In situ loading TiO<Subscript>2</Subscript> and its photocatalysis and UV resistance on cotton fabric

Anatase TiO₂ nanoparticles was in-situ formed on the cotton fabric by using tetrabutyl titanate (TBT) as a precursor through the normal pressure hydrothermal method. X-ray diffraction (XRD), Scanning electron microscopy (SEM), UV visible spectra (UV-VIS), ATR-IR were used as the characterization techniques. Photocatalytic performance of TiO₂ on the fabric surface was evaluated by methylene blue (MB), 4 kinds of the common living stains and three dyes under ultraviolet and visible light radiation. XRD analysis found that the TiO₂ loaded on the fabric was mainly anatase crystalline phase with particle size of 6.4 nm. SEM observed that a large number of nano TiO₂ particles are distributed on the fabric surface. UV-VIS test indicated that theTiO₂-coated fabric possessed an obvious absorption for ultraviolet. ATR-IR analysis indicated that the nano-TiO₂ possesses a strong affinity with the hydroxyl group of the cotton fabric, and the soaping tests showed that the TiO₂ was firmly bonded with the fabrics. The treated fabrics have good degradation ability for MB aqueous solution, and could degrade azo, anthraquinone and phthalocyanine dyes. The order of degradation of the common life stains was: pepper oil> tea > coffee > soy sauce.     

Self-cleaning Properties of Nylon 6 Fabrics Treated with Corona and TiO<Subscript>2</Subscript> Nanoparticles under Both Ultraviolet and Daylight Irradiations

Nylon 6 fabric with self-cleaning properties was prepared by corona discharge pre-treatment and coating with TiO₂ nanoparticles (NPs) using pad-dry-cure technique. The self-cleaning property was studied by discoloration of methylene blue (MB), ketchup, tea and coffee stains from the corona+TiO₂ treated nylon-6 fabric. Color difference (ΔΕ*), reflectance (R) and K/S of MB stain were investigated by diffuse reflectance spectrophotometry. The MB stain was almost completely removed from the corona+TiO₂ treated nylon surface after 24 h under UV light/daylight irradiation. Both of these phenomena (corona and TiO₂) led to an increase in the discoloration of stains under UV and daylight irradiations. The EDS analysis showed an increase in the concentration of deposited TiO₂ NPs coating after corona treatment. The FE-SEM images revealed that the surface of nylon 6 was coarser after the corona treatment. Also, the FE-SEM micrographs exhibited that a uniform layer of TiO₂ NPs was formed on the corona treated nylon fabric. The corona+TiO₂ treated nylon illustrated antibacterial activity against E. coli and B. subtillis microorganisms. The EDS and FE-SEM analysis confirmed that after 5 washing cycles, the amount of TiO₂ NPs was higher on the surface of corona+TiO₂ treated nylon than that of the fabric only treated with TiO₂ without corona pretreatment. This result justifies that the corona+TiO₂ treated nylon fabric with appropriate self-cleaning property can be applied cost-effectively in the textile industry.     

Immobilization of TiO2 nanoparticles on PET fabric modified with silane coupling agent by low temperature hydrothermal method

PET fabric was first modified with silane coupling agent KH-560, and then was loaded with a layer of nano-scaled TiO₂ particles using tetrabutyl titanate as precursor by low temperature hydrothermal method, followed by dyeing with Disperse Blue 56. The morphology, crystalline phase, chemical modification, thermal stability and optical property of PET fiber before and after treatments were studied by scanning electron microscope, X-ray diffraction, X-ray photoelectron spectroscopy, thermal gravimetric and diffuse reflectance spectrum techniques. The properties of tensile, air permeability, luster, ultraviolet (UV) protection, photocatalytic activity, K/S value and color fastness were also measured. It was found that compared with the TiO₂-coated fabric without modification with KH-560, the loading of TiO₂ nanoparticles on the surface of the TiO₂-coated fabric modified with KH-560 was obviously improved. The pure anatase TiO₂ nanoparticle was grafted onto the fiber surface. The onset decomposition temperature increased. The absorbing capability to ultraviolet radiation was enhanced. The properties of tensile, air permeability, luster, K/S value and color fastness changed slightly. The UV protection ability and photodegradation of methyl orange under UV illumination were enhanced to some extent.     

Multifunctional modification of wool fabric using graphene/TiO<Subscript>2</Subscript> nanocomposite

In this study, a new finishing technique is introduced through treatment of wool fabric with graphene/TiO₂ nanocomposite. Graphene oxide/titanium dioxide nanocomposite first applied on the wool fabric by hydrolysis of titanium isopropoxide in graphene oxide suspension and then this coating chemically converted by sodium hydrosulfite to graphene/TiO₂ nanocomposite. The homogenous distribution of the graphene/TiO₂ nanocomposite on the fiber surface was confirmed by field emission scanning electron microscopy (FE-SEM), Energy-dispersive X-ray spectroscopy (EDS) and X-ray mapping. X-ray diffraction patterns proved the presence of titanium dioxide nanoparticles with a crystal size of 127 Å on the treated wool fabric. Also, the defect analysis based on X-ray photoelectron spectroscopy (XPS) established the composition of the nanocomposite. Other characteristics of treated fabrics such as antibacterial activity, photo-catalytic self-cleaning, electrical resistivity, ultraviolet (UV) blocking activity and cytotoxicity were also assessed. The treated wool fabrics possess significant antibacterial activity and photo-catalytic self-cleaning property by degradation of methylene blue under sunlight irradiation. Moreover, this process has no negative effect on cytotoxicity of the treated fabric even reduces electrical resistivity and improves UV blocking activity.     

Development of UV Protective,Superhydrophobic and Antibacterial Textiles Using ZnO and TiO<Subscript>2</Subscript> Nanoparticles

In this research work, multifunctional cotton fabric comprising of UV protection, superhydrophobicity and antibacterial activity has been developed using facile pad-dry-cure method. In the first step, the concentration of repellent chemical has been optimized. Then, formulations containing nanoparticles of ZnO or TiO₂ along with optimized concentration of repellent chemical and organic-inorganic binder have been applied to cotton fabric followed by the evaluation of functional properties. The surface morphology and elemental composition of treated fabric has been characterized through SEM and EDX, respectively. The treated samples have shown promising UV protection, superhydrophobicity and antibacterial properties durable upto 20 washing cycles.     

Nano-TiO<Subscript>2</Subscript> based multilayer film deposition on cotton fabrics for UV-protection

Nano-TiO₂ based multilayer nanocomposite films were fabricated on cationically modified woven cotton fabrics by layer-by-layer molecular self-assembly technique. Cationization process was used to obtain cationic surface charge on cotton fabrics. Attenuated total reflectance Fourier transform infrared spectroscopy analyses were used to verify the presence of cationic surface charge and multilayer films deposited on the fabrics. Scanning electron microscope micrographs of poly(sodium 4-styrene sulfonate)/TiO₂, nano polyurethane/TiO₂, and TiO₂/poly(diallyldimethylammonium chloride) multilayer films deposited on cotton fabrics were taken. With nano-TiO₂ based multilayer film deposition, the protection of cotton fabrics against UV radiation is enhanced. The UV protection durability of the self-assembled multilayer films deposited on the cotton fabrics was analyzed after 10 and 20 washing cycles at 40 °C for 30 min. Air permeability and whiteness value analysis were performed on the untreated and multilayer film deposited cotton fabrics. The effect of layer-by-layer deposition process on tensile strength properties of the warp and weft yarns was determined.     

Preparation of TiO<Subscript>2</Subscript>-coated ZnO Nanoparticles and Their Effect on the UV Absorption of a Poly(vinyl alcohol) Composite Film

Titanium oxide (TiO₂) and zinc oxide (ZnO) composite structured nanoparticles were prepared by combining a sol-gel process and a solvothermal method. Titanium (IV) isoproxide (TTIP), used as a TiO₂ precursor, was dissolved in a colloidal ZnO nanoparticle solution synthesized by the sol-gel method, and TiO₂ was synthesized via solvothermal synthesis onto the ZnO nanoparticles. The effects of reaction conditions such as pH, reaction temperature, and reaction time on the morphology of the composite nanoparticles and the ultraviolet (UV) absorbance of their polymer composite films were investigated. The UV absorption of the poly(vinyl alcohol) (PVA) composite film with TiO₂-coated ZnO nanoparticles was higher than that of the TiO₂, ZnO, and ZnO-coated TiO₂ composite films. The reaction pH was found to have the strongest influence on the UV absorbance of the PVA/(TiO₂/ZnO) composite film. A pH of 7.0, reaction temperature of 250 °C, and reaction time of 24 h were the optimum conditions for UV absorption.     

Modification and Characterization of Nano-TiO<Subscript>2</Subscript> for Efficient Fixation on Cotton Fibers

In this paper, a silane coupling agent, 3-aminopropyltriethoxysilane, was reacted with nano-TiO₂ to introduce amino group onto it which was then reacted with trichlorotriazine to obtain a dichlorotriazine functionalized nano-TiO₂ for the firm fixation of it on cotton fibers. The reaction process was monitored by the titration of primary and secondary amino groups, and the reaction conditions were optimized with orthogonal method accordingly. The dichlorotriazine functionalized nano-TiO₂ was reacted with cotton fabric by the nucleophile substitution reaction to afford nano-TiO₂ functionalized cotton fabric, the structure and surface morphology of the nano-TiO₂ finished cotton fibers were studied by FT-TR and SEM. In addition, the fixation duration of the nano-TiO₂ modified cotton was studied according to AATCC test method 61–2010. The results show that the washing fastness of the nano-TiO₂ is excellent.     

Fabric objective measurement of the plasma-treated cotton fabric subjected to wrinkle-resistant finishing with BTCA and TiO<Subscript>2</Subscript> system

Handle is an important factor when designing the end-uses of fabric as it is also a critical factor for purchasing decision. In the present study, the Kawabata Evaluation System for Fabrics (KES-F) was used for measuring the fabric handle of BTCA-TiO₂ treated cotton fabric with or without plasma pre-treatment. The results revealed that the BTCA-TiO₂ treated cotton fabrics without plasma pre-treatment had a negative effect on tensile, shearing, compressional, and surface properties while the bending properties were improved. On the other hand, the plasma pre-treatment improved the tensile and compressional properties, but not the bending, shearing, and surface properties.     

Preparation of the silk fabric with ultraviolet protection and yellowing resistance using TiO2/La(III) composite nanoparticles

In order to develop ultraviolet protection and yellowing resistance silk fabric, the silk fabric was treated with dispersive TiO₂/La(III) composite solution. The morphology, microstructure, ultraviolet protection and whiteness of the treated silk fabric were characterized by means of transmission electron microscopy, scanning electron microscopy, Fourier transform infrared spectra, X-ray diffraction and ultraviolet transmittance. Furthermore, the mechanism of the ultraviolet protection was investigated. The results show that the TiO₂/La(III) composite particles disperse uniformly. The TiO₂/La(III) particles can not only be treated onto the surface of the silk fabric but also can be treated into the interior of the silk fabric successfully. The result of Fourier transform infrared spectra and X-ray diffraction demonstrates that there are hydrogen bonds between the silk fabric and composite particles, and crystallinity of the treated silk fabric decrease when compares to the untreated silk fabric. The ultraviolet protection factor of the TiO₂/La (III) treated silk fabric is significantly higher than that of the untreated silk fabric. The main ultraviolet shielding effect of TiO₂ treated silk fabric is absorption. The La(III) treated SF has a bad ultraviolet shielding effect, but it has a certain reflection and absorption.     

Development of zero formaldehyde easy care finishing system by using nano titanium dioxide with citric acid and its impact on physical properties

The Performance of nano TiO₂ with citric acid cross-linker was assessed by using pad-dry-cure method on cotton fabric. Significant increase in crease recovery performance was observed which was previously only associated with the lengthy ultraviolet irradiation process. The optimum amount of only 0.1 % nano TiO₂ was needed with the citric acid to exhibit significant increase in easy care performance of the fabric. Typically, application of a cross-linker to cellulosics will impart a deleterious effect on the softness of the fabric; however, incorporation of nano-TiO₂ with the citric acid cross-linker significantly improved the softness of the fabric which was reflected in the mean deviation of coefficient of friction (MMD) and interyarn friction (2HG5) KES-F values. In addition, there was improvement in tensile strength retention of the fabric as well.     

Experimental study on dyeing technical PET yarns having different TiO<Subscript>2</Subscript> contents

TiO₂ contents in yarns can influence color yield so that dyeing quality of industrial poly ethylene terephthalate (PET) yarns can be improved through the adjustment of TiO₂ contents. To evaluate the dyeing performance of color yield, the chips which included the different TiO₂ contents of 330, 550, and 1,100 ppm respectively were used to produce the yarns of different TiO₂ content by a spin-draft machine. The physical and structural properties of the yarns were measured to investigate effect of the TiO₂ contents on them. Dye uptake and dyeing rate were also evaluated using a colorimeter to compare the yarns having different TiO₂ contents. The experimental results showed that there were no appreciable variation in physical and structural properties among the yarn samples and no difference were observed among the dyed fabric samples with regard to dyeing uptake and dyeing rate. However, the color yield of dyed fabrics increased as TiO₂ contents decreased in the yarns especially when the fabric samples were dyed to pale shade. The physical reasoning could be proposed on why the yarns having low TiO₂ contents appeared to have higher color yield after dyeing.     

A study of physical modification on grey cotton by laser irradiation

The surface morphology of the CO₂ laser treated grey cotton fabrics was studied which showed a characteristics sponge-like structure on cotton fibres after treating with CO₂ laser irradiation. The laser treatment parameters ranging from 100 to 150 pixel time and 40 to 70 dot per inch (dpi) were irradiated on the grey cotton fabrics directly and the degree of physical modifications, such as surface morphology, wettability and fabric strength, were changed accordingly with various laser treatment parameters. The surface morphology, wettability and tensile strength of cotton fibre treating with laser were evaluated using different instruments, such as Scanning Electron Microscope (SEM), contact angle meter and tensile strength machine. In spite of creating a sponge-like structure on fibre surface after treating with laser, the wettability of the samples was highly improved but the tensile strength was decreased.     

Durable multifunctional properties on acrylic fabric using nano TiO2 and polysiloxane

Producing fabric with multifunctional properties has been recently a center of research and utilizing nanoparticles is an efficient approach to gain this purpose. Here, nano TiO₂ photo catalyst and polysiloxane softener were utilized as stabilizer on the acrylic fabric to obtain soft handle, hydrophilic, and self-cleaning features on the fabric. The effect of various concentrations of nano TiO₂ and polysiloxane on the fabric handle, water droplet absorption time, and self-cleaning properties of the fabric has been mathematically modeled based on the response surface methodology (RSM). The optimized treatment conditions indicated that treated acrylic fabric with 2.19 % polysiloxane and 0.68 % nano TiO₂ produced the rigidity of 26.8 g.cm, water absorption time of 15.8 s and self-cleaning of ΔE _T *=18.1. Also increasing the concentration of polysiloxane enhanced both wettability and photoactive properties of nano TiO₂ treated acrylic fabrics. Further, the nano TiO₂/polysiloxane treated acrylic fabrics is significantly enable to absorb the light with wavelength lower than 400 nm and improve discoloration of C.I. Reactive Yellow 1.     

Effect of UV irradiation on cellulase degradation of cellulose acetate containing TiO<Subscript>2</Subscript>

Cellulose acetate (CA) films containing anatase type titanium dioxide (TiO₂) nanoparticles were prepared by solution casting. The film surface was modified by UV irradiation using a grid type UV irradiator. The UV irradiation caused slight increase in photodegradation of the CA films with TiO₂ compared to the CA film alone. However, CA films irrespective of TiO₂ content did not show a significant enzymatic degradation by a cellulase fromAspergillus niger without UV irradiation. Upon UV irradiation, the biodegradability remarkably improved even in the CA film without TiO₂. The irradiation of CA films decreased both the water contact angle and the degree of substitution (DS) implying the decrease in acetyl groups of the CA film surface due to the photo-scission of the acetyl group and photooxidation, resulting in more facile biodegradation of the surface film layer. The substantial enhancement in biodegradation of the UV irradiated CA film containing TiO₂ was attributed to the increased hydrophilicity, lowered DS and zeta potential due to the photoscission and the photooxidation effect of UV light. Also the increased surface area of the CA film due to the photocatalysis of TiO₂ particles may encourage the facile biodegradation.     

Preparation of electroconductive,magnetic, antibacterial,and ultraviolet-blocking cotton fabric using reduced graphene oxide nanosheets and magnetite nanoparticles

The main goal of present study was the fabrication of cotton fabric with special functions, including electrical conductivity, magnetic, antibacterial, and ultraviolet (UV) blocking. In this regard, the cotton fabric was primarily coated with graphene oxide and then reduction of graphene oxide and synthesis of magnetite nanoparticles accomplished in one step. The alkaline hydrolysis of magnetite precursors and reduction of graphene oxide was simultaneously performed using sodium hydroxide to produce reduced graphene oxide/Fe₃O₄ nanocomposite on the fabric surface. The prepared cotton fabrics were characterized with field emission scanning electron microscope (FE-SEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). The treated fabrics with reduced graphene oxide/Fe₃O₄ nanocomposite displayed a low electrical resistivity i.e. 80 kΩ/sq. Furthermore, the coated fabrics showed reasonable magnetic properties due to the presence of magnetite nanoparticles on the surface of cotton fabrics. Moreover, this process imparted proper antibacterial properties and UV blocking activity to cotton samples.     

Spherical Bacterial Cellulose/TiO<Subscript>2</Subscript> Nanocomposite with Potential Application in Contaminants Removal from Wastewater by Photocatalysis

Contaminants are often found in aquatic environments, for instance, heavy metals, dyes, parasites, pesticides, hormones and pharmaceuticals. Therefore, large amounts of these contaminants reaches wastewater via industrial and domestic effluents, causing major concern to human health. Heterogeneous photocatalysis is a technique for removing these contaminants in order to achieve better efficiency in water treatment. Then, bacterial cellulose (BC) produced in an agitated culture can form spherical bodies composed of nanofibers with high specific surface area. Moreover, Titanium dioxide (TiO₂) is a semiconductor containing high photocatalytic activity capacity. Thus, the main objective in this work was to produce spherical BC/TiO₂ nanocomposites for contaminants removal from wastewater by photocatalysis process. The incorporation of TiO₂ nanoparticles in the spherical BC matrix was performed by ex situ and in situ methods. In addition, Scanning Electron Microscope (SEM), Energy Dispersive Spectroscopy (EDS), Fourier Transform Infrared Spectroscopy (FTIR) and Thermogravimetric Analysis (TGA) were used as tools of morphological, chemical and thermal characterizations of the nanocomposites. Besides, photocatalysis tests were performed in order to evaluate the removal efficiency of methylene blue from aqueous solutions. The results of these tests exhibited a percentage of methylene blue removal of 70.83 and 89.58 % after 35 minutes for spherical BC/TiO₂ nanocomposites both, in situ and ex situ, respectively. Therefore, these results demonstrated that BC/TiO₂ to be a low cost material with high capacity of contaminants removing and a great potential for industrial applications.     

Polyaniline-doped TiO<Subscript>2</Subscript>/PLLA fibers with enhanced visible-light photocatalytic degradation performance

A simple and practical strategy has been developed for preparing polyaniline(PANi)-doped TiO₂/poly(l-lactide) (P@TiP-C) fibers by a combination of coaxial-electrospinning and in-situ polymerization. The TiO₂/PLLA composite fibers with TiO₂ located on the surface were fabricated by coaxial-electrospinning, with PLLA as the core phase and a dispersion of TiO₂ particles, a well-known photocatalyst, in the sheath phase. The aniline monomers were also located in the core phase and in-situ polymerized by ammonium persulfate (APS) after electrospinning. SEM images show that TiO₂ particles were located on the surface of PLLA fibers. Photocatalytic degradation tests show that the P@TiP-C fibers exhibit enhanced photocatalytic activity for degradation of methyl orange under visible light, likely due to the synergistic effect of PANi and TiO₂.     

Developing UV-protective cotton fabric based on SiO<Subscript>x</Subscript> nanoparticles

Nano-SiO_x suspension was prepared for its unique optical performance to improve the anti-ultraviolet property of cotton fabric in this paper. The experimental results showed that UV-resistance property of thus treated fabrics had been enhanced significantly. The spectrum of absorption, reflection, and transmittance of the treated fabric was analyzed during the optimized processing. The mechanical property of the treated fabric displayed a little increase compared with the original untreated fabric. The morphology of the treated fabric was studied by SEM. The UPF (Ultraviolet Protection Factor) of the fabric treated with nano-SiO_x suspension reached 62, much higher than that of the original untreated fabric. Moreover, after 50 home launderings, the UV-blocking property of treated fabric changed little due to the strong affinity between the nano-SiO_x particles and cotton fiber.     

Hard Surface-adhesive Properties of TiO<Subscript>2</Subscript> Nanoparticles-encapsulated Microparticles Prepared by Spray Drying and Surface Coating Method

The aim of this study is to compare hard surface-adhesive properties of TiO₂ nanoparticles (TNPs)-encapsulated microparticles prepared by spray drying and surface coating method. Thus, TNPs were encapsulated with chitosan by spray drying and poly(L-lysine) by surface coating method, which were selected as positively charged materials. And then, the TNPs-encapsulated microparticles were investigated by particle surface properties and adhesion properties on hydroxyapatite (HAP) surface as model for hard surface-adhesion. The characteristics of TNPs-encapsulated Chitosan microcapsules (CM) and TiO₂ nanoparticles coated with cationic poly(L-lysine) polymer (TNPs-PLL) were determined with scanning electron microscope (SEM) image and zeta-potentials. The hard surface-adhesive properties on HAP surface were confirmed with SEM and whitening test. The zeta-potentials of TNPs and HAP were negative, -13 mV and -18 mV respectively, while TNPsencapsulated CM, and TNPs-PLL of positively charged polymers were positive, 13 mV and 57 mV respectively. Whitening test was carried out on model surface when shaking the samples. TNPs-PLL were adhered to HAP surface very much more than those of TNPs-encapsulated CM. Also, the change value of whiteness of the HAP surface treated with TNPs-PLL is large evidently, compared with TNPs-encapsulated CM.