Eco-friendly and Durable Antibacterial Cotton Fabrics Prepared with Polysulfopropylbetaine

A novel antibacterial agent polysulfopropylbetaine (PSPB) bearing carboxyl groups was synthesized and its application on cotton fabric to provide durable antibacterial property was also presented. The successful synthesis of PSPB and its immobilization onto the cotton fabric surface were verified by a series of tests including FTIR, ¹H NMR, XPS and SEM. Viable cell counting method was employed to investigate antibacterial properties of the finished cotton fabrics. It was found that the cotton fabrics treated with PSPB were endowed with desirable antibacterial activity against both gram-negative bacteria Esherichia coli (E.coli, AATCC 6538) and gram-positive bacteria Staphylococcus aureus (S.aureus, AATCC 25922), with the bacterisotatic rates of 99.69 % and 99.95 %, respectively. Notably, the bacterial reduction rates still maintained over 90 % against both bacteria even after 50 consecutive laundering cycles. Moreover, tests concerning the hydrophilicity, air permeability, water vapor transmission, mechanical properties as well as thermal properties were carried out systematically. The experimental results indicated the hydrophilic performance, air permeability and moisture penetrability of the cotton fabrics finished with PSPB were improved greatly in spite of a slight reduction in thermal performance and little obvious influence on mechanical performance. The antibacterial cotton fabric has the potential to be applied in sportswear, underwear, household textiles, medical fields and much more.     

Facile Fabrication of Durable Antibacterial Cotton Fabric Realized by Thioglycolic Acid and Silver Nanoparticles

In this study, durable antibacterial cotton fabrics were prepared by a simple two-step impregnation method. Firstly, thioglycolic acid (TGA) was grafted onto cotton fabric via esterification with the hydroxyl groups of cellulose, then silver nanoparticles (Ag NPs) were immobilized on the cotton fabric surface via coordination bonds with the TGA thiol groups. As a result, the mean size of Ag NPs coating on the cotton fabric is around 74 nm, and these functionalized cotton fabrics show superior antibacterial properties and excellent laundering durability. After withstand 50 laundering cycles, the obtained cotton fabrics still showed outstanding bacterial reduction rates (BR) against both S. aureus and E. coli, and the rates are all higher than 97 %. Therefore, this method to prepare antibacterial cotton fabric shows great potential applications in socks, cosmetic, and medical textiles.     

Removal of methylene blue by amidoxime polyacrylonitrile-grafted cotton fabrics: Kinetic,equilibrium, and simulation studies

In this study, an amidoxime-grafted cotton fabric ion exchanger was developed for methylene blue (MB) removal from wastewater. The ability of the amidoxime-grafted cotton fabrics to remove MB ions from an aqueous solution was investigated in equilibrium, kinetics and thermodynamics studies. Equilibrium data agreed well with the Freundlich and Langmuir isotherm models. The result indicated that, based on the Langmuir coefficient, the maximum capacity (monolayer saturation at equilibrium) of the amidoxime-grafted cotton fabric was 22.27 mg/g. The kinetic data were found to follow the pseudo-second-order model, and intra-particle diffusion is the sole rate-controlling factor. Negative values of ΔG ⁰, ΔH ⁰, and ΔS ⁰ revealed the spontaneous, exothermic and entropy-driven nature of the process.     

Double Protect Copper Nanoparticles Loaded on L-cysteine Modified Cotton Fabric with Durable Antibacterial Properties

In this work, we developed a new method that can achieve immobilization and protection of the Cu NPs coating on the cotton fabrics by a simple two-step impregnation method. Firstly, L-cysteine (Cys) was grafted onto cotton fabric via esterification with the hydroxyl groups of cellulose, then Cu NPs were introduced on the fabric surface in the presence of a protective reagent, citric acid. Due to the doubled stabilization acts of Cys and citric acid, the Cu NPs immobilized on the fabric surface showed an excellent antibacterial effect and outstanding laundering durability. As a result, the mean size of the Cu NPs coating on the cotton fabric is about 62.4 nm, and the modified cotton fabrics showed satisfactory antibacterial ability against both S. aureus and E. coli, which the bacterial reduction rates are all higher than 98 % even withstand 50 washing cycles. Therefore, this method to prepare antibacterial cotton fabrics showed great potential applications in socks, cosmetic, and medical textiles.     

Highly flame retardancy of cotton fabrics with a novel phosphorus/nitrogen/silicon flame-retardant treating system

A novel reactive flame retardant (FR) containing phosphorus, nitrogen, and silicon was synthesized successfully, and its chemical structure was fully characterized by Fourier transform infrared spectrometry and nuclear magnetic resonance spectrometry (¹H-NMR and ³¹P-NMR). Then it was used to impart flame resistance to cotton fabrics. Vertical flammability and limiting oxygen index test were used to evaluate the flame retardancy of the cotton fabrics treated with FR. When the cotton treated with 150 g/l FR and 50 g/l sodium hypophosphite, the finished cotton can pass the vertical flammability test. Thermogravimetry (TG) was used to evaluate thermal behavior of FR and cotton fabrics. TG results demonstrated that the FR has good thermostability and char-forming ability. After treatment with FR, the thermal stability of the cotton fabrics was clearly improved, indicating that the FR can protect cotton fabric from fire to a certain degree. Furthermore, attenuated total reflection Fourier transform infrared spectroscopy was utilized to characterize the chemical structure of FR treated cotton fabrics. Finally, the surface morphology in different regions of the treated cotton was observed using scanning electron microscopy.     

Durable antibacterial cotton modified by silver nanoparticles and chitosan derivative binder

This article focuses on the functional finishing of textiles using silver nanoparticles (AgNPs) and chitosan derivative binder, which was synthesized by a modification of chitosan using α-ketoglutaric acid. The binder covalently linked to cotton fabric via esterification of the hydroxyl groups on the cotton surface, and tightly adhered to surface of the AgNPs by coordination bonds. As a result, the coating of AgNPs on the cotton fabric showed excellent antibacterial property and laundering durability. After 30 consecutive laundering cycles, the Ag content on the fabrics decreased to 37.6 %, but the bacterial reduction rates against both S. aureus and E. coli were maintained over 95 %. It has potential applications in a wide variety of fields such as sportswear, socks, and medical textile.     

Leveraging the Antibacterial Properties of Knitted Fabrics by Admixture of Polyester-Silver Nanocomposite Fibres

Leveraging the antibacterial properties of polyester-cotton knitted fabrics has been attempted in this research by admixture of small proportion of polyester-silver nanocomposite fibres. Polyester-cotton (50:50) yarns were spun by mixing 10, 20 and 30 % (wt.%) polyester-silver nanocomposite fibres with normal polyester fibres so that overall proportion of polyester fibre becomes 50 %. The proportion of cotton fibre was constant (50 %) in all the yarns. Three parameters, namely blend proportion (wt.%) of nanocomposite fibres, yarn count and knitting machine gauge were varied, each at three levels, for producing 27 knitted fabrics. Polyester-cotton knitted fabrics prepared from polyester-silver nanocomposite fibres showed equally good antibacterial activity (65-99 %) against both S. aureus and E. coli bacteria. Antibacterial properties were enhanced with the increase in the proportion of polyester-silver nanocomposite fibres, yarn coarseness and increased compactness of knitted fabrics. Yarn count and blend proportion of nanocomposite fibre were found to have very dominant influence in determining the antibacterial properties of knitted fabrics.     

Preparation of Copper Nanoparticles Coated Cotton Fabrics with Durable Antibacterial Properties

When copper nanoparticles (Cu NPs) were applied as an antimicrobial agent to finish cotton fabrics, there are two issues should be solved: the oxidization and the weak adsorbability onto cotton fiber surface. In the present work, we developed a new method that can achieve both immobilization and protection of the Cu NPs at the same time. As an effective binder, thioglycolic acid (TGA) was covalently linked to cotton fiber surface via an esterification with the hydroxyl groups of cellulose, then Cu NPs were introduced on the fabric surface in the presence of a protective reagent, citric acid. Due to the doubled stabilization acts of TGA and citric acid, the Cu NPs immobilized on the fabric surface showed an excellent antibacterial effect and outstanding laundering durability. Even after 50 consecutive laundering tests, the modified cotton fabrics still showed satisfactory antibacterial ability against both S. aureus and E. coli, which the bacterial reduction rates are all higher than 96 %. It is believed that this methodology has potential applications in a wide variety of textile productions such as sportswear, socks, and medical textiles.     

A study on combining natural dyes and environmentally-friendly mordant to improve color strength and ultraviolet protection of textiles

In this study, natural dyes were extracted from five plants, namely diospyros kaki, dioscorea cirrhosa, millettia (jixueteng), ecliptae, and macrocarpa nucuma, using environmentally-friendly solvents, including ethanol and deionized (DI) water. A plant mordant, tannin extracted from Emblica officinalis G., and a metal mordant, copper sulfate, were used in the pre-dyeing process. Cotton and silk fabric samples were treated using the five natural dyes without and with mordanting for comparison on their color strength and characteristics as well as protection against ultraviolet radiation (UVR). Results revealed that Emblica officinalis G. had the highest total phenol content, followed by dioscorea cirrhosa. The presence of abundant phenolic groups in the natural dyes and mordant makes them effective coloration agents for fabrics. Cotton and silk fabrics dyed using ecliptae without pre-mordanting had the highest K/S values. Silk fabrics had higher K/S values than cotton fabrics, indicating greater color strength in pre-mordanted silk treated with DI water-extracted dyes. Natural mordant used before treatment with natural dyes contribute to significant enhancement in color strength, and Emblica officinalis G. alone could darken the color of cotton and silk fabrics dyed with plant pigment. Moreover, treatment with natural dyes after mordanting can increase ultraviolet protection factor (UPF) and the enhancement in UVR protection is greater and more significant in cotton fabrics than in silk fabrics, and in fabrics treated with DI water-extracted natural dyes than in those treated with ethanol-extracted ones. In conclusion, pre-dyeing with natural mordant followed by treatment with natural dyes extracted using environmentally-friendly solvents can enhance significantly K/S and UPF, offering directions for manufacturing textiles without environmental hazards but with good appearance and health benefits.     

Durable antibacterial cotton fabrics with chitosan based quaternary ammonium salt

A water soluble quaternary ammonium chitosan derivative, N-benzyl-N,N-diethyl chitosan quaternary ammonium salt (BDCQA), was prepared for antibacterial finish of cotton textiles. The effects of concentrations of finish agents and treatment time on the add-on ratio of cotton treated BDCQA (BDCQA-cotton) were studied in details. The morphology and thermal property of BDCQA-cotton were characterized by scanning electron microscopy (SEM) and thermagravimetric (TG) analysis. Gram-positive bacterium Staphylococcus aureus (S. aureus) and Bacillus cereus (B. cereus), Gram-negative bacterium Escherichia coli (E. coli) and drug-resistant bacterium Methicillin-resistant Staphylococcus aureus (MRSA), were used to evaluate the antibacterial activity and durability of BDCQA-cotton. The results showed that BDCQA-cotton possessed good antibacterial activity and high durability against broad spectrum bacterium. The preliminary investigation on the antibacterial mechanism was discussed in this work.     

Preparation of Durable Antibacterial Cellulose with AgCl Nanoparticles

In this study, a facile method was developed to coat AgCl nanoparticles (NPs) onto knitted cotton fabrics. The AgCl NPs were characterized by ultraviolet absorption spectrum, X-ray diffraction (XRD) and dynamic laser light scattering (DLS). The AgCl NPs were coated onto cotton fabrics through a pad-dry-cure process with the assistance of 1,2,3,4- butanetetracarboxylic acid (BTCA). Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), ICP-OES analysis and energy-dispersive X-ray spectroscopy (EDX) confirmed that AgCl NPs were successfully coated onto cotton fabrics. The prepared cotton samples exhibited excellent antimicrobial activity against both Gram-positive S. aureus and Gram-negative K. pneumonia bacteria. Rat skin fibroblast cytotoxicity testing demonstrated the treated cotton fabrics to be non-toxic. The washing durability evaluation showed that the antimicrobial function of cotton fabrics was durable to washing. In addition, the wrinkle resistance of the coated cotton fabrics was improved and there was no obvious change in whiteness.     

Simultaneous synthesis of nano ZnO and surface modification of polyester fabric

In this study, synthesis of zinc oxide nanoparticles was carried out along with the hydrolysis of polyester fabric using sodium hydroxide to increase the surface activity and enhance the nanoparticles adsorption. The polyester fabrics were treated with zinc acetate and sodium hydroxide at different bath conditions, ultrasound and stirrer, resulting in formation of ZnO nanospheres and ZnO nanorods. The presence of zinc oxide with different shapes on the surface of the polyester fabrics was confirmed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Also, the X-ray diffraction patterns established the composition of wurtzite structure of zinc oxide. The self-cleaning property of treated polyester fabrics was evaluated through discoloring dye stain under sunlight irradiation. The antibacterial activities of the samples against two common pathogenic bacteria including Escherichia coli and Staphylococcus aureus were also assessed. The results indicated that the photocatalytic and antibacterial activities of the ultrasound treated polyester fabrics were superior compared to the stirrer treated samples.     

Characterization of the surface properties of cellulosic fibers in fibrous and ground forms by IGC and contact angle measurements

Surface properties of fibrous and ground cotton and linen were investigated by inverse gas chromatography (IGC) and the contact angle with different liquids was also measured on fabrics composed of both fibers. Results proved that dispersion component of surface tension (γ _s ^d ) determined by IGC depends not only on the surface energy, but also on several factors influencing the adsorbability of probe molecules on the cellulosic substrates. For cotton samples, the trapping of n-alkanes among waxy molecules in the outer layer of fibers can be presumed. This effect results in larger γ _s ^d for cotton fibers than for linen in spite of the higher wettability of the linen fabrics. Besides the surface energy and trapping effects, the grinding also influences the γ _s ^d values. Specific enthalpy of adsorption (ΔH _A ^ab ) of polar probes could be determined on all linen samples, but only on the ground cotton sample. Lewis acid-base character calculated for linen and ground cotton samples depends on the same effects as the γ _s ^d does. The similar ΔH _A ^ab values of chloroform (acidic) and THF (basic) measured on each of the samples support the conclusion that the surface character is amphoteric, which is also proved by the high ΔH _A ^ab values of the amphoteric ethyl acetate and acetone probes.     

One Step Thermochromic Pigment Printing and Ag NPs Antibacterial Functional Finishing of Cotton and Cotton/PET Fabrics

One step thermochromic pigment printing and antibacterial functionality of cotton (100 %) and cotton/polyester blend (50/50 %) were demonstrated in this study. The improvement in antimicrobial activity against G+ve (Bacillus cereus) and G-ve (E. coli), and pigment printability were achieved by inclusion of Ag-NPs (30 g/kg) into pigment printing paste followed by printing and microwave curing at 700 W for 5 min. Modes of interactions were proposed, and surface modification was also confirmed by SEM and EDX analysis that proved the presence of Ag-NPs in cotton and cotton/ polyester blended samples. The results indicated that the colour fastness to wash and rubbing was excellent, the surface roughness reduced, and exhibited good antibacterial activity against Bacillus cereus and E. coli bacteria.     

Multifunctionalised silk using <Emphasis Type="Italic">Delonix regia</Emphasis> stem shell waste

The use of natural dyes and natural finishes on textiles has become a matter of significant importance because of the increased environmental awareness to avoid some hazardous synthetic dyes and synthetic chemicals. The Delonix regia stem shells were extracted in distilled water methanol and ethanol solvents. Phytochemical analysis was carried out for the presence of bioactive chemical constituents such as saponin, terpenoid, flavonoid, glycoside, phenol and tannin using the standard procedure. All the tests showed positive for the presence of components except saponin in methanol and ethanol extract. The qualitative antibacterial analysis was done by AATCC 147 method with excerpts from three different solvents both against S. aureus (gram-positive) and E. coli (gram-negative) bacteria. Delonix regia stem shell extract (DSE) in distil water was used for natural dyeing of mulberry silk fabric. Pre-mordanting and post-mordanting of silk fabric were carried out using alum and myrobalan mordants. Treated fabrics showed a substantial increase in colour depth (K/S) and adequate wash, light and rubbing fastness properties without and with mordanted and dyed silk fabrics. Quantitative antibacterial analysis by AATCC 100 method was done on dyed silk fabric which showed very good resistance both against bacteria S. aureus and E. coli bacteria. Dyed silk fabric also showed good to very good ultraviolet (UV) protection property. The physicochemical composition of the untreated and without mordant treated silk fabrics were analysed by attenuated total reflection (ATR) Fourier transforms infrared (FTIR) spectroscopy, scanning electron microscope (SEM), energy dispersive spectrometry (EDS) and atomic absorption spectrophotometer (AAS). In addition to that wash, durability was also measured of dyed silk fabric for antibacterial and ultraviolet protection (UPF) properties according to AATCC 61 2A washing method.     

Graphene Oxide/Polyester Fabric Composite by Electrostatic Self-Assembly as a New Recyclable Adsorbent for the Removal of Methylene Blue

A novel graphene oxide/polyester (GO/PET) composite fabric as a recyclable adsorbent was prepared via electrostatic self-assembly. The structure, morphology, and properties of the GO/PET composite fabrics were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), Fourier transformed infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and contact angle (CA), respectively. The absorption property was evaluated by the absorption amount and removal efficiency of methylene blue (MB) solution on the GO/PET composite fabric. The results indicated that the absorption amount was found to be 21.80 mg/g and the removal efficiency reached 99.93 % under the experimental conditions of GO concentration of 2 mg/ml, initial concentration of 50 mg/l, and area of 64 cm². The experimental parameters were investigated including the concentration of GO, the initial concentration of MB solutions, and adsorbent area. Simultaneously, according to a series of dynamic analysis, the absorption process revealed that the kinetics was well-described by pseudo-second-order model. This study showed that the GO/PET composite fabric could be a recyclable, efficient adsorbent material for the environmental cleanup.     

Antibacterial Coating of Cellulose by Iso-bifunctional Reactive N-halamine with the Dyeing Process of Reactive Dye

In this study, we synthesized a novel N-halamine precursor, sulfuric acid mono-[2-(4-[4-chloro-6-(2-[4,4- dimethyl-2,5-dioxo-imidazolidin-1-yl]-ethylamino)-[1,3,5]triazin-2-ylamino]-benzenesulfonyl)-ethyl] ester sodium (TB), which contains two reactive groups of monochloro triazine reactive groups and bis-sulphatoethylsolphone reactive groups. The structure of TB is similar to iso-bifunctional group reactive dyes and could be coated on cotton fabrics by covalent bonds through a reactive dyeing process. The cotton coated with TB was characterized by FTIR and SEM. After chlorination, the treated cotton fabrics showed excellent antibacterial efficacy and inactivated all inoculated S. aureus (ATCC 6538) and E. coli O157: H7 (ATCC 43895) within 1 min of contact. Over 85 % of tensile strength retained both in warp and weft directions after treatment and chlorination. Almost 80 % of active chlorine can be regained by treating with household bleach after extensive washing and long time storage.     

Electrical Resistivity of Plasma Treated Viscose and Cotton Fabrics with Incorporated Metal Ions

Cellulose fabrics (viscose and cotton) were treated with atmospheric pressure dielectric barrier discharge (DBD) in air. After DBD treatment, samples were characterized and volume electrical resistance was measured under different relative humidity conditions (φ=40-55 %). Results have shown that DBD treatment increases wettability and polar surface functional groups content, which consequently causes a decrease of volume electrical resistivity of cellulose fabrics in measured relative humidity range (φ=40-55 %). Metal ions (silver, copper, and zinc) were incorporated in untreated and plasma treated samples through sorption from aqueous solutions and incorporation of metal ions into plasma treated cellulose samples decreased electrical resistivity even further. Resistivity of cotton and viscose fabrics with incorporated metal ions followed the order Zn²⁺ > Cu²⁺ > Ag⁺. The most pronounced decrease, for entire order of a magnitude, was obtained by modification of cotton fabric with DBD and silver ions, where value of resistivity dropped from GΩ to a several dozens of MΩ.     

Multifunctional colored polyester fabric treated with dopamine hydrochloride at room temperature: higher tensile,hydrophilicity and anti-bacterial properties along with aminolysis

In this work, dopamine hydrochloride, an environmental friendly compound, was applied on polyester fabric through conventional simple impregnation method in alkaline solution (pH=8.5) at room temperature. In situ spontaneous oxidative polymerization of dopamine form polydopamine (PDA) along with aminolysis of polyester fabric surface. Also, a range of colored polyester fabric were successfully achieved by formation of polydopamine adhesive coating layer at different concentration of dopamine hydrochloride (0.001-4 g/l). Fourier transform infrared spectroscopy and field emission scanning electron microscopy showed deposition of polydopmaine on the polyester fabric surface. The modified colored polyester fabric showed reasonable durability against washing, rubbing and light. The treated polyester fabric with 2 g/l dopamine hydrochloride as optimum concentration indicated not only lower spreading time for water droplet and electrical resistance with higher tensile strength but also very good bactericidal activity against Staphylococcus aureus and Escherichia coli.     

Dyeability and Antibacterial Finishing of Hemp Fabric Using Natural Bioactive Neem Extract

Two functional compounds were successfully extracted from neem (Azadiracta indica): a tannin-rich natural dye and an antibacterial agent. The dye was extracted from the bark using water, and the antibacterial from the leaf using methanol. These were used to dye hemp fabrics. Higher color strength values (K/S) were found when dyeing was conducted at a higher dye concentration, elevated temperature, and longer dyeing time. Optimal results were achieved when using 5 %w/v of extracted powder at 100 °C for 60 min. The resulting fabrics appeared reddish-brown, and were rated as good to excellent for color fastness against washing, water, sea water, and perspiration. The antibacterial agent from the neem leaf was extracted by Soxhlet apparatus at 65 °C with methanol as solvent. The dyed and antibacterial-finished hemp fabrics were tested against Staphylococcus aureus, following the percentage reduction test of AATCC 100. The treated fabrics demonstrated a 99.99 % reduction in Staphylococcus aureus.