Functional processing of PET fabrics using boehmite/silica/thiazole dye hybrid materials

A series of hybrid materials composed of boehmite/silica/thiazole dyes and prepared via the sol-gel process is synthesized from aluminum isopropoxide (AIP) and tetraethoxysilane using heteroaryl 2-amino-thiazole azo dyes. Heterocyclic 2-amino-thiazole azo dyes undergo a hydrolysis-condensation reaction with an appropriate proportion of AIP under a catalyst, at a constant ratio of vinyltriethoxysilane (VTES) and tetraethoxysilane (TEOS). The structures of these hybrid materials composed of boehmite/silica/thiazole dyes are characterized using Fourier transform infrared (FT-IR) analysis. The surface morphology of polyethylene terephthalate (PET) fabrics is evaluated using scanning electron microscopy (SEM). SEM images show uniform dyeing of the PET fabrics that confirms the reaction of the hybrid materials with the PET fabrics. The water contact angle, washing fastness, color evenness, air permeability, and warmth retention of the PET fabrics dyed with hybrid materials composed of boehmite/silica/thiazole dyes are evaluated. The evaluation results indicate improved warmth retention property and good water repellency.     

Fabrication of novel multifunctional hybrid materials for PET/PA6 nonwoven fabrics finishing

A series of some novel hybrid materials prepared via a sol-gel process have been synthesized from methyltrimethoxysilane and titanium n-butoxide with heterocyclic thiazole azo dyes. Silica/titania/thiazole azo dyes hybrid materials were synthesized via a sol-gel process with a precursor system. Alternatively, the heterocyclic thiazole azo dyes were catalytically processed by means of hydrolysis-condensation reactions with appropriate amounts of a mixture of vinyltriethoxysilane, methyltrimethoxysilane, and titanium n-butoxide at a fixed molar ratio. The structure of these hybrid silica/titania/thiazole dye materials was characterized by Fourier transform infrared (FT-IR) analysis. The surface morphology of processed PET/PA6 nonwoven fabrics was evaluated by scanning electron microscopy (SEM). SEM images showed uniform dyeing, thereby confirming the reaction of the hybrid materials with the PET/PA6 nonwoven fabrics. The water contact angle, washing fastness, color evenness, air permeability, and weatherability characteristics of the as-prepared dyed PET/PA6 nonwoven fabrics were subsequently evaluated. Results revealed improved weatherability and good water repellency. Further, it was also revealed that dyeing and finishing could be achieved in a single bath, which is advantageous to reduce processing costs.     

Performance of PTT fabric treated with CNTs/SiO<Subscript>2</Subscript>/thiazole dye hybrid materials

A series of CNTs/SiO₂/thiazole dye hybrid materials prepared via the sol-gel process is synthesized from carbon nanotubes (CNTs) and tetraethoxysilane with heteroaryl 4-phenyl-2-amino-thiazole dyes. Heterocyclic 4-phenyl-2-aminothiazole dyes are processed with the hydrolysis-condensation reaction at a constant ratio of vinyltriethoxysilane and tetraethoxysilane condensed with modified CNTs in appropriate proportion under a catalyst. The structures of the CNTs/SiO₂/thiazole dye hybrid materials are characterized by Fourier transform infrared spectroscopy (FTIR). Polytrimethylene terephthalate (PTT) fabrics are used to evaluate the morphology structure by scanning electron microscopy (SEM). SEM images show that a uniform dyeing on the PTT fabrics to confirm the reaction of hybrid materials with PTT fabrics. The washing fastness, color evenness, water contact angle, air permeability, electric conductivity, and weatherability of PTT fabrics dyed with CNTs/SiO₂/thiazole dye hybrid materials are evaluated, with results indicating improved conductivity and water-repellent.     

Thermal Insulation Performance of Cotton and PET-based Hybrid Fabrics Impregnated with Silica Aerogel via a Facile Dip-dry Process

We report the morphological features and thermal insulation properties of a series of cotton- and PET-based hybrid fabrics impregnated with silica aerogel. For the purpose, commercially available cotton and PET knitted fabrics were dipped into aqueous dispersions including different silica aerogel contents, dried, and stacked to 1, 3, and 5 layers. The SEM images revealed that the silica aerogel particles were well incorporated into cotton or PET knitted fabrics. The thermal insulating performance of the hybrid fabrics as functions of the silica aerogel content and the number of layers of stacked fabrics were characterized by monitoring the surface temperatures of the fabrics on a plate with a wide temperature range of ~50-80 oC using an infrared camera. The higher thermal insulation performance was attained for both cotton- and PET-based hybrid fabrics with higher silica aerogel contents. In addition, 3-layered hybrid fabrics exhibited noticeably improved thermal insulation performance, compared to 1- or 5-layered fabrics. The thermal insulation property of the cotton-based hybrid fabrics was dominantly influenced by silica aerogel than that of PET-based hybrid fabrics. The overall results demonstrated that the cotton- and PET-based hybrid fabrics with silica aerogel manufactured by a facile dip-dry process could be utilized as protective garments, heat-sensitive devices, pipes, automotive, aircrafts, and buildings for thermal insulation applications.     

Plasma-assisted surface modification of polyester fabric for developing halochromic properties

In the field of textiles, introducing pH-sensitive dyes onto fibrous materials is a promising approach for the development of flexible sensor. In this study, poly(ethylene terephthalate) (PET) textile surface with halochromic properties was fabricated by plasma-assisted sol-gel coating, followed by immobilization of two different azo pH-indicator dyes; namely Brilliant yellow and Congo red by conventional printing technique of fabrics. 3-aminopropyltriethoxysilane (APTES) was used as a coupling agent for attaching the pH-sensitive dyes through its terminal amines. The surface immobilization of APTES on PET fabric was conducted by the pad-dry-cure method. Moreover, the influence of oxygen plasma pre-treatment and the method of post-treatment either by oxygen plasma or by thermal treatment on the stability of sol-gel based matrix was investigated. The morphology and chemistry of 3-aminopropyltriethoxysilane coated PET surfaces were examined by using surface sensitive methods including electrokinetic and time-dependent contact angle measurements as well as X-ray photoelectron spectroscopy (XPS). In addition, fastness tests of the printed fabrics and color strength were carried out to assess the effectiveness of the fabric surface modification. Results indicate that sol-gel matrix exhibited a more stability by thermal post-treatment at 150 C for 5 min. Also, the results revealed that the printed fabrics with halochromic properties demonstrated sufficient stability against leaching by washing. The current work opens up a novel opportunity to develop flexible sensors based on fibrous materials, which have the potential to be employed in variable industrial applications.     

Dyeing performance of the azo dyes containing trifluoromethyl group for polyester fabrics and its single crystal structure

The structures of disperse dyes and their intermolecular interactions have important impacts on dyeing and printing performances for polyester fabrics. The fluorine dyes show some unique molecular stability and photochemical properties. The dyeing property of the azo dye containing trifluoromethyl group for polyester fabrics, 4'-(N-acetoxyethyl-Nethyl)- amino-2-bromine-4-nitro-6-trifluoromethylazo- benzene (D1), was investigated and compared with the similar structure disperse dye. The results show that the high color yield and good exhaustion of the dyed PET fabrics could be obtained. The polyester fabrics dyed with D1 had excellent light fastness. Its single crystal was prepared and the supramolecular interactions were solved by X-ray diffraction. Dye D1 formed triclinic crystals in a trimeric packing mode. The C-F bond distances of CF3 are 1.2730 Å, 1.2240 Å and 1.2900 Å, respectively. The two benzene rings linked azo unit (-N=N-) are obviously twist. The dihedral angle of the two benzene rings is 50.23 o. There are six weak hydrogen bonds around trifluoromethyl group in the intramolecule and intermolecule. The excellent light stability of the dye should be attributed to its unique supramolecular structure.     

Preparation and flammability properties of hybrid materials containing phosphorous compounds via sol-gel process

Organic-inorganic hybrid coatings containing phosphoric acid (PA) bonded to the organic-inorganic network were prepared from tetraethoxysilane (TEOS) using a sol-gel process. The effect of sol-gel phosphate-based flame retardant coating on polyacrylonitrile fabric properties (flammability, stiffness, and strength) was investigated. Sample characterization of the coated samples were investigated using differential thermal/thermogravimetric analysis (DTA/TGA), Fourier transform infrared spectroscopy (FTIR), X-ray diffractometer (XRD), and scanning electron microscopy (SEM). The results showed that hybrid coating on the polyacrylonitrile fabrics influenced fabric stiffness, strength, and flammability. And also, flammability of the coated samples after washing cycles was investigated, and the flame retardancy properties of the samples after 10 repeated washings were not completely lost.     

Dyeing, color fastness and antimicrobial properties of some mono and disazo disperse dyes derived from thiazole moiety

Three series of mono and disazo disperse dyes were synthesized from 2-amino-4-(pyridin-3-yl) thiazole. The structure of the synthesized dyes was confirmed by elemental analysis, ultraviolet-visible, infrared, proton and carbon nuclear magnetic resonance and mass spectroscopy. The dyeing parameters, perspiration, wash and light fastness of eighteen azo disperse dyes on polyester have been investigated. Application of these dyes on polyester fabric gave yellow to reddish hues for mono azo derivatives and reddish to dark brown hues for disazo derivatives with fair to moderate light fastness and moderate to good wash and perspiration fastness grade. In addition, the synthesized dyes were screened for their antimicrobial activities against some gram positive, gram negative bacteria and fungi. Some of the prepared dyes gave excellent results against most of the tested organisms.     

Dyeing properties of nylon,PET, and N/P mixture fabric with reactive-disperse dyes having a sulfatoethylsulfone group

The dyeing and color fastness properties of two reactive-disperse dyes containing a sulfatoethylsulfone group on nylon, PET and N/P mixture fabrics were examined. The rate of dyeing on nylon fabric was greatly dependent upon dye bath pH. The final dye uptakes at all pH, however, were as high as 97 %. Color strength of the dyed nylon fabric linearly increased up to 0.5 %owf and then slowed down over 1 %owf dyeing. Washing and rubbing fastness of the dyed nylon fabric were excellent, but grade of light fastness was moderate. Dyeability of the reactive-disperse dyes on PET fabric was not much affected by pH, and K/S values of PET fabric dyed at pH 5–8 were lower than those of nylon fabric at all pH examined. Buildup and color fastnesses properties on PET fabric showed the same tendency with nylon fabric. The rate of dyeing of the reactive-disperse dyes on nylon fabric was faster than on PET fabric when both fabrics were dyed simultaneously in the same dye pot, resulting in higher color strength of nylon than PET. The reactive-disperse dyes were found to be adequate to the one-bath, one-step dyeing of N/P mixture fabric when applied at pH 5 and 120 °C.     

Hydrophilic modification of PET fabric via continuous photografting of acrylic acid (AA) and hydroxyethyl methacrylate (HEMA)

Poly(acrylic acid) and poly(hydroxyethyl methacrylate) were introduced onto PET fabrics by UV-induced photografting to improve its hydrophilicity. Several factors affecting the photografting were studied including irradiation energy, monomer, and photoinitiator (PI) concentrations. ATR and ESCA analyses proved successful grafting of the two monomers onto PET. Morphology of fabric surface was examined using FE-SEM. Both zeta potential and water wetting time of the grafted PET fabrics decreased with increasing grafting yield. Also cationic dyeability of the grafted PET fabrics increased because of the increased electrostatic interactions between the anionic dyeing sites and cationic dyes.     

High Sensitive CNT Imbedded Knit Fabrics for Heat Comfort

The functional improvement and high sensitivity of textiles should be combined with advanced technology and aesthetic of environmental sustainability to cope with the ever-changing environment. In this study, the physical properties of a shaggy double knit of carbon nanotube (CNT) and ceramic composite thermal yarn (TYn) with napping and shaggy finished textiles were investigated to achieve high sensitivity and comfortable heat retention. The surface properties of the shaggy double knit were investigated by scanning electron microscopy (SEM), the mechanical properties by the Kawabata Evaluation System (KES) and the elements of the CNT composite yarn by energy dispersive X-ray spectroscopy (EDX). Experiments on the heat retention of the shaggy double knit were conducted to determine the warmth retention, thermal resistance by Clo value, and surface temperature compared with those of regular polyester (PET) and PET/TYn/polyurethane (PU). Comfort properties determined by measuring the water vapor permeability (WVP) and air permeability demonstrated that the double knit can be used to produce comfortable garments. Durability was confirmed by measuring the warmth retention, Qmax, and the washing fastness was analyzed by the satisfactory maintenance of the physical appearance. The farinfrared (FIR) emissivity properties of PET/TYn/PU contributed to its enhanced performance, but it is necessary to ensure that the effect is stable. The results obtained in this study demonstrate that shaggy double knit with insulation composite yarn can be used in high sensitivity fashion clothing due to its improved and comfortable heat retention properties, and further advanced research is expected to be performed in this field.     

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.     

Study of moisture and thermal transfer properties as a function of the fiber material variation

The properties of moisture transfer and the comfort of mesh-structured fabrics with various knit compositions and properties were investigated. The comfort effects of the double knitted fabrics combined with different cross-shaped fibers composed of dyeable-polypropylene (PPd) and regular polyester (PET) double-knitted fabrics were studied. A series of PET, PPd, Coolmax^® (Cm) with single knitted fabrics and PPd/Cm with double knitted fabrics were evaluated to determine the physical properties and wearing performance for comfortable clothing. To compare the structural properties involving the vapor transfer of 4 types of fabrics with different fiber compositions, fiber types, weights, and thicknesses, the surface structure and pore characteristics were evaluated by scanning electron microscopy and a capillary flow porometer. The properties of moisture transfer were tested using vertical wicking and gravimetric absorbent testing system (GATS). In addition, the comfort performance measured by the thermal insulation value (Rt) and moisture permeability index (im) with a thermal manikin in a conditioned walk-in environmental test chamber was predicted. The result showed that the PPd/Cm sample has potential applications as good comfort fabric materials.     

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.     

Lipase treatment of polyester fabrics

The aim of this paper is to improve moisture regain of PET fabrics using a lipase treatment. Effects of nine lipase sources, lipase activator and nonionic surfactant on moisture regain of PET fabrics are examined. Moisture regains of lipase-treated samples improve by two times in average compared with untreated and buffer-treated samples. Alkaline treatment creates larger pitting by more aggressive attack into fiber which is proved by SEM and water contact angle measurement. Moisture regain by alkaline treatment (0.568 % ± 0.08) does not improve. However, lipase-treatment (L2 treatment) improves moisture regain up to 2.4 times (1.272 % ± 0.05). Although lipase treatment is more moderate than alkaline treatment, lipase hydrolysis on PET fabrics improves moisture regain, efficiently. K/S values improved confirm that carboxyl and hydroxyl groups are produced on the surface of PET fabrics by lipase hydrolysis. Moisture regain and dyeability improve by lipase hydrolysis on PET fabrics.     

Dyeing of synthetic fabrics in water using azoic dyes based on boronic acid derivatives

Development of water-soluble dyes for the dyeing of different textile fabrics is essential for the textile industry due to ecological and economical reasons. In this study, a series of new azoic dyes were prepared by diazotization reaction between the phenyl boronic acid and different aniline derivatives, and their dyeing capacity in aqueous solution was evaluated. The synthesized boronic azo dyes present good water solubility and can dye polyamide (nylon), wool, silk, and cellulose acetate fabrics. The effect of factors such as concentration of dye, dyeing temperature, and pH on the level of color strength (K/S) was studied. The dyeing results showed that higher color strength K/S (about 16) and fastness properties (about 4/5) with boronic acid dyes were achieved at higher temperatures avoiding the use of surface agents, mordants, and other polluting chemical additives.     

Dyeing properties of the disperse dyes containing cyano group based on benzisothiazole for polyester fabrics under alkali condition

One step dyeing of polyethylene terephthalate (PET) fabrics combining pretreatment and dyeing under the alkali condition was developed for cleaner production. One step dyeing of PET fabrics required that the dye used has good acid and alkali stability. In this paper, dyeing properties of three azo disperse dyes containing cyano group based on benzisothiazole, 3- (4-N-ethoxyl-N-cyanoethyl -phenyldiazenyl)-5-nitro-2,1-benzisothiazole (D1), 3-(4-N-ethyl-N-cyanoethyl- phenyldiazenyl)- 5-nitro-2,1-benzisothiazole (D2), and 3-(N-benzyl-N-cyanoethyl- phenyldiazenyl)-5-nitro-2,1-benzisothiazole (D3), were investigated under alkali condition. The results showed that polyester fabrics could be well dyed with D1, D2 and D3 under the acid condition. However, D1 was decomposed while dyeing at the alkali solution. D2 and D3 had excellent color yields under the alkali condition. The acid-alkali stability and the structure change were analyzed by UV-vis spectrum and high pressure liquid chromatography (HPLC). Gaussian 09 program package was used to optimize geometry by B3LYP method and 6-31G (d) basis set. The solvation energy of D1 in water was higher than those of D2 and D3. The electron withdrawn effect of the hydroxyl affected the energy gap of HOMO and LUMO orbits. D2 and D3 showed excellent stability in the strong alkali medium. And the dyed polyester fabrics with D2 and D3 at the alkali condition also had good fastness properties.     

Ultra-porous flexible PET/Aerogel blanket for sound absorption and thermal insulation

Ultra porous and flexible PET/Aerogel blankets were prepared at ambient pressure, and their acoustic and thermal insulation properties were characterized. Two methods were selected for the preparation of PET/Aerogel blanket. Method I was a direct gelation of silica on PET. PET non-woven fabric was dipped and swelled in TEOS/ethanol mixture, and pH of reaction media was controlled to 2.5 using HCl to promote hydrolysis. After acid hydrolysis, pH was controlled to 7,8,9, and 10 with NH₄OH for the condensation. Method II was by the dipping of PET non-woven fabric in the dispersion of Silica hydrogel. The gelation process was same with Method I. However, PET fabric was not dipped in reaction media. After the hydrogel was dispersed and aged in EtOH for 24 hrs, then, PET non-woven fabric was dipped in the dispersion of hydrogel/EtOH for 24 hrs. The surface modification was carried out in TMCS/n-hexane solution, then the blanket was washed with nhexane and dried at room temperature to prevent the shrinkage. The silica areogels synthesized in optimum conditions exhibit porous network structure. Silica aerogel of highly homogeneous and smallest spherical particle clusters with pores was prepared by gelation process at pH 7. When direct gelation of silica was performed in PET nonwoven matrix (Method I), silica aerogel clusters were formed efficiently surrounding PET fibers forming network structure. The existence of a great amount of silica aerogel of more homogeneous and smaller size in the cell wall material has positive effect on the sound absorption and thermal insulation.     

Synthesis and application of phthalimide disperse dyes

Three azo dyes had been synthesized using N-propyl substituted, dibromo-substituted and dicyano-substituted phthalimides as diazo components. All of the synthesized intermediates and dyes have been characterized by MS, 1H-NMR and IR analyses. The dyeing behaviour and fastness properties of these dyes had been investigated. The absorption maxima of the dyes were observed in the range 360 to 700 nm. The results indicated that dyes caused hypsochromism effect after -Br substitution and dyes caused bathochromism effect after -CN substitution. IR spectra of hydrolyzed dye showed that C=O groups appeared under relatively mild alkaline conditions. Compared with electron density, steric hindrance effect is an more important influence factor than electron density in hydrolysis reaction process. Exhaustion of dyed polyester/elastane fabrics decreased obviously as the pH value increased. In order to ensure dyeing levelness, heating rate of prepared dyes will be strictly controlled. Due to alkali-clearable property and interaction energy of dye-fiber and dye-dye, the dyes have good colorfastness.     

Fluorosilicone modified polyacrylate emulsifier-free latex: Synthesis,properties, and application in fabric finishing

Fluorosilicone modified polyacrylate emulsion was successfully synthesized via emulsifier-free emulsion polymerization using polymerizable surfactant and sol-gel process. TEM analysis indicated that the hybrid particles were spherical-like particles with narrow size distributions. The influence of synthetic conditions on the physical and chemical properties of fluorosilicone modified polyacrylate was investigated, including the mass ratio of methyl methacrylate (MMA)/butyl acrylate (BA) and the content of dodecafluoroheptyl methacrylate (DFMA) and ethyl silicate (TEOS). The water absorption decreased as the MMA/BA mass ratio was reduced from 5/4 to 2/4, then increased afterwards. With the reducing of MMA/BA mass ratio, the tensile strength decreased, while the elongation at break increased. The thermal stability of the hybrid film was improved with the increasing of TEOS amount. Finally, the contact angle results showed that the finished fabric had the excellent water repellency. Meanwhile, the SEM measurements confirmed that the finished fabric had the rough surface. XPS analysis demonstrated that there was a layer of fluorosilicone modified polyacrylate film covered on the finished fabric surface, and fluorinated segments had the tendency to be enriched at the film-air interface.