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.     

A Novel Green Stabilization of TiO<Subscript>2</Subscript> Nanoparticles onto Cotton

Facile embedding of TiO₂ nanoparticles onto cotton fabric has been successfully attained by ultraviolet light irradiations. The adhesion of nanoparticles with fibre surface, tensile behaviour and physicochemical changes before and after ultraviolet treatment were investigated by scanning electron microscopy, energy dispersive X-ray and inductive couple plasma-atomic emission spectroscopy. Experimental variables i.e. dosage of TiO₂ nanoparticles, temperature of the system and time of ultraviolet irradiations were optimised by central composite design and response surface methodology. Moreover, two different mathematical models were developed for incorporated TiO₂ onto cotton and tensile strength of cotton after ultraviolet treatment and used further to testify the obtained results. Self-clean fabric through a synergistic combination of cotton with highly photo active TiO₂ nanoparticles was produced. Stability against ultraviolet irradiations and self-cleaning properties of the produced fabric were evaluated.     

Preparation and property of TiO2/SiO2 multilayer film on the fabric by sol-gel process

The high light reflection of multilayer TiO₂/SiO₂ film was prepared on the fabric by the sol-gel process. The size of titania and silica particles in hydrosol was analyzed by Nanosizer, and the morphology of TiO₂/SiO₂ multilayer film on the fabric was characterized by SEM. The reflection spectra of the samples were tested accordingly, and it showed that the reflection of the fabric coated by multilayer film was higher than that of the monolayer film. Moreover, the reflection increased with the increase of layer number. For sunlight fastness testing, the fabric color changed less with the increase of layer number, which showed the multilayer film on the fabric can improve the light resistance of the fabric. The mechanical property, the bending property and air permeability testing results showed that there was little change for the coated fabric compared with the original fabric.     

Bioactive and multifunctional textile using plant-based madder dye: Characterization of UV protection ability and antibacterial activity

In the present work the natural madder dye (Rubia tinctorum L.) was applied to the simultaneous dyeing and functionalization of polyester (PET) fabric. In the first part of the study the color performance and the durability were revealed for exhaustion dyed fabric. The dyed fabric was then characterized with respect to ultraviolet (UV) protection ability and antibacterial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). CIELab color coordinates, namely the positive a* and b* values, confirmed a yellow/orange color of the dyed fabric. From durability tests, the color showed a moderate to good light fastness and good to excellent fastness to washing and rubbing. The madder dye improved both the UV protective performance and the antibacterial activity of the fabric. With 3 % on weight of fiber (owf) the UV protection factor increased up to 106, and the antibacterial activity up to 86 % against both types of bacteria tested.     

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.     

Investigation on the effect of titanium dioxide nano particles on camouflage properties of cotton fabrics

Cotton fabrics were dyed with three commercial vat dyes in order to provide camouflage in Vis-NIR regions and imitate reflectance profile of greenish leaves. To investigate the effect of nano particles on camouflage properties of dyed fabric, nano particles of TiO₂ were applied on dyed fabrics using pad-dry-cure method. The nano TiO₂ padded dyed fabrics were investigated using scanning electron microscopy (SEM). Reflectance curves of coated dyed samples with different concentrations of nano TiO₂ were measured. Results showed that in both of the standard shades, nano TiO₂ increases the reflectance value in NIR region and with increasing the concentration of nano TiO₂, the reflectance curves of samples tend to show the maximum reflection of greenish leaves (deciduous leaves) in NIR region. Chromatic values (CIE1976 L*, a*, and b*) and color difference (according to CIECMC color difference ΔE*cmc (2:1)) of each of the coated samples were measured using the reflection spectrophotometer. By considering the influence of white color of nano TiO₂ on green shade of dyed cotton fabrics and increasing the color difference (between coated samples and the standard shades of the 1948 U.S army pattern) in visible range, optimum concentrations of nano TiO₂ for development of camouflage properties on cotton fabrics in both NIR and visible region were determined. These values for NATO and forest green shades were 0.75 % and 0.5 %, respectively. Fastness results showed that both of the samples have acceptable color fastness. The effect of washing and exposure to light on camouflage properties of coated dyed fabrics in visible (in term of chromatic values) and NIR region (in term of spectral reflectance) was investigated when those were coated in optimum concentrations of nano TiO₂. The results showed that the effect of after treatments (washing and exposure to light) on surface color spectral characteristics and camouflage properties was inconsiderable.     

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.     

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.     

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.     

Properties of basic dyes on polyacrylonitrile treated m-aramid fabrics

Treatment of polyacrylonitrile (PAN) onto m-aramid fabric was carried out by pad-dry-cure method using dimethylformamide (DMF) dissolved acrylic fiber solution. The obtained PAN treated m-aramid fabric was dyed using exhaustion method with basic dyes. The effect of PAN treatment on fabric stiffness property was acceptable with acrylic fiber solutions ranging from 1 wt% to 4 wt%. Whilst, more than 4 wt% PAN treated fabrics exhibited undesirable stiffness. The dyeing results showed that PAN treated m-aramid fabrics exhibited a significant increase in color strength when compared to untreated fabric, arising from an increase in anionic dye sites (styrene SO₃ ^? group). Wash fastness was comparable to that of untreated fabric, indicating the strong interaction between dye molecules and the PAN. Rubbing fastness of treated fabrics was not affected by treatments with PAN concentrations lower than 4 wt%. Further increase in PAN concentration led to poorer rubbing fastness property due to the problem of surface dyeing. For light fastness, the PAN treatment failed to improve the light fastness property which is the main disadvantage of basic dyeing of aramid fabric. Finally, in case of PAN treatments with the range of 1 wt% to 4 wt%, the flame retardancy property of PAN treated m-aramid fabrics was found not affected by the percent add-on. However, above 4 wt% PAN treatment, the flame retardancy performance became deteriorated.     

Transfer printing with disperse dyes on cotton fabric modified with an aqueous tolylene diisocyanate derivative

Transfer printing with disperse dyes on cotton fabric modified with an aqueous tolylene diisocyanate derivative (TDD) was discussed in this paper. The effect of the degree of substitution (DS) on color strength (K/S value) of the modified and transfer printed fabric was investigated. The DS of the cotton fabric increased with increases in TDD concentration and curing temperature and time, while the sample whiteness decreased with the increasing curing temperature and time. And the change of structure of the modified cotton fabric was characterized by FT-IR spectra, DSC curves, and SEM images. All of the factors, such as the concentration and molecular weight of poly(ethylene glycol), the DS of the modified fabric, the transfer printing temperature and time would affect the K/S value of the sample. After transfer printing with disperse dye, the K/S value and printing fastness of TDD-modified cotton fabric were higher than those of cotton control fabric, the change of chromatic difference was not obvious, but the tensile strength of the modified fabric was lower than that of original cotton.     

Natural dyeing of cotton with <Emphasis Type="Italic">Xylocarpus granatum</Emphasis> bark extract: Dyeing,fastness, and ultraviolet protection properties

In this research we investigated the dyeing of cotton fabrics with extracts of Xylocarpus granatum, a mangrove plant with a long history of use in leather tanning and textile dyeing. X. granatum bark was extracted and spray-dried, yielding a tannin-rich, reddish-brown powder. This powder proved a suitable colorant for the natural dyeing of cotton with promising color fastness properties to wet treatments (washing, water, sea water, and perspiration), hot pressing, crocking, and light exposure. However, the dye alone produced only weak levels of coloration and therefore metallic salt mordants were employed to improve the color strength, through the formation of insoluble tannate complexes. The resulting fabric K/S values were dependent on the mordant used and exhibited the following trend: ferric sulfate > sodium dichromate > copper sulfate > potassium aluminum sulfate > no mordant, for fabrics exposed to mordants before and after dyeing. Mordanting resulted in slight variations in shade and color fastness. In most cases, the color fastness properties were preserved, except for color fastness to light and hot pressing, for which lowered ratings were found for some mordants. Stiffness and mechanical performance were not greatly affected by dyeing or mordanting, except for sodium dichromate mordanting which significantly stiffened and weakened the fabric. The ultraviolet protection factor (UPF) of all the dyed samples achieved the maximum (50+) level, highlighting the excellent UV shielding properties of the fabric. Overall, X. granatum bark extract is a promising, effective colorant for the natural dyeing of cotton in terms of appearance, fastness, and physical characteristics.     

Improvement of ink-jet printing performances using β-cyclodextrin forming inclusion complex on cotton fabric

Cotton fabric was modified with β-cyclodextrin (β-CD) forming inclusion complex to yield color strength, pattern sharpness, and color fastness for ink-jet printing. The modified cotton fabric was confirmed with the presence of new strong absorption peaks around 1713 cm^-1 and 1243 cm^-1 in FT-IR. β-CD had been covalently grafted on cotton fabric via the esterification reaction of citric acid (CTR) with cellulose and β-CD. The results indicated that printing performances of the ink-jet printed fabric were enhanced through β-CD modification. The K/S value was enhanced from 4.21 to 6.72, the width of printed line was decreased from 1.48 mm to 1.25 mm, and the color fastness was improved to 3-4 level. These improvements were due to the truncated cone structure of β-CD, which can form inclusions with water-based pigment. Meanwhile, the crease recovery performance was also improved with the aid of CTR. A comparison between the unmodified and modified cotton fabric suggested that the crease recovery angle of β-CD modified cotton fabric was increased by 25.0 % in the warp direction. Therefore, printing performance and crease recovery performance of β-CD modified and water-based pigment printed cotton fabric were enhanced remarkably.     

Union dyeing of the photografted PET/wool blend fabrics with dimethylaminopropyl methacrylamide

Dimethylaminopropyl methacrylamide (DMAPMA) was grafted onto PET/wool blend fabrics by continuous UV irradiation. Union dyeing of the photografted fabrics was investigated using three reactive dyes of α-bromoacrylamide reactive groups. The influence of grafting yield, DMAPMA concentration, NaCl amount, pH value, and dyeing temperature on the dyeability was evaluated. The dyeability of both PET and wool components was improved significantly by the DMAPMA photografting and successive reactive dyeing. Although the dyeability of the PET component in the blend substantially was improved with higher grafting, equal dyeability between PET and wool was difficult to achieve due to more facile grafting and higher reactivity of the wool component compared with the modified PET component. However, the color fastness of the PET/wool blend fabric was excellent for all three colors. This study may offer a way to achieve union dyeing of PET/wool blend fabrics.     

Application of <Emphasis Type="Italic">Sterculia Foetida</Emphasis> Fruit Shell Waste Biomolecules on Silk for Aesthetic and Wellness Properties

There has been growing interest in the use of bioresource waste for natural dyeing and finishing. This paper discusses dye extraction from the novel source fruit shell waste of Sterculia foetida and its application on mulberry silk fabric to confer aesthetic coloration and wellness properties such as ultra-violet (UV) protection and antibacterial properties. Treated fabrics showed a substantial increase in color depth and adequate wash, light, and rubbing fastness properties for dyed silk fabrics with and without mordanting. Pre-and post-mordanting of silk fabrics were carried out using mordants such as alum, harda (myrobalan), and copper sulfate. UV-visible spectrophotometric analysis of fruit shell extract (FSE) at different pHs and FSE with three different mordants at neutral pH was used to understand the phenomena of dye-fiber interaction. The treated fabrics characterised by ATR-FTIR, SEM-EDS, and XRD analysis indicate the nature of dye fiber interaction justifying the multifunctional properties. The treated fabric also showed very good ultraviolet protection property and antibacterial properties both against S. aureus and E. coli bacteria even after ten washes. The results indicate that Sterculia foetida fruit shell extract offers an excellent potential as coloration, antibacterial, and ultraviolet protective agent for mulberry silk fabric.     

Structural Transformation and Dyeing Performance of Poly(Ethylene Terephthalate) Filament Using Dicationic Imidazolium Ionic Liquid

3,3'-[1,2-ethanediylbis (oxy-2,1-ethanediyl)]-bis[1-methyl-imidazolium]-dibromide (DImDBr), a gemini imidazolium ionic liquid, was synthesized for the modification and dyeing promotion of poly(ethylene terephthalate) (PET) filaments. The results showed that parameters such as treatment temperature, time, and DImDBr concentration played a critical role on the tensile strength and tensile strength retention of modified PET filaments. The optimal treatment parameters of the PET filaments were 120 °C for 90 min with addition of 6 % ionic liquid. The influence of disperse dyeing parameters (temperature, time, and dye concentration) on DImDBr modified PET filaments were also studied. The disperse dyed PET filaments (after treatment with DImDBr) exhibited a desirable color strength (K/S value), excellent soap washing fastness, light fastness, and rubbing fastness. Furthermore, the native PET filaments and DImDBr treated PET filaments were characterized by FT-IR, XRD, DSC, TGA, and SEM. Density functional theory (DFT) simulation showed the presence of two kinds of hydrogen bonds (C-H/O and O-H/Br) and eight strong hydrogen bonds in the DImDBr/cis-PET monomers, while only three hydrogen bonds were found in the DImDBr/trans-PET monomers. The structural transformation from the crystalline phase to the amorphous phase (FT-IR, XRD, and DFT simulation) after DImDBr modification confirmed the dyeing promotion of PET filaments at lower temperature.     

Study on the natural dyeing of wool modified with enzyme

In this study, the natural pigment from sappan was used for the dyeing of wool fabrics after treatment with the protease and transglutaminase. The influences of protease and transglutaminase on the UV/visible absorption spectrum of aqueous extract of sappan were studied. The enzymatic modified wool was compared with non-modified wool in K/S value and fastness after direct dyeing and mordant dyeing. It was shown that protease and transglutaminase made the absorbance at the λ _max 540 nm in visible region increase. It suggested that there might be some interaction between the enzymes and sappan dye and the residual enzyme on wool fabric might affect the color of following dyeing. Compared to untreated wool, treatments with protease and transglutaminase enhance K/S value of wool dyed subsequently with sappan. Modification of protease led to some decrease in wet rubbing fastness, whereas transglutaminase had almost no influence on rubbing fastness. Enzymatic treatments have no influence on the washing fastness for samples dyed with sappan.     

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.     

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.