含联苯三羧酸及二咪唑基吡啶配体的两个锌配位聚合物的合成、结构及荧光性质

以3,3′,5-联苯三羧酸(biphenyl-3,3′,5-tricarboxylic acid,H3bpta)、2,6-二(1-咪唑基)吡啶(2,6-bis(imidazole-1-yl)pyridine,bip)、Zn(NO3)2·6H2O和ZnCl2为原料,在水热条件下合成了配位聚合物{[Zn3(H2O)7(bpta)2]·5H2O}n(1)和{[Zn2Cl(bpta)(bip)2]·2H2O}n(2)。并利用红外、元素分析和X-射线单晶衍射等对其结构进行表征。X-射线单晶衍射分析表明:化合物1属于单斜晶系,C2/c空间群,a=3.317 1(11)nm,b=1.495 7(5)nm,c=0.695 1(2)nm,β=91.50°,Z=4;化合物2属于单斜晶系,P2/c空间群,a=1.960 4(4)nm,b=1.035 7(2)nm,c=1.998 7(4)nm,β=101.97(3)°,Z=4。化合物1通过bpta桥联Zn髤形成1D链,通过配位水与羧基氧之间的氢键作用构筑成3D结构。化合物2中bip桥联Zn髤构成1D螺旋链状结构,进一步通过bpta桥连形成2D网状结构。此外,对化合物1和2进行了热稳定性分析和荧光性质研究。     

Preparation of Fluorescent Polystyrene via ATRP with Dimethylamino Chalcones as Initiator

4‐(3‐(4‐(Dimethylamino)phenyl)acryloyl)phenyl‐2‐bromo‐2‐methylpropanoate (APPBr) was used for the heterogeneous atom transfer radical polymerization (ATRP) of styrene (St) with copper(I) bromide/N,N,N′,N′′,N′′‐pentamethyldiethylenetriamine (PMDETA) catalytic system. The functional end group was characterized via UV‐Vis and ¹H NMR spectra. The polymerization showed a first‐order kinetic characteristic and each of the obtained polymers had well‐controlled molecular weight and relatively low polydispersity index (PDI). Furthermore, the obtained end‐functionalized polystyrene (PS) in solution showed strong green‐light emission which is further affected by mixing different metal cations. In particular, the fluorescent intensity of the polymer was decreased in the presence of Ag⁺, Cu²⁺ and Fe³⁺.     

Simultaneous determination of dihydroxybenzene isomers utilizing a thiadiazole film electrode

The present study reports a sensitive electro-analytical method for the simultaneous determination of dihydroxybenzene isomers by using a thiadiazole film electrode, which was readily prepared by electropolymerization of 2,5-dimercapto-1,3,4-thiadiazole on a glassy carbon electrode with cyclic voltammetry. The functionalized electrode has a distinguishable and sensitive response to dihydroxybenzene isomers. Under the optimized conditions, the linear stripping peak currents showed good linear relationships with hydroquinone, catechol and resorcinol at concentration ranges 0.50-120, 0.50-110 and 1.00-110 μmol/L, and the detection limits are 0.1, 0.1 and 0.3 μmol/L, respectively. The proposed method is applicable to the simultaneous determination of dihydroxybenzene isomers in real samples with the relative standard deviations of less than 5.7% and the recovery rates of 95.6%-106%. The constructed electrode is characterized by simple preparation, good selectivity, and high sensitivity advantages.     

Exponentially modified Gaussian relevance to the distributions of translocation events in nanopore-based single molecule detection

Nanopore technique plays an important role in single molecule detection, which illuminates the properties of an individual molecule by analyzing the blockage durations and currents. However, the traditional exponential function is lack of efficiency to describe the distributions of blockage durations in nanopore experiments. Herein, we introduced an exponentially modified Gaussian （EMG） function to fit the duration histograms of both simulated events and experimental events. In comparison with the traditional exponential function, our results demonstrated that the EMG provides a better fit while covers the entire range of the distributions. In particular, the fitted parameters of EMG could be directly used to discriminate the sequence length of the oligonucleotides at single molecule level.     

Synthesis and properties of poly(3-hydroxybutyrate-co-3-hydroxyvalerate)/chitin nanocrystals composite scaffolds for tissue engineering

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)/chitin nanocrystals (CNC) composite scaffolds were synthesized by the salt leaching and thermally induced phase separation (TIPS) technique. The scaffolds have porous structures with macro-pores (100-300 mm in diameters) and micro-pores (10 mm). The surface characteristics of the scaffolds were characterized by X-ray photoelectron spectroscopy (XPS) and static water contact angle measurement, and the mechanical properties were investigated by a compression test. Human adipose-derived stem cells (hADSCs) were seeded onto the PHBV/CNC scaffolds and in vitro cell culture results showed that the composite scaffolds enhanced the hADSCs adhesion, which implies that the material may have potential application in tissue engineering.     

湿式氧化用于染料废水脱色:过去20年回顾（英文）

Wet air oxidation(WAO), a liquid phase reaction between organic materials in water and oxygen, is one of the most economical and technologically viable advanced oxidation processes for wastewater treatment, particularly toxic and high organic content wastewater. WAO is the liquid phase oxidation of organics or oxidizable inorganic components at elevated temperatures(125–320 °C) and pressures(0.5–20 MPa) using gaseous oxygen(or air) as oxidant. In the past two decades, the WAO process was widely studied and applied in the treatment of dye wastewater. Compared to conventional WAO, catalytic WAO processes have higher efficiency and use moderate reaction conditions. The catalysts included homogenous and heterogeneous types. The key points that need to be solved are recycling of homogenous catalysts and better stability of heterogeneous catalysts. In the present review, the technological processes are first introduced, then some research history and hotspots of WAO research are presented, and finally, its application in the treatment of dye wastewater in the past two decades is summarized to reveal the impressive changes in modes, trends, and conditions used. The application includes model pollutant studies and wastewater tests.     

非晶Ce-Ti氧化物用于NH3选择性催化还原NO的原位红外研究

采用原位红外光谱研究了在具有短程有序Ce-O-Ti结构的非晶Ce-Ti氧化物上NH₃选择性催化还原（SCR） NO_x反应. 在反应条件下,催化剂表面主要被NH₃吸附物种覆盖,而检测不到NO_x吸附物种. 经测定,NO的反应级数为0.5-0.6,表明Langmuir-Hinshelwood机理和Eley-Rideal机理同时存在. 可能的机理是NH₃吸附物种和弱吸附的NO_x反应,生成NH_yNO₃ （y = 0-4）活性中间物种,并通过GAUSSIAN计算和原位红外结果证实了它们的存在. Ce-O-Ti结构中Ce与Ti之间表现出原子尺度的相互作用,所以在SCR反应的活性温度窗口下,催化剂的氧化还原活性提高.     

Toughening of polycarbonate through reactive melt blending: Effect of hydroxyl content and viscosity of hydroxyl-terminated polydimethysiloxane

In this study, four hydroxyl-terminated polydimethylsiloxanes(PDMSOH) with different viscosities and hydroxyl contents were used to improve the toughness of polycarbonate(PC) through reactive melt blending. A largely improved toughness of PC has been achieved, and the low temperature toughness of PC/PDMSOH blends could overtake that of PC homopolymer in much higher temperatures(e.g.-10 °C versus 23 °C). Moreover, it was found that the more the hydroxyl content, the less the PDMSOH was needed to reach the highest toughness, suggesting that equivalent molar ratio between the carbonyl group content of PC and the hydroxyl group content of PDMSOH was required for the toughening of PC. Ultraviolet spectrophotometry was used to analyze the possible reaction between PC and PDMSOH. Contact angle was measured to assess the change of interfacial interaction between PC and PDMSOH as change of viscosity and hydroxyl content. The formation of PC-co-PDMSOH copolymer was believed to be the key for the toughening effect. This work gives a profound recommendation of the optimum kind and dosage of PDMSOH which should be used to improve the toughness of PC and will find immediate industrial applications.     

Effect of Molecular Weight on the Properties of Poly（butylene succinate）

Poly（butylene succinate） （PBS） with different molecular weight was synthesized from 1, 4-butanediol and succinic acid by direct melt condensation. The synthesized PBS was identified by IH-NMR and FTIR spectrometry. The molecular weight was calculated from the intrinsic viscosity, and its value was between 20000 and 70000. The crystallization behavior and crystal morphology as function of molecular weight were investigated by DSC and PLM, respectively. The mechanical properties and hydrolytic degradation behaviors related with change of molecular weight were also studied in this work. The results demonstrated that the properties of PBS were determined by both molecular weight and crystallization properties （crystallinity as well as crystal morphology）. Our work is important for the design and preparation of PBS with proper molecular weight for its practical application.     

Morphology Evolution of Poly（vinylidene fluoride） Membranes during Supercritical CO2 Assisted Phase Inversion

A supercritical carbon dioxide（Sc CO2） assisted phase inversion was developed to produce microporous poly（vinylidene fluoride）（PVDF） membranes whose morphology characteristics arise from both liquid-liquid demixing and solid-liquid demixing（crystallization）. This result was confirmed by Fourier transform infrared spectroscopy（FTIR）, from which both α and β crystals were found. As revealed by contact angle experiment, the PVDF membranes prepared via Sc CO2 assisted phase inversion were more hydrophobic compared with the control membrane produced via conventional immersionprecipitation technique. In particular, the sample with 15 wt% PVDF prepared at 45 °C and 13 MPa exhibited a contact angle of 142°, which was mainly caused by the multilevel micro- and nano- structure. The effects of polyethylene glycol（PEG）, polyvinyl pyrrolidone（PVP） and lithium chloride（Li Cl） on the structures and crystal form were investigated. PVP promoted the formation of β phase crystal form, while PEG boosts the evolution of α phase. Li Cl restrained the crystallization degree of PVDF membrane under Sc CO2.