Influence of Low Temperature Dyeing Accelerant on Acrylic Fiber Dyed with Cationic Dyes

The dyeing behavior of cationic dyes to acrylic fiber with self-made low temperature dyeing accelerant was investigated in this study. Compared with conventional dyeing, the acrylic yarn was dyed with Cationic Turquoise Blue X-GB at 85℃ in the presence of accelerant and absence of accelerant, respectively. The influence of low temperature dyeing aceelerant on the dyeing mechanism of acrylic fiber dyed with cationic dye was analyzed through kinetics and thermodynamics study. The results show that adding dyeing accelerant ran heighten the equilibrium dye-uptake, dyeing rate constants, diffusion coefficients, and shorten half-dyeing time for acrylic fiber dyed with cationic dyes. Furthermore, the partition coefficient, the standard affinity, and the dye saturation value also increased in the dyeing at 85℃.

Dyeing Properties of Basofil Fiber

The structures and properties of Basofil fiber were studied using X- rays small angle diffraction analysis,differential- scanuing calorimeter and scanning electron microscopy. Disperse dyes, acid dyes and reactive dyes had been tried for dyeing Basefil fiber. It was shown disperse dyes were superior to other ones. The two series of high temperature dyes and low temperature dyes were compared for their suitability for Basofil fiber, and their dyeing behaviors were determined.

A Novel Approach of Dyeing Jute Fiber with Reactive Dye after Treating with Chitosan

Jute is generally not dyed with reactive dye though it is a cellulosic fiber. Reactive dye is extensively used to dye cotton, viscose and other cellulosic fibers whereas jute is dyed with basic dye. This paper presents a novel approach to dye the jute fiber with reactive dye after treating with chitosan. Jute fabric was treated with chitosan solution at different con- centrations (0.5%, 1%, 2%, 3% and 4%) and then dyed with reactive dye. The depth and fastness of shade of dyed fabric were analyzed by comparing the chitosan treated samples with untreated dyed fabric samples. It has been found that, the dyebath exhaustion is increased with the increment of chitosan concentrations. The exhaustion percentages have found 36.79%, 41.59%, 48.33%, 54.46% and 58.75% for the fabric treated with 0.5%, 1%, 2%, 3% and 4% chitosan solution respectively, while the exhaustion of dyebath is only 23.15% for untreated fabric. The K/S values (at λmax = 540 nm) of dyed samples have found 4.93, 6.77, 10.5, 14.07, 15.57 and 2.37 for 0.5%, 1%, 2%, 3%, 4% and untreated fabric respectively. The color fastness to washing and rubbing of the dyed fabrics was also evaluated. In case of dry rubbing, both types of fabric have shown almost similar fastness ratings. However, chitosan treated fabrics have shown inferior fastness rating in case of wet rubbing and washing, particularly for the fabrics at higher chitosan concentrations.

Comparison between the Direct Dyeing Kinetics of Bamboo and Conventional Viscose Fibers

Two direct dyes were applied to conventional viscose(CV)and bamboo viscose(BV)fibers,which were prepared from bamboo cellulose pulps,and the dyeing kinetics of two fibers were compared.Three kinetic equations,namely Chrastil,Cegarra-Puente,and Vickerstaff,were used to fit the experimental dyeing rate points,showing that the best result was obtained by the Chrastil equation.BV fibers displayed slightly higher dyeing rates and dye adsorption values at initial stages,but a bit lower dye adsorption values at equilibrium than CV fibers.Furthermore,the dyeing of BV fibers exhibited lower activation energies and higher dyeing rate constants than that of CV fibers,and therefore showed slightly lower dependence on temperature.

Dyeing Performance of Soybean Fiber Treated with Low Temperature Plasma

The soybean fiber was treated with low temperature plasma and the dyeing performance of the treated soybean fiber was also researched. The results show that the speed of dyeing and the percentages of balance dyeing have a sharp increase after being treated. So the dyeing temperature and the dosage of acid can be reduced without damaging the bulk fiber structure.

Low Temperature Dyeing of Cashmere Fibers and Products

A special designed multi-functional dyeing auxiliary, SFR-503, is adopted in mordant dyeing process for cashmere fibers, sliver and fabric. The results of decreasing dyeing temperature, shortening the dyeing period, reducing the fiber damage and improved quality of the cashmere have been obtained. The percentage of dyeing exhaustion and color fastness of final products were further improved in this regards. A suggested technique, bath ratio, dyeing process curve and dye recipe were raised in the paper. SFR-503’s swelling, wetting, leveling, brightening effect for cashmere during dyeing process were discussed.

The Effects of Dyeing and Finishing Pretreatment Process to the Sliver Fiber Shielding Fabric and the Reasons

Through the silver fiber and cotton mixed silver fiber shielding fabric,not only soft and comfortable,it can wear personal,but also has excellent anti electromagnetic shielding effect. Fabric in dyeing and finishing process,may cause some damage on the silver fiber,influence the shielding performance of shielding fabric. Therefore,in this paper,through the experimental and analysis,find dyeing and finishing process may affect silver fiber shielding fabric and the reasons.

MIIT Released Entry Criteria for Dyeing & Viscose Fiber Industry

To regulate the industry structure adjustment and implement the energy-saving & emission-reducing strategy,the Ministry of Industry and Information Technology recently released the

Structure and Properties of Degradable Polybutylene Succinate Fibers

Polybutylene succinate(PBS)fiber is a kind of synthetic fibers with excellent properties and biodegradability,which has been produced on a large scale in China.To investigate the application properties of PBS fibers,the structure and properties were systematically studied in this paper.The microstructures and thermal properties of PBS fibers were analyzed by Fourier transform infrared(FTIR)spectroscopy,X-ray diffraction(XRD),scanning electron microscopy(SEM),thermo gravimetric(TG)and differential scanning calorimetry(DSC).The mechanical properties,chemical stability and dyeing properties of PBS fibers were also studied.The results show that PBS fibers areα-crystalline with a crystallinity of 58.56%.PBS fibers have an excellent thermal stability and the initial temperature of thermal degradation is 370℃.The tensile strength,the elongation at break,the elastic recovery rate at a fixed elongation(5%)and the moisture regain rate of PBS fibers are 29.57 cN/tex,90.94%,44.55%and 5.04%,respectively.The chemical stability is as follows:alkali resistance<acid resistance<oxidation resistance.PBS fibers have an excellent dye uptake by carrier dyeing of disperse dyes.

RELATION BETWEEN DYNAMIC LOSS MODULUS AND DIFFUSION COEFFICIENT IN A MODIFIED PET FIBER

The mobility of polymer chain segments is shown to play a major role in the diffusion ofdisperse dyes in a copolymerization modified PET system, monoepoxy compoundCH_3 (CH_3),OCH_2CH--CH_2 modified PET. The rate of dye diffusion (diffusion coefficient D) hasbeen related to the time-dependent mechanical property, dynamic loss modulus E', which iscontrolled by the mobility of chain segments. In this modified copolyester system, the variance ofamount of modifier in the copolyester fibers causes the change in disperse dye diffusion coefficientto fiber, and in the dynamic loss modulus of the fibers, but the relationship between the diffusionand the dynamic loss modulus is in agreement with the theoretical relation derived by Bell andDumbleton. The relation obtained in this paper is:Ln D=-2. 28Ln E'+26. 81

Preparation of Acid Dyeable Polypropylene Fiber

A series of basic copolyamides has been synthesized withadipic acid(AA),hexamethylene diamine(HMDA)anddiethylenetriamine(DETA).Intrinsic viscosity determi-nation,thermal analysis and infrared spectrum analysisof the copolyamide indicates that molecular weight,ther-mal stability reduce whereas alkalinity increase with theincreasing fraction of DETA.Then acid dyeable polypro-pylene fibers are prepared by admixing polypropylene(PP)with those copolyamides prior to extrusion.Lowconcentration of the additive affects slightly on the crys-tallinity and the mechanical property of PP fiber.Themodified PP fibers have a nice acidic dyeability.

Hydrolysation and Characterization of Acrylic Fibers

Effect of the cationic surfactant on the hydrolysis of acrylic staple fiber dispersed in alkaline aqueous solution was studied.The cationic dyestuff uptake of the resultant hydrolysates was investigated as well.The results showed that the surfactant accelerated the hydrolysis of cyano-and ester-groups.The carboxyl content of the hydrolyzed fibers reached the maximum 6.85 mmol/g(i.e.,total molar conversion of the two groups 38.7%) while keeping fiber integrity.The scanning electron microscopy(SEM) images implied that hydrolysis happened both on fiber surface and in the inner part of the fiber in the presence of surfactant.The cationic dye removal due to adsorption onto the hydrolyzed fibers increased with increasing temperature,with the removal 97.4% at 60℃.The adsorption of the fibers followed the Freundlich's adsorption isotherm and the Lagergren's pseudo-second order dynamic equation with the activation energy 5.4 kJ/mol.Unexpectedly,the steric hindrance of access to the inside carboxyl groups of the hydrolyzed fibers caused a low dye sorption capacity,5-6 mg/g.

Studies on the Crystallization Properties and Morphology Structure of the Cationic Dyeable Polypropylene Fibers

The crystallization properties and morphology structure of the cationic dyeable polypropylene fibers which were produced by the blending spinning method were studied by making use of X-ray and scanning electron microscopy (SEM). It comes to the conclusions that the larger the crystallite size in the fibers is , the better the dyeable properties of the fibers are and there is a little compatibility between the dyeable agent and polypropylene resin. And the dye-uptake of the fibers may be up to 90% because the dyeable agent can uniformly be scattered in polypropylene.

ADSORPTION OF DYES ON ACTIVATED CARBON FIBERS

The adsorplion behavior of dyes on a variety of sisal based activated carbonfibers (SACF) has been studied in this paper The results show that this kind of ACFhas excellent adsorption capacities for some organic (dye) molecules. SACF canremove nearly all methylene blue, crystal violet, bromophenol blue and Eriochromeblue black R from water after static adsorption for 24 h. at 30℃ The adsorptionamounts can reach more than 400 mg/g when adding 50 mg SACF into 50 ml dyesolution. Under the same conditions, the absorption amounts of xylenol orangefluorescein and Eriochrome black T were lower On the other hand, the adsorptionamounts change along with the characteristics of adsorbents. The SACFs activatedabove 840 ℃ which have higher specific surface areas and wider pore radii, havehigher adsorption amounts for the dyes. The researching results also show that foeadsorption rates of dyes onto SACFs decrease by the order of methylene blue,Eriochrome blue black R and crystal violet.

N-Doped graphene fiber anchored Pd nanoparticles as a fixed-bed catalyst for continuous-flow reduction of N-containing unsaturated compounds

Catalytic fixed-bed is an efficient and facile system for scalable organic synthesis due to its continuous and fast flow operation process.As a key unit in the fixed-bed system,catalytically active packing materials are required to possess some properties,such as high activity,excellent stability,and porous packing structure.Herein,we prepare a fibrous fixed-bed catalyst by anchoring Pd nanoparticles on N-doped graphene fiber(NHG)(Pd/NGF).Due to the porous and loose packing structure,the resultant Pd/NGF catalyst can be easily filled into the continuous-flow reactor to construct a fixed-bed system with low flow resistance.The corresponding catalytic fixed-bed system exhibits a favourable flow rate(8 mL/min)and excellent durability toward reduction reactions of N-containing unsaturated compounds to produce aromatic amines.This work provides a new design concept of fibrous fixed-bed catalysts with dual-active components(i.e.,graphene-derived active materials and metal nanoparticles)and catalytic organic synthesis in a continuous-flow process.

Review on Recent Developments of Fluorescent Oxygen and Carbon Dioxide Optical Fiber Sensors

Oxygen and carbon dioxide sensors are involved in many chemical and biochemical reactions. Consequently, considerable efforts over years have been devoted to discover and improve suitable techniques for measuring gas concentrations by optical fiber sensors. Optical gas sensors consist of a gas-sensitive dye entrapped in a matrix with a high permeability to gas. With such sensors, gas concentration is evaluated based upon the reduction in luminescence intensity caused by gas quenching of the emitting state. However, the luminescence quenching effect of oxygen is highly sensitive to temperature. Thus, a simple, low-cost plastic optical fiber sensor for dual sensing of temperature and oxygen is presented. Also, a modified Stern-Volmer model is introduced to compensate for the temperature drift while the temperature is obtained by above dual sensor. Recently, we presented highly-sensitive oxygen and dissolved oxygen sensors comprising an optical fiber coated at one end with platinum （II） meso-tetrakis（pentafluorophenyl）porphyrin （PtTFPP） and PtTFPP entrapped core-shell silica nanoparticles embedded in an n-octyltriethoxysilane（Octyl-triEOS）/tetraethylorthosilane （TEOS） composite xerogel. Also, two-dimensional gas measurement for the distribution of chemical parameters in non-homogeneous samples is developed and is of interest in medical and biological researches.

Enhanced electrocatalytic oxidation of dyes in aqueous solution using cobalt phthalocyanine modified activated carbon fiber anode

Cobalt tetra（2,4-dichloro-1,3,5-triazine）aminophthalocyanine （CoPc） was immobilized covalently on activated carbon fiber （ACF） felt to obtain CoPc-modified ACF （CoPc-ACF） catalyst, and an electrocatalytic oxidation system using CoPc-ACF as the anode was constructed. The electrocatalytic oxidation of Acid Red 1 （ARI） was investigated in aqueous solution by an UV-vis spectrophotometer and UPLC. The results indicated that AR1 could be eliminated efficiently in this electrocatalytic oxidation system. In addition, the results of FTIR, TOC and GC-MS suggested that the electrocatalytic oxidation experienced the decoloration achieved by destroying the azo linkage and the further mineralization due to the cleavages of benzene ring and naphthalene ring. The intermediates were mainly small molecular compounds such as maleic acid and succinic acid, etc. Re- petitive tests showed that CoPc-ACF can maintain high electrocatalytic activity over several cycles. The further EPR spin-trap experiments indicated that the hydroxyl radicals did not dominate the reaction in this electrocatalytic system, which was com- pletely different from the traditional electro-Fenton system. Based on the non-radical reaction mechanism, the CoPc-modified ACF electrocatalyst has potential application in treating actual dyestuffs wastewaters, which are accompanied with high concentration of hydroxyl radical scavengers such as chlorine ions and additives in the textile printing and dyeing industry.

Facile and scalable preparation of ZIF-67 decorated cotton fibers as recoverable and efficient adsorbents for removal of malachite green

Recently,metal–organic frameworks(MOFs)have received considerable attention as highly efficient adsorbents for dye wastewater remediation.However,the immobilization of MOFs on the substrate surfaces to fabricate easy recy-clable adsorbents via a facile route is still a challenge.In this work,ZIF-67/cotton fibers as adsorbents for dye removal were prepared in a large-scale using a simple coordination replication method.The successful fabrication of the ZIF-67/cotton fibers was confirmed by FTIR,XRD,XPS,SEM and BET analysis,respectively.As expected,the as-prepared ZIF-67/cotton fibers exhibited high adsorption capacity of 3787 mg/g towards malachite green(MG).Meanwhile,the adsorption kinetics and isotherm obeyed the pseudo-second-order kinetics and Langmuir model,respectively.Moreover,its removal efficiency towards MG was not significantly influenced by the pH and ionic strength of aque-ous solution.Most importantly,the ZIF-67/cotton fibers can remove MG from synthetic effluents,and it can be easily regenerated without filtration or centrifugation processes,with the regeneration efficiency remaining over 90%even after 10 cycles.Additionally,the ZIF-67/cotton fibers presented excellent antimicrobial performance against E.coli and S.aureus.Hence,the distinctive features of the as-prepared ZIF-67/cotton fibers make it promisingly applicable for the colored wastewater treatment.

Composite nanofiltration membrane with tannic acid coordinated collagen fibers for enhanced molecule separation

Biomass-based membranes have attracted increasing attentions due to their cheap and sustainable advantages.In this work,a novel thin-fiilm composite(TFC)nanofiltration(NF)membrane was fabricated through a facial interfacial polymerization(IP)process by initiate the crosslinking reaction between collagen fibers(CFs)and tannic acid(TA).The increased TA concentrations endowed the TFC membrane with a higher crosslinking degree,a thicker active layer and a rougher top surface.At optimized condition with 0.60 mg TA decoration,the TFC-3 membrane exhibited a high water permeability of 23.49 L m^(-2)h^(-1)bar^(-1)with high rejections above 98.0%for congo red,reactive blue 19,coomassie blue G-250,and methyl blue.Furthermore,the membrane preserved remarkable salt retentions(93.3%for Na_(2)SO_(4),83.4%for MgSO_(4),36.2%for MgCl_(2),and 26.4%for NaCl)and satisfying operation stability.This facial fabrication method offered a new insight to employ biomass for molecular precise separation.

Role of the surface chemistry of activated carbons in dye removal from aqueous solution

Commercial activated carbons were modified by a series of chemical or physical treatments using H202, NH3, and heating under N2 flow without notably changing their pore structures. The resultant carbons were characterized by N2 adsorption and Bohem titration and then used to remove Ponceau 4R, methyl orange and brilliant blue from aqueous solutions. Surface chemistry was found to play a signifi- cantly different role in removing these three compounds. The removal of anionic Ponceau 4R increases with increasing carbon surface ba- sicity due to the predominant dispersive interaction mechanism. In contrast, surface chemistry has little effect on the removal of anionic methyl orange, which can be explained by two parallel mechanisms involving electrostatic and dispersive interactions due to the basic amine group in a dye molecule. The influence of surface chemistry on the removal of amphoteric brilliant blue dye can also be ignored due to a weak interaction between the carbons and dye molecules, which is resulted from strong cohesive energy from electrostatic forces inside amphoteric dye molecules.