Study of the desorption of hydrolysed reactive dyes from cotton fabrics in an ethanol–water solvent system

The factors influencing the desorption of hydrolysed dyes resulting from reactive cotton dyeings in an ethanol–water solvent system, including the volume ratio of ethanol to water, pH, and temperature, were investigated. The maximum desorption was achieved when the volume ratio of ethanol to water was optimised to 4:6. Desorption increased with an increase in pH and temperature. The kinetic curves of dye desorption at three different temperatures fit a two‐step kinetic model. The dye desorbability at 60 °C in an ethanol–water system was similar to that observed using conventional water washing in the presence of detergent at 95 °C. Findings suggest that wash‐off in an ethanol–water system can be considered as an alternative, more effective process for removing hydrolysed dyes from reactive cotton dyeings.     

Preparation of porous polycaprolactone tubular matrix by salt leaching process

Salt leaching technique has been employed to produce polycaprolactone (PCL) based porous tubular matrix. Salt was dispersed into PCL solution in chloroform and the subsequent leaching of salt was accomplished in water. The effect of salt and polymer concentration on the mechanical properties, porosity and surface characteristics was studied. It was observed that salt concentration has significant influence over crystalline nature of the scaffold. The porous structures became more interconnected as the salt concentration increased. This process yields a tubular porous matrix with maximum porosity of 61%, strength of 1.84 (±0.04) MPa and tensile strain of 120 (±7.94). © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Studies on chemically modified cotton. V. Effect of zinc chloride solutions on swelling and other properties of cotton

This paper describes the effect of zinc chloride solutions of different molarity at different temperatures, viz., 10°, 25°, 36°, 55°, and 75°C, on various properties of cotton fiber such as degree of swelling, accessibility to water vapor and iodine absorption, infrared ratio, barium activity number (BAN), and leveling-off degree of polymerization (LODP). Zinc chloride solution caused inter- and intrafibrillar swelling in cotton fiber depending on conditions of treatment, viz., concentration of solution and temperature employed. Fibers treated in 10.07 moles/1. (M) solution of zinc chloride in slack state showed rapid increase in degree of swelling up to 2 hr, followed by a slow increase, reaching the maximum after 3 hr of treatment. Fibers swollen with fixed ends without allowing shrinkage showed gradual increase with maximum swelling after 6 hr of treatment. Cotton fibers treated in different molar solutions of zinc chloride at 55°C showed varying degrees of swelling (inter- and intrafibrillar) and a somewhat different trend compared to that observed at 10°C. Electron micrographs revealed mostly intercrystalline swelling in case of samples treated with 9.26M at 10°C, while the same concentration produced intracrystalline swelling at 55°C. Accessibility to water vapor, iodine absorption, and BAN of treated samples showed specific effect of temperature with regard to effectiveness of concentrations of zinc chloride solutions. Similar effects of temperature with regard to concentrations of reagent were observed on infrared ratio and LODP. Accessibility by iodine absorption and LODP correlate with BAN; also, the accessibility by iodine absorption correlates with the LODP.     

One-pot fabrication of robust hydrophobia and superoleophilic cotton fabrics for effective oil-water separation

A one-pot sonochemical irradiation method was developed for the fabrication of superhydrophobic and superoleophilic cotton fabric from a solution consisting of branched silica nanoparticles and tetraethoxysilane-dodecyltrimethoxysilane sol. The silica/sol-coated cotton fabric could be wetted by liquids of low surface tension, but was water repellent with a water contact angle of 159 ± 1.2° and water shedding angle of 6 ± 0.8°. The as-prepared cotton fabric could be used as effective materials for the separation of oil from water with separation efficiency as high as 98.2% and maintained separation efficiency above 94% after 30 separation cycles for the kerosene-water mixture. Moreover, the superhydrophobic and superoleophilic cotton fabric could maintain stable superhydrophobicity after treatment with strong acidic and alkali solutions, and harsh mechanical damage. Therefore, this reported robust superhydrophobic cotton fabric exhibits encouraging practical application for oil-water separation.     

Effect of solvent on surface wettability of electrospun polyphosphazene nanofibers

Two kinds of biodegradable polymers, poly(ε‐caprolactone) (PCL) and poly[(alanino ethyl ester)_0.67 (glycino ethyl ester)_0.33 phosphazene] (PAGP), were electrospun by using four different solvents. All PCL nanofibrous mats had similar surface water contact angles independent of solvents. However, it was found that the water contact angles of PAGP nanofibrous mats were 102.2° ± 2.3°, 113.5° ± 2.2°, 115.8° ± 1.4°, and 119.1° ± 0.7°, respectively, when trifluoroethanol, chloroform, dichloromethane, and tetrahydrofuran were used as a solvent. This difference was supposed mainly due to phosphorous and nitrous atoms in PAGP being dragged to fiber surface with solvent evaporation during the solidification of nanofibers, because of the strong interaction between positive phosphorous atoms and electronegative atoms in solvents. This interaction was confirmed by Fourier Transform Infrared, and the accumulation of phosphorous and nitrous atoms in the solvent‐casting PAGP film surface was identified by X‐ray photoelectron spectrometry analysis. PCL samples did not show the solvent‐controlled surface wettability because it contained fewer polar atoms. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

基于单宁酸制备可喷涂超疏水材料

通过正硅酸乙酯水解合成了二氧化硅纳米粒子并形成凝胶颗粒,加入单宁酸以优化其形貌,以六甲基二硅氮烷为表面改性剂,合成了具有低表面能的超疏水喷涂材料。并用动态光散射仪(DLS)与扫描电镜(SEM)对其表征。将其分散于乙醇,并对纸张、玻璃、铝箔、木板、棉质纺织物、塑料泡沫等常见表面进行喷涂,均在短时间内构成了超疏水表面,水接触角均在150.0°以上。随后,考察了所制备超疏水涂层在受外力破坏后的自修复性与耐磨性。结果显示:1 g/L的喷涂液仅需喷三层即可构建超疏水表面,得到的涂层具有良好的透明性;超疏水涂层在受外力损坏后可用有机溶剂进行快速简易的自修复;且喷涂后的玻璃片在砂纸上负重磨损距离达到1000 mm后,接触角从153.5°降至105.5°,再喷一层即可恢复到154.0°。     

Fabricating translucent polydimethylsiloxane (PDMS) super-hydrophobic surface greenly by facile water-dissolved fillers

In this study, a polydimethylsiloxane (PDMS) colloid was cast onto a template made of recycled polypropylene for structural duplication to fabricate translucent super-hydrophobic surfaces greenly without the use of any complicated method. The surface structure of the template was formed by hot embossing using salt grain fillers dissolved in water. The resulting contact angle (CA) values of fabricated PDMS surfaces were 153.4 ± 0.6°, 152.3 ± 1.8°, 152.2 ± 0.8°, and 152.0 ± 1.6° and the associated slide angle (SA) values were 5.8 ± 0.6°, 8.7 ± 1.5°, 8.6 ± 1.1°, and 16.3 ± 1.9° for filler grain size categories A, B, C, and D, respectively. The surfaces with grain sizes A, B, and C exhibited super-hydrophobic conditions, where CA > 150° and SA < 10°; on the other hand, the surface with grain size D exhibited an SA value greater than 10°. The measured percentages of light transmittance in the visible wavelength range of 400–800 nm were 75–80% for grain sizes B, C, and D and 85–90% for grain size A. Furthermore, a green laser light was diffused from a spot of 0.5–7.7 cm in diameter; related glare was also eliminated.     

Preparation and characterization of glass-ceramics via co-sintering of coal fly ash and oil shale ash-derived amorphous slag

A novel preparation method of glass-ceramics from coal fly ash (CFA) and oil shale ash-derived amorphous slag (OSAS) was developed in this study. Effects of important factors such as OSAS/CFA ratio and sintering temperature on the crystalline phase compositions, microstructure, mechanical-chemical properties, heavy metals leaching characteristics, and potential ecological risk assessment of glass-ceramics were investigated. The results showed that the properties of glass-ceramics increased with increasing OSAS/CFA ratio and sintering temperature, and S4 glass-ceramics (100% OSAS) showed the most superior product performances, followed by the S3 (80%OSAS-20%CFA), S2 (60%OSAS-40%CFA), and S1 (100% CFA). As for the products from the mixed sources, the best product properties of S2 glass-ceramics (density, 2.00 ± 0.04 g/cm³; water absorption, 3.11 ± 0.22%; and compressive strength, 106.67 ± 28.42 MPa) were achieved at 1085 °C. S3 glass-ceramics showed the highest density of 2.16 ± 0.04 g/cm³, and lowest water absorption of 0.22 ± 0.01%, and highest compressive strength of 195.99 ± 23.85 MPa at 1085 °C. Specially, the overall energy consumption for preparing S2 and S3 glass-ceramics was estimated to be reduced 23.66–27.00% and 11.67–13.50%, respectively, compared to that of S4 glass-ceramics. In addition, the good chemical stability, low heavy metals leaching concentrations and low potential ecological risk of OSAS-CFA-derived glass-ceramics further confirmed its potential and feasibility as building material in engineering application.     

Syndiotacticity-rich poly(vinyl alcohol) fibers spun from N-methylmorpholine-N-oxide/water mixture

Aqueous NMMO solutions containing NMMO above 50% are good solvents for syndiotacticity-rich poly(vinyl alcohol) (s-PVA). Although water is not a good solvent and dissolves s-PVA at temperatures above 100°C, the mixtures dissolve it at temperatures below 100°C. s-PVA fibers were prepared through gel-spinning of s-PVA/NMMO/water (NMMO: water = 70 : 30) mixtures in cold water and wet-spinning of the solution in methanol. The mechanical properties and fine structure of the drawn fibers were examined based on the results of measurements of tensile properties, thermal properties, birefringence, and optical and electron microscopic observations. The strength and Young's modulus of the drawn fibers were approximately to 2.0 and 45 GPa, respectively. The reason why the fibers with theoretical mechanical properties could not be prepared was surmised to be related to the structure of the amorphous regions. © 1993 John Wiley & Sons, Inc.     

High‐temperature resistant superabsorbent based on poly(acrylic acid) with triallylammonium chloride as crosslinking agent

A novel high‐temperature resistant superabsorbent was prepared by solution polymerization of partially neutralized acrylic acid (AA), using triallylammonium chloride as crosslinker, potassium persulfate as initiator. The factors that influence the water‐absorbing capacity at 25 and 200°C such as mass concentration of monomer, mass ratio of crosslinker to AA, mass ratio of initiator to AA, and neutralization degree were investigated. The structure of the superabsorbent was characterized by Fourier transform infrared, thermogravimetric analysis, and scanning electron microscopy. The optimum conditions were obtained and the swelling ratios in distilled water and 1 wt % of NaCl solution could reach 841 and 74 g/g at 300°C, respectively. The superabsorbent also showed high swelling rate and good salt resistance. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41243.     

Dyeing and deodorizing properties of cotton,silk, wool fabrics dyed with Amur Corktree,Dryopteris crassirhizoma,Chrysanthemum boreale,Artemisia extracts

This study used four kinds of natural colorant solutions extracted from Amur Corktree, Dryopteris crassirhizoma, Chrysanthemum boreale, Artemisia using water at 90°C for 90 min with a liquor ratio (solid natural colorant material/solvent water, weight ratio) of 1/10. The dyeing, color fastness, deodorizing properties of cotton, silk, wool fabrics dyed with natural colorant extracts were compared. These properties were found to be significantly dependent on the extract concentration, colorant structure, fabric type. Color fastness (light, water, perspiration fastness) ranged between second and fifth grades and deodorizing performance of fabrics dyed with various natural colorant extracts between 34 and 99%. It is worth noting that the use of natural colorants notably enhanced the deodorizing performance. Wool fabrics showed the highest performance increase at 98–99%, followed by silk and cotton. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Assessment of interfacial polymerization modalities on the performance of polyaniline doped polyethersulphone hollow fiber membranes

Polyethersulfone hollow fiber membranes doped with polyaniline were coated by interfacial polymerization (IP) using different monomer pairs. The coated fibers were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, and atomic force microscopy, water contact angle (CA), porosity, and mechanical properties. Moreover, the performance of coated fibers has been tested at low to medium pressure by measuring pure water flux and magnesium sulfate salt solution. Characteristics and performance have been assessed and compared for all samples. Porosity decreased for all coated samples as compared to the raw sample. Optimum results were obtained using m-phenylenediamine and trimesoyl chloride depicting the lowest water CA (68°), highest Young's modulus (183 MPa), lowest pure water flux (0.28 LMH/bar), and the highest salt rejection (63% at 9 bar).     

Durable,self-cleaning and superhydrophobic bamboo timber surfaces based on TiO2 films combined with fluoroalkylsilane

Decorative materials, including bamboo timber, have been proposed to exploit their superhydrophobic and self-cleaning properties, but a comprehensive appraisal of their environmental adaptability is still deficient. In this paper, a robust and durable superhydrophobic surface was formed on bamboo timber substrate through a process combining chemical solution deposition and chemical modification. The superhydrophobic surface resulted from micro-nanoscale binary-structured TiO₂ films and the assembly of low-surface-energy fluorinated components, which exhibited a water contact angle of 163±1° and a sliding angle of 3±1°. The surface maintained superhydrophobicity after mechanical abrasion against 1500 mesh SiC sandpaper for 800 mm at the applied pressure of 1.2 kPa, indicating good mechanical stability. Moreover, the superhydrophobic surface exhibited good chemical stability against both acidic and basic aqueous solutions (e.g., simulated acid rain). After exposure to atmosphere for more than 180 days, the obtained surface still maintained a contact angle of 155±2° and a sliding angle of 6±2°, revealing good long-term stability. In addition, the as-prepared superhydrophobic surface exhibited almost complete wet self-cleaning of dirt particles with water droplets. It is believed that the method presented in this study can provide a straightforward and effective route to fabricate a large-area, mechanically robust, anticorrosive and self-cleaning superhydrophobic surface on woody materials for a great number of potential applications.     

The Effect of Skin Layer Composition and Operating Parameters on the Performance of Sulfonated Polysulfone-Poly(Vinyl Alcohol) Composite Reverse Osmosis Membrane

Abstract

A composite membrane for reverse osmosis was prepared from sulfonated polysulfone and poly(vinyl alcohol). The effects of overall polymer solution concentration, composition of casting solution, and heat-curing periods on the reverse osmosis performance of the resulting membrane have been examined. The composite membrane was formed by casting the polymer solution as an ultrathin film on a microporous polysulfone supporter, evaporating the solvent, and heat curing at 120°C for a proper period. The influence of different operating parameters on the performance of the resulting membrane was examined. The results showed that the flux of water increased and salt rejection increased with an increase in the ratio of sulfonated polysulfone to poly(vinyl alcohol) (SPSf/PVA). The flux of water is proportional to the operating pressure of the formed membrane with an SPSf/PVA ratio of 3/3–4/2. The flux of water was found to be a highly nonlinear function of the operating pressure of the formed membrane with an SPSf/PVA ratio of 2/4–0/6.     

The influence of solvent composition in the sol-gel synthesis of cobalt ferrite (CoFe2O4): A route to tuning its magnetic and mechanical properties

This work presents a successful, environmentally-friendly route for tuning the magnetic and mechanical properties of CoFe₂O₄ sintered ceramics. The precursor powders were prepared from mixtures containing 100, 50 and 20% water, with the remaining volume composed of isopropanol. The synthesised powders were pressed into pellets and sintered at 1150 and 1200 °C. SEM micrographs indicate that the solvent exerts a major influence over the morphology of the ferrite grains. Vickers hardness shows a maximum for products from a medium containing 50% water, which could be directly related to the smaller average size of the CoFe₂O₄ grains. The coercivity of the pellets is strongly influenced by the reactional medium, with a maximum of 501.7 Oe (sample prepared at 20% water and fired at 1150 °C). This work opens up possibilities for fine tuning of the final properties of CoFe₂O₄ sintered ceramics, further enabling the utilisation of this material in advanced applications.     

Antimicrobial characteristics of N-halaminated chitosan salt/cotton knit composites

Chlorinated chitosan salt/cotton knit composites were prepared, and their water absorbencies, physical and antimicrobial properties, and rechargeabilities were investigated. The water absorbencies of the composites dissolved in acetic acid were higher than in hydrochloric acid. The tensile stress and strain of the composites decreased with increasing citric acid content. The active-chlorine contents of the composites increased with both increasing chlorination time and increasing concentration of the chlorination solution. Antimicrobial tests indicated that the composites had high antimicrobial activity: they completely eliminated Esherichia coli and Staphylococcus aureus. After rechlorination, the active-chlorine content of the composite was slightly higher than that after the initial chlorination, which indicates that the chitosan salt/cotton knit composites are highly rechargeable.     

Production of superhydrophobic polymer fibers with embedded particles using the electrospinning technique

Superhydrophobic materials are currently used for their water‐repelling, self‐cleaning and anti‐fouling properties but are also potentially attractive to prevent snow or ice accumulation on exposed structures. Using the electrospinning technique, polymer mats made of polystyrene and poly[tetrafluoroethylene‐co‐(vinylidene fluoride)‐co‐propylene] (PTVFP) were prepared. They were found to show highly hydrophobic properties, water contact angle (CA) between 130 and 150°, when a dual fiber–bead microstructure was observed. Superhydrophobicity, CA > 150°, was reached when PTVFP mats were electrospun from a polymer solution containing dispersed polytetrafluoroethylene (PTFE) nanoparticles. Using atomic force microscopy imaging, protruding nanosized asperities on fiber and bead surfaces were observed and this structure led to superhydrophobic properties. Materials prepared from a high‐viscosity PTVFP/ethyl acetate solution with PTFE particles, 200 nm diameter and 8% (w/w), showed an 11.2% improvement in hydrophobicity, CA = 161°, compared to the materials obtained from a particle‐free polymer solution (CA = 143°). Copyright © 2007 Society of Chemical Industry     

Discussion of aqueous urethane acrylate oligomers with sulfoisophthalate on the antistatic hydrophilic finishing of different fabrics

In this study, PEG(SE) containing sulfonic acid group was produced by transesterification of dimethyl 5‐sulfoisophthalate sodium salt (SIP) with PEG. The reactive urethane acrylate oligomers were synthesized by using SE as soft segment, isophorone diisocyanate (IPDI) as hard segment, and hydroxyethyl methacrylate (HEMA) as blocking agent. Their solution properties and thermal properties were investigated. Dipping process was carried out on polyethylene terephthalate (PET) fabric, polyamide (nylon) fabric, and cotton fabric for hydrophilic finishing and the effects of processing condition on the fixation behavior and hydrophilic property of treated fabric have been discussed. The conclusions are as follows: the particle size of oligomer solutions are about 45–90 μm, surface tension of solutions are below 43 dyn/cm, and they have smaller contact angle than water. The particle size, particle variance, and streaming current reading decreased, but the surface tension and contact angle enhanced upon increasing PEG molecular weight. The melting point of oligomer is 38°C–52°C and the glass transition point is −18°C to −25°C. In comparison with the fabric finishing, the add‐on of PET fabric is the highest, followed by nylon, then cotton. The durability of treated cotton fabric is the highest, followed by PET, then nylon. The hydrophilicity is most stable for nylon fabric with PEG molecular weight of 2,000, and cotton and PET fabric with molecular weight of 1,000. POLYM. COMPOS., 29:45–57, 2008. © 2007 Society of Plastics Engineers     

Membranes composites preparees a partir d'alcool polyvinylique et de diisocyanate de toluylene destinees a l'osmose inverse

Composite reverse osmosis membranes have been prepared by coating a Millipore filter with an ultrathin layer of polyvinyl alcohol crosslinked by toluene diisocyanate. The membranes present a good selectivity towards aqueous salt solutions (for instance water flux of 500 liters/m²-day at 28°C, salt rejection of 98% with a 3.5% NaCl solution under a pressure of 100 bars) and have better temper-ature and pressure stabilities than cellulose acetate membranes. Their resistance to acid and alkaline hydrolysis is satisfactory. The influence of different preparation factors on the osmotic properties of the membranes was examined.     

Separation of non-sulfonated oil from industrial petroleum sulfonate

Abstract

The non-sulfonated oil in industrial petroleum sulfonate was separated by centrifugal method and extraction method, respectively. The oil separation rates of each method were compared, and the effects of oil separation rates under different conditions on the purity of non-sulfonated oil were investigated. The purity information of non-sulfonated oil separated by different methods was analyzed by infrared spectroscopy. The experimental results showed that the oil separation rate of centrifugation was low, and the oil extraction rate was higher. The purity of non-sulfonated oil separated with alcohol–water solution as extractant was lower, while the purity of non-sulfonated oil separated by water extraction method was the highest, and the extractant was nontoxic and environmentally friendly. Water was preferred as extractant. Solvent ratio, temperature and pressure all had great influence on oil separation rate. The optimum conditions for SL petroleum sulfonate were: solvent ratio 1.5:1, 90?°C, atmospheric pressure, which the oil separation rate was 78.51%; and for DQ petroleum sulfonate, the optimum conditions were: solvent ratio 2:1, 90?°C, atmospheric pressure, which the oil separation rate was 79.86%. Non-sulfonated oil separated by water extraction had the least petroleum sulfonate, followed by ethanol single solvent extraction. Although the extraction efficiency of isopropanol aqueous solution and n-pentane was the highest, the content of petroleum sulfonate in non-sulfonated oil was the highest, which affected the product performance and should not be used.