Synthesis, Crystal Structures and Fluorescence Properties of Two One-Dimensional Cadmium(II) Coordination Polymers Containing Flexible Bis(benzimidazole) Ligands

Two one-dimensional Cd(II) coordination polymers constructed by ribbon-like molecules, {[Cd(L₁)₂(NO₃)]·NO₃} _n (1) (L₁ = 1,3-bis(5,6-dimethylbenzimidazol-1-yl)benzene) and [Cd(L₂)₂(NO₃)₂] _n (2) (L₂ = 1,3-bis(benzimidazol-1-yl)benzene) have been obtained through assembly of the two structurally similar flexible bis(benzimidazole)-based ligands and cadmium nitrate tetrahydrate. The cadmium(II) centers display different coordination environments with trigonal-bipyramidal geometry in 1, and a octahedral geometry in 2. Weak C–H···O interactions in 1 result in a two-dimensional supramolecular layer; two π–π interactions are present in 2 forming a three-dimensional supramolecular network structure. The solid state fluorescence properties of 1 and 2 were investigated.     

我国DSD酸产品标准化工作30年

自1982年原化工部首次颁布了我国DSD酸产品第一部化工部标的化工行业标准）HG2—1436-82以来迄今已有30年。30年来对该标准先订,标准号先后改为HG2279．1992、HG／T2279—2000、HG／T2279-2011。版本标准的主要内容及每次修订的主要内容,详细解读于2012年7月1HG／T2279—2011。准（相当于现行后进行了三次修该文介绍这四个日实施的新标准     

喜旱莲子草基活性炭制备及其对苯酚吸附性能的研究

利用喜旱莲子草制备活性炭,选择了活化剂、活化剂浓度、碳化时间、碳化温度等作为实验的四个因素,每个因素选取三个水平,采用正交实验法,得出了最佳制备条件:以2 mol/L的H3PO4作为活化剂,碳化温度400℃,碳化时间1 h。比较了不同时间、不同活性炭用量、不同温度下,喜旱莲子草基活性炭对苯酚的吸附效果。此外,动态吸附实验表明:提高活性炭用量(即增加填料高度),降低进水苯酚浓度以及减小进水流量均能相应延长喜旱莲子草基活性炭去除苯酚到达穿透点的时间,从而增加最大吸附容量。     

海南火山岩滤料BAF工艺的高温挂膜启动中试研究

通过构建上向流曝气生物滤池(BAF)污水处理系统,在高温(28～30℃)条件下,试验了基于海南火山岩滤料的BAF处理城市污水的挂膜启动过程。结果表明,高温条件下挂膜启动时间较中低温大大缩短。25 d后挂膜启动完成,此时COD、NH4+-N的去除率分别稳定在80%、98%,出水COD和NH4+-N的质量浓度分别稳定在50 mg/L和5mg/L以下,水质良好且运行稳定,满足GB 18918-2002中规定的一级A排放要求。证明海南火山岩滤料挂膜性能良好,具实用价值。     

Preparation of Platinum‐Poly(O‐dihydroxybenzene) Composite Catalyst and Its Electrocatalytic Activity Toward Methanol and Formic Acid Oxidation

A composite catalyst has been successfully prepared by dispersing Pt nanoparticles on a poly(o‐dihydroxybenzene) (PoDHB) modified glassy carbon (GC) electrode and characterized by SEM, EDX, and electrochemical analysis. Compared with Pt nanoparticles deposited on the bare GC, the Pt/PoDHB/GC exhibits higher catalytic activity and stronger poisoning tolerance for electro‐oxidation of methanol and formic acid. The enhanced performance could be attributed to the increase of electrochemical active surface area (EASA) arisen from the PoDHB modification. Furthermore, performance limiting factors such as platinum loading, polymer mass, H₂SO₄, methanol, and formic acid concentrations have been evaluated for optimizing the electrocatalytic activities.     

Preparation and characterization of electrospun polyurethane/inorganic‐particles nanofibers

To develop a novel functional fibrous scaffold, a blend‐electrospinning technique was applied to transfer polyurethane/inorganic‐particles solutions into nanofibers, in which titanium dioxide, copper, or/and silver nanoparticles were used. The resultant nanofibers were subsequently characterized by means of scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and tensile mechanical test. Furthermore, the structural change and the thermal properties of the electrospun fabrics were examined by X‐ray diffraction and differential scanning calorimetry, respectively. Antibacterial performance of the resulting nanofibrous mats on Escherichia coli and Staphylococcus aureus was also measured. Experimental results have shown that when the ratio of polyurethane solution and titanium dioxide sol was in 3.5:1, 89.55% of the Escherichia coli and 82.35% of the Staphylococcus aureus bacteria were killed under a UV‐light activation. However, the introduction of silver or/and cuprum nanoparticles into the polyurethane/TiO₂ (in the ratio of 3.5:1) nanofibers led to a significant improvement in their antibacterial ability without any photocatalysis.POLYM. COMPOS., 33:2045–2057, 2012. © 2012 Society of Plastics Engineers     

光学遥感舰船目标识别方法

提出一种基于粗糙集理论和分层判别回归技术的光学遥感舰船目标识别方法。该方法首先提出新的光学遥感舰船识别特征———面积比编码,并与四类特征组合作为备选特征;然后基于粗糙集理论按同可区分度来计算各备选特征的重要性权值,自动选择出对正确识别贡献较大的特征组合;最后根据分层判别回归原理生成分类判决树来识别光学遥感舰船目标。实验结果表明,本文方法在识别精度和速度方面优于最近邻和支持向量机方法,且通用可行。     

High‐performance printable paper‐like composites derived from plastic flexible film wastes

Owing to lack of proper recycling methods, plastic flexible film wastes are usually directly discarded or incinerated, which brings about severe environmental pollution. Therefore, converting plastic wastes into value‐added products has received more and more attention in recent years. In this work, paper‐like composites derived from plastic flexible film wastes were prepared via the thermally induced phase separation method by adding polyethylene‐graft‐maleic anhydride (PE‐g‐MAH) as a compatibilizer and fumed silica as an additive. The resulting paper‐like composites were characterized by SEM and infrared spectroscopy. Other properties such as mechanical properties, thermal properties, whiteness, printability and adsorption performance were also tested in detail. It was found that remarkable enhancements in mechanical, thermal and printable properties of the paper‐like composites were obtained when nano‐SiO₂ loading was 2.5–3 wt%. Uniformly distributed holes that can endow good printability by providing space for ink or other functional molecules were observed by using SEM. Furthermore, the CIE whiteness value of the resulting composites can reach 91.6%–96.7% on adding nano‐SiO₂. Additionally, the paper‐like composites integrating nano‐SiO₂ and PE‐g‐MAH exhibited good solid ink affinity and high water or oil adsorption capacity. Thus, according to this research, high‐performance printable paper‐like composites used as major components of multifunctional papers can be prepared based on plastic flexible film wastes. © 2019 Society of Chemical Industry     

Synthesis,aggregation and adsorption behaviour of a thermoresponsive pentablock copolymer

Poly(ethylene oxide)–poly(propylene oxide)–poly(ethylene oxide) (PEO–PPO–PEO) triblock copolymer (Pluronic F127) was modified by introducing poly(N‐isopropylacrylamide) (PNIPAM) at both the PEO ends, and the pentablock copolymer (PNIPAM₄₁–F127–PNIPAM₄₁, PN41) so prepared was characterized using gel permeation chromatography and ¹H NMR spectroscopy. The degree of polymerization of NIPAM blocks at the two ends was 41. The solution behaviour and microstructure of PN41 aggregates in water were examined using UV–visible spectroscopy, micro‐differential scanning calorimetry and small‐angle neutron scattering (SANS) and compared with F127. Two lower critical solution temperatures (LCSTs) were observed for the pentablock copolymer, corresponding to PPO and PNIPAM blocks, respectively. The adsorption of PN41 on thiol‐grafted hydrophobic gold surfaces at various temperatures was investigated using a quartz crystal microbalance. It was found that the adsorption behaviour and mechanism of PN41 were mainly determined by the interactions of the pentablock copolymers with different chain conformations in dilute aqueous solutions at various temperatures. SANS measurements were used to determine the temperature‐dependent structural evolution of polymer micelles in aqueous solution. A NOESY study revealed that above the LSCT of PNIPAM, the interaction of PPO and PNIPAM protons increases and the distance between PPO and PNIPAM decreases. © 2019 Society of Chemical Industry     

Excellent Mechanical and Transparency Properties of Cationic Waterborne Polyurethane Films Modified by Boehmite Sol

The strategies for nanosol from metal alkoxide have enabled production of ultratransparent and mechanically robust polymer nanocomposites at extremely high loading. Herein, a simple approach to fabricate high‐performance polyurethane‐based nanocomposites via unmodified boehmite nanoparticles is reported. Evaluating their physical properties, the uniform dispersion of boehmite in the matrix caused nanocomposites retains ultrahigh transparency. Hydrogen bonding and intermolecular entanglement between boehmite and polyurethane brings about the mechanical properties of the nanocomposites material enhanced, i.e., strength, stiffness, and toughness. Optimized strength, stiffness, and toughness of Boehmite/Cationic waterborne polyurethane at 40 wt% (BNC40) are up to 58.1 MPa, 1096.7 MPa, 249.5 MJ m^?3, respectively. Furthermore, the feasibility and mechanism of polymer strengthening and toughening by inorganic rigid nanoparticles is explored from the aspects of crystallinity and micromorphology.