- Email: [email protected]
Surface treatment of cotton using β-cyclodextrins sol–gel method
Applied Surface Science 252 (2006) 6348–6352 www.elsevier.com/locate/apsusc
Surface treatment of cotton using b-cyclodextrins sol–gel method C.X. Wang a,*, Sh.L. Chen b a
College of Textile and Garment, Southern Yangtze University, Lihu Ave. 1800, Wuxi 214122, PR China b College of Chemistry and Chemical Engineering, Donghua University, Shanghai 200051, PR China Received 19 August 2005; received in revised form 12 September 2005; accepted 12 September 2005 Available online 19 October 2005
Abstract b-Cyclodextrin can be added into sol–gel solution which consists of 3-glycidyloxypropyl-trimethoxysilane (GPTMS), tetraethoxysilane (TEOS), catalyzer and solvent. This b-cyclodextrianto sol–gel solution is able to anchor b-cyclodextrin on cotton fabrics in gelation process in order to impart new surface property of cotton. The suitable technical conditions of forming stable b-cyclodextrin sol–gel solution were presented. b-Cyclodextrins are able to form inclusion complexes with other guest components. As a result of the inclusions, the treated fabrics achieved new functional properties by the selective inclusion of the guest substances into the fixed cavities on fabrics. A novel functional surface treatment of fabrics is presented by sol–gel methods. The new functionalities were verified simply by decreasing the rate of volatile fragrance substances. # 2005 Elsevier B.V. All rights reserved. Keywords: Surface treatment; b-Cyclodextrin; Sol–gel method; Cotton
1. Introduction A novel functional surface treatment of cotton based on the permanent fixation of b-cyclodextrins on fabric is receiving increased attention in textile field [1–5]. Cyclodextrins are non-reducing cyclic linked oligosaccharides produced by certain microorganisms cultivated starch, which are capable of forming inclusion compounds with molecules that fit into * Corresponding author. Tel.: +86 510 5912105; fax: +86 510 5912105. E-mail address: [email protected] (C.X. Wang).
their cone-shaped hydrophobic cavity. The encapsulation process is accompanied by changes of the properties of the substance within the cavity. The stability of the complexed molecules against oxidation, hydrolysis and photochemical reactions is increased. The speed of evaporation of volatile substances is reduced drastically [6,7]. Cyclodextrins are considered as very important environment friendly auxiliaries because they are biodegradable and no toxic symptoms [8]. Some scientific reports have demonstrated that cyclodextrin fixed to cotton did not affect the hydrophilic properties of cellulose and the immobilized cavities of cyclodextrins did not lose
0169-4332/$ – see front matter # 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.apsusc.2005.09.016
C.X. Wang, S.L. Chen / Applied Surface Science 252 (2006) 6348–6352
6349
their complexing power to form inclusion complexes with other molecules. It is well known that some pharmaceutically active compounds and fungicidal and bactericidal substances are able to form complexes with cyclodextrins. This may represent medical or other functional purpose textile [9]. It is possible to remove most of nicotine and tar from smoke with treated domestic textile. Also, the bad sweat odor is reduced because the sweat components can be incorporated into the cyclodextrin cavities attached on fabrics. The sol–gel method is a new versatile tool to create transparent and well adhesive silicon oxide films onto various materials [10–16]. The chemical and physical modification of such coating allows a wide range in variation of surface properties of textile [17–21]. The controlled release of coronary therapeuticum nifedipine used in drug by the sol–gel technique has been researched [22–24]. In the paper, the b-cyclodextrins are chosen to be anchored to modify the surface of cotton fabric by sol– gel processes. Guest compounds such as the fragrance molecules that fit with the cavity of b-cyclodextrins are capable of forming inclusion with b-cyclodextrins on the fabrics. The new functionalities were verified simply by decreasing the rate of volatile fragrance substances. The various new functional textiles can be achieved in the way.
chased from Chemical Auxiliary Factory, Zhangjiagang, China. The high-speed shearing emulsifiers BME 1001 was from Weiyu Mechanical-Electronic Co. Ltd. Shanghai. UV-3000 reflectance spectrophotometer was from Shimadzu, Japan. The shaker was from apparatus factory, Shanghai.
2. Experimental
The b-cyclodextrins sol–gel solution was diluted for six times with water. The cotton was immersed in diluted solution at room temperature for 10 min. The fabric sample was padded to a wet pick up of 100%. Then cotton was heated at 80 8C for 5 min.
2.1. Materials and laboratory apparatus The desized, scoured and bleached cotton fabric (Poplin 130 g/m2) was purchased from a factory of dyeing and printing. The fabric was purified in the laboratory by scouring at 100 8C for 60 min using a solution containing sodium carbonate (2 g/l). It is then thoroughly washed with water and dried at ambient conditions. The b-cyclodextrin (CD) was available in the market. Essential oils such as lemon, rose, jasmine, lavender, sandalwood, rosemary were kindly supplied by the Perfume Institute, Shanghai, China. Alcohol, hydrochloric acid was analytical reagent grade. 3-Glycidyloxypropyl-trimethoxysilane (GPTMS) and tetraethoxysilane (TEOS) was pur-
2.2. Preparation of sol–gel solution b-Cyclodextrins were resolute with a mixture solution containing ethanol and distilled water. The solution was emulsified with a high-speed mixer at a speed of about 500 rpm for 15 min. TEOS and GPTMS were added into emulsified solution under stirring, respectively. Then the system was kept shaking while the temperature was kept at 40 8C in water shaker for further 8 h. The sol–gel solutions were composed of as below: GPTMS (g) TEOS (g) b-Cyclodextrins (g) Hydrochloric acid (ml) Ethanol (ml) Water (ml)
23.7 20.8 0.1–3.5 40 116 36
2.3. Application of b-cyclodextrins sol–gel solution on the cotton
2.4. Application of fragrance on the cotton The three methods padding, immersing and spraying are used to load the fragrance on the textile. The fragrance substances (1 g) dissolved in water or ethanol (1000 ml) were stirred with a high-speed mixer at a speed of about 10,000 rpm for 5 min. The cotton anchored with b-cyclodextrins was immersed in fragrance solution for 24 h, sprayed with sprayer evenly or padded twice to a wet pick up of 100% by conventional pad method.
6350
C.X. Wang, S.L. Chen / Applied Surface Science 252 (2006) 6348–6352
2.5. Amount of CD on the fabric The visualization agent phenolphthalein (PP) was used as an indicator for measuring CD concentration on the fabric. The treated sample with given weight was put into water solution containing a known amount of PP, which was tested at the maximum absorption wavelength 553 nm by the UV-3000 reflectance spectrophotometer. 2.6. Amount of fragrance on the fabric The treated fabric by fragrance was extracted by ethanol for 12 h. Fragrance concentration on the fabric was measured on the UV-3000 reflectance spectrophotometer every week. The excitation wavelength was 276 nm.
3. Results and discussion 3.1. Effect of b-cyclodextrins on sol–gel solution The amount of b-cyclodextrins in sol–gel solution decide the surface properties of treated cotton. The effect of concentration of b-cyclodextrins on the stability of sol–gel solution is given in table (see Section 2.2). It was clear that the stability of sol–gel solution decrease greatly when b-cyclodextrins added into sol– gel solution. The more b-cyclodextrins, the less stability of sol–gel solution is. This may due to the OH group in b-cyclodextrins react with OH group of hydrolyzed GPTMS. The amount of b-cyclodextrins is no more than 0.5 mol L 1 in order to ensure the stability of sol–gel solution.
containing essential oils. The fragrance depositing properties of the three loading methods were measured by UV-3000. The results were shown in Fig. 1. Fig. 1 showed that fragrance-release properties were related to the methods of loading. Spraying seemed to be the simple and most effective approach to loading-fragrance. Spraying might impart more essential oils on fabric because of the pressure. It could be concluded that the environment of CD will influence the formation of inclusions. It was also showed that solvent of essential oils solution influenced the amount of inclusion. Ethanol seemed to benefit the essential oil getting into the cavity of cyclodextrin. This might be explained that the ethanol made essential oil easy to disperse into single molecules, which are in favor of permeating and pushing into hydrophobic cavity of CD. The fragrance depositing property of the fabric is dependent on CD amount on the fabric. The larger amount of CD was anchored on fabric, the more hosts which could offer nests for guest molecules. This means that much fragrance have chances to get into cavities of CD molecules and form inclusions. The inclusions were able to decrease the rate of fragrancerelease. It was also confirmed from Fig. 1 that the essence-release rates were different when different fragrance loading methods were be used. It could be explained that the amount of CD on fabric was responsible for the fragrance-release rate. The reloading methods determined the efficiency of the fragrance to be put into CD.
3.2. Loading methods and amount of CD on fabric After the fabric was treated with sol–gel solution, the b-cyclodextrins anchored on the fabric can form inclusion complexes with other guest components which molecules are fit with their cavities in the usual procedure utilized as for free cyclodextrin. There were several methods to load essential oil into cyclodextrin, such as padding, immersing and spraying. The fabric anchored cyclodextrin was treated by aqueous solution or ethanol solution
Fig. 1. Fragrance depositing properties of fabric. (1) Padding with aqueous solution; (2) immersing with aqueous solution; (3) immersing with ethanol solution; (4) spraying with aqueous solution; (5) spraying with ethanol solution.
C.X. Wang, S.L. Chen / Applied Surface Science 252 (2006) 6348–6352
Fig. 2. Washing durability of CD on fabric.
6351
Fig. 4. Comparison of fragrance-release with and without CD treatment.
The b-cyclodextrins molecules were anchored on the cellulose fibre by sol–gel coating technique. The new functionalities were verified by inclusion compound formed with fragrance substances. The forms of inclusion compound were able to decrease the rate of fragrance-release obviously. The controlled-release
properties had to be measured. The results were shown in Figs. 3 and 4. It was clear that the rates of fragrance-release of inclusion compound were related to the nature of fragrance oils themselves. The rate of rosemary and sandalwood fragrance-release of inclusion compounds is higher than that of other fragrance. It could be explained that they are more fit with cavities of CD. At the same time, the free inclusion compounds can be complexed with fragrance substance by the usual procedure utilized as for free cyclodextrins, that is to say it can be reloaded. When treated fabrics have no scent on it, they can be immersed or sprayed by a concentrated solution containing fragrance substances directly. Compared with fabric without anchoring CD by sol–gel treatment, fragrance-release of inclusion compound formed with CD on fabric decreases greatly. A sensorial evaluation of results has also been performed by a panel of 10 well-trained subjects. The perfumed fabrics were smelled every five days in order to feel the perfume scents. The test panel evaluation results were listed in Fig. 5.
Fig. 3. Rate of fragrance-release of inclusion compounds.
Fig. 5. Sensorial evaluation of scent intensity: (5) expressed as very strong; (4) strong; (3) common; (2) weak; (1) very weak.
3.3. Finishing durability CD anchored on the fabric was mainly determined by the gelation film, which was shaped from sol resolution containing GPTMS as silane coupling agent. The gelation films form the networks which could combine the CD. The results of CD durability were presented in Fig. 2. The results in Fig. 2 revealed that CD concentration on fabric tended to decrease by launderings. When launderings is 20 times, the CD concentration on fabric is too low to form inclusion compound. 3.4. Fragrance depositing properties
6352
C.X. Wang, S.L. Chen / Applied Surface Science 252 (2006) 6348–6352
Besides the rate of fragrance-release, the detection threshold determines the perfume of treated fabric. The lower rate of fragrance-release and detection threshold makes perfume smell well for long time. All the essential oils used in experience on cotton fabric can be reserved over 30 days.
4. Conclusion b-Cyclodextrins molecules were anchored on the cellulose fibre by sol–gel coating technique. The bcyclodextrins are able to form complexes with a lot of fragrance oils. Functionalities of treated fabric were verified by decreasing the rate of volatile fragrance substances. The rates of fragrance-release decreased greatly. All the essential oils used in experience on cotton fabric can be reserved over 30 days by with by sol–gel coating. Furthermore, the anchoring finishing durability of CD can withstand more than 15 laundering cycles. It is possible that customers can reload fragrance according to their willing in daily life. That is to say, they can change the smell easily. A novel functional chemistry modification of fabrics by b-cyclodextrins sol–gel coating can be achieved in this way.
References [1] Textor, Th. Bahners, E. Schollmeyer, Surface modification of textile fabrics by coatings based on the sol–gel process, Melliand Textilber 10 (1999) 229–230. [2] D. Knittel, E. Schollmeyer, Technologies for a new century, surface modification of fibres, J. Text. Inst. 3 (2000) 151–165. [3] C.-X. Wang, C.-L. Chen, Fragrance-release property of bcyclodextrin inclusion compounds and their application, J. Ind. Text. 34 (1) (2005) 157–166. [4] H.-J. Buschmann, U. Denter, D. Knittel, E. Schollmeyer, The use of cyclodextrins in textile process, J. Text. Inst. 89 (1988) 554–561. [5] C.-X. Wang, C.-L. Chen, Anchoring b-cyclodextrin to retain fragrances on cotton by means of heterobifunctional reactive dyes, Coloration Technol. 120 (2004) 14–18. [6] H.-J. Buschmann, U. Denter, D. Knittel, E. Schollmeyer, Textile materials with cyclodextrins, Melliand Textilberichte Int. Text. Rep. 82 (2001) 36–39.
[7] H.-J. Buschmann, Resin finishing of cotton in the presence of cyclodextrins for depositing fragrances, Melliand Textilberichte 72 (1991) 198–200. [8] H.-J. Buschmann, Cyclodextrins and dextrins as new auxiliaries in dyeing, Melliand Textilberichte 72 (1991) 1012–1014. [9] H.-J. Buschmann, R. Benkan, D. Knittel, Removal of residual surfactant deposits from textile materials with the aid of cyclodextrins, Melliand Textilberichte 9 (1995) 216–218. [10] K.L. Yan, Y.P. Zhang, F.X. Song, K. Schaefer, H. Hoecker, Permanent finishing of UV protecting textiles with nanoparticles by using the sol–gel technique, DWI Rep. 127 (2003) 68–74. [11] B. Mahltig, H. Bo¨ttcher, Light fading and wash fastness of dyed nanosol-coated textile, Text. Res. J. 74 (2004) 521– 527. [12] C. Schramm, W.H. Binder, R. Tessadri, Durable press finishing of cotton fabric with 1,2,3,4-butanetetracaraboxylic acid and TEOS/GPTMS, J. Sol–Gel Sci. Technol. 29 (2004) 155–165. [13] B. Mahltig, H. Bo¨ttcher, Refining of textiles by nanosol coating, Melliand Textilber 3 (2002) 213–215. [14] Luo Min, Zhang Xiaoli, Chen Shuilin, Enhancing the wash fastness of dyeing by a sol–gel process. Part 1. Direct dyes on cotton, Coloration Technol. 119 (2003) 297–300. [15] M. Dreja, W. Von Rybinski, System for releasing active substances and active agents manufactured by the sol–gel process, EP5752 24 May 2002. [16] B. Mahltig, D. Knittel, E. Schollmeyer, Incorporation of triarylmethane dyes into sol–gel matrices deposited on textiles, J. Sol–Gel Sci. Technol. 31 (2004) 293–298. [17] J.H.Z. Xin, W.A. Daoud, X.M. Tao, Multifunctional nanostructural surface treatment for textile, USP 2004117915 A1 24 June 2004. [18] J. Mrazek, V. Matejec, I. Kasik, M. Hayer, Application of the sol–gel method at the fabrication of microstructure fibers, J. Sol–Gel Sci. Technol. 31 (2004) 175–178. [19] Klas, Pa¨ffgen, Thomas, Coating of industrial textiles, Techn. Text. 48 (2005) 112–116. [20] Holme Lan, Dyeing cellulosic fibres: colour fastness and quality, Int. Dyer 190 (2005) 5–10. [21] B. Mahltig, D. Fiedler, A. Thron, H. Bo¨ttcher, Biocidal coatings based on silica nanosols, VDI-Berichte 1803 (2003) 291– 294. [22] H. Bo¨ttcher, P. Slowik, W. Su¨ß, Sol–gel carrier systems for controlled drug delivery, J. Sol–Gel Sci. Technol. 13 (1998) 277–281. [23] B. Mahltig, D. Fiedler, H. Bo¨ttcher, Antimicrobial sol–gel coatings, J. Sol–Gel Sci. Technol. 32 (2004) 219–222. [24] H. Haufe, A. Thron, D. Fiedler, B. Mahltig, H. Bo¨ttcher, Biocidal nanosol coatings, Surface Coat. Int. Part B Coat. Trans. 88 (2005) 55–60.
Surface treatment of cotton using b-cyclodextrins sol–gel method C.X. Wang a,*, Sh.L. Chen b a
College of Textile and Garment, Southern Yangtze University, Lihu Ave. 1800, Wuxi 214122, PR China b College of Chemistry and Chemical Engineering, Donghua University, Shanghai 200051, PR China Received 19 August 2005; received in revised form 12 September 2005; accepted 12 September 2005 Available online 19 October 2005
Abstract b-Cyclodextrin can be added into sol–gel solution which consists of 3-glycidyloxypropyl-trimethoxysilane (GPTMS), tetraethoxysilane (TEOS), catalyzer and solvent. This b-cyclodextrianto sol–gel solution is able to anchor b-cyclodextrin on cotton fabrics in gelation process in order to impart new surface property of cotton. The suitable technical conditions of forming stable b-cyclodextrin sol–gel solution were presented. b-Cyclodextrins are able to form inclusion complexes with other guest components. As a result of the inclusions, the treated fabrics achieved new functional properties by the selective inclusion of the guest substances into the fixed cavities on fabrics. A novel functional surface treatment of fabrics is presented by sol–gel methods. The new functionalities were verified simply by decreasing the rate of volatile fragrance substances. # 2005 Elsevier B.V. All rights reserved. Keywords: Surface treatment; b-Cyclodextrin; Sol–gel method; Cotton
1. Introduction A novel functional surface treatment of cotton based on the permanent fixation of b-cyclodextrins on fabric is receiving increased attention in textile field [1–5]. Cyclodextrins are non-reducing cyclic linked oligosaccharides produced by certain microorganisms cultivated starch, which are capable of forming inclusion compounds with molecules that fit into * Corresponding author. Tel.: +86 510 5912105; fax: +86 510 5912105. E-mail address: [email protected] (C.X. Wang).
their cone-shaped hydrophobic cavity. The encapsulation process is accompanied by changes of the properties of the substance within the cavity. The stability of the complexed molecules against oxidation, hydrolysis and photochemical reactions is increased. The speed of evaporation of volatile substances is reduced drastically [6,7]. Cyclodextrins are considered as very important environment friendly auxiliaries because they are biodegradable and no toxic symptoms [8]. Some scientific reports have demonstrated that cyclodextrin fixed to cotton did not affect the hydrophilic properties of cellulose and the immobilized cavities of cyclodextrins did not lose
0169-4332/$ – see front matter # 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.apsusc.2005.09.016
C.X. Wang, S.L. Chen / Applied Surface Science 252 (2006) 6348–6352
6349
their complexing power to form inclusion complexes with other molecules. It is well known that some pharmaceutically active compounds and fungicidal and bactericidal substances are able to form complexes with cyclodextrins. This may represent medical or other functional purpose textile [9]. It is possible to remove most of nicotine and tar from smoke with treated domestic textile. Also, the bad sweat odor is reduced because the sweat components can be incorporated into the cyclodextrin cavities attached on fabrics. The sol–gel method is a new versatile tool to create transparent and well adhesive silicon oxide films onto various materials [10–16]. The chemical and physical modification of such coating allows a wide range in variation of surface properties of textile [17–21]. The controlled release of coronary therapeuticum nifedipine used in drug by the sol–gel technique has been researched [22–24]. In the paper, the b-cyclodextrins are chosen to be anchored to modify the surface of cotton fabric by sol– gel processes. Guest compounds such as the fragrance molecules that fit with the cavity of b-cyclodextrins are capable of forming inclusion with b-cyclodextrins on the fabrics. The new functionalities were verified simply by decreasing the rate of volatile fragrance substances. The various new functional textiles can be achieved in the way.
chased from Chemical Auxiliary Factory, Zhangjiagang, China. The high-speed shearing emulsifiers BME 1001 was from Weiyu Mechanical-Electronic Co. Ltd. Shanghai. UV-3000 reflectance spectrophotometer was from Shimadzu, Japan. The shaker was from apparatus factory, Shanghai.
2. Experimental
The b-cyclodextrins sol–gel solution was diluted for six times with water. The cotton was immersed in diluted solution at room temperature for 10 min. The fabric sample was padded to a wet pick up of 100%. Then cotton was heated at 80 8C for 5 min.
2.1. Materials and laboratory apparatus The desized, scoured and bleached cotton fabric (Poplin 130 g/m2) was purchased from a factory of dyeing and printing. The fabric was purified in the laboratory by scouring at 100 8C for 60 min using a solution containing sodium carbonate (2 g/l). It is then thoroughly washed with water and dried at ambient conditions. The b-cyclodextrin (CD) was available in the market. Essential oils such as lemon, rose, jasmine, lavender, sandalwood, rosemary were kindly supplied by the Perfume Institute, Shanghai, China. Alcohol, hydrochloric acid was analytical reagent grade. 3-Glycidyloxypropyl-trimethoxysilane (GPTMS) and tetraethoxysilane (TEOS) was pur-
2.2. Preparation of sol–gel solution b-Cyclodextrins were resolute with a mixture solution containing ethanol and distilled water. The solution was emulsified with a high-speed mixer at a speed of about 500 rpm for 15 min. TEOS and GPTMS were added into emulsified solution under stirring, respectively. Then the system was kept shaking while the temperature was kept at 40 8C in water shaker for further 8 h. The sol–gel solutions were composed of as below: GPTMS (g) TEOS (g) b-Cyclodextrins (g) Hydrochloric acid (ml) Ethanol (ml) Water (ml)
23.7 20.8 0.1–3.5 40 116 36
2.3. Application of b-cyclodextrins sol–gel solution on the cotton
2.4. Application of fragrance on the cotton The three methods padding, immersing and spraying are used to load the fragrance on the textile. The fragrance substances (1 g) dissolved in water or ethanol (1000 ml) were stirred with a high-speed mixer at a speed of about 10,000 rpm for 5 min. The cotton anchored with b-cyclodextrins was immersed in fragrance solution for 24 h, sprayed with sprayer evenly or padded twice to a wet pick up of 100% by conventional pad method.
6350
C.X. Wang, S.L. Chen / Applied Surface Science 252 (2006) 6348–6352
2.5. Amount of CD on the fabric The visualization agent phenolphthalein (PP) was used as an indicator for measuring CD concentration on the fabric. The treated sample with given weight was put into water solution containing a known amount of PP, which was tested at the maximum absorption wavelength 553 nm by the UV-3000 reflectance spectrophotometer. 2.6. Amount of fragrance on the fabric The treated fabric by fragrance was extracted by ethanol for 12 h. Fragrance concentration on the fabric was measured on the UV-3000 reflectance spectrophotometer every week. The excitation wavelength was 276 nm.
3. Results and discussion 3.1. Effect of b-cyclodextrins on sol–gel solution The amount of b-cyclodextrins in sol–gel solution decide the surface properties of treated cotton. The effect of concentration of b-cyclodextrins on the stability of sol–gel solution is given in table (see Section 2.2). It was clear that the stability of sol–gel solution decrease greatly when b-cyclodextrins added into sol– gel solution. The more b-cyclodextrins, the less stability of sol–gel solution is. This may due to the OH group in b-cyclodextrins react with OH group of hydrolyzed GPTMS. The amount of b-cyclodextrins is no more than 0.5 mol L 1 in order to ensure the stability of sol–gel solution.
containing essential oils. The fragrance depositing properties of the three loading methods were measured by UV-3000. The results were shown in Fig. 1. Fig. 1 showed that fragrance-release properties were related to the methods of loading. Spraying seemed to be the simple and most effective approach to loading-fragrance. Spraying might impart more essential oils on fabric because of the pressure. It could be concluded that the environment of CD will influence the formation of inclusions. It was also showed that solvent of essential oils solution influenced the amount of inclusion. Ethanol seemed to benefit the essential oil getting into the cavity of cyclodextrin. This might be explained that the ethanol made essential oil easy to disperse into single molecules, which are in favor of permeating and pushing into hydrophobic cavity of CD. The fragrance depositing property of the fabric is dependent on CD amount on the fabric. The larger amount of CD was anchored on fabric, the more hosts which could offer nests for guest molecules. This means that much fragrance have chances to get into cavities of CD molecules and form inclusions. The inclusions were able to decrease the rate of fragrancerelease. It was also confirmed from Fig. 1 that the essence-release rates were different when different fragrance loading methods were be used. It could be explained that the amount of CD on fabric was responsible for the fragrance-release rate. The reloading methods determined the efficiency of the fragrance to be put into CD.
3.2. Loading methods and amount of CD on fabric After the fabric was treated with sol–gel solution, the b-cyclodextrins anchored on the fabric can form inclusion complexes with other guest components which molecules are fit with their cavities in the usual procedure utilized as for free cyclodextrin. There were several methods to load essential oil into cyclodextrin, such as padding, immersing and spraying. The fabric anchored cyclodextrin was treated by aqueous solution or ethanol solution
Fig. 1. Fragrance depositing properties of fabric. (1) Padding with aqueous solution; (2) immersing with aqueous solution; (3) immersing with ethanol solution; (4) spraying with aqueous solution; (5) spraying with ethanol solution.
C.X. Wang, S.L. Chen / Applied Surface Science 252 (2006) 6348–6352
Fig. 2. Washing durability of CD on fabric.
6351
Fig. 4. Comparison of fragrance-release with and without CD treatment.
The b-cyclodextrins molecules were anchored on the cellulose fibre by sol–gel coating technique. The new functionalities were verified by inclusion compound formed with fragrance substances. The forms of inclusion compound were able to decrease the rate of fragrance-release obviously. The controlled-release
properties had to be measured. The results were shown in Figs. 3 and 4. It was clear that the rates of fragrance-release of inclusion compound were related to the nature of fragrance oils themselves. The rate of rosemary and sandalwood fragrance-release of inclusion compounds is higher than that of other fragrance. It could be explained that they are more fit with cavities of CD. At the same time, the free inclusion compounds can be complexed with fragrance substance by the usual procedure utilized as for free cyclodextrins, that is to say it can be reloaded. When treated fabrics have no scent on it, they can be immersed or sprayed by a concentrated solution containing fragrance substances directly. Compared with fabric without anchoring CD by sol–gel treatment, fragrance-release of inclusion compound formed with CD on fabric decreases greatly. A sensorial evaluation of results has also been performed by a panel of 10 well-trained subjects. The perfumed fabrics were smelled every five days in order to feel the perfume scents. The test panel evaluation results were listed in Fig. 5.
Fig. 3. Rate of fragrance-release of inclusion compounds.
Fig. 5. Sensorial evaluation of scent intensity: (5) expressed as very strong; (4) strong; (3) common; (2) weak; (1) very weak.
3.3. Finishing durability CD anchored on the fabric was mainly determined by the gelation film, which was shaped from sol resolution containing GPTMS as silane coupling agent. The gelation films form the networks which could combine the CD. The results of CD durability were presented in Fig. 2. The results in Fig. 2 revealed that CD concentration on fabric tended to decrease by launderings. When launderings is 20 times, the CD concentration on fabric is too low to form inclusion compound. 3.4. Fragrance depositing properties
6352
C.X. Wang, S.L. Chen / Applied Surface Science 252 (2006) 6348–6352
Besides the rate of fragrance-release, the detection threshold determines the perfume of treated fabric. The lower rate of fragrance-release and detection threshold makes perfume smell well for long time. All the essential oils used in experience on cotton fabric can be reserved over 30 days.
4. Conclusion b-Cyclodextrins molecules were anchored on the cellulose fibre by sol–gel coating technique. The bcyclodextrins are able to form complexes with a lot of fragrance oils. Functionalities of treated fabric were verified by decreasing the rate of volatile fragrance substances. The rates of fragrance-release decreased greatly. All the essential oils used in experience on cotton fabric can be reserved over 30 days by with by sol–gel coating. Furthermore, the anchoring finishing durability of CD can withstand more than 15 laundering cycles. It is possible that customers can reload fragrance according to their willing in daily life. That is to say, they can change the smell easily. A novel functional chemistry modification of fabrics by b-cyclodextrins sol–gel coating can be achieved in this way.
References [1] Textor, Th. Bahners, E. Schollmeyer, Surface modification of textile fabrics by coatings based on the sol–gel process, Melliand Textilber 10 (1999) 229–230. [2] D. Knittel, E. Schollmeyer, Technologies for a new century, surface modification of fibres, J. Text. Inst. 3 (2000) 151–165. [3] C.-X. Wang, C.-L. Chen, Fragrance-release property of bcyclodextrin inclusion compounds and their application, J. Ind. Text. 34 (1) (2005) 157–166. [4] H.-J. Buschmann, U. Denter, D. Knittel, E. Schollmeyer, The use of cyclodextrins in textile process, J. Text. Inst. 89 (1988) 554–561. [5] C.-X. Wang, C.-L. Chen, Anchoring b-cyclodextrin to retain fragrances on cotton by means of heterobifunctional reactive dyes, Coloration Technol. 120 (2004) 14–18. [6] H.-J. Buschmann, U. Denter, D. Knittel, E. Schollmeyer, Textile materials with cyclodextrins, Melliand Textilberichte Int. Text. Rep. 82 (2001) 36–39.
[7] H.-J. Buschmann, Resin finishing of cotton in the presence of cyclodextrins for depositing fragrances, Melliand Textilberichte 72 (1991) 198–200. [8] H.-J. Buschmann, Cyclodextrins and dextrins as new auxiliaries in dyeing, Melliand Textilberichte 72 (1991) 1012–1014. [9] H.-J. Buschmann, R. Benkan, D. Knittel, Removal of residual surfactant deposits from textile materials with the aid of cyclodextrins, Melliand Textilberichte 9 (1995) 216–218. [10] K.L. Yan, Y.P. Zhang, F.X. Song, K. Schaefer, H. Hoecker, Permanent finishing of UV protecting textiles with nanoparticles by using the sol–gel technique, DWI Rep. 127 (2003) 68–74. [11] B. Mahltig, H. Bo¨ttcher, Light fading and wash fastness of dyed nanosol-coated textile, Text. Res. J. 74 (2004) 521– 527. [12] C. Schramm, W.H. Binder, R. Tessadri, Durable press finishing of cotton fabric with 1,2,3,4-butanetetracaraboxylic acid and TEOS/GPTMS, J. Sol–Gel Sci. Technol. 29 (2004) 155–165. [13] B. Mahltig, H. Bo¨ttcher, Refining of textiles by nanosol coating, Melliand Textilber 3 (2002) 213–215. [14] Luo Min, Zhang Xiaoli, Chen Shuilin, Enhancing the wash fastness of dyeing by a sol–gel process. Part 1. Direct dyes on cotton, Coloration Technol. 119 (2003) 297–300. [15] M. Dreja, W. Von Rybinski, System for releasing active substances and active agents manufactured by the sol–gel process, EP5752 24 May 2002. [16] B. Mahltig, D. Knittel, E. Schollmeyer, Incorporation of triarylmethane dyes into sol–gel matrices deposited on textiles, J. Sol–Gel Sci. Technol. 31 (2004) 293–298. [17] J.H.Z. Xin, W.A. Daoud, X.M. Tao, Multifunctional nanostructural surface treatment for textile, USP 2004117915 A1 24 June 2004. [18] J. Mrazek, V. Matejec, I. Kasik, M. Hayer, Application of the sol–gel method at the fabrication of microstructure fibers, J. Sol–Gel Sci. Technol. 31 (2004) 175–178. [19] Klas, Pa¨ffgen, Thomas, Coating of industrial textiles, Techn. Text. 48 (2005) 112–116. [20] Holme Lan, Dyeing cellulosic fibres: colour fastness and quality, Int. Dyer 190 (2005) 5–10. [21] B. Mahltig, D. Fiedler, A. Thron, H. Bo¨ttcher, Biocidal coatings based on silica nanosols, VDI-Berichte 1803 (2003) 291– 294. [22] H. Bo¨ttcher, P. Slowik, W. Su¨ß, Sol–gel carrier systems for controlled drug delivery, J. Sol–Gel Sci. Technol. 13 (1998) 277–281. [23] B. Mahltig, D. Fiedler, H. Bo¨ttcher, Antimicrobial sol–gel coatings, J. Sol–Gel Sci. Technol. 32 (2004) 219–222. [24] H. Haufe, A. Thron, D. Fiedler, B. Mahltig, H. Bo¨ttcher, Biocidal nanosol coatings, Surface Coat. Int. Part B Coat. Trans. 88 (2005) 55–60.