Surface cationization of cellulose to enhance durable antibacterial finish in phytosynthesized silver nanoparticle treated cotton fabric

Cellulose - Elimination of disease-causing bacteria from cotton fabrics is critically important to control several bacteria-mediated infections in humans. Antibacterial nanoparticles, particularly...     

Surface and bulk cotton fibre modifications: plasma and cationization. Influence on dyeing with reactive dye

The surface of cotton fabrics was functionalized through corona plasma treatments and/or by cationising the whole of the fibre with an epihalohydrin. The effects of both treatments, individually and in combination are analyzed through wettability studies, by X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM), and also by dyeing studies with an hetero bis functional reactive dye. Plasma improved wetting properties, exhaustion of the dyebaths and K/S_corr of the fabrics through surface functionalisation. Cationising of the cotton highly increased the exhaustion of the dyebaths and produced a dramatic improvement in K/S_corr. Plasma treatment previous to cationising increased the impregnation of the fabrics, but the effects of both treatments on dyeing parameters are additive only in column water rise and generally the effects obtained by cationising with the epihalohydrin prevail. The differences between both treatments are discussed in terms of surface functionalisation of the cotton fibres.     

High efficiency ultra-deep dyeing of cotton via mercerization and cationization

A potentially environmentally responsible dyeing procedure for ultra-deep shades on cotton was developed using a cationization method in combination with mercerization. The effects of both treatments on dyeing performance and colorfastness properties of cotton fabrics dyed with reactive dyes were analyzed individually and in combination. Both mercerization and cationization have been proved to be effective in increasing the depth of shade on cotton. The colorfastness properties, except colorfastness to wet crocking, of mercerized–cationized cotton fabrics dyed without salt were much better than untreated cotton dyed using a conventional dyeing procedure. Unlike untreated cotton fabrics, the concentration of Na₂CO₃ in the dyeing process of mercerized–cationized cotton fabrics was lowered from 20 to 5 g/L without compromising dye fixation and colorfastness properties. With low concentrations of dyes and Na₂CO₃ and no electrolyte in the dye bath effluent, the dyeing procedure of mercerized–cationized cotton fabrics for ultra-deep shades is potentially a more environmentally benign method than conventional dyeing with reactive dyes.     

Constructing recyclable photocatalytic BiOBr/Ag nanowires/cotton fabric for efficient dye degradation under visible light

In this study, a highly-efficient photocatalytic and recyclable BiOBr/Ag nanowires (AgNW)/cotton fabric (CF) composite was fabricated by successive ionic layer adsorption and reaction (SILAR) for rapid treatment of dye wastewater. The integration of AgNW and BiOBr aims to establish a channel for faster and easier charge transfer to enhance the photocatalytic performance. The chemical structure and morphology of BiOBr/AgNW/CF, as well as its photo-degradation of Rhodamine B (RhB) under visible light radiation were explored. Results reveal that BiOBr/AgNW/CF exhibits remarkably enhanced photocatalytic activity over BiOBr/CF, which degrades 97 % of RhB within 90 min. BiOBr/AgNW/CF still maintains 88 % of photocatalytic degradation capacity after five reusing cycles due to the effective encapsulation of BiOBr that protects AgNW from oxidation. Photoluminescence, electron spin resonance, and free radical trapping experiments confirm that the separation efficiency of photo-generated electron-hole pairs plays an important role in improving photocatalytic performance. In all, this work exhibits great potential in the development of textile-based photocatalytic materials that integrates two significant merits, the high degradation efficiency and easy recovery.     

Bio-derived efficient flame-retardants for cotton fabric

Cellulose - This paper presents a facile synthesis method for bio-derived (from the bark of Terminalia arjuna and tea powder) phosphorus-functionalized materials (AB-P and TP-P). The resulting...     

A swift dye uptake procedure for dye sensitized solar cells

Solar cells based on swift self-assembled sensitizer bis(tetrabutylammonium)-cis-di(thiocyanato)-N,N'-bis(4-carboxylato-4'-carboxylic acid-2,2'-bipyridine)ruthenium(II) (N719) on double layers of 12 + 4 microm thick nanocrystalline TiO2 films exhibit the incident monochromatic photon-to-current conversion efficiency (IPCE) 90% and show a short circuit current density of 17 mA cm(-2), 750 mV open circuit potential and 0.72 fill factor yielding power conversion efficiencies over 9.18% under AM 1.5 sun. For the first time highest power conversion efficiencies are obtained for dye sensitized solar cells using a swift self-assembled procedure.     

Effect of surface cationization on the conformal deposition of polyelectrolytes over cotton fibers

The effect of surface cationization on the conformal deposition of alternating nanolayers of poly(sodium styrene sulfonate) (PSS) [Kleinfeld E, Ferguson G (1996) Chem Mater 8:1575–1578] and poly(allylamine hydrochloride) (PAH) over cotton fibers is reported. Three different levels of cotton cationization were evaluated. Variations in the cationization degree were achieved by manipulating the ratio of 3-chloro-2-hydroxy propyl trimethyl ammonium to NaOH. Experimental results obtained via Carbon–Hydrogen–Nitrogen–Sulfur (CHNS) elemental analysis and X-ray Photoelectron Spectroscopy (XPS) indicated that the deposition process was not significantly influenced by the degree of cotton cationization. The build up of further polyelectrolyte layers was found to be less sensitive to variations in the cationic character of the substrates once a critical number of alternating layers was deposited.     

Dyeing behaviour of gamma irradiated cotton fabric using Lawson dye extracted from henna leaves (Lawsonia inermis)

Dyeing behavior of gamma irradiated cotton fabric using Lawson dye extracted from henna leaves has been investigated. Cotton and dye powder are irradiated to different absorbed doses of 2, 4, 6, 8 and 10 kGy using Cs-137 gamma irradiator. The dyeing parameters such as dyeing time, electrolyte (salt) concentration and mordant concentrations using copper and iron as mordants are optimized. Dyeing is performed using un-irradiated and irradiated cotton with dye solutions and their color strength values are evaluated in CIE Lab system using Spectraflash –SF650. Methods suggested by International Standard Organization (ISO) have been employed to investigate the colourfastness properties such as colourfastness to light, washing and rubbing of irradiated dyed fabric. It is found that gamma ray treatment of cotton dyed with extracts of henna leaves has significantly improved the color strength as well as enhanced the rating of fastness properties.     

Durable phosphorus/nitrogen flame retardant for cotton fabric

Cellulose - A new phosphorus/nitrogen flame retardant (FR) containing reactive –P–O−NH4+ groups was synthesized from glycerol, phosphoric acid, and urea. At high temperatures, the...     

Effect of cationization on adsorption of silver nanoparticles on cotton surfaces and its antibacterial activity

Cotton was cationized by exhaustion method using 3-chloro-2-hydroxypropyl trimethyl ammonium chloride (CHPTAC) as a cation-generating agent. Adsorption of silver nanoparticles on normal and cationized cotton was studied by exhaustion method at temperatures of 80°C and 100°C. Two exhaustion baths were used, containing nanosilver colloidal solutions stabilized by two different stabilizers and various concentrations of silver nanoparticles. Fourier-transform infrared (FT-IR) spectra of normal and cationized samples confirmed the existence of quaternary ammonium groups on cationized cellulose fibers. X-ray diffraction (XRD) patterns showed that crystallinity of the modified cellulose fibers was decreased. Scanning electron microscope (SEM) images revealed that the surface of the modified cotton was rougher than that of normal cotton. In addition, SEM images showed the presence of silver nanoparticles on the surface of treated fabric samples. The amount of silver particles adsorbed on the fabric samples was determined using inductively coupled plasma-optical emission spectrometer. Antibacterial tests were performed against Escherichia coli bacteria as an indication of antibacterial effect of samples. Cationized cotton samples adsorbed more silver nanoparticles and then had greater ability to inhibit bacteria.     

Development of antimicrobial cotton fabric using bionanocomposites

In order to provide antimicrobial activity to cotton, cotton fabrics were treated by montmorillonite (KSF), montmorillonite–dihydroxy ethylene urea (KSF–MDEU), KSF–chitosan (CS) and KSF–CS–MDEU solutions containing 12.5, 25 and 50 ppm silver ion. The effect of modification on the antibacterial activity of cotton fabrics was also evaluated after 10 cycles of washings. MDEU exhibited better antimicrobial activities after washing process. By using 25 ppm silver, KSF and CS modification solution, good performance in terms of antibacterial activity was obtained. The addition of CS and MDEU increased the whiteness index values of cotton fabrics treated with KSF containing different silver concentrations. The characterization of modified cotton samples was done by Fourier transform infrared spectroscopy, X-ray diffraction analysis, inductively coupled plasma-mass spectroscopy, scanning electron microscopy and thermogravimetric analysis.     

Preparation and flame retardancy of reactive flame retardant for cotton fabric

Journal of Thermal Analysis and Calorimetry - Monochlorotriazine aminopropyl silanol phosphate (MCASP) was synthesized as a novel flame retardant agent for cotton fabric. It was characterized by...     

Self-extinguishing cotton fabric with minimal phosphorus deposition

The phosphorus-containing acrylate monomer, 2-acryloyloxyethyl diethyl phosphate (ADEP), was synthesized and applied to cotton fabric by using the admicellar polymerization technique. A cationic surfactant (cetylpyridinium chloride, CPC) was used as the surfactant for admicellar polymerization. Results from FTIR-ATR and SEM showed that PADEP polymer film was successfully formed on the cotton fabric surface. TGA and DTG analyses showed that the phosphorus-containing PADEP lowered the decomposition temperature of the treated fabric resulting in a higher char yield than in the case of untreated cotton. The flammability tests showed that PADEP-coated cotton with the phosphorus content 4.18 mg/g cotton was self-extinguishing, with the flame extinguishing right after the removal of the ignition source leaving a small area of char formation.     

Antibacterial properties of Aloe vera gel-finished cotton fabric

In this study, cotton fabrics were finished with Aloe vera gel along with 1,2,3,4-butanetetracarboxlic acid as a crosslinking agent using the pad-dry-cure method. The finished fabrics were characterized by Fourier transform infrared spectroscopy. The infrared spectra confirmed that the active ingredients of A. vera gel attached to the hydroxyl groups of cotton fabric via a carboxylic acid cross-linking agent. The antibacterial activity of A. vera-finished fabrics was qualitatively evaluated by the AATCC-147 method and scanning electron microscopy. It was observed that A. vera gel-finished fabric has much less bacterial adhesion. The A. vera gel-finished [concentration ≥3 % (w/v)] cotton fabric inhibited the growth of both gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria. The mechanism of cell death by A. vera gel was evaluated using transmission electron microscopy (TEM). TEM photographs suggested that the cell death is due to the destruction of the bacterial cell wall. The finished fabric was also evaluated for its performance properties such as tensile strength, crease recovery angle, bending length, etc.     

Thermogravimetry of deposited caustic soda used as a flame-retardant for cotton fabric

We have investigated the effect of caustic soda as a nondurable finish on the flammability of 100% cotton fabric (plain 180 g m^?2). On the contrary to the mercerization, during the impregnation process, no tension was applied. In order to attain the alkali cellulose onto the fabric, the subsequent neutralization was not followed. Each bunches of fabrics were dipped into individual aqueous solutions of sodium hydroxide, followed by means of squeeze rolls and drying at 110°C. After conditioning nightlong, by using our ‘vertical flame test’ the optimum add-on values to impart flame-retardancy into cotton fabric was determined as 1.3 g sodium hydroxide per 100 g fabric. Thermogravimetry and derivative thermogravimetry (TG/DTG) of pure cotton, treated cotton with sodium hydroxide at its optimum efficiency to impart flame-retardancy into the fabric was fulfilled and the obtained curves were compared and commented. The effectiveness of this hydroxide is attributed to the heat dissipation by the remaining material in the consumed ash. The results obtained are in favour of ‘dust or wall effect theory’ and also gas dilution theory.     

Development of a novel method for investigation the uptake behaviors of acid dye on silk fabric at various flow statuses in a coloration circular pipe

A novel methodology and a special fluid dynamics coloration machine were successfully constructed, and then the uptake behaviors of an acid dye on silk fabric under different flow statuses and parameters were explored for the first time. The obtained results show that the traditional additions of auxiliaries will not significantly change the kinematic viscosity of the dyeing bath. As coloration flow status was in laminar, transitional and turbulent flow, respectively, the dye uptake behaviors on the silk fabric were significantly different. Meanwhile, decreasing the bath pH value and increasing the temperature of the dyeing bath had a significant positive effect on the dye uptake behaviors in different flow statuses. Additionally, coloration in laminar or transitional flow preferred a relatively low dosage of neutral salt, which benefits to a cleaner production. Additionally, high coloration performance with color-fastness to washing and rubbing of the dyed silk at 4-grade or above was achieved under different flow statuses. The results further clearly indicate that the constructed method and self-built fluid dynamics coloration machine are helpful to investigate dye uptake behavior in different flow statuses, and are potentially beneficial to an efficient process and parameters design for cleaner production in textile coloration.     

Effects of ammonia/ammonium thiocyanate on cotton fabric

The effect of ammonia/ammonium thiocyanate (NH₃/NH₄SCN) treatment of the swelling behavior, structural changes, and physical properties of cotton sheeting was compared with that of sodium hydroxide and liquid ammonia mercerization. Increased percent shrinkage, accessibility to a large dye molecule, dyestuff absorption, swelling with water, and water imbibition showed that NH₃/NH₄SCN had improved the accessibility of the cotton fabric. X-ray diffractograms showed the characteristic Cellulose I crystal lattice. X-ray diffraction and infrared absorption spectroscopy indicated that the crystallite size was unchanged and the swelling from the NH₃/NH₄SCN treatment occurred in the amorphous regions of the cellulose since the observed crystal structure was unchanged. Moisture regain determinations and barium hydroxide absorption suggested that some recrystallization of the cellulose may have occurred from the NH₃/NH₄SCN treatment. Fibers treated with NH₃/NH₄SCN showed a cross sectional shape similar to that of the origianl fibers but with reduced lumen area.     

Polypyrrole-coated cotton textile as adsorbent of methylene blue dye

Pollution caused by organic dyes is of serious environmental and health concern to the population. Dyes are widely used in textile coloring applications. In the present work, cotton textile was coated with a conducting polymer, polypyrrole (PPy), in situ during the oxidative polymerization of pyrrole. The resulting materials were utilized as easily separated and recyclable adsorbent for the removal of methylene blue (MB) as a model of cationic dyes in alkaline solutions. It showed also some affinity to remove Acid Green 25 as an anionic dye in acidic medium. The adsorption was assessed by monitoring the decrease in dye concentration by UV–Visible absorption spectroscopy. The influence of various parameters such as initial dye concentration, contact time, pH, temperature, and adsorbent dose on the adsorption process was studied. The pseudo-second-order kinetic model and Freundlich isotherm model were found to describe the adsorption process. The thermodynamic study revealed that the adsorption of MB by PPy was feasible, spontaneous, and exothermic process. Investigation of the substrate regeneration revealed that PPy deposited on cotton textile can be reused for dye adsorption several times with good efficiency and it allows for the recovery of MB for recycling purposes.     

Modified cotton fabric with durable anti-fouling performance for separation of surfactant-stabilized oil-in-water emulsions

Membrane applications for the separation of surfactant-stabilized emulsions are often constrained by a deficiency in permeability and anti-fouling properties. Herein, special wetted cotton fabric with a protective layer (P-MH@CF) for durable anti-fouling performance was synthesized by a two-step method, which was related to interfacial ion migration technology and unilateral spraying treatment. Permeability of water and separation performance of P-MH@CF membrane were investigated systematically. Emulsions stabilized by anionic, cationic, or non-ionic surfactant were successfully separated with high efficiency. In the process of separation, the oil droplets surrounded by surfactants were difficult to demulsify and gathered physically on the membrane surface to form a “cream layer”. The stearic acid acted as a protective layer, like a quilt, protecting the membrane from contamination. The membrane retained robust reusability for separation even after the “cream layer” had been washed off, which was promising for the remediation of oily wastewater containing surfactants.

Graphical abstract