Table 10 Effect of dyeing and antimicrobial treatment sequence on the properties of ActigardÒ treated cotton fabric. Treatment sequence
Reactive dyeing
Vat dyeing
Direct dyeing
Dyed sample Dyed then ActigardÒ treated (post-treatment) ActigardÒ treated then dyed (post-Dyeing) Dyed sample Dyed then ActigardÒ treated (post-treatment) ActigardÒ treated then dyed (post-Dyeing) Dyed sample Dyed then ActigardÒ treated (post-treatment) ActigardÒ treated then dyed(post-Dyeing)
K/Sa
Wettability (s)
5.89 5.30 4.95 1.77 1.92 1.72 14.05 16.37 14.68
2 2 2 2 2 2 2 2 2
Inhibition zone (mm) S. aureus
E. coli
0 0 32 0 14 29 0 19 29
0 0 26 0 18 33 0 24 25
a K/S was measured at 550 nm. Dyeing conditions: See the experimental part. Antimicrobial treatment condition: cotton fabric was treated with an aqueous solution containing ActigardÒ 6%, pH was adjusted at 5 using 1% formic acid, wet pick up 100%, drying at 80 °C for 5 min, fixation at 100 °C for 150 s.
Table 11 Industrial trials for antimicrobial treatment of 100% cotton. Fabric
Dye name
Shade (%)
K/S
Inhibition zone (mm) S. aureus
E. coli
0.46
3.5
3.8
2.60 0.25 0.014
19.67
3.3
0.6
Remazol brilliant blue R Spec. plus Remazol Brilliant Red 3BS
2.40 0.23
7.51
3.2
4.5
Reactive black B plus Reactive black HFGR plus Reactive red ME4BL
3.90 3.36 0.65
34.16
3.0
3.4
A-colored fabrics Plain weave bleached mercerized cotton fabric dyed with reactive then treated with ActigardÒ Twill weave bleached mercerized cotton fabric dyed with reactive then treated with ActigardÒ
Cibacron Red FNR 0.05%
0.05
Remazol turquoise G plus Remazol brilliant yellow 4GL plus Remazol brilliant Red 3BS
Simple weave bleached cotton fabric dyed with reactive dye then treated with ActigardÒ Knitted cotton dyed with reactive dye then treated with ActigardÒ
Fabric
B-white fabrics Bleached twill weave ActigardÒ treated cotton fabric Bleached twill weave ActigardÒ treated cotton fabric and mercerized Dyeing and antimicrobial conditions used are detailed in the experimental part.
WI
109.82 95.13
Inhibition zone (mm) S. aureus
E. coli
3.2 3
3.3 3.1
510
M. Hashem et al. / Carbohydrate Polymers 78 (2009) 502–510
ii. Cotton fabric reactive dyed then treated with ActigardÒ shows higher antimicrobial properties as indicated by higher inhibition zone (32, 26 mm against S. aureus and E. coli, respectively) on the other hand, the fabric exhibit lower K/ S than untreated then dyed (see Table 11). 3.10. Effect of vat dyeing sequence Results obtained are set-out in Table 10. It is clear that: i. Vat dyeing of pre-treated cotton fabric samples reduces their antimicrobial properties. This was evidenced by (14, 18 mm for both S. aureus and E. coli, respectively). On the other hand the K/S was slightly increased than that obtained with untreated then dyed samples. Decreasing the antimicrobial properties of ActigardÒ 87 treated sample then vat dyed compared with sample dyed then antimicrobial treated is attributed to solubilization of ActigardÒ under the effect of vat dyeing conditions (higher temp and alkali). ii. Vat dyed Cotton fabric then treated with ActigardÒ shows higher antimicrobial properties as indicated by higher inhibition zone (29, 33 mm against S. aureus and E. coli, respectively) along with decrease in K/S values.
3.11. Effect of direct dyeing sequence Results obtained from Table 10 show that the antimicrobial properties of cotton fabric treated with ActigardÒ followed by direct dyeing are decreased. This was evidenced by (19, 24 mm for both S. aureus and E. coli, respectively). On the other hand the K/ S was slightly increased than that obtained with untreated than dyed samples. Decreasing the antimicrobial properties of ActigardÒ treated sample then direct dyeing compared with sample dyed then antimicrobial treated is attributed to solubilization of ActigardÒ under the effect of direct dyeing conditions (higher temp). Post-treatment of direct dyed cotton fabric samples shows higher antimicrobial properties as indicated by higher inhibition zone (29, 27 mm against S. aureus and E. coli, respectively). Whereas, the fabric exhibit slightly increase in K/S compared to untreated then dyed sample. 4. Conclusion The most appropriate conditions for treatment cotton fabric with ActigardÒ are: padding the cotton fabric in aqueous solution containing 6% ActigardÒ at pH 5 (adjusted using formic acid) the squeezed to wet pick up of 100%, drying at 80 °C for 5 min, fixation at 100 °C for 150 s. Untreated cotton fabric did not show any antimicrobial activity towards S. aureus or E. coli. Treatment of with ActigardÒ improves
its antimicrobial properties towards S. aureus and E. coli where the inhibition zone increased to 20 mm and 24 mm, respectively, before washing and increased to 15 mm and 18 mm, respectively, after washing. Treatment of cotton fabric with ActigardÒ marginally decrease TS, elongation at break, roughness and WI whereas, both wettability and crease recovery angle remain practically intact. This was observed irrespective to whether, the fabric pre-mercerized or not. Moreover, the antimicrobial properties of ActigardÒ treated cotton fabric did not rely on fabric construction or premercerization. Incorporating ActigardÒ in softening finishing formulation or easy care finishing formulation using FixapretÒ Eco, citric acid or gluteraldehyde, enhance the antimicrobial properties of the cotton fabric compared with those treated with ActigardÒ only whereas other physical properties are comparable. The results show also that cotton fabrics dyed with reactive dye, direct dye or vat dye then treated with ActigardÒ show higher antimicrobial and lower K/S properties than those ActigardÒ treated fabric the similarly dyed.
References Allen, S. J., Auer, P. D., & Pailthorpe, M. T. (2005). Textile Research Journal, 65(7), 198. Anand, S., Kennedy, J., Miraftab, M., & Rajendran, S. (2006). Medical textiles and biomaterials for health care. Cambridge, England: Woodhead Publishing Limited. Böhringer, A., Rupp, J., & Yonenaga, A. (2000). International Textile Bulletin, 46(5), 115. Chung, Y. S., Lee, K. K., & Kim, J. W. (1998). Textile Research Journal, 68(10), 772. Convert, R., Schacher, L., & Viallier, P. (1999). Textile Research Journal, 69(5), 357. Ha, N. J., Jung, Y. J., Lee, J. S., Kim, Y. T., & Kim, Y. M. (1998). Archives of Pharmacal Research, 21(5), 47. Holme, I. (2007). Innovative technologies for high performance textile. Coloration Technology, 123, 59. Joseph & Marjory, L. (1998). In Essentials of textiles (4th ed.). New York: Holt Rinehart and Winston, Inc.. Lee, H. J., & Jeong, S. H. (2005). Bacteriostasis and skin innoxiousness of nanosize silver colloids on textile fabrics. Textile Research Journal, 75(7), 551. Parkih, V., Fink, T., Rajasekharan, K., Sachinvala, N., Sawhney, A., Calamari, T., & Parkih, A. (2005). Antimicrobial silver/sodium carboxymethyl cotton dressings for burn wounds. Textile Research Journal, 75(2), 134. Payne, J. (1997). JSDC, 113, 70. Rastogi, S., Krongaard, T., & Jensen, G. (2003). In Antibacterial compounds in clothing articles. Roskilde, Danish EPA: National Environmental Research Institute. Rouette, H. K. (2001). Encyclopedia of textile finishing (Vol. 1–2). Germany: Springer Verlag Berlin Heidelberg Publisher. Rowe, M. (1978). Textile chemistry and colorist, 10, 207. Schatz, K. (2001). International Dyers, 186, 125. Schindler, W., & Hauser, P. (2004). Antimicrobial finishes chemical finishing of textiles. Cambridge, England: Woodhead Publishing Limited. p. 213. Sekar, N. (2001). Colourage, 48(12), 73. Seo, H., Mitsuhashi, K., & Tanibe, H. (1992). Antibacterial and antifungal fiber blend by chitosan. In C. J. Brine, P. A. Sandford, & J. P. Zikakis (Eds.), Advanced in chitin and chitosan. Elsevier Applied Science. Sun, G., & Xu, X. (1998). Textile Chemist and Colorist, 30(6), 26. Sun, G., & Xu, X. (1999). Textile Chemist and Colorist, 31(1), 21. Washino, Y. (1993). Functional fibers. In Trends in technology and product development in Japan. Japan: Toray Research Center, Inc.. Wenming, X., Peixin, U., Wei, W., & Oing, L. (2002). Carbohydrate Polymers, 50, 35.
Contents lists available at ScienceDirect
Carbohydrate Polymers journal homepage: www.elsevier.com/locate/carbpol
Enhancing antimicrobial properties of dyed and finished cotton fabrics Mohamed Hashem a, Nabil A. Ibrahim a,*, Wfaa A. El-Sayed b, Shereef El-Husseiny b, Elham El-Enany b a b
Textile Division, National Research Centre, Dokki, Cairo, Egypt Faculty of Girls, Ain-Shams University, Cairo, Egypt
a r t i c l e
i n f o
Article history: Received 6 April 2009 Received in revised form 8 May 2009 Accepted 11 May 2009 Available online 18 May 2009 Keywords: 1,2,3-Benzothiazole-7-thiocarboxylic acidS-methylester Antimicrobial Biocides Cotton fabric Finishing
a b s t r a c t 1,2,3-Benzothiazole-7-thiocarboxylic acid-S-methylester (commercially known as ActigardÒ AM-87) was utilized to impart cotton fabric durable antimicrobial properties. Finishing treatment was carried out under a variety of conditions. The latter were included, effect of pH, concentration of antibacterial agents, curing temperature and curing time. The effect of fabric construction, mercerization, and dyeing with different dyestuff were also investigated. The study was also extended to investigate the technical feasibility of combining antimicrobial finishing treatment in question with other finishing treatment generally carried out on cotton fabric, like soft finishing and crease recovery finishing. The treated fabrics were monitored for antimicrobial properties before and after washing. The treated fabrics were also evaluated for the physio-mechanical properties like fabric tensile strength, elongation at break (or bursting strength for knitted fabric), wettability, crease recovery angle, whiteness index and roughness. Results obtained show that, the most appropriate conditions for treatment cotton fabric with ActigardÒ are: padding the cotton fabric in aqueous solution containing 6% ActigardÒ at pH 5 (adjusted using formic acid) then squeezed to wet pick up of 100%, dried at 80 °C for 5 min then cured at 100 °C for 150 s. The untreated cotton fabric did not show any antimicrobial activity towards Staphylococcus aureus or Escherichia coli. Treatment of cotton fabric with ActigardÒ improves its antimicrobial properties towards S. aureus or E. coli. It is also observed that, treatment of cotton fabric with ActigardÒ marginally decreases fabric tensile strength, elongation at break, roughness and WI, whereas; both wettability and crease recovery angle remain practically intact. This was observed whether the fabric was pre-mercerized or not. Ó 2009 Elsevier Ltd. All rights reserved.
1. Introduction In industrial practices, each decade brings into focus new technologies as a marketing strategy to boost the sale both in domestic and export markets. Textile industry is no exception to this. One of the themes which are dominating the present decade in the textile industry is the ‘‘medical textile”. Microbial damage to raw cotton is a common problem, because cotton fabrics have poor resistance to microorganisms and thus the possibility of harming the human body due to the close contact between skin and textile after only short wearing times they are crowded by microorganisms. Additionally, the environmental conditions on textiles are similarly favorable as on the skin and thus support the bacteria growth (Allen, Auer, & Pailthorpe, 2005; Böhringer, Rupp, & Yonenaga, 2000). Antimicrobial finishes prevent the growth of microorganisms on fabrics used in wide variety of apparel, home furnishing, commercial and industrial products. Fabrics for tents, tarpaulins, and auto fabrics will have a longer life when treated with some type of antimicrobial finish that reduces or prevents damage from rot and mildew (Joseph & Marjory, 1998). * Corresponding author. E-mail address: [email protected] (N.A. Ibrahim). 0144-8617/$ - see front matter Ó 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.carbpol.2009.05.007
The purpose of an antimicrobial finish is to (Böhringer et al., 2000; Rouette, 2001): – Prevent the transmission and spreading of pathogenic (disease causing) microbes. – Inhibit odor development resulting from microbial degradation. – Avoid losses of textile performance properties. Antimicrobial finishes should have the following requirements (Holme, 2007; Payne, 1997; Schatz, 2001; Sun & Xu, 1998, 1999). – – – – – –
Durability of activity to laundering dry cleaning. Selective activity towards undesirable micro organisms. Acceptable moisture transport properties. Compatibility with other finishing agents and easy to apply. Absence of toxic effects for both the manufacturer and consumer. Applicable with no adverse effect on the fabric properties including wear comfort. – Should be low cost. – Resistant to body fluids and to disinfections (sterilization). Graft polymerization of cellulosic textiles with poly(2-methyl-5vinylpyridine) followed by treatment with potassium iodide solution imparts antibacterial and antifungal activity (Holme,
503
M. Hashem et al. / Carbohydrate Polymers 78 (2009) 502–510
2007; Payne, 1997; Schatz, 2001; Sun & Xu, 1998, 1999). One of the most durable type of antimicrobial products is based on a diphenyl ether (bis-phenyl) derivative like 2,4,40 -trichloro0 -2-hydroxy diphenyl ether or 5-chloro-2-(2-dichloro-phenoxyl) phenol (Chung, Lee, & Kim, 1998; Sekar, 2001; Washino, 1993; Wenming, Peixin, Wei, & Oing, 2002). Quaternary ammonium compounds, biguanide, amines and glucoprotamine show polycationic, porous and absorbent properties. Fibres finished with these substances bind microorganisms to their cell membrane resulting in the breakdown of the cell (Ha, Jung, Lee, Kim, & Kim, 1998; Lee & Jeong, 2005; Schindler & Hauser, 2004). Complexing metallic compounds based on metals like cadmium, silver, copper and mercury cause inhibition of the active enzyme center (inhibition of metabolism). Amongst these, the silver compounds are very popular and already been used in the preparation of antimicrobial drinking water (Ha et al., 1998; Lee & Jeong, 2005; Schindler & Hauser, 2004; Seo, Mitsuhashi, & Tanibe, 1992). Chitosan is an effective natural antimicrobial agent derived from chitin, a major component in crustacean shells. Coatings of chitosan on conventional fibres appear to be the more realistic prospect since; they do not provoke an immunological response. A fibre made from chitosan is also available in the market place (Ha et al., 1998; Lee & Jeong, 2005; Schindler & Hauser, 2004; Seo et al., 1992). The work presented in this paper aimed essentially at imparting cotton fabric an antimicrobial properties using 1,2,3-benzothiadiazole-7-thiocarboxylic acid-S-methyl ester (commercially known as ActigardÒ 87). The study was also extended to investigate the technical feasibility of combination between the antimicrobial treatment with other finishing treatment of cotton fabrics like easy care finishing, softener finishing and dyeing. 2. Experimental
2.2. Microorganisms used Both Staphylococcus aureus (S. aureus) (gram positive) and Escherichia coli (E. coli) (gram negative) were used for determination the antimicrobial properties of the treated samples according to AATCC standard test method (Rowe, 1978). 2.3. Dyes Table 2 summarizes the commercial name and colour index as well as the manufacture of dyes used. 2.4. Treatment of 100% cotton fabric with ActigardÒ 100% cotton fabric were padded to a wet pick up of 100% using laboratory padding machine in an aqueous solution containing ActigardÒ (0–9%), at pH (2.5–9). Acidic pH was adjusted using 1% formic acid whereas alkaline pH was adjusted using 1% aqueous NaOH. The fabric was then dried at 80 °C for 5 min then cured at (100–150 °C) for (60–210 s) in laboratory oven. The treated samples were then evaluated to antimicrobial activity before and after washing.
Table 2 Name, color index and the manufacture of the dyes used in our study.
2.1. Materials and chemicals Fabrics used and its specification are set out in Table 1. The fabrics were pre washed using an aqueous solution containing Na2CO3, (10 g/L), wetting agent (2 g/L) at 95 °C for 30 min, followed by washed several times with hot water then with cold water and dried at ambient conditions. ActigardÒ AM-87 was kindly supplied by Clariant international Ltd. (It is based on 1,2,3-benzothiadiazole-7-thiocarboxylic acid-Smethyl ester – shown by structure I): O
Silicon softener under commercial name of SiligenÒ SIA, cationic softener under commercial name of LeomineÒ NI and FixapretÒ Eco, were of technical grade chemicals kindly supplied by BASF International Ltd. MgCl26H2O, citric acid, sodium hypophosphite, gluteraldehyde, zinc sulphate, formic acid, sodium carbonate, sodium sulphate, sodium hydrosulphite, peptone, beef extract, agar, and sodium chloride, were of laboratory grade chemicals.
C
SCH3 S N
1,2,3-benzothiazole-7-thiocarboxylic acid-s-methylester (Actigard ®87)
Commercial name of dye
CI
Company
SunfixÒ Supra REd S3B SPE 150%
Reactive red 195
Alwan Misr Co., Egypt
Cibanon Navy Blue-01 Cibanon Scarlet BNIE 200% Cibacron Red FNR 0.05%
Vat Blue 20 Vat 89 Reactive Mix
Ciba Specialty Chemicals
Remazol plus Remazol Remazol Plus Remazol Remazol
Brilliant Blue R. Spec
Reactive blue 19
Dyestar
Brilliant Red 3BS Brilliant Yellow 4GL
Reactive Reactive 160 Reactive Reactive
Brilliant Red B.B. Turquoise Blue G plus
Reactive black B plus Reactive black HFGR plus Reactive red ME 4 BL
red 195 yellow red 21 blue 220
Reactive black 5 Reactive Mix Reactive red 195
Dyes and Intermediates Ltd.
Table 3 Dyeing recipes and conditions.
Table 1 Specification of the used substrates.
Dye
Shade (%)
[Salt] (g/L)
[Na2CO3] (g/L)
Temp. (°C)
Subs. No.
Fabrics specification
20
60
100% woven cotton fabric (Gabardine), bleached, not mercerized (229 g/m2), weave construction 1/3 carded yarn 100% woven cotton fabric (Popline), bleached, not mercerized (189 g/ m2), weave construction 1/1 carded yarn 100% woven cotton fabric (Gabardine), bleached, mercerized (229 g/ m2), weave construction 1/3 carded yarn 100% woven cotton fabric (Popline), bleached, mercerized (189 g/m2), weave construction 1/1 carded yarn 100% cotton, simple weave, (73/m2), weave construction 1/1 carded yarn 100% knitted cotton fabric, Single jersey (58 g/m2)
3.90 3.36 0.65
40
Subs (1)
Reactive black B plus Reactive black HFGR plus Reactive Red ME4BL Remazol Turquoise Blue G plus Remazol Brilliant Yellow 4 GL plus Remazol Brilliant Red BB
2.60
40
20
60
2.40
40
20
60
0.23 0.05
40
20
60
Subs. (2) Subs (3) Subs. (4) Subs. (5) Subs. (6)
Remazol Brilliant Blue R Spec. plus Remazol Brilliant Red 3BS Cibacron Red FNR 0.05%
0.25 0.014
504
M. Hashem et al. / Carbohydrate Polymers 78 (2009) 502–510
2.5. Pilot-scale experiment
E. coli Before
The antimicrobial activity of the treated samples against S. aureus and E. coli were determined using agar diffusion method. The experimental technique was adopted as follows: known diameter of a swatch treated fabric put in the center of an agar plate. The plates were incubated at 37 °C for 24 h, a growth free ‘‘zone of inhibition” around the fabric appears as the antibacterial agent migrates from the fabric onto the agar, and diffuses outward. Diameters of inhibition zones were determined according to AATCC test method 100–1999 (Fig. 1). Tensile strength and elongation at break of woven fabrics were determined according to ASTM standard test method D-168294 (1994). Bursting strength of the knitted fabrics was determined according to ASTM standard test method D-3786-01 (2002). Crease recovery angle of the fabric was determined according to AATCC test method 66-1972. Surface Roughness was measured according to JIS 94 Standard using measuring instrument SE 1700a made in Japan. Wettability was assessed in terms of drop disappearance, AATCC standard test method, D-79-1968. The degree of whiteness of the fabric sample expressed as whiteness index was measured using Colour EyeÒ 3100 spectrophotometer supplied with SDL international according to reported method (Rowe, 1978). The colour strength (K/S) of dyed fabric was assessed using Kubeka-Munk equation (Convert, Schacher, & Viallier, 1999):
Inhibition zone (mm)
2.6. Testing and analysis
Staph. Before
Staph. After
25
20
15
10
5
0 2.5
5
7
9
pH Fig. 2. Effect of pH on the antimicrobial properties of treated cotton fabric. Conditions used: bleached cotton fabric padded in aqueous solution containing 6% ActigardÒ, acidic pH was adjusted using 1% formic acid solution whereas alkaline pH was adjusted using 1% NaOH aqueous solution, wet pick up 100%, drying at 80 °C for 5 min, fixation at 120 °C for 90 s. (For interpretation of color mentioned in this figure legend the reader is referred to the web version of the article.)
E. coli Before
E. coli After
Staph. Before
Staph. After
30
Inhibition zone (mm)
Ten meters from each kind of cotton fabric (plain weave mercerized, twill weave and knitted cotton fabric) were dyed in winch machine (Barazoly). Dyeing recipes and conditions are set out in Table 3.
E. coli After
25 20 15 10 5 0 0
1
2
3
6
9
Actigard Concentration (% owb)
K=S ¼ ð1 RÞ2 =2R where K, S, and R are the absorption coefficient, scattering coefficient, and reflectance, respectively. 3. Results and discussion
Fig. 3. Effect of ActigardÒ concentration on the antimicrobial properties of the treated cotton fabric. Conditions used: bleached cotton fabric padded in aqueous solution containing ActigardÒ, pH was adjusted at 5 using 1% diluted formic acid, wet pick up, 100%, drying at 80 °C for 5 min, fixation at 120 °C for 90 s. (For interpretation of color mentioned in this figure legend the reader is referred to the web version of the article.)
3.1. Effect of pH 100% cotton fabric was treated with an aqueous solution containing 1,2,3-benzothiazol-7-thiocarboxylic acid-S-methyl-ester (commercially known ActigardÒ AM-87) at different pH’s as ex-
plained in the experimental part. The treated fabric samples were evaluated for antimicrobial properties against S. aureus and E. coli before and after washing. Results obtained are set out in Fig. 2. It is seen from Fig. 2 that the inhibition zone observed with treated
Fig. 1. Photograph showing inhibition zone technique.
M. Hashem et al. / Carbohydrate Polymers 78 (2009) 502–510
E. coli Before
E. coli After
Staph. Before
Staph. After
30
505
3.3. Effect of curing temperature
15
Fig. 4 shows the effect of curing temperature on antimicrobial properties of ActigardÒ treated cotton fabric before and after washing. It is seen from Fig. 4 that increasing curing temperature from 100 to 150 °C exerts no effect on the antimicrobial properties of the treated fabric. Therefore, curing at 100 °C was selected as optimum curing temperature.
10
3.4. Fixation time
25 20
5 0 100
110
120
130
140
150
Curing Temperature ( °C) Fig. 4. Effect of curing temperature on the antimicrobial properties of the treated cotton fabric. Conditions used: bleached cotton fabric was padded in aqueous solution containing 6% ActigardÒ, pH was adjusted at 5 using formic acid, wet pick up 100%, drying at 80 °C for 5 min, fixation time 90 s. (For interpretation of color mentioned in this figure legend the reader is referred to the web version of the article.)
samples before washing increases as pH of the treated bath increases from 2.5 to 5. Further increase in pH to 9 decreases the inhibition zone. The observed inhibition zone is higher with S. aureus than that with E. coli at the same pH. After washing the inhibition zone remain practically intact with E. coli whereas marginally decrease with S. aureus. Result of Fig. 2 show that optimum pH for treated 100% cotton fabric with ActigardÒ is 5. 3.2. Effect of ActigardÒ concentration Fig. 3 shows the effect of ActigardÒ concentration on the antimicrobial properties of treated cotton fabric before and after washing. Zero ActigardÒ concentration represents the untreated samples. It is seen from Fig. 3 that the inhibition zone increases as the concentration of ActigardÒ increased from 1% to 9%. This is observed before and after washing. Results of Fig. 3 show also that, the inhibition zone observed with S. aureus is higher than that observed with E. coli.
E. coli Before
E. coli After
Staph. Before
Staph. After
25
Inhibition zone (mm)
20
15
10
5
0 60
90
120
150
180
210
Fixationtime (sec.) Fig. 5. Effect of fixation time on the antimicrobial properties of the treated cotton fabric. Conditions used: bleached cotton fabric was padded in aqueous solution containing 6% ActigardÒ, pH was adjusted at 5 using formic acid, wet pick up 100%, drying at 80 °C for 5 min, fixation at 100 °C. (For interpretation of color mentioned in this figure legend the reader is referred to the web version of the article.)
Fig. 5 shows the effect of fixation time on the antimicrobial properties of the treated 100% cotton fabric. The treated samples were evaluated for antimicrobial properties against S. aureus and E. coli before and after washing. It is seen from Fig. 5 that the inhibition zone increase as the fixation time increases from 150 to 180 s. Further increase in the reaction time decreases the inhibition zone. 3.5. Mechanism of antimicrobial activity of Actigard Antimicrobial finishes inhibit or preferably kill microorganisms by a number of different mechanisms that act around the cell wall of the microorganism. Thus cell wall damage, alteration of cytoplasm membrane permeability, alteration of the physical or chemical state of proteins and nucleic acids, inhibition of enzyme action, or inhibition of protein or nucleic acids, inhibition of enzyme action, or inhibition of protein or nucleic acid synthesis are all chemical approaches that can be utilized by antimicrobial finishes to inhibit or kill the microorganism (Anand, Kennedy, Miraftab, & Rajendran, 2006; Parkih et al., 2005; Rastogi et al., 2003). 3.6. Effect of type of substrate Releasing ActigardÒ leached from the treated cotton fabric and its interaction with E. coli or S. aureus would account for the antimicrobial activity of the fabrics. It can be feasible that, for the same ActigardÒ concentration, fabric construction and surface area may have a rule in alteration the antimicrobial properties of the fabric. In order to investigate the effect of fabric construction and fabric state, different bleached cotton fabric having different construction with and without premercerization, were subjected to antimicrobial treatment with ActigardÒ. Optimum conditions obtained previously (Figs. 1–5) were used to carry out the treatments. The fabrics were monitored for strength properties, wettability, roughness, crease recovery angle, whiteness index and antimicrobial properties before and after treatment. It should be noted here that, strength properties of the treated woven fabric was expressed as tensile strength and elongation at break, whereas for knitted fabric was expressed as bursting coefficient. Different fabric construction include, twill, plain and simple weave as knitted fabric. Results obtained for untreated and treated fabrics are set-out in Table 4. Results obtained for untreated and treated fabrics reveal that: i. For the same fabric construction, both tensile strength and crease recovery angle are higher for mercerized compared with unmercerized cotton fabric whereas elongation at break, wettability are comparable. Moreover, the WI is marginally lower for mercerized fabric than unmercerized one. ii. Treatment of cotton fabric with ActigardÒ marginally decrease tensile strength elongation at break, roughness and WI whereas, both wettability and crease recovery angle remain practically intact. This was observed irrespective to whether, the fabric pre-mercerized or not.
506
M. Hashem et al. / Carbohydrate Polymers 78 (2009) 502–510
Table 4 Effect of cotton fabric construction and mercerization on the antimicrobial properties of ActigardÒ treated fabric. TS (Kgf)a (BC)
State of the fabric
El (%)
Wett (s)
Rous (lm)
CRA (deg)
WI
Inhibition zone (mm) Before washing
After washing
S. aureus
E. coli
S. aureus
E. coli
Bleached twill weave
Mercerized Unmercerized
139 (144) 103 (109)
13 (15) 8 (14)
2 (2) 2 (2)
10.80 (14) 10.31 (17.31)
113 (114) 163 (184)
109.82 (114.1) 95.13 (99.44)
20 (0) 20 (0)
24 (0) 22 (0)
15 (0) 15 (0)
18 (0) 16 (0)
Bleached plain weave
Mercerized Unmercerized
85.5 (88) 72.5 (76)
6 (7.5) 8 (8.5)
2 (2) 2 (2)
16.39 (19.85) 13.79 (19.44)
163 (191) 145 (155)
107.72 (112) 103.81 (109.37)
18 (0) 19 (0)
23 (0) 24 (0)
14 (0) 15 (0)
16 (0) 16 (0)
Simple weave cotton fabric
22 (30.5)
9 (9.5)
2 (2)
23 (24.95)
185 (259)
83.4 (98.28)
25 (0)
25 (0)
20 (0)
19 (0)
Knitted cotton fabric
8.9 (8.55)
– (–)
5.5 (72)
13 (21.02)
– (–)
100.62 (104.98)
19 (0)
22 (0)
15 (0)
18 (0)
TS, tensile strength; BC, bursting coefficient. El, elongation at break; Wett, wettability; Rou, roughness; CRA, crease recovery angle; WI, whiteness index; IZ, inhibition zone. ActigardÒ (6% owb), pH was adjusted at 5 using 1% formic acid, wet pick up 100% and drying at 80 °C for 5 min, fixation at 100 °C for 150 s. Bursting coefficient was measured for Knitted fabric. Values in parentheses represent those obtained with untreated fabrics.
iii. Untreated twill weave cotton fabric did not show any antimicrobial activity towards S. aureus or E. coli. This was evidenced by zero inhibition zone observed with mercerized and unmercerized fabrics. Treatment of twill weave cotton fabric with ActigardÒ improves its antimicrobial properties and the inhibition zone increased to 20 mm and 24 mm towards S. aureus and E. coli, respectively, before washing and increased to 15 mm and 18 mm, respectively, after washing. Similar results are obtained with plain weave, simple weave and knitted fabrics. iv. For given fabric construction, pre-mercerization did not improve the antimicrobial properties of Actigard treated samples.
3.7. Combined easy care and antimicrobial finishing One stage process for antimicrobial treatment and low formaldehyde finishing was undertaken using ActigardÒ as antimicrobial agent whereas FixapretÒ. Eco was selected as low formaldehyde finishing agent. The treated fabrics were evaluated for antimicrobial and easy care properties. Results obtained are set-out in Table 5. It is seen from Table 5 that: i. Treatment of cotton fabric with ActigardÒ only did not improve easy care properties of cotton fabric whereas whiteness index slightly decrease. This was observed irrespective to the weaving structure. ii. Cotton samples treated with antimicrobial and easy care finishing in one-step process exhibit higher crease recovery angle compared with the untreated or treated with ActigardÒ only, the crease recovery angle increase from 113°
It could be emphasized from results of Table 4 that, the antimicrobial properties of ActigardÒ treated cotton fabric did not rely on fabric construction or pre-mercerization.
Table 5 Properties of cotton fabric treated with ActigardÒ and FixapretÒ Eco in one step. Types of cotton fabric
Treatment
TS (Kgf)
El. (%)
Wett (s)
CRA
WI
IZ (mm) before washing S. aureus
E. coli
Twill weave bleached mercerized
Untreated I II
144 139 117
15 13 16
2 2 3
114 113 286
114.1 109.82 86.35
0 20 30
0 24 32
Twill weave bleached not mercerized
Untreated I II
109 103 87
14 8 12
2 2 3
184 163 270
99.44 95.13 85.96
0 20 30
0 22 34
Plain weave bleached mercerized
Untreated I II
88 85.5 83
7.5 6 6.5
2 2 3
191 163 291
112 107.72 86.65
0 18 31
0 23 35
Plain weave bleached not mercerized
Untreated I II
76 72.5 63
8.5 8 8.5
2 2 3
155 145 268
109.37 103.81 87.1
0 19 31
0 24 34
Simple weave lawn
Untreated I II
30.5 22 19
9.5 9 7
2 2 3
259 185 262
98.28 83.4 78.61
0 25 32
0 25 38
Wett (s)
WI
Types of cotton fabric
Knitted fabric
Treatment
Untreated I II
BC (Kgf/cm2)
6.90 8.90 6.15
7.2 5.5 4.5
104.98 100.62 94.4
IZ (mm) before washing S. aureus
E. coli
0 19 30
0 22 31
TS, tensile strength; El, elongation at break; Wett, wettability; CRA, crease recovery angle; WI, whiteness index; IZ, inhibition zone; BC, bursting coefficient. Cotton fabric was treated with an aqueous solution containing ActigardÒ, 6%, FixapretÒ-Eco, 6%, and MgCl2, 2%. pH was adjusted at 5 using 1% formic acid, wet pick up 100%, curing at 80 °C for 5 min, fixation at 160 °C for 150 s. Treatment I: cotton fabric treated with ActigardÒ; treatment II: one-step process for ActigardÒ and FixapretÒ-Eco treatments.
507
M. Hashem et al. / Carbohydrate Polymers 78 (2009) 502–510 Table 6 Properties of cotton fabric treated with ActigardÒ and citric acid in one step. Types of cotton fabric
Treatment
TS (Kgf)
El. (%)
Wett (s)
CRA
WI
IZ (mm) before washing S. aureus
E. coli
Twill weave bleached mercerized
Untreated I II
144 139 145
15 13 14
2 2 3
114 113 278
114.1 109.8 86.6
0 20 24
0 24 25
Twill weave bleached not mercerized
Untreated I II
109 103 108
14 8 10.5
2 2 3
184 163 273
99.44 95.13 82.54
0 20 27
0 22 24
Plain weave bleached mercerized
Untreated I II
88 85.5 86
7.5 6.0 6.5
2 2 3
191 163 286
112 107.7 91.2
0 18 32
0 23 24
Plain weave bleached not mercerized
Untreated I II
76 72.5 76.5
8.5 8 7.5
2 2 3
155 145 273
109.37 103.8 92.93
0 19 33
0 24 25
Simple weave lawn
Untreated I II
30.5 22 25.5
9.5 9 5.5
2 2 3
259 185 261
98.28 83.4 72.03
0 25 33
0 25 26
Types of cotton fabric
Knitted fabric
Treatment
Untreated I II
BC (Kgf/cm2)
Wett (s)
8.55 8.9 7.7
72 5.5 3
WI
IZ (mm) before washing
104.98 100.62 88.34
S. aureus
E. coli
0 19 31
0 22 24
TS, tensile strength; El, elongation at break; Wett, wettability; CRA, crease recovery angle; WI, whiteness index; IZ, inhibition zone; BC, bursting coefficient. Cotton fabric was treated with an aqueous solution containing ActigardÒ, 6%, citric acid, 7%, and sodium hypophosphate, 3%, pH was adjusted at 5 using 1% formic acid, wet pick up 100%, drying at 80 °C for 5 min, fixation at 170 °C for 120 s. Treatment I: cotton fabric treated with ActigardÒ; treatment II: one-step process for ActigardÒ and citric acid finishing treatments.
and 163° to 286° and 270° for mercerized and unmercerized twill weave cotton fabric, respectively. Similar results were obtained for plain weave and simple weave fabric. iii. The salient feature observed in Table 5 is the higher antimicrobial properties of cotton fabric treated with ActigardÒ and DMDHEU (FixapretÒ Eco.) in one bath. The inhibition zone
increased significantly in the presence than in the absence of Fixapret Eco. This was observed with all kind of cotton fabric under investigation, whether mercerized or not. Results of Table 5 demonstrate that, combination between antimicrobial finishing with ActigardÒ and easy care finishing treatment
Table 7 Properties of cotton fabric treated with ActigardÒ and gluteraldehyde in one step. Types of cotton fabric
Treatment
TS (Kgf)
El. (%)
Wett (s)
CRA
WI
IZ (mm) before washing S. aureus
E .coli
Twill weave bleached mercerized
Untreated I II
144 139 157
15 13 15
2 2 3
114 113 276
114.1 109.8 90.4
0 20 41
0 24 30
Twill weave bleached not mercerized
Untreated I II
109 103 101
14 8 9
2 2 3
184 163 270
99.44 95.13 74
0 20 42
0 22 30
Plain weave bleached mercerized
Untreated I II
88 85.5 89
7.5 6 7
2 2 3
191 163 285
112 107.7 94
0 18 40
0 23 28
Plain weave bleached not mercerized
Untreated I II
76 72.5 95
8.5 8 7.5
2 2 3
155 145 270
109.37 103.8 91.18
0 19 40
0 24 27
Simple weave lawn
Untreated I II
30.5 22 32
9.5 9 7.5
2 2 3
259 185 260
98.28 83.4 52.27
0 25 36
0 25 33
Types of cotton fabric
Treatment
BC (Kgf/cm2)
Wett (s)
WI
Knitted fabric
Untreated I II
8.55 8.9 7.4
72 5.5 40
104.98 100.62 77.59
IZ (mm) before washing S. aureus
E. coli
0 19 37
0 22 24
TS, tensile strength; El, elongation at break; Wett, wettability; CRA, crease recovery angle; WI, whiteness index; IZ, inhibition zone; BC, brusting coefficient. Cotton fabrics treated with an aqueous solution containing, ActigardÒ, 6%, gluteraldhyde, 5%, and Zn sulphate, 2%. pH was adjusted at 5 using 1% formic acid, wet pick up 100%, drying at 80 °C for 5 min, fixation at 160 °C for 150 s. Treatment I: cotton fabric treated with ActigardÒ; treatment II: one-step process for ActigardÒ and gluteraldehyde.
508
M. Hashem et al. / Carbohydrate Polymers 78 (2009) 502–510
with FixapretÒ Eco can be carried out successfully and the fabrics show improved antimicrobial properties towards S. aureus and E. coli. Similar results are obtained when antimicrobial finishing treatment is combined with anti-crease finishing using citric acid and gluteraldehyde. Results obtained are set in Tables 6 and 7, respectively. Results of Tables 6 and 7 are similar to that obtained in Table 5 and could be explained on similar basis.
3.8. One-step process for antimicrobial and soft finishing of cotton fabric In this regards, bleached cotton fabric was treated separately with two kind of softening agent, namely SiligenÒ SIA Co. (silicon based softener) and LeargineÒ NIA (cationic based softener) in absence and presence of ActigardÒ as antimicrobial finishing agent.
Table 8 Properties of cotton fabric treated with ActigardÒ and silicon softener in one step. Types of cotton fabric
Treatment
TS (Kgf)
El. (%)
Wett (s)
Rou (lm)
WI
IZ (mm) before washing S. aureus
E. coli
Twill weave bleached mercerized
Untreated I II
144 139 118
15 13 12
2 2 5
14 10.80 10.45
114.1 109.8 104
0 20 39
0 24 29
Twill weave bleached not mercerized
Untreated I II
109 103 84
14 8 15
2 2 5
17.31 10.31 10.15
99.44 95.13 90.65
0 20 37
0 22 31
Plain weave bleached mercerized
Untreated I II
8.8 85.5 64
10 7.5 8
2 2 5
19.85 16.39 15.89
112 107.7 105.1
0 18 39
0 23 30
Plain weave bleached not mercerized
Untreated I II
76 72.5 68
8.5 8 9
2 2 5
19.44 13.79 13.59
109.37 104 103.21
0 19 38
0 24 31
Simple weave lawn
Untreated I II
30.5 22 20.5
9.5 9 10
2 2 5
24.95 23 22.31
98.28 83.4 82.81
0 25 39
0 25 30
Types of cotton fabric
Treatment
BC (Kgf/cm2)
Wett (s)
Rou (lm)
WI
IZ (mm) before washing S. aureus
E. coli
Knitted fabric
Untreated I II
8.55 8.9 8.2
72 5.5 90
21.02 13 12
104.98 100.62 98.18
0 19 34
0 22 33
TS, tensile strength; El, elongation at break; Wett, wettability; Rou, roughness; WI, whiteness index; IZ, inhibition zone; BC, bursting coefficient. Cotton fabric was treated with an aqueous solution containing ActigardÒ, 6%, silicon softener (SiligenÒ SIA), 30 g/L. pH was adjusted at 5 using 1% formic acid, wet pick up 100%, drying at 80 °C for 5 min, fixation at 100 °C for 150 s. Treatment I: cotton fabric treated with ActigardÒ; treatment II: one-step process for ActigardÒ and silicon softener.
Table 9 Properties of cotton fabric treated with ActigardÒ and cationic softener in one step. Types of cotton fabric
Treatment
TS (Kg)
El. (%)
Wett (s)
Rou (lm)
WI
IZ (mm) before washing S. aureus
E. coli
Twill weave bleached mercerized
Untreated I II
144 139 130
15 13 12
2 2 5
14 10.80 10.8
114.1 109.9 108
0 20 27
0 24 33
Twill weave bleached not mercerized
Untreated I II
109 103 93
14 8 12
2 2 5
17.31 10.31 9
99.44 95.13 90.67
0 20 25
0 22 31
Plain weave bleached mercerized
Untreated I II
88 85.5 84
7.5 6 7
2 2 5
19.85 16.39 14.39
112 107.8 106.8
0 18 28
0 23 33
Plain weave bleached not mercerized
Untreated I II
76 72.5 71
8.5 8 10.5
2 2 5
19.44 13.79 12.79
109.37 103.8 101.74
0 19 26
0 24 32
Simple weave lawn
Untreated I II
30.5 22 21
9.5 9 10
2 2 5
24.95 23 18.49
98.28 83.4 82.1
0 25 28
0 25 35
Types of cotton fabric
Treatment
B. C (Kgf/cm2)
Wet (s)
Rou (lm)
WI
IZ (mm) before washing S. aureus
E. coli
Knitted fabric
Untreated I II
8.55 8.9 8.4
72 5.5 37
21.02 13.76 13.0
104.98 100.62 98.23
0 19 27
0 22 29
TS, tensile strength; El, elongation at break; Wett, wettability; Rou, roughness; WI, whiteness index; IZ, inhibition zone; BC, bursting coefficient. Cotton fabric was treated with an aqueous solution containing ActigardÒ 6%, and cationic softener (LeargineÒ NIA), 30 g/L. pH was adjusted at 5 using 1% formic acid, wet pick up 100%, drying at 80 °C for 5 min, fixation at 100 °C for 150 sec. Treatment I: cotton fabric treated with ActigardÒ; treatment II: ActigardÒ and cationic softener.
509
M. Hashem et al. / Carbohydrate Polymers 78 (2009) 502–510
It is seen from Table 8 that, the antimicrobial properties of cotton fabric treated with ActigardÒ and silicon softener in one bath is much higher than those treated with ActigardÒ only. This was observed irrespective of type of cotton fabric. Higher antimicrobial properties of cotton fabric treated with ActigardÒ in presence of silicon softener may be attributed to the protective coating action of silicon softener to the surface of fabric. This in turn prevents the microorganism to reach the surface of fabric and create unsuitable condition for bacterial growth. This was confirmed by decrease in the wettability of cotton fabric treated with Silicon softener and ActigardÒ in one bath, from 2 s to 5 s. It is also seen from results in Table 8 that the decrease in fabric roughness follows the decreasing order: II > I > untreated regardless the used substrate. Similar trend was obtained by using LeargineÒ NIA (cationic softener) in combination with ActigardÒ. Results obtained are set-out in Table 9. Results of Table 9 are similar to that of Table 8 and could be explained on similar basis. It could be emphasized from results of Tables 8 and 9 that, incorporating ActigardÒ in soft finishing formulation enhance the antimicrobial properties of the cotton fabric compared with those treated with ActigardÒ alone whereas other physical properties are comparable.
3.9. Effect of reactive dyeing sequence In order to investigate the effect of reactive dying sequence on the antimicrobial properties of ActigardÒ treated cotton fabric, bleached unmercerized plain weave cotton fabric was treated with ActigardÒ then dyed. For other set of samples, reactive dyeing was carried out before the treatment with ActigardÒ, the reactive dye used in our study is SunfixÒ supra red and the dyeing conditions were taken from the manufactures. The treated samples were evaluated for K/S, wettability and antimicrobial properties. Results obtained are set-out in Table 10. Results of Table 10 depict the following: i. Cotton fabric treated with ActigardÒ followed by reactive dyeing loses its antimicrobial properties. This was evidenced by zero inhibition zone either with S. aureus or E. coli. At the same time, the K/S was slightly lower than that obtained with untreated and dyed samples. Losing the antimicrobial properties of ActigardÒ treated samples, and then reactive dyeing is attributed to the solubility and removability of ActigardÒ under the effect of reactive dyeing conditions (higher temp. and alkali).
Table 10 Effect of dyeing and antimicrobial treatment sequence on the properties of ActigardÒ treated cotton fabric. Treatment sequence
Reactive dyeing
Vat dyeing
Direct dyeing
Dyed sample Dyed then ActigardÒ treated (post-treatment) ActigardÒ treated then dyed (post-Dyeing) Dyed sample Dyed then ActigardÒ treated (post-treatment) ActigardÒ treated then dyed (post-Dyeing) Dyed sample Dyed then ActigardÒ treated (post-treatment) ActigardÒ treated then dyed(post-Dyeing)
K/Sa
Wettability (s)
5.89 5.30 4.95 1.77 1.92 1.72 14.05 16.37 14.68
2 2 2 2 2 2 2 2 2
Inhibition zone (mm) S. aureus
E. coli
0 0 32 0 14 29 0 19 29
0 0 26 0 18 33 0 24 25
a K/S was measured at 550 nm. Dyeing conditions: See the experimental part. Antimicrobial treatment condition: cotton fabric was treated with an aqueous solution containing ActigardÒ 6%, pH was adjusted at 5 using 1% formic acid, wet pick up 100%, drying at 80 °C for 5 min, fixation at 100 °C for 150 s.
Table 11 Industrial trials for antimicrobial treatment of 100% cotton. Fabric
Dye name
Shade (%)
K/S
Inhibition zone (mm) S. aureus
E. coli
0.46
3.5
3.8
2.60 0.25 0.014
19.67
3.3
0.6
Remazol brilliant blue R Spec. plus Remazol Brilliant Red 3BS
2.40 0.23
7.51
3.2
4.5
Reactive black B plus Reactive black HFGR plus Reactive red ME4BL
3.90 3.36 0.65
34.16
3.0
3.4
A-colored fabrics Plain weave bleached mercerized cotton fabric dyed with reactive then treated with ActigardÒ Twill weave bleached mercerized cotton fabric dyed with reactive then treated with ActigardÒ
Cibacron Red FNR 0.05%
0.05
Remazol turquoise G plus Remazol brilliant yellow 4GL plus Remazol brilliant Red 3BS
Simple weave bleached cotton fabric dyed with reactive dye then treated with ActigardÒ Knitted cotton dyed with reactive dye then treated with ActigardÒ
Fabric
B-white fabrics Bleached twill weave ActigardÒ treated cotton fabric Bleached twill weave ActigardÒ treated cotton fabric and mercerized Dyeing and antimicrobial conditions used are detailed in the experimental part.
WI
109.82 95.13
Inhibition zone (mm) S. aureus
E. coli
3.2 3
3.3 3.1
510
M. Hashem et al. / Carbohydrate Polymers 78 (2009) 502–510
ii. Cotton fabric reactive dyed then treated with ActigardÒ shows higher antimicrobial properties as indicated by higher inhibition zone (32, 26 mm against S. aureus and E. coli, respectively) on the other hand, the fabric exhibit lower K/ S than untreated then dyed (see Table 11). 3.10. Effect of vat dyeing sequence Results obtained are set-out in Table 10. It is clear that: i. Vat dyeing of pre-treated cotton fabric samples reduces their antimicrobial properties. This was evidenced by (14, 18 mm for both S. aureus and E. coli, respectively). On the other hand the K/S was slightly increased than that obtained with untreated then dyed samples. Decreasing the antimicrobial properties of ActigardÒ 87 treated sample then vat dyed compared with sample dyed then antimicrobial treated is attributed to solubilization of ActigardÒ under the effect of vat dyeing conditions (higher temp and alkali). ii. Vat dyed Cotton fabric then treated with ActigardÒ shows higher antimicrobial properties as indicated by higher inhibition zone (29, 33 mm against S. aureus and E. coli, respectively) along with decrease in K/S values.
3.11. Effect of direct dyeing sequence Results obtained from Table 10 show that the antimicrobial properties of cotton fabric treated with ActigardÒ followed by direct dyeing are decreased. This was evidenced by (19, 24 mm for both S. aureus and E. coli, respectively). On the other hand the K/ S was slightly increased than that obtained with untreated than dyed samples. Decreasing the antimicrobial properties of ActigardÒ treated sample then direct dyeing compared with sample dyed then antimicrobial treated is attributed to solubilization of ActigardÒ under the effect of direct dyeing conditions (higher temp). Post-treatment of direct dyed cotton fabric samples shows higher antimicrobial properties as indicated by higher inhibition zone (29, 27 mm against S. aureus and E. coli, respectively). Whereas, the fabric exhibit slightly increase in K/S compared to untreated then dyed sample. 4. Conclusion The most appropriate conditions for treatment cotton fabric with ActigardÒ are: padding the cotton fabric in aqueous solution containing 6% ActigardÒ at pH 5 (adjusted using formic acid) the squeezed to wet pick up of 100%, drying at 80 °C for 5 min, fixation at 100 °C for 150 s. Untreated cotton fabric did not show any antimicrobial activity towards S. aureus or E. coli. Treatment of with ActigardÒ improves
its antimicrobial properties towards S. aureus and E. coli where the inhibition zone increased to 20 mm and 24 mm, respectively, before washing and increased to 15 mm and 18 mm, respectively, after washing. Treatment of cotton fabric with ActigardÒ marginally decrease TS, elongation at break, roughness and WI whereas, both wettability and crease recovery angle remain practically intact. This was observed irrespective to whether, the fabric pre-mercerized or not. Moreover, the antimicrobial properties of ActigardÒ treated cotton fabric did not rely on fabric construction or premercerization. Incorporating ActigardÒ in softening finishing formulation or easy care finishing formulation using FixapretÒ Eco, citric acid or gluteraldehyde, enhance the antimicrobial properties of the cotton fabric compared with those treated with ActigardÒ only whereas other physical properties are comparable. The results show also that cotton fabrics dyed with reactive dye, direct dye or vat dye then treated with ActigardÒ show higher antimicrobial and lower K/S properties than those ActigardÒ treated fabric the similarly dyed.
References Allen, S. J., Auer, P. D., & Pailthorpe, M. T. (2005). Textile Research Journal, 65(7), 198. Anand, S., Kennedy, J., Miraftab, M., & Rajendran, S. (2006). Medical textiles and biomaterials for health care. Cambridge, England: Woodhead Publishing Limited. Böhringer, A., Rupp, J., & Yonenaga, A. (2000). International Textile Bulletin, 46(5), 115. Chung, Y. S., Lee, K. K., & Kim, J. W. (1998). Textile Research Journal, 68(10), 772. Convert, R., Schacher, L., & Viallier, P. (1999). Textile Research Journal, 69(5), 357. Ha, N. J., Jung, Y. J., Lee, J. S., Kim, Y. T., & Kim, Y. M. (1998). Archives of Pharmacal Research, 21(5), 47. Holme, I. (2007). Innovative technologies for high performance textile. Coloration Technology, 123, 59. Joseph & Marjory, L. (1998). In Essentials of textiles (4th ed.). New York: Holt Rinehart and Winston, Inc.. Lee, H. J., & Jeong, S. H. (2005). Bacteriostasis and skin innoxiousness of nanosize silver colloids on textile fabrics. Textile Research Journal, 75(7), 551. Parkih, V., Fink, T., Rajasekharan, K., Sachinvala, N., Sawhney, A., Calamari, T., & Parkih, A. (2005). Antimicrobial silver/sodium carboxymethyl cotton dressings for burn wounds. Textile Research Journal, 75(2), 134. Payne, J. (1997). JSDC, 113, 70. Rastogi, S., Krongaard, T., & Jensen, G. (2003). In Antibacterial compounds in clothing articles. Roskilde, Danish EPA: National Environmental Research Institute. Rouette, H. K. (2001). Encyclopedia of textile finishing (Vol. 1–2). Germany: Springer Verlag Berlin Heidelberg Publisher. Rowe, M. (1978). Textile chemistry and colorist, 10, 207. Schatz, K. (2001). International Dyers, 186, 125. Schindler, W., & Hauser, P. (2004). Antimicrobial finishes chemical finishing of textiles. Cambridge, England: Woodhead Publishing Limited. p. 213. Sekar, N. (2001). Colourage, 48(12), 73. Seo, H., Mitsuhashi, K., & Tanibe, H. (1992). Antibacterial and antifungal fiber blend by chitosan. In C. J. Brine, P. A. Sandford, & J. P. Zikakis (Eds.), Advanced in chitin and chitosan. Elsevier Applied Science. Sun, G., & Xu, X. (1998). Textile Chemist and Colorist, 30(6), 26. Sun, G., & Xu, X. (1999). Textile Chemist and Colorist, 31(1), 21. Washino, Y. (1993). Functional fibers. In Trends in technology and product development in Japan. Japan: Toray Research Center, Inc.. Wenming, X., Peixin, U., Wei, W., & Oing, L. (2002). Carbohydrate Polymers, 50, 35.