Antibacterial finishing of cotton fabrics using biologically active natural compounds

The paper discusses a method to functionalize cotton fabrics using biologically active natural compounds to achieve the antibacterial characteristics required for medical application. The biologically active natural compounds include propolis, beeswax, and chitosan. Three 100 % cotton knitted fabrics with different degrees of compactness were impregnated in the emulsions containing the active ingredients and fabric variant G3 with the highest degree of impregnation was considered for the evaluation of the antibacterial properties and comfort characteristics. The results show that the treated cotton fabric had high antibacterial activity against both gram positive bacteria Staphylococcus aureus and Streptococcus β haemolytic, and gram negative bacteria Escherichia coli and Pseudomonas aeruginosa. The presence of the biologically active natural compounds on the cotton substrates modified the surface of the textile fibers as seen in the SEM images. The treatment also improved fabric comfort properties, the cotton substrates became less air permissive and more hygroscopic after the treatment. The experimental results indicated that propolis, beeswax and chitosan can be applied as an emulsion to functionalize cotton textile materials. The antibacterial performance of the functionalized fabrics suggested that the cotton fabrics treated with those biologically active natural compounds have the potentials to be used in medical fields.     

Cutinase treatment of cotton fabrics

Our study proposes an enzymatic scouring method for cotton fabrics using the enzyme cutinase. We established cutinase treatment conditions for cotton fabrics from their relative activity at different pH levels, temperatures, enzyme concentrations, and treatment times. Weight loss, moisture regain, K/S value, tensile strength, and SEM micrographs of cotton fabrics were analyzed. We determined the optimum cutinase treatment conditions to be as follows: pH of 9.0, temperature of 50°C, cutinase concentration of 100 %, and a treatment duration time of 60 min. We discovered that this cutinase treatment hydrolyzed the cuticle of cotton fabrics. The cutinase treatment did not decrease the moisture regain and the K/S value. The optimum concentrations of Triton X-100 and calcium chloride, which were used as auxiliaries for cutinase treatment, were found to be 0.5 % (v/v) and 70 mM, respectively. Some cracks were observed on the surface of the cotton fibers; however, the tensile strength did not decrease.     

UV-grafting coloration of cotton and wool fabrics using bismethacrylated quinizarin dye

A novel bifunctional quinizarin dye possessing two photoactive methacrylate groups was synthesized by the reaction of quinizarin with methacryloyl chloride. The synthesized dye, a low substantive dye under the conventional dyeing process, can be photografted onto cotton and wool fabrics at room temperature without neutral salts, which makes it a novel coloration process of excellent environmental friendliness. The concurrent polymerization and grafting of the synthesized dye onto cotton or wool can be assisted by a photoinitiator and acrylic acid in the case of cotton grafting. Moreover, color yields of the grafted fabrics improved significantly with the photografting of the bifunctional dye. The bifunctional dye can be photopolymerized with the increase in UV energy to 25 J/cm² and the oligomeric dye has a degree of polymerization of 5 or more. Furthermore, the color fastness properties of the grafted fabrics were superior to those of the dyed fabrics via exhaustion.     

UV-induced coloration of cotton fabrics by photografting of acrylamido dyes using acrylamide as a comonomer

Formulations of acrylamido dyes containing comonomers can be photografted onto cotton fabric upon UV irradiation at room temperature without neutral salts, which makes it a novel coloration process of excellent environmental friendliness. The photografting of the dyes can be assisted by the copolymerization of the acrylamide comonomer which may reduce the steric hindrance of the bulky dyes. About 90 % of the dyes and 94 % of the acrylamide are photopolymerized in the solution and the degree of polymerization is estimated to be 13.2 according to ¹H-NMR and MALDI-TOF mass analyses. The optimal K/S values of the grafted cotton fabrics showed 13.3 and 12.3 for red and yellow dyes, respectively. The optimal UV-grafting coloration can be achieved when a UV energy of 25 J/cm² was irradiated on the padded fabrics with a formulation of 0.65 mole ratio of acrylamide to the dyes, 7 wt% acetophenone photoinitiator (Irgacure 2959) based on the dye weight under pH 6. Furthermore, the color fastness properties of the grafted fabric were superior to those of conventional reactive dyeing of the dyes due to higher molecular weight of the polymerized dyes.     

Water repellent cotton fabrics prepared by PTFE RF sputtering

A poly(tetrafluoroethylene) (PTFE) sputtering technique was employed to introduce water repellency onto the surfaces of commercial cotton fabrics. Sputtering power, time, and argon pressure were varied as processing parameters, when PTFE coatings were applied on the fabrics. Total 27 different samples were prepared to compare their water repellent properties, which were investigated by contact angle measurements. Morphology of the PTFE coatings were probed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Also, the extent of the coating was examined by X-ray photoelectron spectroscopy (XPS). Maximum hydrophobicity was obtained when PTFE coating was extensive enough to cover cotton fabrics almost completely, and the extensive coating was the roughest among the samples prepared in this study.     

Water repellent treatment of cotton fabrics by electron beam irradiation

In this study, traditional dip-pad-cure (DPC) process and electron beam (EB) irradiation were used to graft cotton fabrics with fluorine containing chemical, 1H,1H,2H,2H-perfluorooctyl acrylate (PFA). The grafted cotton fabrics were characterized by FT-IR and SEM. The water repellent properties were measured by contact angle, hydrostatic pressure, and spry test. It was found that there was no significant difference between the grafted cotton fabrics with DPC and EB methods, and the treated fabrics showed good water-resistant properties. The grafted cotton fabrics also showed good washing stability. By measuring the bending rigidity and bending hysteresis, it was found that the cotton fabrics grafted with PFA became softer than untreated samples.     

Properties of anti-UV-finished cotton fabrics cured by blue light irradiation

To decrease the pollution discharge and energy consumption resulting from textile finishing using the conventional pad-dry-cure process, a blue light-curable digital finishing for textile was innovatively proposed. Based on the mechanism of blue light curing technique, a combination of the blue light curing process and anti-UV finishing was established in this study. A blue light-curable anti-UV finishing solution containing oligomers, monomers, photoinitiators, and anti-UV agents was padded onto the surface of the cotton fabrics, and then cured to form a tough film under blue light irradiation. The ultraviolet protection factor (UPF) value of the finished cotton fabrics was 50, the top level of international standards, demonstrating excellent UV resistance. The finished cotton fabrics also showed good rubbing and washing durability, and acceptable handle. The integration of an anti-UV finishing with the blue light curing technique presents some unique advantages in terms of environmental protection and application potential.     

Self-decontaminating cotton fabrics based on photo-induced macromolecular radicals

Photoactive blend films consisting of sulfonated polyether ether ketone and polyvinyl alcohol were incorporated onto cotton fibers to prepare self-decontaminating cotton fabrics. Electron paramagnetic resonance (EPR) spectroscopy was used to confirm the free-radical nature of the photoactive film and the cotton fabric. Several physical and mechanical properties of the fabrics, such as surface morphology, tensile strength, softness, whiteness, and water vapor permeability, were investigated, and it was found that the treated cottons basically maintained the original performance. Moreover, favorable photo-induced self-decontaminating capabilities of the treated fabrics were demonstrated against three kinds of pollutants, including decomposition of 80.2 % diuron under UVA light irradiation for 3 hours, inactivation of 93.33 % of E.coli and 86.67 % of S.aureus, and degradation of 64.1 % methyl orange under the light irradiation for 1 hour.     

Electrically conductive and hydrophobic cotton fabrics by polypyrrole-oleic acid coating

Hydrophobic polypyrrole-coated fabrics with improved electrical conductivity were produced embedding oleic acid as counter-ion. Hydrophobisation of polypyrrole was carried out by means of an ion exchange process after deposition of polypyrrole on cotton fabrics. The fabrics coated with oleic acid-doped polypyrrole showed contact angle of 111°, drop absorption time of 7 minutes and high water repellence, while electrical conductivity increased of ～2 times and heat generation improved, too. Moreover, oleic acid demonstrated a great stability as counter-ion in polypyrrole matrix being present also after washing.     

Conductive cotton fabrics for heat generation prepared by mist polymerization

Cotton fabrics were coated with conducting polypyrrole (PPy) by mist polymerization derived from aqueous solution of pyrrole (Py) with ferric chloride (FeCl₃) as oxidant. The polymerization conditions, such as the reaction time and the concentrations of monomer and oxidant, were systematically investigated. The prepared PPy-coated fabrics could keep their temperature at about 24–44 °C when charged by a fixed DC voltage of 1–3 V. The results indicate that these PPy-coated fabrics can be used potentially as heating pads and integrated into the apparel to make the wearer warm enough using a portable battery. Furthermore, such fabrics are more comfortable than the conventional heating pads due to their flexibility and breathability.     

Effect of softeners and crosslinking conditions on the performance of easy-care cotton fabrics with different weave constructions

This study reports an experimental investigation on the effect of softeners, crosslinking conditions, and laundering on the comfort related and low stress mechanical properties of cotton fabrics with different weave constructions. Softeners with different chemical natures, in conjunction with the crosslinking agent and catalyst, were padded onto the cotton fabrics of three types of weave constructions, viz. plain, twill, and a newly developed plant-structured weave design. Two crosslinking conditions, namely dry and moist curing conditions, were compared. Scanning electron microscope (SEM) and Fourier transform infrared (FTIR) spectroscope were used to visualize and quantify the morphological and chemical changes on fabrics. The experimental results showed that the dry-crosslinking condition is preferable to achieve better comfort and easy-care properties, while moist-crosslinking condition is a better choice when strength-related properties are the main requirement. The study further showed that silicone elastomer softener can be applied to improve fabric strength whereas micro-emulsion of functional amino-polysiloxane plus emulsion containing polyalkylene is beneficial for comfort characteristic. The plant-structured cotton fabric finished in the dry-crosslinking condition with softener in nano-emulsion form can result in superb water absorption, excellent air permeability, good handle, acceptable strength, and improved easycare property.     

Layer by layer assembly of nanosilver for high performance cotton fabrics

High performance cellulosic fabrics are of increasing attention as a wearable fabric with special functions. The current report deals with preparation of multifunctional cotton fabrics by using simple and facile layer by layer technique. Firstly, silver nitrate was reacted with carboxymethyl cellulose to prepare Ag nanoparticles-carboxymethyl cellulose composite. Multi-layers of the so-obtained composite were applied on the cotton fabrics using pad-dry-cure method. Ag nanoparticles were deposited with mean size of 18.2 nm onto cotton fabrics which served as a cross linker between carboxymethyl cellulose macromolecules and cotton macromolecular blocks. Application of composite multilayers brought new properties for the finished cloths such like coloration, ultraviolet resistance, electrical resistance and biocidal action. The ultraviolet transmission radiation was significantly reduced to 7-10 % after applying ten composite layers. Valuable antibacterial textiles which are required in different medical purposes could be successfully produced, as excellent antibacterial activities were achieved by using the reported method. The developed process can be easily adapted to the existing textile machinery, making it industrially viable to produce fabric’s versatility.     

Assessment of the surface roughness of cotton fabrics through different yarn and fabric structural properties

The effects of some yarn properties (i.e. type, count, twist level, ply number, unevenness and crimp) and fabric constructional properties (i.e. cover, thickness and balance) on surface roughness values of cotton woven fabrics were investigated. A general overview of the results showed that surface roughness values of fabrics were affected from yarn and fabric properties and the effects were related to fabric balance, fabric cover (not cover factor), fabric thickness and crimp values of yarns in fabric structures. Surface roughness values of fabrics decreased as yarn fineness and yarn twist levels increased but as yarn ply number decreased. Also, surface roughness values gradually decreased from open-end yarn constituting fabrics to combed yarn constituting fabrics. Results showed that different properties of yarns caused changes in yarn crimps in fabric structure and also governed the changes in fabric balance, as well as changes in roughness of fabric surfaces. The changing properties of yarns and impact of these properties on fabric construction affected the formation of cotton fabric surfaces from smooth to coarse.     

Investigation of antibacterial properties of nano-ZnO assembled cotton fibers

Nano-ZnO assembled cotton fibers (NZCF) with excellent antibacterial properties were fabricated using microwave synthesis method. The effects of ZnO size, ZnO content, assembly times, microwave power and Zn²⁺ concentration of the synthesis solution on the antibacterial activity of the NZCF were studied using bacteriological tests such as Petri dish and agar diffusion method. The results show that NZCF has the antibacterial circle width (ACW) of about 1.5–2.3 mm and 2.3–3.4 mm against Escherichia coli (E. coli, gram-positive organism) and Staphylococcus aureus (S. aureus, gram-negative organism), respectively. It is also found that the antibacterial activity of NZCF increases with decreasing ZnO size, increasing ZnO content in NZCF and increasing Zn²⁺ concentration in synthesis solution.     

Evaluation of aroma functionality imparted on natural indigo-dyed cotton fabrics

Long-term efficacy of aroma microcapsules on natural indigo-dyed cotton fabric was evaluated by objective and subjective tests. The fixation of aroma microcapsules was carried out by pad-dry-cure process on dyed cotton fabric. Mercerized cotton fabric was dyed with natural indigo obtained from Polygonum tintorium (via the modified Niram method) and subsequently padded with melamine-formaldehyde microcapsules containing aroma essential oil (natural source of a Chinese arborvitae 20-25 %). Softener was applied in the same (one-step) or sequential (two-step) padding bath. We confirmed that microcapsules were fixed on cotton fibers by SEM analysis. The addition of softener was not much effective for the fabric performances on softness or air permeability. All the colorfastness ratings were above 4/5 and the color difference was within the acceptable range of 1.62-2.08. The efficacy of fabric samples stored for 2 years was evaluated using the GC/MS-headspace technique and the samples stored for 0.5, 1.5, and 2.5 years were also evaluated in terms of aroma release by the human perception test. Bornyl acetate was confirmed as the main component of essential oil, which was continuously released by the microcapsule-treated fabric (D/MC) during storage for more than 2 years. In durability and human perception tests, the microcapsules on the cotton fabric were stable to laundering, rubbing, ironing, and light.     

Crosslinking phenolic compounds with cotton fabrics using succinic acid to develop functional clothing materials

There is currently much interest in natural compounds as bioactive functional components to replace synthetic functional agents in many industrial fields. This trend has also arisen in the textile industry. Phenolic compounds, existing in many fruits and vegetables, are a well-known group of secondary metabolites with a wide range of pharmacological activities. Thus, they have been attracting attention as part of the effort to realize environmentally friendly functional agents for textile finishing. In current research, cotton fabrics were treated with several phenolic compounds to transpose their beneficial characteristics onto clothing material. In particular, the treatment was conducted in two steps; the first to incorporate a crosslinker onto cotton cellulose, and the second to bond the phenolic compound to the crosslinker already anchored onto the cotton fabrics. A more efficient textile treatment was expected after employing the two-step process. After the finishing process, the cotton fabrics treated with phenolic compounds were investigated by FT-IR, SEM, an antibacterial test, and an antioxidant test. It was discovered that cotton fabrics treated with the two-step process showed >99.9 % of antibacterial ability and >80 % of antioxidant ability, even at lower concentrations of the crosslinker and phenolic compounds compared to those in earlier work.     

Effect of pigment particle character on dyeing performance of cotton fabrics

The cotton fabrics were dyed by exhaust method using the pigment dispersions as colorant, and meanwhile the effects of particle character on dyeing performance were further investigated. The results showed that the larger zeta potentials, the higher K/S value, pigment uptakes, rubbing and washing fastness of the dyed cotton fabrics were. Adsorption isotherms were belonging to Langmuir type when zeta potentials were about 0.46 mV and 31.39 mV respectively. The cotton fabrics that dyed by the pigment dispersions with small particles had high K/S value, rubbing and washing fastness. The chemical structure of pigment had little influence on pigment uptakes, and all kind of pigment dispersions reach to 98 % uptakes after 30 min but exhibit various uptake rates at initial stage.     

Bioscouring of cotton fabrics using pectinase enzyme its optimization and comparison with conventional scouring process

The conventional scouring process involving the harsh environment is slowly being replaced with environment friendly approach using enzymes. These enzymes remove the non cellulosic impurities present in the fabric. Such a process would enhance the absorbency of the fabric without appreciable strength loss and also would help in the proper dyeing and finishing of the fabric. In the present work pectinase enzyme was isolated from Fusariumn sp. and was optimized under different cultural conditions. The partially purified pectinase enzyme was used in the scouring of cotton fabric. The efficiency of the bioscoured cotton fabric was compared with that of the conventionally scoured fabric. It was found that the water absorbing character of the bioscoured fabric was found to be considerably higher than that of the conventionally scoured fabric. Also, the tensile strength of the cotton fabric was found to be higher for the sample treated using pectinase enzyme than the sample treated conventionally. The results of FTIR confer that the pectin and wax impurities were removed from the cotton surface in both the conventionally scoured and bioscoured fabrics.     

Study on the aging and yellowing properties of sebum-soiled cotton fabrics

The accumulation and autoxidation of residual oily soil from human sebum is regarded as a major reason for the aging and yellowing of clothing and household textiles. In this study, the yellowing degree of cotton fabrics soiled with human sebum components and aged under various environmental conditions (various temperatures, humidities and light intensities etc.) were investigated. The representative sebum components including olive oil, squalene, oleic acid and cottonseed oil were selected and their chemical changes were studied by FTIR analysis. The results showed that, olive oil, squalene, oleic acid and cottonseed oil could caused more significant fabric-yellowing than other components in human sebum, and the yellowing degree could become higher with increasing temperatures, humidities and/or light intensities of aging environments. The chemical structures of olive oil, squalene and oleic acid changed remarkably after aging treatment. The aging products contained hydroxyl groups and carbonyl groups, and the conjugated C=O group was considered to be the chemical species leading to the yellowing of sebum-soiled fabrics.     

Effect of glycols and catalysts on cotton fabrics treated with glyoxal

The optimum conditions for durable press treatment of cotton fabrics using glyoxal as a nonformaldehyde crosslinking agent were investigated. Crosslinking reaction was conducted in the presence of different catalysts such as aluminum sulfate, magnesium chloride, or magnesium chloride-citric acid mixture at various mole ratios of catalyst to glyoxal. Aluminum sulfate was proven the most effective one among those used. Glycol addition into a glyoxal padding bath increased the wrinkle recovery angle(WRA) and whiteness of treated fabrics. The optimum mole ratio of glycol to glyoxal was 1:1. Diethylene glycol addition produced better overall performance to the glyoxal-crosslinked fabric compared to ethylene glycol addition.