Surface Modification Of Cotton Fabrics Research Articles

Surface modification of cotton fabric with dual‐responsive PNIPAAm/chitosan nano hydrogel

The present study deals with preparing stimuli‐responsive poly N‐isopropyl acryl amide/chitosan (PNCS) nano hydrogel and looks into their effects as a surface modifying system of cotton fabric. The semi‐batch surfactant‐free emulsion polymerization method was proposed to reduce the size of particle and synthesis of PNCS nano particles. Fourier transform infrared, nuclear magnetic resonance, differential scanning calorimetry, scanning electron microscopy and dynamic light scattering methods confirmed the nano size of synthesized PNCS particles and sensitivity of these nano particles to the different temperature and pH, respectively. The water retention capacity (WRC) and carboxyl content of modified cotton with PNCS nano particles were assessed through the central composite design. The bounded PNCS nano particles to the surface of cotton fabrics made them responsive to these dual stimuli. The results demonstrated the dual effect of BTCA amount on WRC. Increase of the amount of BTCA itself led to the decrease of the WRC of modified cotton, but in the presence of PNCS, WRC was significantly increased. Copyright © 2013 John Wiley & Sons, Ltd.

Improve the Dyeing Property of Cotton Fabric via Corona Discharge

In this study, corona discharge treatment is applied to cotton fabric at various discharge voltages and time. The dye uptake of treated fabric was increased when the applied voltage and treating time increased. Its effects on surface modification of cotton fabric and its application in finishing are investigated with a range of analytical methods. The results suggest that corona discharge can be successfully applied the finishing of cotton fabric, especially in the green processing of dyeing.

A Study on Process Parameters for Imparting Hydrophobic Effect on Cotton Fiber with CF<sub>4</sub>-Plasma Treatment

The acquisition of hydrophobic surface offering liquid repellency is exploitable for diverse applications. This study examined the possibility of developing hydrophobic cotton fiber by employing atmospheric pressure plasma technique which is an environmentally friendly approach. We seek to determine a controlled hydrophobic modification of textile materials through the optimization of the fabrication process. A hydrophobic surface modification of cotton fabric was conducted with atmospheric pressure plasma using tetrafluoromethane (CF4) as the reactive gas. The resultant hydrophobic behavior was quantified macroscopically by a wetted area measurement. To control the degree of modification of the substrate, an orthogonal experimental design technique was utilized. The optimum process conditions were established based on the reduction of the wetted area of the plasma-modified fabrics.

Improve the Dyeing Property of Cotton Fabric via Corona Discharge

In this study, corona discharge treatment is applied to cotton fabric at various discharge voltages and time. The dye uptake of treated fabric was increased when the applied voltage and treating time increased. Its effects on surface modification of cotton fabric and its application in finishing are investigated with a range of analytical methods. The results suggest that corona discharge can be successfully applied the finishing of cotton fabric, especially in the green processing of dyeing.

Graphene oxide nanostructures modified multifunctional cotton fabrics

Surface modification of cotton fabrics using graphene oxide (GO) nanostructures was reported. Scanning electron microscopic (SEM) investigations revealed that the GO nanostructure was coated onto the cotton fabric. The molecular level interaction between the graphene oxide and the cotton fabric is studied in detail using the Fourier transform infra-red (FTIR) spectra. Thermogravimetric analysis (TGA) showed that GO loaded cotton fabrics have enhanced thermal stability compared to the bare cotton fabrics. The photocatalytic activity of the GO-coated cotton fabrics was investigated by measuring the photoreduction of resazurin (RZ) into resorufin (RF) under UV light irradiation. The antibacterial activity was evaluated against both Gram-negative and Gram-positive bacteria and the results indicated that the GO-coated cotton fabrics are more toxic towards the Gram-positive ones. Our results provide a way to develop graphene oxide-based devices for the biomedical applications for improving health care.

Surface modification of cotton fabrics by transesterification with ion-paired subtilisin Carlsberg in solvents

The transesterification-active enzyme subtilisin Carlsberg was successfully solubilized into organic solvents such as isooctane by enzyme–bis(2-ethylhexyl) sulfosuccinate (AOT) ion-pairing while retaining its natural secondary structure and catalytic activity. The optimal CaCl2 concentration and pH for enzyme extraction were 2 mM and 5.0, respectively, while the optimal pH for transesterification capability of enzyme was around 7.5. Within the critical micellar concentration (CMC) of AOT in isooctane, increasing the initial AOT concentration enhanced the extraction efficiency. As the hydrophobicity of the solvent decreased, so did the catalytic efficiency of the enzyme, while transesterification of cotton fabrics (medical gauze and knitted cotton cloth) occurred only in less hydrophobic solvents such as toluene. Transesterification was verified by infrared spectral analysis. The final degree of substitution (DS, the number of propionate groups per cellulose monosaccharide unit) of the medical gauze and knitted cotton cloth was 0.00282 and 0.00228, respectively. The surface properties of the modified cotton fabrics were characterized using X-ray diffraction, scanning electron microscopy, thermogravimetry, water contact angle, etc.

Preparation and Comparison of Hydrophobic Cotton Fabric Obtained by Direct Fluorination and Admicellar Polymerization of Fluoromonomers

Two different methods of surface modification of cotton fabrics are compared: direct fluorination using elemental fluorine and admicellar polymerization, which uses a surfactant and fluoromonomer system. Sample characterization includes infrared spectroscopy, analysis of mechanical properties, analysis of wetting times, contact angle measurements, scanning electron microscopy, elemental analysis, and atomic force microscopy analysis. Fourier transform infrared spectroscopy and elemental analysis showed the presence of fluorine moieties. For direct fluorinated cotton fabric, the static contact angle was found to be 117°, and for cotton fabric modified by admicellar polymerization, the contact angle was 125°. In all cases, the presence of a very thin fluorocarbon layer on the surface was confirmed, but differences in terms of the amount of fluorochemical formed and in surface structure were also found.

Surface Modification of Cotton Fabric by Wet Chemical Treatments to Impart Hydrophobicity

Temporary surface modifications of cotton fabrics with different water repellent agents by wet chemical treatments were examined. The hydrophobicity of the treated substrates was determined by contact angle. The results show that the cotton fabric became hydrophobic. Three hydrophobic finishing agents were used in this study. The fabric properties were investigated in terms of moisture regain. Significant changes in properties were observed for the different finished materials. The surface investigation conducted by scanning electron microscopy (SEM) provided distinctive features of the untreated and treated fabric samples. Elementary analysis was also carried out on the substrate through energy dispersive x-ray (EDX) to confirm the presence of hydrophobic groups. In this study, a unique approach based on the double coating method was found to be a promising technique for modifying cotton fabrics temporarily and the hydrophobic finishing agent was easily removable which in turn would be beneficial for dyeing in supercritical CO2 medium. The method therefore offers great advantages in terms of regaining natural properties of cotton fabrics after suitable modifications.

Surface modification of cotton fabric by grafting of polyurethane

Chemical modification of cotton was investigated using blocked isocyanates prepared from reaction of 4,4-diphenylmethane diisocyanate (MDI) with Poly(propylene glyols) followed by addition of methyl ethyl ketoxime (MEKO). The products were characterized by Fourier transform infrared spectroscopy (IR) and X-ray photoelectron spectroscopy (XPS). Evidences of grafting were obtained by IR from the appearance of CO bands absorbance and the reducing of relative intensity of OH, with respect to cotton. The results of XPS and SEM also give the same evidences that polyurethane has been grafted onto the surface of cotton.