Lime mud CaCO3 for use as a filler material in papermaking: Impact of its preflocculation with cationic polyacrylamide

Cationic polyacrylamide with different molecular weights were used to preflocculate the lime mud (LM) before it was added to the paper stock for handsheet preparation. The particle sizes, ζ potential, and morphology of the unpreflocculated and resulting preflocculated LM were studied. We found that high‐molecular‐weight cationic polyacrylamide (H‐CPAM) led to larger LM flocs with a more positive ζ potential. The scanning electron microscopy images indicated that the morphological structure of the filler hardly changed during the preflocculation process. The effects of the preflocculation on the filler retention and paper properties were also investigated. The results show that the handsheets filled with preflocculated LM had better hydrophobicity and strength properties compared to handsheets filled with unpreflocculated LM, especially for H‐CPAM‐preflocculated LM. The paper formation was also improved, and the optical properties nearly remained the same. In addition, the LM preflocculated with H‐CPAM had the highest filler retention. At a filler loading of 30%, the filler retention of the H‐CPAM‐preflocculated LM was higher than 86; it was less than 82.5% in other cases. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41640.     

Boronic acid‐based thin films that show saccharide‐responsive multicolor changes

A novel saccharide sensor that displays a distinct color change resembling a “traffic signal” was developed. By copolymerizing boronic acid and amine monomers on a glass plate, a boronic acid‐containing thin film was obtained. Anionic blue and yellow dyes were adsorbed on the thin film, and the film was immersed in aqueous saccharide solutions containing a cationic red dye. With increase in the saccharide concentration in the solution, the thin film changes color from green to red via yellow. The observed distinct changes in color were attributed to a stepwise release and binding of dyes. The sensitivity of the saccharide sensor was dependent on the monomer composition of the thin film and increased with increasing the boronic acid content. The pH of the saccharide solution was another key factor affecting the sensing behavior, and glucose‐responsive color changes were significantly enhanced at pH 7.8. By optimizing these conditions, significant color changes in response to glucose were achieved. Saccharide selectivity was found to be in the following order: fructose > glucose > galactose = mannose > sucrose. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42679.     

TiO_2-海藻酸钙复合膜的表征、对染料的光催化降解及TiO_2回收

为了解决TiO2纳米粒子难分离,负载的催化剂难回收等问题,首先,将TiO2与海藻酸钠充分混合制成铸膜液,在玻璃板上刮膜,经钙离子交联制备了TiO2-海藻酸钙(T-CA)复合膜。然后,对T-CA复合膜进行了SEM和XRD表征,并研究了T-CA复合膜对染料的光催化降解性能。最后,将T-CA复合膜从染料降解液中取出,浸泡在柠檬酸钠水溶液中,柠檬酸根对钙离子的结合力较强,可使海藻酸盐水凝胶溶解,离心分离TiO2纳米粒子并清洗干燥后,得到了回收TiO2;利用SEM、TEM、FTIR和XRD对回收TiO2进行了表征。结果表明:T-CA复合膜对甲基橙的光催化降解率可达82.37%。回收TiO2与初始的TiO2几乎完全一样,可重新使用且催化能力不变。该方法是一种绿色环保、方便快速的从载体中回收TiO2纳米粒子的方法。     

Low‐temperature plasma processing for the enhancement of surface properties and dyeability of wool fabric

In the present investigation, wool fabric was treated with a low‐temperature air plasma. The plasma discharge power and treatment time were varied. The effect of plasma treatment on various fabric properties such as wettability, wickability, dyeability, crease recovery angle, breaking strength, and elongation at break was investigated. Surface morphology was studied using SEM micrographs. The fabric became substantially hydrophilic even with a short duration of air plasma treatment of 30 s with improvement in dye uptake and in the rate of dyeing when dyed at a lower temperature. Under these treatment conditions, aging was almost nil in a dry environment, even after 45 days, whereas some aging was observed in a humid (75% relative humidity) environment. A 20% increase in the breaking strength and 24% increase in the elongation at break were observed with reduction in wrinkle recovery angle to 133–144° from 169° for untreated fabric. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43097.     

Synthesis,characterization, and photo‐responsive properties of Y‐shaped amphiphilic azo triblock copolymer

In this study, we report the synthesis, characterization, and photo‐responsive properties of a new Y‐shaped amphiphilic azo triblock copolymer composed of two isotropic polyethylene glycol (PEG) blocks and an azobenzene liquid crystalline block. The azo block, with two ending groups suitable for the azo coupling reaction, is polymerized by atom transfer radical polymerization with a synthesized initiator containing two functional terminal groups. The macromolecular diazonium salts are prepared by the diazotization of PEG terminated with an amino group. The triblock copolymer is obtained by the azo coupling reaction between the azo block and macromolecular diazonium salts in DMF under mild condition. The intermediates and the obtained triblock copolymer are characterized by ¹H NMR, FT‐IR, GPC, POM, DSC, TEM, and UV‐vis. The photoinduced isomerization behavior of the azo copolymer is investigated by UV‐vis. With the addition of water into the solution of the triblock copolymer, spherical aggregates with an average diameter of about 400 nm can be easily obtained. The aggregates are elongated when irradiated with polarized 365 nm UV light. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43695.     

Bioaugmentation of floating treatment wetlands for the remediation of textile effluent

This pilot study evaluated the effects of bacterial augmentation on the efficiency of floating treatment wetlands (FTWs) to remediate textile wastewater. Two wetland plants, Phragmites australis and Typha domingensis, were used to develop FTWs, which were then augmented with a bacterial consortium of three strains (Acinetobacter junii, Pseudomonas indoloxydans, and Rhodococcus sp.). Results showed that both plant species removed colour, organic matter, toxicity, and heavy metals from textile wastewater and their removal efficiency was further enhanced by augmentation with bacteria. The maximum removal efficiencies of colour, COD and BOD after an 8‐day period were 97, 87 and 92%, respectively, by FTWs carrying P. australis inoculated with the bacterial consortium. Furthermore, the same combination showed 87–99% reduction of heavy metals in the textile wastewater as well. These results indicate that FTWs can be used for the treatment of textile effluent and their working efficiency can be improved by plant‐bacterial synergism.     

膨润土在织物印花中应用研究

研究了膨润土矿物糊料制备及其流变性能、与常用糊料染料和各种助剂的相容性、印花工艺及配方.结果表明:膨润土经选矿提纯制备矿物印花糊料,可部分替代海藻酸钠用于活性染料印花,印制效果良好,产品得色浓艳,各项牢度指标符合标准要求,     

Synthesis of novel polyaniline/MgO composite for enhanced adsorption of reactive dye

In this investigation, the porous structure of polyaniline/MgO (PANI/MgO) composites has been successfully synthesized by in‐situ oxidative polymerization method. The as‐prepared materials were characterized by Ultraviolet–visible absorption spectroscopy, Fourier transform infrared spectroscopy, X‐ray diffraction, and scanning electron microscopy. The obtained composites, for the first time, are used as an adsorbent for the removal of the sulfonated anionic dye reactive orange 16 (RO) from aqueous solution. The equilibrium adsorption isotherms of RO on the PANI/MgO composites were analyzed by Langmuir and Freundlich models, suggesting that the Langmuir model provides the better correlation of the experimental data and maximum adsorption capacity was found to be 558.4 mg g^?1. In addition, adsorption kinetics was followed by both pseudo‐first‐order and pseudo‐second‐order, but the latter model matches the results much better than the former one. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40210.     

Feldspar/titanium dioxide/chitosan as a biophotocatalyst hybrid for the removal of organic dyes from aquatic phases

Feldspar/titanium dioxide/chitosan hybrid, a photoactive biocompatible adsorbent for anionic dyes, was synthesized, characterized, and successfully tested. The adsorbent characterization, pH role, adsorbent dose effect, equilibrium data, kinetic plats, and thermodynamic parameters are reported. The point of zero charge for the hybrid was measured to be 8.3, and the most favorable pH range for the adsorption process was found to be below this pH value. The adsorption equilibrium study demonstrated that the Freundlich model was best fitted to the experimental data. Without UV light exposure, the prepared adsorbent adsorbed 72 mg of Acid Black 1 (AB1)/g of sorbent (86% removal) from a 100‐mL solution with an initial dye concentration of 50 mg/L, whereas UV irradiation resulted in an increase in the elimination of AB1 dye (97% removal). The kinetic data was depicted well by the pseudo‐second‐order model. The thermodynamic parameters indicated that the reaction between the hybrid and the dye was exothermic and also spontaneous at lower temperatures. In the batch desorption process, several aqueous solutions adjusted to different pH values were tested, and the best desorption performance (90% desorption) was achieved at pH 11. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40247.