Microwave curing for producing cotton fabrics with easy care and antibacterial properties

A new microwave curing system was used to affect crosslinking of cotton fabric with nonformaldehyde finishes, namely, glyoxal, glutaraldehyde and 1,2,3,4 butanetetracarboxylic acid (BTCA). Water soluble chitosan was incorporated in the finishing bath in order to impart antibacterial activity to the fabric in addition to the ease of care characteristics. Glyoxal proved to be the best finish and, hence, it was studied along with the chitosan under a variety of conditions including chitosan concentrations, power and time of microwave curing. Besides the crease recovery and strength properties of the finished fabrics, the latter were also monitored for N%, antibacterial activity and characterized using scanning electron microscope (SEM) and FTIR spectra when compared. With conventional curing system, the microwave curing system was found advantageous in production of cotton fabrics with easy care antibacterial properties without high losses in strength properties.     

A novel approach for adding smart functionalities to cellulosic fabrics

A water soluble nanocomposite, based on Ag-nanoparticles (Ag-NPs) loaded on hyperbranched poly (amide-amine, HBPAA) was prepared, characterized and utilized in functional finishing as well as in combined reactive dyeing/and functional finishing of linen, cotton and viscose fabrics. Incorporation of the nanocomposite alone and in combination with reactive dyes in easy care finishing formulations brought about an outstanding antibacterial functionality of the finished and the dyed/finished fabrics even after 15 laundering cycles along with a slight negative impact on other performance properties. Improvement or decrement in the functional, comfort, and dyeing properties is governed by the type of cellulosic substrate.     

Functional finishing of health care cotton for enhanced efficiency of antibacterial activity by chitosan and herbal nanocomposites

To enhance the efficiency of biological, chemical and physical properties like antibacterial activity, wash durability, air-permeability and biocompatibility of cotton fabric finished with chitosan and herbal nanocomposites. Extracts of Cassia angustifolia and Tamarindus indica with chitosan solution was bulk finished on 40s cotton fabrics. To increase the functional properties, chitosan and herbal extract nanocomposites were finished on to another set of fabrics (nanocomposite finishing). Different functional properties were carried out for both the sets of fabrics and comparatively analyzed. Antibacterial activity, physical properties and biocompatible properties of the finished fabric were determined. Antibacterial activity of nanocomposite finished fabrics showed inhibitory zones of 33 mm for E. coli and 31.6 mm for S. aureus. Nanocomposite finished fabrics showed good durable properties and physical properties than bulk finished fabrics. The study concludes that, nanocomposites could provide better functional properties than the bulk finished fabrics. The nano sized particles in the composites was considered significant for its functional applications in hospital based fabrics to prevent the transmission of nosocomial infections.     

Finishing of cotton fabrics with poly (N-vinyl-2-pyrrolidone) to improve their performance and antibacterial properties

Cotton fabric was thermally crosslinked with poly (N-vinyl-2-pyrrolidone) (PVP) at different conditions including temperature, time, PVP concentrations and molecular weights. Results indicated that treating the cotton fabrics with 4% aqueous solution of PVP of molecular weight 10,000 Dalton followed by drying at 85 °C for 5 min then curing at 160 °C for 3 min results in crosslinking as will as an improvement in some performance properties of that fabrics such as resiliency, tensile strength, and acid dyeability. Post-treating PVP crosslinked fabric with 5% iodine in ethanol solution for 5 h at 50 °C imparts antibacterial activity against Staphylococcus aureus and Escherichia coli. Moreover, incorporation of PVP in the easy-care finishing of cotton fabrics, as polymer additive, with N,N-dimethylol 4,5-dihydroxyethylene urea as a crosslinker enhances some of the performance properties of finished fabrics such as the nitrogen content, tensile strength and acid dyeability along with decreasing resiliency as well as whiteness index, whereas the ester crosslinking with citric acid, in presence of PVP, enhances resilience, tensile strength and whiteness indices accompanied with a reduction in the %N of the treated fabrics. Infra red spectrum of PVP crosslinked fabric as well as EDX analysis of loaded iodine on PVP crosslinked cotton fabric were investigated.     

Functionalization of cotton fabric with PVP/ZnO nanoparticles for improved reactive dyeability and antibacterial activity

Poly-N-vinyl-2-pyrrolidone functionalization was done for improved the dyeability of dichlorotriazine dyes on cotton fabric. The synthesized ZnO nanoparticles were padded on functionalized cotton fabrics to improve antibacterial activity. The modification effects were characterized by FTIR, XRD, SEM and EDX studies. The antibacterial activity was done against Staphylococcus aureus and Escherichia coli bacterium. The dye exhaustion and fastness properties were analyzed for dyeing with sodium chloride, sodium sulfate and trisodium citrate bio-salt as exhausting agents. The functionalized cotton fabric showed improved dye uptake and good fastness properties. Poly-N-vinyl-2-pyrrolidone with ZnO nanoparticles padded fabrics showed very good antibacterial activity.     

Flame retardant finishing of cotton fabric based on synergistic compounds containing boron and nitrogen

Boric acid and compound containing nitrogen, 2,4,6-tri[(2-hydroxy-3-trimethyl-ammonium)propyl]-1,3,5-triazine chloride (Tri-HTAC) were used to finish cotton fabric. The flame retardant properties of the finished cotton fabrics and the synergetic effects of boron and nitrogen elements were investigated and evaluated by limited oxygen index (LOI) method. The mechanism of cross-linking reaction among cotton fiber, Tri-HTAC, and boric acid was discussed by FTIR and element analysis. The thermal stability and surface morphology of the finished cotton fabrics were investigated by thermogravimetric analysis (TGA) and scanning electron microscope (SEM), respectively. The finishing system of the mixture containing boron and nitrogen showed excellent synergistic flame retardancy for cotton fabric. The cotton fabric finished with mixture system had excellent flame retardancy. The LOI value of the treated cotton fabric increased over 27.5. Tri-HTAC could form covalent bonds with cellulose fiber and boric acid. The flame retardant cotton fabric showed a slight decrease in tensile strength and whiteness. The surface morphology of flame retardant cotton fiber was smooth.     

Chitosan‐templated bio‐coloration of cotton fabrics via laccase‐catalyzed polymerization of hydroquinone

There is an increasing interest in the development of enzymatic coloration of textile fabrics as an alternative to conventional textile dyeing processes, which is successful for dyeing protein fibers. However, unmodified cotton fabrics are difficult to be dyed through enzyme catalysis due to the lack of affinity of biosynthesized dyes to cotton fibers. In order to improve the enzyme‐catalyzed dyeability of cotton fibers, chitosan was used to coat cotton fabrics as template. A novel and facile bio‐coloration technique using laccase catalysis of hydroquinone was developed to dye chitosan‐templated cotton fabrics. The polymerization of hydroquinone with the template of chitosan under the laccase catalysis was monitored by ultraviolet‐vis spectrophotometer on the absorbance of reaction solution. A significant peak of UV‐vis spectrum at 246 nm corresponding to large conjugated structures appeared and increased with increasing the duration of enzymatic catalysis. The effect of different treatment conditions on the laccase‐catalyzed dyeing of cotton fabric was investigated to determine their optimal parameters of laccase‐catalyzed coloration. Fourier‐transform infrared spectroscopy spectra demonstrated the formation of H‐bond and Schiff base reaction between chitosan and polymerized hydroquinone. Scanning electron microscopy indicated that the surface of dyed cotton fiber was much rougher than that of the control sample. Moreover, X‐ray photoelectron spectroscopy also revealed the existence of the chitosan/polymerized hydroquinone complex and polymerized hydroquinone on the dyed cotton fibers. This chitosan‐templated approach offers possibility for biological dyeing coloration of cotton fabrics and other cellulosic materials.     

Enhancing antimicrobial properties of dyed and finished cotton fabrics

1,2,3-Benzothiazole-7-thiocarboxylic acid-S-methylester (commercially known as Actigard^® AM-87) was utilized to impart cotton fabric durable antimicrobial properties. Finishing treatment was carried out under a variety of conditions. The latter were included, effect of pH, concentration of antibacterial agents, curing temperature and curing time. The effect of fabric construction, mercerization, and dyeing with different dyestuff were also investigated. The study was also extended to investigate the technical feasibility of combining antimicrobial finishing treatment in question with other finishing treatment generally carried out on cotton fabric, like soft finishing and crease recovery finishing. The treated fabrics were monitored for antimicrobial properties before and after washing. The treated fabrics were also evaluated for the physio-mechanical properties like fabric tensile strength, elongation at break (or bursting strength for knitted fabric), wettability, crease recovery angle, whiteness index and roughness. Results obtained show that, the most appropriate conditions for treatment cotton fabric with Actigard^® are: padding the cotton fabric in aqueous solution containing 6% Actigard^® at pH 5 (adjusted using formic acid) then squeezed to wet pick up of 100%, dried at 80 °C for 5 min then cured at 100 °C for 150 s. The untreated cotton fabric did not show any antimicrobial activity towards Staphylococcus aureus or Escherichia coli. Treatment of cotton fabric with Actigard^® improves its antimicrobial properties towards S. aureus or E. coli. It is also observed that, treatment of cotton fabric with Actigard^® marginally decreases fabric tensile strength, elongation at break, roughness and WI, whereas; both wettability and crease recovery angle remain practically intact. This was observed whether the fabric was pre-mercerized or not.     

Antibacterial cotton fabrics treated with core-shell nanoparticles

Multifinishing treatment of cotton fabrics was carried out using core-shell nanoparticles that consists of silver nanoparticles (Ag(0)) as core and chitosan-O-methoxy polyethylene glycol (CTS-O-MPEG) as shell. The synthesized (Ag(0)-CTS-O-MPEG) core-shell nanoparticle was applied to cotton fabrics using the conventional pad-dry-cure method. The finished fabrics were examined for their morphological features and surface characteristics by making use of scanning electron microscope (SEM-EDX), which reveals the well dispersion of (Ag(0)-CTS-O-MPEG) core-shell nanoparticles on cotton fabrics. Factors affecting the treatment such as core shell nanoparticles, citric acid (CA) concentration as well as curing temperature were studied. The treated fabrics, at optimum condition of 1% core shell nanoparticles, 5% citric acid, drying at 80°C, curing at 160°C for 2 min, showed excellent antibacterial activity against Gram-negative Escherichia coli (E. coli) and Gram-positive bacteria Staphylococcus aureus (S. aureus), even after 20 washing cycles in addition to an enhancement in crease recovery angles (CRA) along with a slight improvement in tensile strength (TS).     

麻栎壳斗染料在羊毛染色中的应用

本文研究了提取自麻栎壳斗的植物染料(麻栎染料)的耐酸、碱稳定性,染浴pH值及铝、铁离子等环保型媒染剂对其染毛织物效果的影响,并且探究了其染色动力学.研究表明,麻栎染料在强酸性染浴(pH=3)中对羊毛织物直接性好,染色后毛织物得棕色,也可采用铝离子、铁离子对直接染色后的毛织物进行后媒染,以得到不同色相的毛织物,尤其是铁后...     

Preparation of polyethylene glycol/polyacrylamide adduct and utilization in cotton finishing

Highly concentrated aqueous solutions of acrylamide (Am) were polymerized in presence of polyethylene glycol (PEG) using ammonium persulfate as initiator under different conditions including ammonium persulfate concentration (0.02–0.06 g/gAm) temperature (60–95 °C), Am/PEG400 ratio (1/1–1/5 g/g), PEG molecular weight (400–6000). At optimum reaction conditions a PEG 400/PAm adduct was prepared with a % total conversion of 99.7 in 2 min using ammonium persulfate (0.05 g/gAm), Am/PEG (1/2 g/g) at 70 °C. The structure of the adduct was confirmed by FT-IR spectra. The adduct was utilized as a finishing additive for cotton fabric in presence and absence of dimethyloldihydroxy ethylene urea (DMDHEU) by the bad – dry – cure method. In absence of DMDHEU, the adduct improves the fabric tensile strength, stiffness and oily stain release rating without affect the wettability along with decreasing the fabric resiliency compared to the blank sample. Inclusion DMDHEU the finishing bath (50 g/l) results in improving the fabric resiliency and stiffness as well as decreasing the strength, wettability and oily stain release compared to those of fabric treated with adduct in absence of DMDHEU. However, at an adduct concentration of 40 g/l and in presence of 50 g/l DMDHEU the fabric properties are in general, superior to those of blank fabric.     

Functionalization of cellulose-containing fabrics by plasma and subsequent metal salt treatments

In order to upgrade the UV-protection and antibacterial functional properties of cotton/polyester (80/20), cotton/linen (50/50) and linen/viscose-polyester (50/50) fabric blends, they were treated with different plasma gases (oxygen, air, and argon) followed by subsequent treatment with certain metal salts namely Zn-acetate, Cu-acetate, Al-chloride, and Zr-oxychloride. The obtained results show that the type of plasma gas, the kind of metal salt as well as the nature of the treated substrate play an important role in the extent of enhancing the demanded functional properties. Oxygen plasma treatment followed by Cu-acetate or Zn-acetate treatment gives the best UV-protection or antibacterial activity respectively, keeping other parameters constant. The surface morphology of some untreated and plasma-treated samples was also analyzed by SEM.     

Preparation of cationic cotton with two-bath pad-bake process and its application in salt-free dyeing

Cationic cotton was prepared by a designed two-bath pad-bake process with 3-chloro-2-hydroxypropyltrimethylammonium chloride as cationizing reagent to realize recycle utilization of the reagent and continuous processing of cationization. Experiments showed that 8.0% (o.w.bath) of the reagent, 1:1 of molar ratio of sodium hydroxide to the reagent, 60 °C and 6 min of baking temperature and time were selected for cationization and the obtained cationic cotton was suitable for application in salt-free reactive dyeing. The structures of both the untreated and cationic fibers were investigated by X-ray diffraction and scanning electronic microscopy. Higher dye utilization and color yields could be realized on the cationic cotton than that on the untreated one in the conventional dyeing. Levelness dyeing and good fastness properties of the dyes on the cationic fabrics were obtained. Besides, colorimetric properties and mechanical strength of the dyed fabrics were both evaluated to show applicability of this preparation process of cationic cotton.     

An eco-friendly – novel approach for attaining wrinkle – free/soft-hand cotton fabric

A novel approach for upgrading both the wrinkle free and softness properties of cotton fabrics without adversely affecting their strength properties using an eco-friendly finishing regimes was investigated. Factors affecting the performance properties of the finished substrate such as pre-treatment, i.e., carboxymethylation (CMC) or ionic-crosslinking, post-treatment with amino functional silicone softener and its concentration, degree of carboxymethylation as well as thermofixation conditions were studied. The obtained results revealed that post-treatment with the amino based silicone micro emulsion (SiE) up to 30 g/L at pH 4 to a wet pickup of 100% followed by drying at 100 °C for 5 min and curing at 170 °C for 3 min results in a remarkable improvement in fabric resiliency (expressed as dry and wet wrinkle recovery angles), as well as in softness degree, without seriously affecting its retained strength. Improvement extent of the aforementioned properties is governed by the nature of the pre-treatment steps. Fixation of the amino-functional silicone softener onto/or within the modified cellulose structure is accompanied by a formation of semi-inter and/or intra-penetrated network (semi-IPN) thereby enhancing both the extent of crosslinking and networking as well as providing very high softness. FTIR analysis proved the formation of Si–O–Si–cellulose complex. Scanning electron micrograph shows that cotton, CMC and ionic crosslinked cotton fabrics treated with SiE shows higher surface smoothness and considerable reduction in protruding loose fibers, ditches and grooves compared with the untreated one.     

Specificities of a chemically modified laccase from Trametes hirsuta on soluble and cellulose-bound substrates

Laccases could prevent fabrics and garments from re-deposition of dyes during washing and finishing processes by degrading the solubilized dye. However, laccase action must be restricted to solubilized dye molecules thereby avoiding decolorization of fabrics. Chemical modification of enzymes can provide a powerful tool to change the adsorption behaviour of enzymes on water insoluble polymers. Polyethylene glycol (PEG) was covalently attached onto a laccase from Trametes hirsuta. Different molecular weights of the synthetic polymer were tested in terms of adsorption behaviour and retained laccase activity. Covalent attachment of PEG onto the laccase resulted in enhanced enzyme stability while with increasing molecular weight of attached PEG the substrate affinity for the laccase conjugate decreased. The activity of the modified laccases on fibre bound dye was drastically reduced decreasing the adsorption of the enzyme on various fabrics. Compared to the 5 kDa PEG laccase conjugate (K/S value 47.60) the K/S value decreased much more (47.96–46.35) after the treatment of dyed cotton fabrics with native laccase.     

Thyme essential oil for antimicrobial protection of natural textiles

The study was aimed at increasing the resistance of lignocellulosic textiles to bacteria and mould action using a biocide of plant origin. The biocide used in the study was thyme essential oil. This kind of oil is characterized by low toxicity for humans and the environment. The antimicrobial efficiency of thyme essential oil applied to linen–cotton blended fabric and linen fabric was evaluated by determining bacterial growth, degree of mould growth, and their impact on fabric strength. Thyme essential oil applied as 8% concentration in methanol to linen–cotton blended fabric showed very high antibacterial and antifungal activity – no mould growth and no significant loss of breaking force were observed. Microscopic evaluation of the tested fabrics was also performed by Scanning Electron Microscopy. Applying the eco-friendly biocide to fabrics containing natural fibres in the finishing process produces antimicrobial barrier properties.     

Dyeing and antimicrobial characteristics of chitosan treated wool fabrics with henna dye

Chitosan, a naturally available biopolymer which is now increasingly being used as a functional finish on textile substrates to impart antimicrobial characteristics and increase dye uptake of fabrics was applied on wool fabrics. Henna a natural dye with proven bactericidal properties was applied on wool fabrics along with chitosan to impart antimicrobial characteristics. The effect of chitosan application on the dyeing properties of wool fabrics was studied by measuring the K/S values of the treated substrates at various concentrations of chitosan and the dye. The antimicrobial properties of chitosan and natural dyes both when applied independently and collectively on fabrics were assessed. The results proved that the chitosan treated wool fabrics showed increase dye uptake of fabrics. The treated fabrics were found to be antimicrobial and the chitosan treatment enhances the antimicrobial characteristics of the dyes. Fastness properties of the applied finish to washing, rubbing and perspiration have also been discussed.     

Nano photo scouring and nano photo bleaching of raw cellulosic fabric using nano TiO2

Photo catalytic action of nano TiO(2) for decomposing of some organic compounds is a well known phenomenon. This can be extended to the application on nano TiO(2) on the desized cotton fabric to decompose the hydrophobic impurities and coloring matters of the fabric. This can be nominating as a replacement for the conventional scouring and bleaching processes on cotton fabric producing the hydrophilic white cotton fabric. The photo activities of the nano TiO(2) on the desized cotton through decomposition of the cotton impurities compared for two different light exposures: UV rays and daylight. The desized cotton fabrics treated in the ultrasonic bath containing a colloidal aqueous solution of nano TiO(2)/citric acid (CA)/sodium hypophosphite (SHP). Incorporating CA in the treatment bath enhanced the treatment durability against washing, created a durable hydrophilic white cotton fabric even after several successive washings. Increasing the nano TiO(2) content enhanced the fabric hydrophilicity and whiteness features. Overall, the nano photo scouring and nano photo bleaching on the cotton fabric introduced and thoroughly discussed. This gains the application of nano TiO(2) on textile materials besides the other well known characteristics obtained on the textiles including self-cleaning, antibacterial and UV protection.     

HBP-NH2 grafted cotton fiber: Preparation and salt-free dyeing properties

In order to achieve salt-free dyeing on cotton fiber with reactive dyes, an amino-terminated hyperbranched polymer (HBP-NH₂) grafted cotton fiber (HGCF) was prepared by the oxidation of cotton fiber with sodium periodate in water and subsequent grafted with an aqueous solution of HBP-NH₂. Fourier transform infrared spectrophotometry (FTIR) of the HGCF indicated that all aldehyde groups of the oxidized cotton fiber have reacted with amino groups of the HBP-NH₂. As a result, the HGCF fabrics prepared under the optimum conditions displayed markedly enhanced colour strength when dyed with reactive dyes using salt-free dyeing. The washing fastness, rubbing fastness and levelling properties of the dyed HGCF fabrics were also good compared with those obtained by conventional dyeing. The zeta-potential of the HGCF in liquid phase was tested and found to be positive at pHs lower than 6.5. The dyeing behaviour of Reactive Brilliant Yellow A-4GLN on the HGCF was found to follow a Langmuir-type adsorption curve.     

Thermal stability, flame retardancy and mechanical properties of cotton fabrics treated with inorganic coatings synthesized through sol-gel processes

Cotton was sol-gel treated employing several metal alkoxide precursors (namely, tetraethylortho-silicate, -titanate, -zirconate and aluminium isopropylate) in order to get inorganic phases able to improve the thermal stability and flame retardancy of the fabric, without changing its mechanical features. Indeed, after the sol-gel treatment the fibre/fabric surface was morphologically modified: a homogeneous and compact film located in the fibre interstices (warp and weft) and partially covering their walls was observed for all the systems investigated. These coatings turned out to be responsible of an overall enhancement of the thermal and fire stability of the fabrics preserving, at the same time, the original mechanical properties of the neat cotton in terms of tensile strength and deformation. In addition, such inorganic coatings increased the abrasion resistance of the cotton in a remarkable way.