In situ generation and deposition of nano-ZnO on cotton fabric by hyperbranched polymer for its functional finishing

Abstract

Due to the advantage of hyperbranched polymers on controlling synthesis of nanoparticles (NPs), this paper presents a method to fabricate ZnO NPs coated cotton fabrics via in situ generation and deposition in one-step reaction with amino-terminated hyperbranched polymer (HBP-NH₂) to explore its application in textile finishing. Firstly, the mechanism of this reaction was proposed in detail. The treated cotton fabrics were then characterized by field emission scanning electron microscopy (FESEM) and x-ray diffraction (XRD), and the ultraviolet (UV) protective properties and antibacterial activities of the fabrics were measured. The results indicated that ZnO NPs with a diameter around 80 nm dispersed on the surface of the cotton fabric well, the ultraviolet protection factor (UPF) value of the treated cotton fabric was 136 and the bacterial reduction rates against Staphylococcus aureus and Escherichia coli both exceeded 99%, when the concentration of HBP-NH₂ and zinc nitrate were 16 g/L and 96 mM respectively.

Keywords

ZnO nanoparticles fabric hyperbranched polymer antibacterial activity UV protection

Natural fiber products, especially cotton fabrics, are highly popular with people and used in daily life widely because of their excellent properties, such as softness, hygroscopicity, affinity to skin, biodegradability and regeneration property.^1–3 These products, however, can be easily damaged by microorganisms and ultraviolet (UV) radiation, which not only cause discoloration, mechanical strength loss and foul odor generation of the products but also result in a series of negative health effects to human beings.^4,5 Therefore, the modification of natural fiber products is an important method to provide those products with improved properties to overcome the above mentioned problems. The modification usually involves introducing functional materials to the surface or interior of the natural fibers, or grafting them on the macromolecule of the fibers.^6–8 Nanoparticles (NPs) among these functional materials exhibit significantly novel physical, chemical and biological properties, phenomena and functionality due to their nanoscaled size.⁹ ZnO NPs have been considered as one of the most important nano materials which are characterized by their photocatalytic ability, electrical conductivity, UV absorption, photooxidizing capacity versus chemical and biological species, antibacterial and self-sterilization.¹⁰ Moreover, regarded as a safe material for human beings and animals, ZnO has been applied extensively in personal care products.¹¹ Therefore, clothing products coated by ZnO NPs, which present new properties, such as UV protection and antibacterial activity, have attracted considerable attention.^12,13

Various methods have been developed to fabricate ZnO treated fabrics, such as the pad–dry–cure method, the layer–by–layer deposition method, thermal treatment, etc.^14–16 For instance, Sricharussin et al.¹⁴ synthesized various shapes of ZnO NPs, including ZnO multi-petals, ZnO rods and ZnO spherical particles, which were applied onto cotton fabrics via the pad–dry–cure process. Uğur et al.¹⁶ prepared cationic cotton fabric, using 2,3-epoxypropyl trimethylammonium chloride (EPTMAC), and deposited anionic ZnO and cationic ZnO onto cotton fabric alternately to fabricate multilayer ZnO coated cotton fabric. Yadav et al.¹⁷ synthesized ZnO NPs by a wet chemical method with soluble starch as a stabilizing agent and applied them onto cotton fabrics using acrylic binder. With numerous interior cavities as well as inward and outward oriented functional groups, dendrimers and hyperbranched polymers exhibited their advantages on controlling the synthesis of NPs with small size, outstanding monodispersity and stability, such as silver, gold and ZnO NPs.^18–20 However, to our knowledge, no relevant work on the preparation of ZnO for its application in the textile industry has been reported so far.

In our previous study, an amino-terminated hyperbranched polymer (HBP-NH₂), characterized by a three-dimensional structure and a large number of imino groups and terminal primary amino groups, was synthesized by one-step polycondensation (Figure 1).²¹ It has been utilized to prepare silver NPs colloids in an aqueous solution without any other reducer and stabilizer for antibacterial finishing of the textile.^22,23 In this paper, HBP-NH₂ and zinc nitrate were utilized as reagents to fabricate ZnO coated cotton fabric in an aqueous solution to provide them with excellent UV protective properties and antibacterial activity. This facile process involves in situ generation of ZnO NPs and their subsequent deposition on cotton fabric in a one-step reaction. The mechanism of the generation and deposition of ZnO NPs on cotton fabric was discussed. The ZnO coated cotton fabrics were characterized and their UV protective properties and antibacterial activity were also measured.

Figure 1.

Schematic representation of the molecule structure of HBP-NH₂.

Experimental details

Materials

Zinc nitrate hexahydrate (Zn(NO₃)₂·6H₂O, M = 297.49 g/mol) and nitric acid (HNO₃, 65%) were purchased from Sinopharm Chemical Reagent Co., Ltd (China). The amino-terminated hyperbranched polymer (HBP-NH₂, M_n = 2684, M_w = 7759) was prepared as described in our previous paper.²¹ All chemicals were used as received without any further purification or treatment. Woven, bleached and scoured cotton fabric (58 × 30 number of yarns per cm², 120 g·m⁻²) was obtained from the Huafang Group (China). Staphylococcus aureus (S. aureus, ATCC 6538) and Escherichia coli (E. coli, ATCC 8099) were obtained from the College of Life Science, Soochow University (China). Nutrient broth and nutrient agar were purchased from Scas Ecoscience Technology Inc (China). Deionized water (18 MΩ.cm) was used in the preparation of all samples.

In situ generated and deposited ZnO NPs on cotton fabric

HBP-NH₂ and Zn(NO₃)₂ were dissolved in deionized water to prepare stock solutions at concentrations of 100 g/L and 1 M, respectively. To prepare the hybrid solution of ZnO, the HBP-NH₂ stock solution was added into deionized water, and then the Zn(NO₃)₂ solution was added in a dropping manner into the solution and stirred constantly at room temperature. The final concentration of HBP-NH₂ and Zn(NO₃)₂ was varied to obtain the optimal conditions for the coating of ZnO NPs. The dried cotton fabrics were immersed in the hybrid solutions with liquor–to–fabric ratio of 50:1 (v/m) for 30 minutes with constant stirring. The mixtures were then heated to a boil and held for 1 minute. After cooling, the cotton fabrics were dried at 80℃ and cured in a laboratory oven at 150℃ for 3 minutes. Finally, the treated samples were rinsed with tap water for 3 cycles with 2 minutes per wash cycle and dried at 80℃ in a laboratory oven for 2 hours.

Characterization of treated cotton fabrics

The ultraviolet protection factor (UPF) and transmittance curves of the cotton fabrics were measured by a UV-1000F Labsphere Transmittance Analyzer (USA) using the EN 13758-1:2001 standard. A Hitachi S-4800 field emission scanning electron microscope (FESEM) was employed to observe the morphologies of the cotton fabrics after coating with a platinum layer to provide the proper surface conduction. The x-ray diffraction (XRD) patterns of the product were collected utilizing Cu Kα x-ray radiation with a voltage of 40 kV and a current of 30 mA by X’pert pro diffractometer (Philips, Holland). The scanning rate used was 5.0° min⁻¹ over the range of 2θ = 10–80°. The zeta potential of ZnO/polymer nanocomposite left in the solution after finishing was measured by a Nano ZS90 Zetasizer (Malvern, UK). Fourier transform infrared (FT-IR) spectra for the HBP-NH₂ and ZnO NPs were recorded in a Nicolet 380 FT-IR spectrophotometer (Thermo Electron Corporation, USA). The ZnO content of the treated cotton fabrics was determined by a Vista MPX Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES) (Varian, USA). The procedure was as follows: a sample (100 mg) was cut into small pieces and immersed in a 10 ml solution of HNO₃ (65%). After it dissolved, 90 ml of deionized water was used to dilute it. Then, 1 ml of the diluted solution was drawn to measure the concentration of Zn²⁺. The ZnO content in the cotton fabric was calculated by equation (1)

{Wt}_{(ZnO)} (%) = \frac{C_{{Zn}^{2} +} \times 0.1 \times 81.39}{65.39}

(1)

where,

C_{{Zn}^{2 +}}

is the concentration of Zn²⁺ in the solution, 0.1 (L) is the total volume of the solution and 81.39 and 65.39 are the molar mass of ZnO and Zn, respectively.

Antibacterial testing

The antibacterial activity of the treated cotton fabrics was evaluated using two categories of bacterial tests, qualitative and quantitative, against E. coli and S. aureus. For the qualitative bacterial test, an agar diffusion plate method was applied. The agar plate was prepared by pouring the hot nutrient agar onto sterile Petri dishes until it solidified. One milliliter of microbial culture (1 × 10⁸–5 × 10⁸ cfu/ml) was distributed uniformly on each plate. The treated cotton fabric disks as well as a control cotton fabric disk (7 mm diameter) were placed on the plates simultaneously. After 24 hours of incubation at 37℃, the dimension of the inhibition zone was determined to evaluate the antibacterial properties of the samples.

The quantitative antibacterial test was carried out by a shake flask method according to GB/T 20944.3-2008 (China). The test procedure was performed as follows: a 0.75 g sample fabric was cut into small pieces of dimensions around 0.5 × 0.5 cm and dipped into a flask containing 70 ml of phosphate buffered saline (PBS, pH ≈ 7.2) and 5 ml of bacterial culture which had a cell concentration of 3 × 10⁵–4 × 10⁵ cfu/ml. The flask was placed on a rotary shaker at 150 rpm for 18 hours at 24℃. A solution (1 ml) was drawn from each sample well, diluted and distributed into an agar plate. All plates were incubated at 37℃ for 24–48 hours and the colonies were counted. The percentage reduction (R, %) was determined by equation 2

R (%) = \frac{C - A}{C} \times 100

(2)

where, C and A are the bacterial colonies of the control and treated cotton fabrics, respectively.

Results and discussion

Mechanism of the generation and deposition of ZnO NPs on cotton fabric

ZnO NPs coated cotton fabrics with HBP-NH₂ were fabricated in this work. The coating process involves the in situ generation of ZnO NPs and their subsequent deposition on fabrics in a one-step reaction. The generation mechanism of ZnO NPs can be expressed as follows: the HBP-NH₂ aqueous solution was alkaline when it was dissolved in deionized water due to the protonation of amino groups, a great deal of which were located at the periphery of HBP-NH₂ polymer. As reported by Jiang et al.,²⁴ the zinc nitrate was therefore converted into Zn(OH)₂ colloids firstly in the alkaline solution of HBP-NH₂, which is shown in reaction 1. The fresh product Zn(OH)₂ was dissolved immediately with excessive ${OH}^{-}$ and ${Zn (OH)}_{4}^{2 -}$ was formed according to reaction 2. During the hydrothermal process, the formed ${Zn (OH)}_{4}^{2 -}$ transformed into ZnO nuclei and generated ZnO NPs with the ${Zn (OH)}_{4}^{2 -}$ as the growth unit (reaction 3).

{Zn}^{2 +} + 2 {OH}^{-} \to {Zn (OH)}_{2} (gel) Reaction (1)

{Zn (OH)}_{2} + 2 {OH}^{-} \to {Zn (OH)}_{4}^{2 -} Reaction (2)

{Zn (OH)}_{4}^{2 -} \to Zno + H_{2} O + 2 {OH}^{-} Reaction (3)

The subsequent deposition of ZnO NPs on cotton fabric is demonstrated in Figure 2. As shown in Figure 2, positive charges were formed in the HBP-NH₂ by the protonation of the amino groups. After the ${OH}^{-}$ was exhausted from the generation of ZnO NPs, the positively charged polymer could be adsorbed on the surface of ZnO NPs tightly due to the negative zeta potential and high surface energy of ZnO NPs.²⁵ In order to study the interaction between HBP-NH₂ and ZnO, the FT-IR spectrum of ZnO was measured after repeated washing and centrifugation which was shown in Figure 3. In Figure 3, the spectrum of HBP-NH₂ exhibited absorption peaks at 3272.2, 3068.7, 2928.1, 2823.3, 1638.2, 1551.1, 1431.7, 1358.3 and 1273.5 cm⁻¹ which can be attributed to the characteristic absorption of amide A, amide B, CH₂ asymmetric stretching, CH₂ symmetric stretching, amide I, amide II, CH₂ scissoring, CH₂ wagging and amide III, respectively.²⁶ As for the spectrum of ZnO NPs, the peak at 483.1 cm⁻¹ is the characteristic absorption of Zn-O bond and the broad absorption peak at 3414.4 cm⁻¹ is ascribed to the hydroxyl groups of moisture.²⁷ Otherwise, the relatively weak absorption peaks at 2922.8, 2854.5 and 1636.8 cm⁻¹ corresponding to the absorption of CH₂ asymmetric stretching, CH₂ symmetric stretching and amide I of HBP-NH₂ were also observed which indicated the HBP-NH₂ adsorbed on the surface of ZnO tightly even after repeated washing and centrifugation. Meanwhile, the peaks positions of HBP-NH₂ shifted apparently which also implied the interaction between polymer and ZnO NPs.

Figure 2.

Illustration of generation and deposition of ZnO nanoparticles on cotton fabric.

Figure 3.

FT-IR spectra of HBP-NH₂ and ZnO.

Due to the adsorption of HBP-NH₂ on the surface of ZnO NPs, the zeta potential of ZnO/polymer nanocomposites could convert into positive values. Table 1 shows the zeta potential of ZnO/polymer nanocomposites synthesized under different concentrations of HBP-NH₂. All the zeta potentials were around 50 in the prepared solution. Subsequently, the ZnO/polymer nanocomposites were deposited on the cotton fabric which presents negative zeta potential at neutral and alkaline conditions.²⁸ They could be adsorbed on the fabric efficiently owing to the attractive force between the two of them: the positive nanocomposites and the negative fabric. HBP-NH₂ in this work not only acted as a reagent to generate ZnO but also changed its zeta potential to form a positive ZnO/polymer nanocomposite, which could take initiative to adsorb on the surface of the cotton fabric. Otherwise, HBP-NH₂ served as a binder to fasten the ZnO NPs on the cotton fabric due to the interaction between the numerous terminal functional groups of HBP-NH₂ and the cotton fibers.

Table 1.

pH value of the solution with different concentrations of HBP-NH₂ before and after it was reacted with Zn(NO₃)₂ (24 mM) and the zeta potential of the synthesized ZnO

Concentration of HBP-NH₂ (g/L)		1	2	4	8
pH value	HBP-NH₂	10.93	11.16	11.30	11.41
pH value	ZnO/HBP-NH₂ hybrid	6.82	6.86	6.83	7.65
Zeta potential of synthesized ZnO		53.8 ± 5.68	52.9 ± 5.33	49.8 ± 4.78	50.8 ± 5.46

Optimization of reaction conditions

To optimize the reaction conditions, the concentration of two precursors was selected as the important factor. As the purpose of this treatment is to provide cotton fabrics with excellent UV protective property and antibacterial activity, UPF values and ZnO contents of the treated cotton fabrics were measured to evaluate the treatments. Firstly, the concentration of HBP-NH₂ was set as a constant (2 g/L) with the variation of concentration of zinc nitrate. The results are shown in Figure 4. With the increasing concentration of zinc nitrate, both the ZnO content and UPF value of treated cotton fabrics were enhanced. However, when the concentration of zinc nitrate increased from 6 mM to 24 mM, the UPF value of treated cotton fabric only increased from 10.82 to 16.23. This phenomenon may be due to an over-dose of zinc nitrate. Only a little part of the zinc nitrate transformed into ZnO because of the comparatively lesser HBP-NH₂ present in the reaction.

Figure 4.

ZnO content and UPF value of cotton fabrics treated with different concentrations of zinc nitrate (concentration of HBP-NH₂ was 2 g/L).

Therefore, the concentration of zinc nitrate was then set as a constant (24 mM) with an increasing concentration of HBP-NH₂ (Figure 5). There were two conspicuous peaks in the results (Figure 5) where the concentration of HBP-NH₂ was 4 g/L. The UPF value and ZnO content of the treated cotton fabric at the peaks were 36.84 and 1.91%, respectively. Generally, the UV protective properties of fabrics were evaluated as good when the UPF reached above 30. This treated cotton fabric has good UV protective property due to sufficient ZnO NPs being generated and deposited on cotton fabric which can absorb UV radiation. When the concentration of HBP-NH₂ is further increased, both the UPF value and the content of ZnO of the treated fabric decreased significantly. This indicated that the excess of HBP-NH₂ reduced the generation of ZnO, which could dissolve in the alkaline solution. Table 1 shows the pH value changes of the HBP-NH₂ solution before and after reacting with zinc nitrate corresponding to Figure 5. The pH value of the HBP-NH₂ solution was 10.93 when the concentration was 1 g/L and it increased with the increasing concentration of HBP-NH₂. After generation and deposition of ZnO on the cotton fabrics, the pH values of the first three samples changed to neutrality due to the exhaustion of ${OH}^{-}$ , indicating no excessive amount of HBP-NH₂ at the peak in Figure 5. When the concentration of HBP-NH₂ was 8 g/L, the redundant HBP-NH₂ could dissolve the generated ZnO and made the solution present as a weak alkaline which was in accordance with the results of Figure 5.

Figure 5.

ZnO content and UPF value of cotton fabrics treated with different concentrations of HBP-NH₂ (concentration of zinc nitrate was 24 mM).

The optimal dosage ratio between zinc nitrate and HBP-NH₂ was determined from the above studies. When the dosage ratio between zinc nitrate and HBP-NH₂ was set as a constant (the ratio of the highest point in Figure 5) and the concentration of both the reactants was changed simultaneously, the results are displayed in detail in Table 2 and the UV transmission spectra are shown in Figure 6. For future reference, the control sample was termed sample 0. Samples 1, 2 and 3 represent the treated cotton fabrics under different concentrations of reactants as shown in Table 2. It shows that the control cotton fabric had a high UV transmittance and a low UPF value, while the treated cotton fabrics had a high UPF value and a low UV transmittance. When the concentrations of both reactants were doubled, the UPF value and the UV transmission of the treated fabric increased and decreased respectively, along with the increasing content of ZnO coated on the cotton fabric.

Figure 6.

UV transmission spectra of control and treated cotton fabrics.

Table 2.

ZnO contents and UPF values of the treated cotton fabrics under optimal reaction conditions

Sample	Concentration of Zn(NO₃)₂ (mM)	Concentration of HBP-NH₂ (g/L)	Content of ZnO (wt %)	UPF
0	−	−	−	4.79 ± 0.10
1	24	4	1.91	36.84 ± 3.10
2	48	8	2.39	72.13 ± 2.67
3	96	16	3.50	135.93 ± 4.62

Characterization of ZnO NPs deposited cotton fabrics

The treated cotton fabrics were characterized by FESEM and XRD. Figure 7 shows the surface morphology of the control and treated cotton fabrics with different magnifications. There is an obvious difference between them in terms of the surface roughness of the fiber. The control cotton fibers demonstrate the smooth texture whereas many NPs can be found dispersed on the surface of the treated ones. ZnO particles on sample 1 are rice-like in shape, with a length of 100 nm to 1 µm as determined by FESEM. When the concentration of the reactants increased, the shape of the ZnO NPs become more spherical and are dispersed better on the cotton surface than in sample 1. The size of ZnO NPs on samples 2 and 3 are around 80 nm. Therefore, higher concentrations of the precursors result in more regular sphere shaped, smaller sized ZnO NPs coated on the cotton fabrics, which will show better UV protection and antibacterial activity.

Figure 7.

FESEM images of ZnO nanoparticle treated cotton fabrics: (a) to (c) are the control sample; (d) to (f) are sample 1; (g) to (i) are sample 2; (j) to (l) are sample 3.

To verify the NPs on the cotton fibers were indeed ZnO NPs, XRD measurements were carried out to determine the structure of the treated cotton fabric. Figure 8 shows the XRD patterns of the control and treated cotton fabric (sample 3). For the two samples, the diffraction peaks at 2θ values of 14.81, 16.46, 22.71 and 34.29 degree corresponding to (101), (101), (002), and (040) are the diffraction peaks of cotton fiber (cellulose I).²⁹ Compared to the control sample, the treated cotton fabric shows another diffraction peaks at 2θ values of 31.85, 34.53, 36.36, 47.62, 56.65, 62.93, 66.41, 67.98 and 69.19 degrees, which are assigned to the 100, 002, 101, 102, 110, 103, 200, 112 and 201 planes of the hexagonal wurtzite ZnO (JCPDS No. 36-1451), respectively.¹⁴ These results indicated that ZnO has been coated on the surface of the cotton fabric. Meanwhile, no additional peaks corresponding to other impurities were detected in the patterns.

Figure 8.

(a) XRD patterns of (1) the control cotton fabric and (2) the ZnO treated cotton fabric; (b) magnified XRD pattern of the treated cotton fabric.

Antibacterial activity of the treated cotton fabrics

The qualitative bacterial test of treated cotton fabrics was carried out against S. aureus and E. coli. The zones of inhibition for the control and treated cotton fabrics are shown in Figure 9. Around the untreated cotton fabric, there was a dense population of bacterial colonies which indicated no antibacterial activity. In contrast, a clear inhibition zone could be distinctly seen around the treated samples. The inhibition zones against S. aureus were much larger than those against E. coli suggesting that the ZnO has more effective antibacterial activity against S. aureus. In addition, the size of the inhibition zone against E. coli increased when comparing sample 1 to samples 2 and 3, which demonstrated the tendency to enhance the antibacterial activity with increasing ZnO content in the fabric.

Figure 9.

Photographs of the inhibition zone for the control and treated cotton fabrics against (a) S. aureus and (b) E. coli.

Table 3 shows the quantitative antibacterial test results of the treated cotton fabrics. All the treated cotton fabrics show excellent antibacterial activities against S. aureus. The bacterial reduction rates all exceeded 99.9%. However, the bacterial reduction rate of sample 1 against E. coli was only 50.47%. With the increasing ZnO content in the cotton fabric, the antibacterial activities against E. coli were enhanced. The bacterial reduction rate of sample 3 against E. coli reached 99.16%. The increasing of antibacterial activity of the treated cotton fabrics was not only due to the increasing ZnO content but may also be attributed to the diminution of the particle size. The antibacterial activity of ZnO NPs is considered to be the result of the generation of hydrogen peroxide (H₂O₂) from its surface. ZnO NPs with small size have high specific surface area which produces more H₂O₂, indicating that smaller particle size leads to higher antibacterial activity.³⁰ Table 3 also indicated that the ZnO has more effective antibacterial properties against S. aureus which agrees with the result of the qualitative bacterial test. Therefore, sample 3 which contains 3.5% ZnO is the optimal treated cotton fabric to achieve excellent UV protective properties and antibacterial properties.

Table 3.

Antibacterial activity of treated cotton fabrics

Samples	S. aureus		E. coli
Samples	Surviving cells (CFU/ml)	% Reduction	Surviving cells (CFU/ml)	% Reduction
0	1.27 × 10⁶	–	4.3 × 10⁶	–
1	6.3 × 10²	99.95	2.13 × 10⁶	50.47
2	5.6 × 10²	99.96	9.4 × 10⁵	78.14
3	1. 7 × 10²	99.99	3.6 × 10⁴	99.16

Conclusions

This work expanded the application of hyperbranched polymer in the textile industry and developed a new method to fabricate ZnO coated cotton fabric. The ZnO NPs coated cotton fabrics were fabricated via in situ generated and deposited ZnO on cotton fabrics by HBP-NH₂. HBP-NH₂ not only acted as a reagent to generate ZnO NPs but also protected them and allowed them take initiative to deposit and bond on the cotton fabrics during the coating process. The optimal concentration of zinc nitrate and HBP-NH₂ for fabricating ZnO functional cotton fabric with excellent UV protective properties and antibacterial activity was 96 mM and 16 g/L respectively. ZnO NPs at around 80 nm dispersed on the cotton fibers after treatment. The treated cotton fabrics exhibited more effective antibacterial properties against S. aureus than E. coli. The bacterial reduction rates against the two bacteria exceeded 99% and the UPF value of the treated cotton fabric reached 136.

Footnotes

Funding

The authors are grateful for the financial support from the National High Technology Research and Development Program of China (No. 2012AA030313); the Natural Science Foundation of Jiangsu Higher Education Institutions of China (No. 11KJB540002) and the Suzhou City Key Technology Research and Development Program (No. ZXS2012008).

References

Van Amber

Niven

Wilson

. Effects of laundering and water temperature on the properties of silk and silk-blend knitted fabrics. Text Res 2010; 80(15): 1557–1568.

Lin

Chen

. Structure and performance of Bombyx mori silk modified with nano-TiO₂ and chitosan. Fibers Polym 2007; 8(1): 1–6.

Shafei

Abou-Okeil

. ZnO/carboxymethyl chitosan bionano-composite to impart antibacterial and UV protection for cotton fabric. Carbohyd Poly 2011; 83(2): 920–925.

Zhang

Chen

Ling

. Synthesis of HBP-HTC and its application to cotton fabric as an antimicrobial auxiliary. Fibers Poly 2009; 10(2): 141–147.

Hou

Zhang

Wang

. Preparation and UV protective properties of functional cellulose fabrics based on reactive azobenzene Schiff base derivative. Carbohyd Poly 2012; 87(1): 284–288.

Hou

Zou

. Microwave assisted fabrication of nano-ZnO assembled cotton fibers with excellent UV blocking property and water-wash durability. Fibers Poly 2012; 13(2): 185–190.

Zhang

Chen

. The antimicrobial activity of the cotton fabric grafted with an amino-terminated hyperbranched polymer. Cellulose 2008; 16(2): 281–288.

Simoncic

Tomsic

. Structures of novel antimicrobial agents for textiles - a review. Text Res 2010; 80(16): 1721–1737.

Shchukin

Sukhorukov

. Nanoparticle synthesis in engineered organic nanoscale reactors. Adv Mat 2004; 16(8): 671–682.

10.

Perelshtein

Applerot

Perkas

. Antibacterial properties of an in situ generated, simultaneously deposited nanocrystalline ZnO on fabrics. ACS Appl Mat Interf 2009; 1(2): 361–366.

11.

Stoimenov

Klinger

Marchin

. Metal oxide nanoparticles as bactericidal agents. Langmuir 2002; 18(17): 6679–6686.

12.

Vigneshwaran

Kumar

Kathe

. Functional finishing of cotton fabrics using zinc oxide-soluble starch nanocomposites. Nanotech 2006; 17(20): 5087–5095.

13.

Kan

Zhang

. Optimization of conditions for nanocrystal ZnO in situ growing on SiO2-coated cotton fabric. Text Res 2010; 80(7): 660–670.

14.

Sricharussin

Threepopnatkul

Neamjan

. Effect of various shapes of zinc oxide nanoparticles on cotton fabric for UV blocking and antibacterial properties. Fibers Poly 2011; 12(8): 1037–1041.

15.

Fallah

Zanjanchi

. Synthesis and characterization of nano-sized zinc oxide coating on cellulosic fibers: photoactivity and flame-retardancy study. Chinese Chem 2011; 29(6): 1239–1245.

16.

Uğur

ŞS

Sarıışık

Aktaş

. Modifying of cotton fabric surface with nano-ZnO multilayer films by layer–by–layer deposition method. Nanoscale Res Letters 2010; 5(7): 1204–1210.

17.

Yadav

Prasad

Kathe

. Functional finishing in cotton fabrics using zinc oxide nanoparticles. Mat Sci 2006; 29(6): 641–645.

18.

Castonguay

Kakkar

. Dendrimer templated construction of silver nanoparticles. Colloid Interf Sci 2010; 160(1–2): 76–87.

19.

Scott

RWJ

Wilson

Crooks

. Synthesis, characterization and applications of dendrimer-encapsulated nanoparticles. Phys Chem B 2005; 109(2): 692–704.

20.

Richter

Schüler

Thomann

. Nanocomposites of size-tunable ZnO-nanoparticles and amphiphilic hyperbranched polymers. Macromole Rapid Comm 2009; 30(8): 579–583.

21.

Zhang

Chen

Lin

. Synthesis of an amino-terminated hyperbranched polymer and its application in reactive dyeing on cotton as a salt-free dyeing auxiliary. Color Tech 2007; 123(6): 351–357.

22.

Zhang

Chen

. Application of silver nanoparticles to cotton fabric as an antibacterial textile finish. Fibers Poly 2009; 10(4): 496–501.

23.

Zhang

Toh

GYW

Lin

. In situ synthesis of silver nanoparticles on silk fabric with PNP for antibacterial finishing. Mat Sci 2012; 47(15): 5721–5728.

24.

Jiang

. Morphological control of flower-like ZnO nanostructures. Mat Letters 2007; 61(10): 1964–1967.

25.

Jiang

Tong

. Deposition kinetics of zinc oxide nanoparticles on natural organic matter coated silica surfaces. Colloid Interf Sci 2010; 350(2): 427–434.

26.

Manna

Imae

Aoi

. Synthesis of dendrimer-passivated noble metal nanoparticles in a polar medium comparison of size between silver and gold particles. Chem Mat 2001; 13(5): 1674–1681.

27.

Peng

Chen

. Preparation and optical properties of ZnO@PPEGMA nanoparticles. Appl Surf Sci 2009; 255(16): 7158–7163.

28.

Ontiveros-Ortega

Espinosa-Jiménez

Chibowski

. Effect of tannic acid on the surface free energy of cotton fabric dyed with a cationic dye. Colloid Interf Sci 1998; 202: 189–194.

29.

Lin

Yao

Chen

. Structure and properties of silk fibroin modified cotton. Fibers Poly 2008; 9(2): 113–120.

30.

Yamamoto

. Influence of particle size on the antibacterial activity of zinc oxide. Inorgan Mat 2001; 3(7): 643–646.