1. Introduction An increasing attention has been paid in textile research and development to environmentally benign and non-toxic bio-based colorants and garments due to the public concern about health issues and eco-protection [1-2]. Natural dyes derived from plants, animals, bacteria and fungi are believed to be bio-compatible, safe and renewable alternatives to synthetic colorants because of their biodegradability and low allergic reactions [3-4]. Wool as one of the most popular natural fibers is usually used in high quality textiles and hand-woven carpets. The existence of hydrophobic scales on the surface of wool fibers makes the diffusion of dye molecules difficult [5-6]. This problem is more pronounced when applying natural dyes on wool due to the low affinity of these dyes to protein fibers. Traditionally metal mordants like aluminum, tin, copper, chromium and iron salts are employed to improve the exhaustion and fastness of natural dyes on wool fibers by complex formation between the wool polymeric structure, dye molecule and the metal atom [7-9]. Today it is known that metal mordants are more or less toxic and may impose hazards to human being, animals and environment. So, different studies have been done to minimize the use of metal mordants in natural dyeing recipes or replace them with more environmentally friendly alternatives [7, 10-11]. The use of high energy radiations is one of the vastly studied approaches for surface modification and improving the dyeability of textile fibers by natural and synthetic dyes [12]. The ultrasonic technique was used for increasing the color strength of wool fabric when dyeing with natural dye extracted from grape pomace [13]. This method reduced the dyeing time, temperature and energy consumption of the dyeing process [13-14]. Microwave radiation improved the dyeability of wool and cotton fibers with natural and synthetic dyes [15-16]. Pretreatment of woolen fabric with gamma radiation prior to dyeing with pomegranate rinds as a natural dye increased the sorption capacity of the natural dye and 1

resulted in getting darker and more saturated shades [17]. Similar results were obtained when applying gamma radiation on cotton fabrics and dyed with different natural dyes [18-22]. Pretreatment with UV irradiation improved the dyeing properties of wool fabric with tea as a natural dye and reduced the need for chromium metal mordant [23]. Plasma treatment as an environmentally process for improvement of natural dyeing of wool fibers has been studied in recent years. In one of our recent studies, the effect of oxygen plasma pretreatment parameters on color strength of woolen fabric after dyeing with the extract of grape leaves was investigated and the optimum conditions were obtained [10]. In other studies it was found that pretreatment with oxygen plasma can increase the color strength of woolen fabric when dyed with extracts of barberry wood, cumin seeds, cotton pods and shrimp shell [5, 7, 11, 24]. Other environmentally friendly processes including enzyme and nanoclay treatment [25], chitosan finishing [11, 26], application of chitosan-polypropylene imine dendrimer hybrid [27] and bio-mordanting [28-31] have been used for improvement of natural dyeing of wool fibers. Recently, A number of studies on isotherm and kinetic of natural dyeing of wool have been reported too [4, 32-33]. Dendrimers are highly branched polymers with regular and compact shape having a large number of functional end groups and internal cavities which enables them to interact with guest molecules [34]. They have the ability to influence the dyeing properties of textile fibers if grafted on them. The color strength of cotton and jute fabrics pretreated with a dendrimer with amine end groups was markedly enhanced when dyed with reactive dyes [35-36]. The direct dyeing behavior of PPI dendrimer grafted cotton fabric was also studied and the color strength of the grafted samples was markedly enhanced compared with control samples [37]. To the best of the author’s knowledge, there is not any scientific report about the application of dendrimers on wool fibers and its effect on the dyeability with a natural dye. In this study, wool fibers were treated with a PPI dendrimer. To enhance the diffusion of the dendrimer into the fibers, oxygen plasma pretreatment was performed. The influence of plasma treatment and dendrimer grafting on the dyeing behavior of wool fibers by cochineal natural dye was studied using isotherm and kinetic investigations. Chemical and morphological changes of wool fibers after each treatment was also studied using FESEM, FTIR and AFM techniques.

2. Materials and Methods Pure merino wool fabric (plain weave, 250 g/m2) was obtained from Iran-Merinos Company (Tehran, Iran) and scoured in a bath containing 1% non-ionic detergent (Triton X-100, Sigma-Aldrich) for 30 minutes. The temperature was kept at 50 ºC during the scouring process. Second generation Poly(propylene imine) dendrimer (G2-PPI) was obtained from SyMo-Chem, The Netherlands. Plasma treatment: A radio frequency (13.56 MHz) machine (Model: Junior Advanced, Europlasma, Belgium) working with oxygen as the plasma gas was used. After placing the sample on the holder between the electrodes, the chamber was pumped out by a vacuum pump (base pressure: 100 mTor). Then O2 gas was sent into the chamber with a flow rate adjusted at 100 SCCM (standard cubic centimeter per minute). After one minute for reaching a stable gas flow, plasma treatment was done with a power of 200 W for 5 minutes. Dendrimer treatment: Wool fabrics were immersed in aqueous solution containing 0.05% G2PPI for 30 minutes at 25 ºC, then padded with 100% wet pick-up and dried at 80 ºC for 30 minutes. Curing at 160 ºC for 3 minutes was followed and the sample was finally washed in a bath containing 1% Triton X-100 at 50 ºC and air dried. Dye extraction: To extract the dye molecules, the bodies of cochineal insects (Dactylopius coccus) were finely crushed. 10 grams of the crushed powder was added to a 20/80 mixture

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of methanol/water in a soxhlet and the extraction was continued for 120 minutes at boil. Then the solvent was evaporated at 40 ºC and the remaining dye was used. Dyeing behavior studies: To investigate the effects of different factors including dyeing pH, dye concentration, sorbent dosage and dyeing temperature, the dye sorption studies were conducted in jars containing 100 mL of dye solutions with different concentrations in contact with various amounts of wool fabric. The solution pH was adjusted by means of buffer solutions (pH= 4, 6, 8). Sodium acetate and acetic acid were used for preparation of buffer with pH= 4. Monosodium phosphate and disodium phosphate were used for preparation of buffers with pH= 6 and 8. The changes in the absorbance of each solution were determined at certain time intervals during the sorption process using a DR 5000 UV–Visible spectrophotometer (HACH, USA) at the wavelength of maximum absorption (501 nm at pH=4). Concentrations of dye in solutions were determined by using a previously established calibration curve. The effect of pH on exhaustion of cochineal dye was investigated by adding 0.2 g of wool fibers in a bath containing 100 mL of dye solution (initial concentration of 250 ppm) at 40 °C for 2 h at different pH values (4, 6 and 8 adjusted by appropriate buffer). The effect of dyeing temperature was also investigated by setting different dyebath temperatures (40, 60 and 80 °C). In these experiments the dyebath pH was set at 4 and other factors were as same as the previous experiments. The effect of wool fiber dosages on dye sorption was inspected using 100 mL of dye solution with initial dye concentration of 250 ppm and pH= 4 at 40 °C for different times. The amount of wool fibers was varying from 0.1 g to 0.4 g. The effect of initial dye concentration on dye sorption was studied by choosing different concentrations ranging from 50 ppm to 250 ppm and performing the dyeing process at 40 °C for different times (pH = 4, 100 mL dye solution and 0.2 g wool fibers). The amounts of dye absorption were calculated as described in previous papers [38-39]. The data obtained from changing the initial dye concentration was used for isotherm studies and evaluated for compliance with the Langmuir, Freundlich, and Temkin models. The kinetics of the dyeing of all wool samples was also studied. The pseudo-first-order, pseudosecond-order and intra-particle diffusion models were evaluated for compliance with the data obtained from the absorption of the cochineal dye (100 mL, initial concentration= 250 ppm, 0.2 gr wool fiber, pH= 4) on different wool samples. FTIR spectroscopy: Fourier Transform infrared (FTIR) spectroscopy was performed using an IRAffinity-1 instrument (Shimadzu, Japan) with a resolution of 4 cm-1 in order to investigate the chemical structure of the extracted dye and modifications of wool fibers after plasma and dendrimer treatments. An average of 45 scans was recorded. Scanning Electron Microscopy: Field emission scanning electron micrographs were taken on a Mira 3-XMU scanning electron microscope (TESCAN, Czech Republic) to study the effect of plasma and dendrimer treatments on the surface structure of wool fibers. This microscope was equipped with an energy dispersive X-Ray analyzer (EDX) which was is also used to provide elemental identification and quantitative compositional information of the surface of different samples. Atomic force microscopy: AFM (Dualscope Ds-95-50-5E, DME, Germany) was employed in non-contact mode to observe and compare the surface topology of raw, plasma treated and dendrimer treated wool fibres.

3. Results and Discussion

3.1. Characterization of cochineal dye

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Figure 1 shows the UV-Vis absorbance spectrum of the extracted cochineal dissolved in distilled water (pH= 4, 150 ppm). It can be seen that the wavelength of maximum absorbance was 501 nm at this pH value. Figure 2 shows the FTIR spectrum of the extracted cochineal powder. As can be seen in table 1 the main bands corresponding to the glucose residue (Glu), were appeared in the 1000– 1300 cm-1 region. The characteristic bands of C=O group were appeared as a peak at 1616-1 and a shoulder at 1740 cm-1. Comparing the list of main peaks found in the FTIR spectrum of the cochineal sample with the spectra obtained in the literature, confirms the presence of Carminic acid (C.I. Natural Red 4, figure 3) in the obtained extract sample [40-41].

3.2. FESEM and EDX investigations Figure 4 shows the FESEM images of raw, plasma treated and Dendrimer treated wool fibers. It can be seen that the surface scales have been attacked by the high energy particles of oxygen plasma resulting in etching of scales and creation of sub-micron pits (fig. 4b and 4c). The dendrimer nanoparticles were not seen in fig. 4c because they could penetrate inside the wool fibers due to their very small size (around 1.5 nm [42]). However, the creation of oxygen containing chemical groups on plasma treated fibers and the presence of dendrimer nanoparticles on dendrimer treated sample was confirmed by EDX analysis. As shown in table 2, comparing the raw and plasma treated samples; the amount of oxygen atom has been increased on the surface of wool fibers after plasma treatment which confirms the creation of oxygen containing chemical groups on the surface of wool fibers after plasma treatment. Dendrimer treated sample contains more nitrogen atoms compared with the raw and plasma treated samples which confirms the presence of dendrimer molecules on the wool fibers.

3.3. AFM investigations Figure 5 shows the AFM images of different samples indicating that plasma treatment caused a significant superficial modification of wool fibers. The surface etching of plasma treated samples and creation of sub-micron pits were confirmed again. The treatment time and the gas used determine the extent of surface etching. In this study, oxygen plasma treatment led to a progressive surface etching effect. The permanent effect of etching and increasing the

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roughness obtained through oxygen plasma treatment can increase the adhesion, friction, dyeability and wettability of wool fibers. The roughness of raw, plasma treated and dendrimer treated samples were calculated and are summarized in table 3. As expected, plasma treatment has increased the surface roughness of wool fibers due to the etching of the surface layer of wool fibers. The surface roughness of dendrimer treated samples was a little higher than the plasma treated sample which may be attributed to the presence of small aggregates of dendrimer nanoparticles on the surface resulting in increased roughness.

3.4. FTIR investigations As shown in figure 6a and stated in our previous papers, by comparing the FTIR spectra of raw and oxygen plasma treated wool fibers, the increase in the intensity of bands at 1645 cm-1 and 1534 cm-1 confirmed the formation of new oxygen containing groups on the surface of wool fibers after plasma treatment. These newly introduced functional groups are responsible for improved wetting and dye absorption of plasma treated wool fibers [7, 43-44]. The FTIR spectra of plasma treated and dendrimer treated samples are compared in figure 6b. The intensity of the band appeared at 1645 cm-1 has been increased after dendrimer treatment which confirms the formation of amide bonds between the –NH2 groups of the dendrimer and –COOH groups of wool fibers. The peak at 3430 cm-1 corresponds to free –NH2 groups of dendrimer molecules attached to the polymeric structure of wool fibers which are able to interact with the dye molecules. Figure 7 shows the proposed mechanism for the reaction of plasma treated wool with G2-PPI dendrimer.

3.5. Dye absorption studies

3.5.1. Effect of dyebath pH on dye absorption The effect of dyebath pH on absorption of cochineal dye by wool fibers is shown in figure 8. The dye absorption was decreased as the pH was increased from 4 to 8 for all samples including raw, plasma treated and dendrimer treated wool fabrics. When studying the effect of pH on dyeability of textile fibers, the electrostatic attractions between the polymeric structure of fibers and dye molecules play the most important role. As can be seen in figure 3, carminic acid as the main coloring matter of cochineal natural dye, contains a –COOH group which enables the dye molecule to gain negative charge when dissolved in water. Also, wool fiber gains more positive charges at lower pH values. So, when decreasing the dyebath pH, higher electrostatic attraction forms between the positively charged wool fibers and negatively charged dye molecules leading to more absorption of the dye. Figure 9 shows the proposed mechanism of the interaction between carminic acid and wool (raw and plasma treated) fibers, including ionic and hydrogen bonds. Comparing different wool samples, it can be seen that the dye absorption (%) was as the following order: dendrimer treated > plasma treated > raw. Plasma treated fibers absorbed a higher amount of dye because of etching of surface barrier layer of the fibers [10-11] which made the diffusion of dye molecules inside the fibers easier. The dendrimer used in this study contains 8 amine and 6 imine groups in its chemical structure which makes it positively charged when subjected to acidic pH (see figure 10). The dendrimer treated sample showed the highest dye absorption due to the electrostatic attraction between the negatively charged dye molecules and positively charged dendrimers as well as the positively charged amine groups of wool fibers. Figure 11 shows the proposed mechanism for the interaction of the dendrimer treated wool fibers with carminic acid ions (Dye-COO-) through ionic bonds.

3.5.2. Effect of initial concentration on dye absorption

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Figure 12 shows the effect of the initial concentration of cochineal dye in the dyebath on dye absorption. It is obvious that when the amount of wool fibers is kept constant, the amount of absorbed dye was increased by increasing the initial dye concentration in case of all samples. The reason may be the enhancement in the driving force of the concentration gradient at higher initial dye concentrations which confirmed the strong chemical interactions between the dye molecules and wool fibers. It can be seen that the dye absorption % is much higher for the dendrimer treated sample in all initial dye concentrations, which is due to the higher amount of dye sorption sites in this samples.

3.5.3. Effect of fiber weight on dye absorption The plot of dye absorption (%) vs. time (min) at different wool fiber dosages (g) is shown in Figure 13. After the introduction of wool fibers to the dyebath, dye concentration decreased rapidly with the contact time confirming strong interactions between the dye and the positive sites of the fibers. The adsorption was increased instantly at initial stages due to rapid attachment of dye to the surface of wool fibers and kept increasing gradually until the equilibrium was reached then remained constant after about 60 min. The amount of adsorbed dye showed no significant difference when the contact times were longer. The increase in dye absorption with wool fiber dosage can be attributed to the availability of more positively charged groups as adsorption sites. As expected, the highest amount of dye absorption was obtained in the dyeing of the dendrimer treated wool sample due to the high amount of positively charged amine and imine groups in this sample.

3.5.4. Effect of dyebath temperature on dye absorption As can be seen in figure 14, the dye absorption % was increased for all samples by increasing the dyebath temperature. The increase in dye-uptake can be explained by fibre swelling and de-aggregation of dye molecules at higher temperatures which enhanced the dye diffusion consequently [45].

3.5.5. Kinetic and isotherm studies In practical dyeing, it is important to optimize the process and control the required time to achieve high bath exhaustion. This necessitates the kinetic studies. To this aim, pseudo-firstorder, pseudo-second-order and intra-particle diffusion equations were implemented on the experimental data to find the controlling mechanism of the adsorption process. The linear regression correlation coefficients (R2 values) were considered as the measure to select the best-fit model. The calculation of the dye adsorbed by wool samples was done using equation (1): qt = (C0 − Ct)V/W

(1)

In this equation, qt is the amount of dye adsorbed on the wool samples (mg/g) at time (t), V is the volume of dye bath (mL), W is the weight of wool sample (g), C0 and Ct are the initial dye concentration and the dye concentrations (mg/L) after dyeing time t, respectively [39, 46]. 6

Equations (2) and (3) show the linear forms of the pseudo-first-order and pseudo-secondorder kinetic models. ln(qe − qt) = ln(qe) − k1t

(2)

t/qt = (1/k2qe) + (1/qe)t (3) The intra-particle diffusion model can be shown by equation (4). qt = kp1/2+ I

(4)

To study the applicability the pseudo first-order, pseudo second-order and intra-particle models in the cochineal dyeing of different wool samples, the plots of ln(qe–qt) versus t, t/qt versus t and qt versus t1/2 were drawn respectively and the correlation coefficient values (R2) were considered as a measure of the applicability of the models with the experimental data (figure 15). Langmuir, Freundlich and Temkin models were applied to find the best-fitting isotherm model for adsorption of dye molecules on wool fabric. The linear forms of Langmuir, Freundlich and Temkin isotherms can be expressed as Equation (5), (6) and (7), respectively [39, 46]. Ce/qe= 1/KLQ0+ Ce/Q0 (5) log qe = log KF + (1/n) log Ce (6) qe = B1 lnKT + B1lnCe (7) To study the suitability of the Langmuir, Freundlich and Temkin isotherms for cochineal dye adsorption onto different wool samples at various dye concentrations, linear graphs of Ce/qe against Ce, log qe versus log Ce and qe versus ln Ce were drawn respectively (figure 16). Figure 15 shows that the kinetic of absorption of cochineal on raw, plasma treated and dendrimer treated wool samples were best fitted with the pseudo-second-order model. The R2 for pseudo-second-order model is higher than other models for all samples. It implies that chemisorption took place during the adsorption process of cochineal dye on all samples. Hydrogen Bonding and ionic interactions between fiber surface and dye molecules are the possible interactions for chemisorption process [32] as shown in figures 9 and 11. Figure 16 shows that the isotherm of absorption of cochineal on raw, plasma treated and dendrimer treated wool samples were best fitted with the Freundlich model. The R2 for Freundlich model is higher than other models for all samples. This means that the dye sorption took place at specific heterogeneous sites e.g. amine groups of wool fiber itself and

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amine groups of the dendrimer molecules attached to the wool fibers. This model implies that multilayer adsorption takes place with non-uniform distribution of adsorption heat and affinities over the heterogeneous surface [32].

4. Conclusion In this study, wool fibers were modified with oxygen plasma and G2-PPI dendrimer to increase the dyeability of the fibers with cochineal as a natural dye. FESEM, EDX, AFM and FTIR analysis confirmed the physical and chemical modifications of wool fibers after plasma and dendrimer treatments. Raw, plasma treated and dendrimer treated wool samples were dyed under different conditions of pH, temperature, initial dye concentration and fiber weights and the effect of each factor on the dye absorption was evaluated. The isotherm and kinetics of the dyeing process was also studied. The results showed that the kinetics and isotherms of absorption of cochineal on all samples (including raw, plasma treated and dendrimer treated wool fibers) were best fitted with the pseudo-second-order and Freundlich models respectively. Oxygen plasma and dendrimer treatments improved the dyeability of wool fibers with cochineal natural dye significantly and can be considered as an alternative to replace the toxic metallic salts in natural dyeing recipes. References [1] M. Yusuf, M. Shabbir, F. Mohammad, Natural Colorants: Historical, Processing and;1; Sustainable Prospects,;1; Natural Products and Bioprospecting 7(1) (2017) 123-145. [2] A. Kiumarsi, M. Parvinzadeh Gashti, P. Salehi, M. Dayeni,;1; Extraction of dyes from Delphinium Zalil flowers and dyeing silk yarns, The Journal of The Textile Institute 108(1) (2017) 66-70. [3] M. Shabbir, L.J. Rather, I.;1; Shahid ul, M.N. Bukhari, M. Shahid, M. Ali Khan, F. Mohammad, An eco-friendly dyeing of woolen yarn by Terminalia chebula extract with evaluations of kinetic and adsorption characteristics, Journal of Advanced Research 7(3) (2016) 473-482. [4] L.J. Rather, I.;1; Shahid ul, M.A. Khan, F. Mohammad, Adsorption and Kinetic studies of Adhatoda vasica natural dye onto woolen yarn with evaluations of Colorimetric and Fluorescence Characteristics, Journal of Environmental Chemical Engineering 4(2) (2016) 1780-1796. [5] A. Haji, A.M. Shoushtari,;1; Natural antibacterial finishing of wool fiber using plasma technology, Industria Textila 62(5) (2011) 244-247. [6] M. Shahin, H. El-Khatib,;1; Enhancing Dyeing of Wool Fabrics with Natural Kamala Dye via Bio-Treatment with Safflower Extract, International Journal of Innovation and Applied Studies 15(2) (2016) 443-456. [7] A. Haji, S.S. Qavamnia,;1; Response surface methodology optimized dyeing of wool with cumin seeds extract improved with plasma treatment, Fibers and Polymers 16(1) (2015) 4653. [8] L. Ammayappan, D.B.B. Shakyawar,;1; Dyeing of Carpet Woolen Yarn using Natural Dye from Cochineal, Journal of Natural Fibers 13(1) (2016) 42-53. [9] A. Haji,;1; Antibacterial Dyeing of Wool with Natural Cationic Dye Using Metal Mordants, MATERIALS SCIENCE (MEDŽIAGOTYRA) 18(3) (2012) 267-270. [10] A. Haji, S.S. Qavamnia, F.K. Bizhaem,;1; Optimization of oxygen plasma treatment to improve the dyeing of wool with grape leaves, Industria Textila 67(4) (2016) 244-249.

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[11] A. Haji, M.K. Mehrizi, J. Sharifzadeh,;1; Dyeing of wool with aqueous extract of cotton pods improved by plasma treatment and chitosan: Optimization using response surface methodology, Fibers and Polymers 17(9) (2016) 1480-1488. [12] S.-u. Islam, F. Mohammad,;1; High-Energy Radiation Induced Sustainable Coloration and Functional Finishing of Textile Materials, Industrial & Engineering Chemistry Research 54(15) (2015) 3727–3745. [13] N. Baaka, W. Haddar, M. Ben Ticha, M.T.P. Amorim, M.F. M'Henni,;1; Sustainability issues of ultrasonic wool dyeing with grape pomace colourant, Natural Product Research (2017) 1-8. [14] G. Actis Grande, M. Giansetti, A. Pezzin, G. Rovero, S. Sicardi,;1; Use of the ultrasonic cavitation in wool dyeing process: effect of the dye-bath temperature, Ultrasonics Sonochemistry 35, Part A (2017) 276-284. [15] M. Hussaan, N. Iqbal, S. Adeel, M. Azeem, M. Tariq Javed, A. Raza,;1; Microwaveassisted enhancement of milkweed (Calotropis procera L.) leaves as an eco-friendly source of natural colorants for textile, Environ Sci Pollut Res 24(5) (2017) 5089-5094. [16] Z. Xue,;1; Study of dyeing properties of wool fabrics treated with microwave, The Journal of The Textile Institute 107(2) (2016) 258-263. [17] L. CHIRILA, A. POPESCU, I.R. STANCULESCU, M. CUTRUBINIS, A. CEREMPEI, I. SANDU,;1; Gamma Irradiation Effects on Natural Dyeing Performances of Wool Fabrics, REVISTA DE CHIMIE 67(12) (2016) 2628-2633. [18] S. Adeel, T. Gulzar, M. Azeem, R.;1; Fazal ur, M. Saeed, I. Hanif, N. Iqbal, Appraisal of marigold flower based lutein as natural colourant for textile dyeing under the influence of gamma radiations, Radiation Physics and Chemistry 130 (2017) 35-39. [19] S. Adeel, M. Usman, W. Haider, M. Saeed, M. Muneer, M. Ali,;1; Dyeing of gamma irradiated cotton using Direct Yellow 12 and Direct Yellow 27: improvement in colour strength and fastness properties, Cellulose 22(3) (2015) 2095–2105. [20] T. Gulzar, S. Adeel, I. Hanif, F. Rehman, R. Hanif, M. Zuber, N. Akhtar,;1; EcoFriendly Dyeing of Gamma Ray Induced Cotton Using Natural Quercetin Extracted from Acacia Bark (A. nilotica), Journal of Natural Fibers 12(5) (2015) 494-504. [21] A.A. Khan, N. Iqbal, S. Adeel, M. Azeem, F. Batool, I.A. Bhatti,;1; Extraction of natural dye from red calico leaves: Gamma ray assisted improvements in colour strength and fastness properties, Dyes and Pigments 103(1) (2014) 50-54. [22] M. Zahid, I.A. Bhatti, S. Adeel, S. Saba,;1; Modification of cotton fabric for textile dyeing: industrial mercerization versus gamma irradiation, The Journal of The Textile Institute 108(2) (2017) 287-292. [23] C. Cheng, Y. Wenjun, C. Chuansheng, W. Haiyan,;1; Tea pigment dyeing process with mordant of wool fabric treated by ultraviolet radiation, Journal of Radiation Research and Radiation Process 35(1) (2017) 10303-10311. [24] M. Molakarimi, M. Khajeh Mehrizi, A. Haji,;1; Effect of plasma treatment and grafting of β-cyclodextrin on color properties of wool fabric dyed with Shrimp shell extract, The Journal of The Textile Institute 107(10) (2016) 1314-1321. [25] M. Parvinzadeh Gashti, B. Katozian, M. Shaver, A. Kiumarsi,;1; Clay nanoadsorbent as an environmentally friendly substitute for mordants in the natural dyeing of carpet piles, Coloration Technology 130(1) (2013) 54-61. [26] V.R. Giri Dev, J. Venugopal, S. Sudha, G. Deepika, S. Ramakrishna,;1; Dyeing and antimicrobial characteristics of chitosan treated wool fabrics with henna dye, Carbohydr. Polym. 75(4) (2009) 646-650. [27] L. Mehrparvar, S. Safapour, M. Sadeghi-Kiakhani, K. Gharanjig,;1; Chitosanpolypropylene imine dendrimer hybrid: a new ecological biomordant for cochineal dyeing of wool, Environ Chem Lett 14(4) (2016) 533–539. 9

[28] Ö. Erdem;1; İşmal, L. Yıldırım, E. Özdoğan, Use of almond shell extracts plus biomordants as effective textile dye, Journal of Cleaner Production 70 (2014) 61-67. [29] A. Haji,;1; Functional Dyeing of Wool with Natural Dye Extracted from Berberis vulgaris Wood and Rumex Hymenosepolus Root as Biomordant, Iranian Journal of Chemistry and Chemical Engineering 29(3) (2010) 55-60. [30] Ö.E.;1; İşmal, Greener natural dyeing pathway using a by-product of olive oil; prina and biomordants, Fibers and Polymers 18(4) (2017) 773-785. [31] Ö. Erdem;1; İşmal, L. Yıldırım, E. Özdoğan, Valorisation of almond shell waste in ultrasonic biomordanted dyeing: alternatives to metallic mordants, The Journal of The Textile Institute 106(4) (2015) 343-353. [32] M. Shabbir, L.J. Rather, I.;1; Shahid ul, M.N. Bukhari, M. Shahid, M.A. Khan, F. Mohammad, An eco-friendly dyeing of woolen yarn by Terminalia chebula extract with evaluations of kinetic and adsorption characteristics, Journal of Advanced Research 7(3) (2016) 473-482. [33] M.R. Shahparvari, S. Safapour, K. Gharanjig,;1; Study on Kinetic Behavior and Dyeability of Woolen Yarn With Madder and Cochineal Natural Dyes, Journal of Color Science and Technology 10(3) (2016) 195-206. [34] P.E. Froehling, Dendrimers and dyes;1; -- a review, Dyes and Pigments 48(3) (2001) 187-195. [35] A.A. Zolriasatein, M.E. Yazdanshenas, R. Khajavi, A. Rashidi,;1; The application of poly(amidoamine) dendrimers for modification of jute yarns: Preparation and dyeing properties, Journal of Saudi Chemical Society 19(2) (2015) 155-162. [36] S.M. Burkinshaw, M. Mignanelli, P.E. Froehling, M.J. Bide,;1; The use of dendrimers to modify the dyeing behaviour of reactive dyes on cotton, Dyes and Pigments 47(3) (2000) 259-267. [37] S. Salimpour Abkenar, R. Malek, F. Mazaheri,;1; Salt-free dyeing isotherms of cotton fabric grafted with PPI dendrimers, Cellulose 22(1) (2015) 897-910. [38] M. Abdouss, A. Mousavi Shoushtari, A. Majidi Simakani, S. Akbari, A. Haji,;1; Citric acid-modified acrylic micro and nanofibers for removal of heavy metal ions from aqueous media, Desalination and Water Treatment 52(37-39) (2014) 7133-7142. [39] A. Haji, A. Mousavi Shoushtari, M. Abdouss,;1; Plasma activation and acrylic acid grafting on polypropylene nonwoven surface for the removal of cationic dye from aqueous media, Desalination and Water Treatment 53(13) (2015) 3632-3640. [40] M.E. Borges, R.L. Tejera, L. Díaz, P. Esparza, E. Ibáñez,;1; Natural dyes extraction from cochineal (Dactylopius coccus). New extraction methods, Food Chemistry 132(4) (2012) 1855-1860. [41] M.V. Cañamares, J.V. Garcia-Ramos, C. Domingo, S. Sanchez-Cortes,;1; Surfaceenhanced Raman scattering study of the anthraquinone red pigment carminic acid, Vibrational Spectroscopy 40(2) (2006) 161-167. [42] R. Scherrenberg, B. Coussens,;1; P. van Vliet, G. Edouard, J. Brackman, E. de Brabander, K. Mortensen, The Molecular Characteristics of Poly(propyleneimine) Dendrimers As Studied with Small-Angle Neutron Scattering, Viscosimetry, and Molecular Dynamics, Macromolecules 31(2) (1998) 456-461. [43] A. Haji, M. Khajeh Mehrizi, J. Sharifzadeh,;1; Dyeing of wool with aqueous extract of cotton pods improved by plasma treatment and chitosan: Optimization using response surface methodology, Fibers and Polymers 17(9) (2016) 1480-1488. [44] H. Barani, A. Haji,;1; Analysis of structural transformation in wool fiber resulting from oxygen plasma treatment using vibrational spectroscopy, Journal of Molecular Structure 1079(0) (2015) 35-40.

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[45] M.M. Kamel, R.M. El-Shishtawy, B.M. Yussef, H. Mashaly,;1; Ultrasonic assisted dyeing: III. Dyeing of wool with lac as a natural dye, Dyes and Pigments 65(2) (2005) 103110. [46] F.E. Ahsan, M. Montazer, S.H. Amirshahi, M.G. Afjeh, T. Harifi,;1; Influence of Nano Colloidal Silver in Dyeing of Wool with Acid Blue 92: Isotherm Adsorption, Kinetic Studies and Dyed Wool Characterization, Journal of Natural Fibers 13(2) (2016) 204-214.

Figure 1: UV-Vis spectrum cochineal solution (pH= 4, 150 ppm).

Figure 2: FTIR spectrum of the extracted cochineal powder

Figure 3: The chemical structure and numbering of carminic acid [40-41]

Figure 4: FESEM images of raw (a), plasma treated (b) and dendrimer treated (c) wool fibers

Figure 5: AFM images of raw (a), plasma treated (b) and dendrimer treated (c) wool fibers

Figure 6: FTIR spectra of different wool samples

Figure 7: The mechanism of the reaction between plasma treated wool fibers and dendrimer molecules at pH=4

Figure 8: Effects of pH on cochineal dye absorption on raw (top), plasma treated (middle) and dendrimer treated (down) wool fibers

Figure 9: Ionic and hydrogen bonds between carminic acid and wool fibers

Figure 10: Chemical structure of PPI dendrimer generation 2

Figure 11: The interaction of dendrimer treated wool fibers and cochineal dyes in acidic pH

Figure 12: Effect of initial cochineal dye concentration on absorption % of raw (top), plasma treated (middle) and dendrimer treated (down) wool fibers

11

Figure 13: Effect of wool fiber dosages on absorption % of raw (top), plasma treated (middle) and dendrimer treated (down) wool fibers

Figure 14: Effect of wool dyebath temperature on absorption % of raw, plasma treated and dendrimer treated wool fibers

Figure 15: Pseudo-first-order (top), pseudo-second-order (middle) and intra-particle diffusion models for sorption of cochineal on different wool samples

Figure 16: Langmuir (top), Freundlich (middle) and Temkin (down) isotherm models for absorption of cochineal on different wool samples

Table 1: Characteristic wavelengths of carminic acid spectrum and assignments [4041] Wave numbers (cm-1)

Assignments

1045

νGlu(C–C)/ δGlu(COH)

1078

νGlu(C–O)/ δGlu(COH)

1246

ν(CC)/ δacid(COH)/ δ(COH)/ δGlu(CH)

1280

δ(C5OH)/ δ(C3OH)/ δ(C8OH)/ ν(CC)

1334

δacid(COH)/ δ(C5OH)/ δGlu(CH)

1377

δGlu(CH)/ δGlu(COH)/ δ(COH)

1443

νI/II(CC)/ δ(CH3)/ δGlu(CH)

1570

νI (CC)/δ(C5OH)/ δ(CH)

1616

ν(C=O)/ νI(CC)

1740

νacid(C=O)

2926

ν(CH3)/ νGlu(CH)

3354

ν(OH)

Vibration type: νI–νII, stretching vibrations in benzene rings number I–II; ν, stretching; δ, in-plane bending; Glu, glucose residue.

Table 2: EDX elemental analysis of raw, plasma treated and dendrimer treated wool fibers Weight percent (Wt %) 12

Element

Raw

Plasma Treated

Dendrimer Treated

C

41.78

41.47

47.86

N

17.73

14.27

19.39

O

7.74

11.69

9.11

Table 3: Results of surface roughness analysis measured by AFM Sample

Root mean square roughness Rs (nm)

Raw

14.3

Plasma treated

109

Dendrimer treated

140

TDENDOFDOCTD

13

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