Studies on silk fabric dyed with a hemicyanine dye

Silk fabric was dyed with a hemicyanine dye, DHEASPBr‐C₄, to create the fluorescent silk fabric in this article. The study initially focuses on the dyeing properties of the dyed silk fabric, followed by the reflectance and emission spectra. The results show that the sorption isotherms are the Langmuir type and the dyed silk fabrics using DHEASPBr‐C₄ have an obvious fluorescent effect in the spectral range 570–720 nm, while their peak locations of ca. 590 nm in the emission spectra are under the excitation of 365 nm. Finally, the CIE coordinates of the dyed silk fabric are discussed in order to investigate further potential applications.     

Study on the dyeing properties of hemicyanine dyes. II. Cationic dyeable polyester

The absorption spectra of two hemicyanine fluorescent dyes, namely, trans‐4‐[p‐(N,N‐di(2‐hydroxyethyl))‐amino‐styryl]‐N‐ethyl pyridinium bromide (DHEASPBr‐C₂) and trans‐4‐[p‐(N,N‐di(2‐hydroxyethyl))‐amino‐styryl]‐N‐octyl pyridinium bromide (DHEASPBr‐C₈), were studied at various levels of pH and high temperatures, and were then employed to dye cationic dyeable polyester. Their dyeing properties, fluorescent reflectance and colorimetric properties were explored. The novel fluorescent dyes existed in two forms of monocation and dication in solutions at low pH and high temperature. Overall, the influence of pH on colour depth and the maximum reflectance of dyed cationic dyeable polyester was extremely small. The adsorption mechanism of DHEASPBr‐C₂ and DHEASPBr‐C₈ on cationic dyeable polyester fibres was in good accord with the Langmuir type. Compared with DHEASPBr‐C₂, DHEASPBr‐C₈ exhibited comparatively faster adsorption rate, higher affinity and dye uptake, while its fluorescence shown by cationic dyeable polyester was slightly weak.     

Novel hydrolysable azo disperse dyes based on N‐ester‐1,8‐naphthalimide: dyeing of polyester–cotton blends

The dyeing of polyester–cotton blends with new alkali‐hydrolysable azo disperse dyes based on N‐ester‐1,8‐naphthalimide was investigated. Polyester–cotton blend fabrics were dyed using both one‐ and two‐bath methods. Dyes 3 and 4 offered lower colour yield on polyester using the one‐bath method. For the rest of the dyes, employing either the one‐ or two‐bath method resulted in a similar colour yield on polyester fabric. The results for fastness properties and colour yield of the dyeings showed that the dyes were suitable for dyeing polyester–cotton blends using the one‐bath method. The kinetic study of hydrolysis of the dyes in alkali media obeyed the pseudo first‐order reaction rate.     

Deep‐colour vat dyeing of cotton knit fabric on a modified jet dyeing machine

To improve the vat dyeing of cotton knit fabric with Indanthren Black RB Coll. (CI Vat Black 9), the basic parameters of dyeing, including the concentrations of chemicals, the dyeing temperature and duration, and the apparent diffusion coefficient of the dye, were obtained by test dyeing with a stoppered Erlenmeyer flask and the cellophane film roll method. A stable vat dyeing process has been developed on a modified jet dyeing machine for the first time without using nitrogen to purge oxygen. Modifications were made to improve the airtightness of the machine and the equipment in the liquor circulating system, with a water inlet and outlet for the gentle oxidation of dyed fabric, and with monitoring by means of a sensor inserted in the liquor circulating system for in situ measurements of the redox potential and the pH of the dyeing liquors. These measurements made it possible to follow to their completion the process of dyeing and the process of gentle oxidation by overflow washing with water and final oxidation. Optimal conditions with regard to the amount of reducing agent, the dyeing temperature (80 °C), and oxidising processes were established with this machine. It was found that, by using the modified machine and process conditions, dyeing proceeded stably and reproducibly (at 80 °C) to yield grade A dyed fabric. Visual inspection confirmed that faultless deep‐colour dyeing of the fabric was attained. Production has been proceeding successfully for the past 2 years. Owing to its insolubility, complete removal of the dye from the wastewater has been possible.     

Synthesis of sulfated β‐cyclodextrin/cotton/ZnO nano composite for improve the antibacterial activity and dyeability with Azadirachta indica

The sulfated β‐cyclodextrin (sb‐cd) was prepared from β‐cyclodextrin and the sb‐cd was crosslinked with cotton fabric using ethylenediaminetetraacetic acid (EDTA) as crosslinker. After crosslinking, the synthesized ZnO nanoparticles were padded on this fabric surface. Then, the treated fabrics were dyed with neem extract. The synthesized polymer, crosslinked and nanoparticle‐treated cotton fabrics were characterized using fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), particle sized analyzer, and transmission electron microscopy (TEM) studies. The antibacterial test was done against Staphylococcus aureus and Escherichia coli bacterium. The composite coated with neem dyed cotton fabric has exhibited 71% of dye uptake with 2–3 fastness grade and it has 99% of antibacterial efficiency for S. aureus and 97% for E. coli bacterium. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Fabrication of superhydrophobic fabric coating using microphase‐separated dodecafluoroheptyl‐containing polyacrylate and nanosilica

Superhydrophobic coating was developed on cotton fabric in this article using a dodecafluoroheptyl‐containing polyacrylate (DFPA) and nanosilica. Film morphology of DFPA on cotton fibers/fabrics and chemical compositions of the treated cotton fabric were investigated using scanning electron microscopy (SEM), atomic force microscopy (AFM), and X‐ray photoelectron spectroscopy (XPS), respectively. DFPA could form a relatively even film on the cotton fabric/fiber under SEM observation; however, it presented a rough and microphase‐separated pattern under AFM observation. There were many mountain‐like protuberances. The height of the protuberances and the root mean square roughness (R_ms) of the film reached about 20–50 nm and 12.511 nm in 2 × 2‐μm² scanning field (as the scale data was 100 nm). XPS analysis indicated that the perfluoroalkyl groups had the tendency to enrich at the film–air interface. DFPA could make the treated cotton fabric with a water contact angle (WCA) at about 138.5°. Cotton fabric was previously roughened using a 1 wt % silica sol with an average particle size of 20–30 nm and then finished by DFPA; hydrophobicity of the resultant cotton fabric was strongly improved, and WCA could reach 153.6°. The color of this superhydrophobic fabric would not be influenced, but its softness decreased compared to untreated fabric. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Electrostatic self‐assembly dyeing of cotton fabrics

A new approach to the dyeing of cotton fabrics using an electrostatic self‐assembly method was evaluated. Cotton fabrics were pretreated with 2,3‐epoxypropyltrimethylammonuium chloride and cationic charges were produced on the fabric surfaces. For the dyeing of cotton fabric, reactive and acid dyes were used. Oppositely charged anionic reactive/acid dyes and cationic poly(diallyldimethylammonium chloride) were alternately deposited on the surface of cationised cotton fabrics. Ten multilayer films of dye/poly(diallyldimethylammonium chloride) were deposited on the cotton fabric surfaces using a padder. The build‐up of the multilayer films and the level of colour strength (K/S) achieved are discussed. Samples of cotton fabrics were also dyed with the same dyes, but using the exhaust method, and both types of dyed samples were compared. The washing, rubbing and light fastness properties were evaluated for the dyed fabrics.     

Flame retardant finishing of the polyester/cotton blend fabric using a cross‐linkable hydroxy‐functional organophosphorus oligomer

Blend fabrics of cotton and polyester are widely used in apparel, but high flammability becomes a major obstacle for applications of those fabrics in fire protective clothing. The objective of this research was to investigate the flame retardant finishing of a 50/50 polyester/cotton blend fabric. It was discovered previously that N,N′‐dimethyloldihydroxyethyleneurea (DMDHEU) was able to bond a hydroxy‐functional organophosphorus oligomer (HFPO) onto 50/50 nylon/cotton blend fabrics. In this research, the HFPO/DMDHEU system was applied to a 50/50 polyester/cotton twill fabric. The polyester/cotton fabric treated with 36% HFPO and 10% DMDHEU achieved char length of 165 mm after 20 laundering cycles. The laundering durability of the treated fabric was attributed to the formation of polymeric cross‐linked networks. The HFPO/DMDHEU system significantly reduced peak heat release rate (PHRR) of cotton on the treated polyester/cotton blend fabric, but its effects on polyester were marginal. HFPO/DMDHEU reduced PHRR of both nylon and cotton on the treated nylon/cotton fabric. It was also discovered that the nitrogen of DMDHEU was synergistic to enhance the flame retardant performance of HFPO on the polyester/cotton fabric.     

Assessment of the dyeing properties of pigments from five fungi and anti‐bacterial activity of dyed cotton fabric and leather

The present study was aimed to assess the anti‐bacterial activity and dyeing property of the pigments obtained from five fungal species. Cotton fabric and leather samples were dyed with the purified pigments and their anti‐bacterial activity was assayed under in‐vitro conditions. Post‐mordant cotton fabric and leather samples exhibited maximum bacterial reduction when compared with the pre‐mordant and dyed samples. Pigment exhaustion, colour coordinates and fastness properties of the dyed cotton fabric and leather samples were also assessed. The toxicity of the pigments was evaluated by seed germination assay.     

Pretreatment of cotton fabrics with polyamino carboxylic acids for salt‐free dyeing of cotton with reactive dyes

In this study, polyamino carboxylic acids have been used to improve the dyeability of cotton in a salt‐free reactive dyeing process. These polyamino carboxylic acids were prepared by partial carboxylation of polyvinylamine. Cotton fabric was pretreated with polyamino carboxylic acids and dyed with reactive dyes. The colour strengths of the dyed fabrics were evaluated by measuring the K/S values. The fastness properties (washing, rubbing and light fastness) of the dyed cotton fabrics were also measured. The pretreatment of cotton with polyamino carboxylic acids creates positive charges on the fabric surface. In this way, salt‐free reactive dyeing of cotton or dyeing with only a small amount of electrolyte is possible.     

Synthesis of N‐[4‐(dimethylalkylammoniomethyl) benzoyl]caprolactam chlorides as cationic bleach activators for low‐temperature bleaching of cotton fabric under near‐neutral pH conditions

Low‐temperature bleaching of cotton fabric can be achieved by incorporating a so‐called bleach activator into an aqueous solution of hydrogen peroxide. In this study, a series of N‐[4‐(dimethylalkylammoniomethyl)benzoyl]caprolactam chlorides were synthesised for use as cationic bleach activators with various alkyl chain lengths. All these synthesised cationic bleach activators were confirmed by ¹H and ¹³C nuclear magnetic resonance spectroscopy and mass spectroscopy. Bleaching experiments revealed that these synthesised bleach activators were effective for bleaching of cotton fabric at 50 °C under near‐neutral pH conditions, but the alkyl chain lengths had a great influence on their bleaching performance. Increasing the alkyl chain length from 2 to 6 carbon atoms could slightly enhance bleaching performance, while increasing the alkyl chain length from 8 to 16 carbon atoms markedly reduced bleaching performance.     

Effect of Silicone Nano,Nano/Micro and Nano/Macro‐Emulsion Softeners on Color Yield and Physical Characteristics of Dyed Cotton Fabric

The study of silicone nano‐emulsions and softeners to alter physical properties of undyed cotton fabric has recently gained a substantial interest. However, systematic investigation of silicon nano‐emulsion softeners on dyed cotton fabric has not so far been conducted. This paper deals with the application of silicone nano‐, micro‐, and macro‐emulsion softeners, and combinations of nano/micro and nano/macro, on dyed cotton fabric. We report the effect of silicon nano/micro‐ and nano/macro‐emulsion softeners on color yield and physical characteristics of dyed cotton fabric. All bleached fabrics were dyed with CI Reactive Black 5 and then treated with known concentrations of silicone softeners by the pad‐dry method. The silicone nano‐emulsion was combined with micro‐ and macro‐emulsion softeners using blending ratios of nano/micro (1:1) and nano/macro (1:1). Treated fabrics were compared in terms of physical properties such as fabric handling, wrinkle recovery angle, bending length, abrasion resistance and tensile strength. The color changes were evaluated by color yield (K/S) values and total color difference (ΔE_cmc). The results revealed that the silicon nano‐emulsion had better physical properties than micro‐, macro‐ and combination nano/micro‐ and nano/macro‐emulsion softeners. Among all treated samples, nano‐emulsion softeners showed better ΔE_cmc values. Scanning electron microscopy analysis suggests that the fiber morphology of treated fabrics was very smooth and uniform.     

Yellow‐Emitting Y3Si6N11: Ce3+ Phosphors for White Light–Emitting Diodes (LEDs)

A novel Y_3?xSi₆N₁₁: xCe³⁺ yellow phosphor was synthesized using the carbothermal reduction and nitridition method at 1550°C for 16 h in this letter. Photoluminescence spectra indicated that the phosphor showed broad excitation spectrum and had strong absorption in range of 350–450 nm. It also gave a broad emission band (Full width at half maximum = 153 nm) centered at 575 nm under 425‐nm excitation. With increasing Ce³⁺ concentration, the strongest emission intensity was obtained at 5 mol% Ce³⁺ doping amount and a systematic redshift was observed as the Ce³⁺ concentration increased. The results indicate that this novel yellow phosphor is a promising candidate for using in blue‐chip‐excited white light–emitting diodes (LEDs).     

Effects of a pretreatment with N‐methylmorpholine‐N‐oxide on the structures and properties of ramie

To improve the dyeing properties of ramie, the ecofriendly organic solvent N‐methylmorpholine‐N‐oxide (NMMO) was used to substitute sodium hydroxide as a ramie‐fiber swelling solvent. Through padding and baking pretreatment, ramie fabric was modified by an NMMO aqueous solution. Ultraviolet–visible spectrophotometry, Fourier transform infrared spectroscopy, X‐ray diffraction, and differential scanning calorimetry were used to investigate the effects of NMMO pretreatment on the structure of the ramie, whereas the color strength (K/S, where K is the light absorption coefficient and S is the scattering coefficient), adsorption isotherm, and dye uptake rate curve were measured to investigate the effects of NMMO pretreatment on the dyeing properties of the ramie. The results show that the ramie fiber experienced a limited and irreversible swelling because of the partial breakage of interhydrogen and intrahydrogen bonds of cellulose molecules in the amorphous area, but the crystal and chemical structure of the ramie fiber did not change obviously under the experimental conditions. The K/S value of the NMMO‐modified ramie fabrics dyed with reactive dyes increased by about 100%, and the dye uptake increased by 27.88% compared to that of the raw sample, whereas the standard affinity and diffusion coefficient value of the reactive dyes on the NMMO‐modified ramie fabric were higher than those of the raw ramie fabric. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Use of a predictive colour model for managing the colour appearance of two‐colour woven fabrics

The aim of this study was to implement a two‐dimensional colour appearance model for prediction of the colour values of weft threads when the optical mixing of a two‐colour woven structure had to match the colour appearance of a single‐colour reference woven fabric. Five single‐colour woven fabrics were woven from five threads of similar hue. One of the samples was chosen as a reference, for which the colour appearance was the goal to be achieved in the two‐colour woven fabrics prepared with the other available warp threads and newly dyed weft threads. The colour values of dyed weft threads were predicted by a two‐dimensional colour appearance model. With dyed weft threads, managing the colour appearance of the two‐colour woven fabric was enabled to achieve the colour values of the reference. In the results, colour deviations between the predicted and measured colour values of weft threads revealed some limitations to the colour appearance model and performance of the dyeing process. After the production of the two‐colour woven fabric, the colour appearance matched the appearance of the reference, resulting in deviations of ΔE_CMC(2:1) = 1.2‐7.8. Moreover, the differences between theoretically predicted and measured colour values of the two‐colour woven fabric were evaluated as small, ranging from ΔE_CMC(2:1) = 1.5‐1.9. The results demonstrated the efficiency of implementing the colour appearance model and the dyeing process of weft threads as an approach to achieve the defined colour appearance of two‐colour woven fabrics, which with small colour deviations matches the colour of a single‐colour reference.     

Natural dyeing and antibacterial activity of atmospheric‐plasma‐treated nylon 6 fabric

Atmospheric plasma treatment as an environmentally friendly method was employed to modify the surface properties and improve the absorption of natural cationic dye on to nylon 6 fabric. Nylon fabric was treated in atmospheric air plasma, and the surface characteristics of the fabric were evaluated using attenuated total reflection Fourier Transform‐infrared analysis, scanning electron microscopy, and a wicking test. The effects of plasma treatment and mordanting with copper sulfate on the dye uptake of the samples were investigated. Plasma‐treated and mordanted samples showed the highest colour strength when dyed. The antibacterial activity of samples was evaluated according to AATCC test method 100‐2004. Premordanting with copper sulfate showed a synergistic effect on the antibacterial properties of the dyed fabric. The plasma‐treated and copper‐sulfate‐mordanted sample showed acceptable antibacterial activity against both gram‐negative and gram‐positive bacteria when dyed with an extract from Berberis vulgaris, berberine.     

Eco‐friendly pretreatment of silk fabric for dyeing with Delonix regia extract

The flowers of Delonix regia have been evaluated for the natural dyeing of silk using a biomordant and enzymes. This is an eco‐friendly textile pretreatment that does not utilise metal mordanting. The aqueous extract obtained from the dried red flowers was used for the dyeing of silk fabrics. A bright reddish‐brown hue colour was observed when 30% owf Delonix extract was used on the pretreated silk material. The silk fabric was treated with either an enzyme or biomordant. The resulting dyed fabric showed resistance to fading. Finally, all dyed specimens were tested for wash and light fastness properties, making Delonix a viable alternative to synthetic red dyes. Through desorption studies, the order of reactivity of enzymes towards dye uptake in the one‐step process was found to be lipase > diasterase > protease–amylase = Pyrus(biomordant). For the two‐step process, the order of reactivity of enzymes was found to be protease–amylase > lipase > Pyrus (biomordant) > diasterase. Overall, it can be concluded that, treatments, the two‐step process was better in terms of larger colour yield values, fastness properties and both dye adherence ability.     

Temperature‐sensitive poly(N‐tert‐butylacrylamide‐co‐acrylamide) hydrogels bonded on cotton fabrics by coating technique

Different from the conventional method of developing stimuli‐sensitive textiles by graft copolymerization of environmental responsive polymers onto the fabric, the coating technique was applied to bond temperature‐sensitive hydrogels with cotton fabric through chemical covalent in our work. A temperature‐sensitive linear copolymer of N‐tert‐butylacrylamide (NTBA) and acrylamide (AAm) was prepared in methanol. Then, the cotton fabrics were coated using an aqueous solution of this copolymer containing 1,2,3,4‐butanetertracarboxylic acid as a crosslinker and sodium hypophosphite (SHP) as a catalyst, followed by drying and curing. The surface of the cotton fabrics was bonded on more or less coatings of poly (NTBA‐co‐AAm) hydrogels, as verified by Fourier transform infrared spectroscopy and scanning electron microscopy images. The poly(NTBA‐co‐AAm) hydrogels‐coated fabrics exhibited temperature sensitive, and the temperature interval of the deswelling transition was higher than lower critical solution temperature of linear copolymer solution. The coated fabrics presented good water‐impermeable ability because of the swelling of hydrogels bonded, especially when the add‐on was as high as 14.14%. Environmental scanning electron microscopy images revealed that coating hydrogels swelled and covered on the surface as a barrier to prevent water from penetrating once the coated fabric came into contact with water. The findings demonstrate that the temperature‐sensitive hydrogels can be covalently bonded on the cotton fabrics by coating technique and the coated fabrics have potential on immersion fabrics. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Degradation studies of CI Reactive Blue 19 on biodegraded cellulosic fabrics via liquid chromatography‐photodiode array detection coupled to high resolution mass spectrometry

When textile substrates biodegrade in landfills, the fate of textile colorants is unknown, and potentially poses an ecotoxic threat. In this study, we developed a systematic analytical method to evaluate the biodegradation of reactive dyes, the most common class of dye applied to cotton fabrics. The cotton fabrics were dyed with CI Reactive Blue 19 and biodegraded in soil in a laboratory‐controlled environment over intervals of 45 and 90 days. A dye isolation method using a low concentration of alkali (0.15% sodium hydroxide) was developed and applied (80°C for 1 hour) to isolate intact and degraded dye from the fabric samples. To quantify the intact dye isolated from the fabric samples, a quantification method was then developed using liquid chromatography‐photodiode array detection. The quantification method provided excellent linearity (R² = 0.9997 ± 0.0002), accuracy (% error = ?2% ± 4), precision (% coefficient of variation = 2% ± 4) and sensitivity (lower limit of quantification = 0.4 ± 0.2 µg/mL) for concentrations ranging from 1 to 50 µg/mL. After validation, the method was applied and showed a reduction of dye in biodegraded samples (after 45 and 90 days) compared with undegraded control samples (0 days). To characterise the isolated dye degradation product, quadrupole time‐of‐flight tandem mass spectrometry was utilised. Analysis showed that the degradation product was formed by losing a group from the intact hydrolysed form of the dye, creating a more hydrophobic degradation product compared with the intact hydrolysed form of dye.     

Durable antibacterial finish on cotton fabric by using chitosan‐based polymeric core‐shell particles

Cotton fabric with excellent antibacterial durability was obtained when treated with chitosan‐containing core‐shell particles without any chemical binders. These amphiphilic nanosized particles with antibacterial chitosan shells covalently grafted onto polymer cores were prepared via a surfactant‐free emulsion copolymerization in aqueous chitosan. Herein, two core‐shell particles, one with poly(n‐butyl acrylate) soft core and another with crosslinked poly(N‐isopropylamide) hard core, were synthesized and applied to cotton fabric by a conventional pad‐dry‐cure process. Antimicrobial activity was evaluated quantitatively using a Shake Flask Method in which the reduction of the number of Staphylococcus aureus cells was counted. The results showed that treated fabric had an excellent antibacterial property with bacterial reduction higher than 99%. The antibacterial activity maintained at over 90% reduction level even after 50 times of home laundering. The fabric surface morphology as well as the effect of latex particles with different core flexibilities on fabric hand, air permeability, break tensile strength, and elongation was investigated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1787–1793, 2006