膜分离现状及发展趋向

本文简要综述了近年来国内外反渗透、超过滤、微孔过滤、扩散渗析、电渗析、气体分离、液膜、渗透蒸发、蒸发渗透等一些主要膜分离过程,特别是有关新膜研制方面的开发现状及其发展趋向。     

水中痕量酚的富集和紫外分光光度测定法的研究

本文研究了用微型树脂柱快速富集,分离,紫外分光光度测定水中痕量酚的方法。结果表明,以GDX-502为吸附剂,水样pH为1～3并含0.2mol/L氯化钠,以每分种15～20ml的速度通过吸附柱,以热的1％氢氧化钠水溶液为淋洗剂时,在291nm处测定苯酚的回收率为89～98％。此外探讨了干扰物的消除方法。吸附柱对苯酚的富集倍数达300倍,最低检测限为0.001ppm。方法精密度为0.3(％),相对标准偏差为3.18％。本法对实际水样进行了测定。结果满意。     

Polyol-mediated solvothermal synthesis and luminescence properties of CeF3, and CeF3:Tb nanocrystals

CeF₃ and CeF₃:Tb³⁺ nanocrystals were successfully synthesized through a facile and effective polyol-mediated route with ethylene glycol (EG) as solvent. Various experimental techniques including X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and photoluminescence (PL) spectra as well as decay dynamics were used to characterize the samples. The results indicated that the content of NH₄F and reactant concentrations were key factors in the product shape and size. Excessive NH₄F was necessary for the formation of hexagonal nanoplates. The specific morphology of product can be controlled by changing the NH₄F content and reactant concentrations. In addition, Tb³⁺ doped-CeF₃ sample shows strong green emission centered at 544 nm corresponding to the ⁵D₄-⁷F₅ transition of Tb³⁺. Due to the decrease of nonradiative decay rate, the lifetime of ⁵D₄ level of Tb³⁺ become longer gradually upon increasing the size of product.     

以芳胺为电子给体的D-π-A有机光敏染料———— 染料敏化太阳电池中的应用

不含金属的有机染料在染料敏化太阳电池（DSC）中的应用愈加广泛,以芳胺为电子给体的D-π-A分子是其中重要的一类。本文依据芳香胺的结构,将近5年来应用于DSC中一百多个D-π-A分子分成四类,包括：基于N-烷基-苯胺的D-π-A光敏染料,基于三苯胺的D-π-A光敏染料,由包含芴基团的三芳胺构建的D-π-A光敏染料,包含芳胺基团的其它结构类型的D-π-A光敏染料。评述了它们的光电转换性能。     

Synthesis and self-assembly behavior of thermoresponsive triblock copolymer

Block copolymers comprising thermosensitive poly(N-isopropylacrylamide) (PNIPAM) and hydrophobic poly(n-butyl acrylate) (PBA) blocks, were synthesized using the reversible addition-fragmentation chain transfer polymerization (RAFT), their thermosensitive behavior was studied by ultraviolet spectrophotometer (UV) and dynamic light scattering (DLS). The lower critical solution temperature (LCST) was strongly correlated to the hydrophobic/hydrophilic ratio of the copolymers. Their micellization and self-assembly behavior in dilute aqueous solution were studied by surface tension (SFT), DLS and TEM. The resulting block copolymers reversibly formed or deformed micellar assemblies during their LCSTs. The critical micelle concentration (CMC) was controlled by the composition of PBA and PNIPAM, indicating the successful formation of the block copolymers.     

Nickel‐Catalyzed Site‐Selective Amidation of Unactivated C(sp3)H Bonds

Intramolecular dehydrogenative cyclization of aliphatic amides was achieved on unactivated sp³ carbon atoms by a nickel‐catalyzed C?H bond functionalization process with the assistance of a bidentate directing group. The reaction favors the C?H bonds of β‐methyl groups over the γ‐methyl or β‐methylene groups. Additionally, a predominant preference for the β‐methyl C?H bonds over the aromatic sp² C?H bonds was observed. Moreover, this process also allows for the effective functionalization of benzylic secondary sp³ C?H bonds.     

Determination of phthalate esters in liquor samples by vortex‐assisted surfactant‐enhanced‐emulsification liquid–liquid microextraction followed by GC–MS

A novel method using vortex‐assisted surfactant‐enhanced‐emulsification liquid–liquid microextraction has been developed for the extraction of phthalate esters (PAEs) in Chinese liquor samples prior to analysis by GC–MS. In the proposed method, a high‐density extraction solvent (carbon tetrachloride) was dispersed into samples with the aid of a surfactant (Triton X‐100) and vortex agitation, resulting in a short extraction equilibrium (30 s). After centrifugation, a single microdrop of solvent was easily collected for GC–MS analysis. Key factors that affected the extraction efficiency were optimized. Under the optimum conditions, linearity was found in the range from 0.05 to 50 μg/L. Coefficients of determination varied from 0.9938 to 0.9971. LODs, based on an S/N of 3, ranged from 4.9 to 13 ng/L. Enrichment factors varied from 140 to 184. Reproducibility and recoveries were assessed by testing a series of three liquor samples that were spiked with different concentration levels. Finally, the proposed method was successfully applied to the determination of PAEs in 16 Chinese liquor samples. In this work, high‐density‐solvent vortex‐assisted surfactant‐enhanced‐emulsification liquid–liquid microextraction was applied for the first time for the extraction of PAEs in Chinese liquor samples and was proved to be simple, rapid, and sensitive.     

Single‐electron transfer‐living radical polymerization of oligo(ethylene oxide) methyl ether methacrylate in the absence and presence of air

The efficient Cu(0) wire‐catalyzed single‐electron transfer‐living radical polymerization (SET‐LRP) of oligo(ethylene oxide) methyl ether methacrylate (OEOMA) in DMSO and binary mixtures of DMSO with H₂O is reported. Addition of 10–80% H₂O to DMSO resulted in an increase in the apparent rate constant of propagation ( ), corresponding to an increase in the polarity and extent of disproportionation. At higher H₂O content, decreases, and in H₂O is slightly lower than that in DMSO. This unexpected behavior was attributed to the physical inaccessibility of Cu(0) wire catalyst to the hydrophobic reactive centers of OEOMA and initiator which self‐assemble in H₂O into micellar aggregates and vesicles. This hypothesis was confirmed by the faster polymerization in H₂O than in DMSO during catalysis with Cu(0) nanoparticles generated by disproportionation of CuBr. SET‐LRP of OEOMA can be performed in protic and dipolar aprotic solvents in air by the addition of hydrazine hydrate. The polymerization exhibited no induction period and identical as in the degassed experiment, and led to polymers with narrow molecular weigh distribution. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 3110–3122