含倍半硅氧烷的大分子光引发剂的合成及其光引发性能

通过笼型八氯丙基倍半硅氧烷(POSS-Cl)与4-羟基二苯甲酮(HBP)的反应得到一种新型夺氢型大分子光引发剂(POSS-HBP),利用磁共振谱和红外光谱对其分子结构进行表征.通过实时红外光谱比较研究了光引发剂HBP与POSS-HBP在紫外光照下引发1,6-已二醇二丙烯酸酯(HDDA)的聚合性能.同时,分别考察了POSSHBP和供氢体N,N-二甲基苯胺(DMA)的浓度对HDDA光聚合速率的影响,当POSS-HBP的质量分数为1.0%(以HBP计),供氢体(DMA)的质量分数为3.0%时,HDDA的光聚合只需要8s,较相同情况下HBP光引发聚合缩短了4s.同时,该聚合材料还具有抗黄变及基本无气味等优点.     

推广的EZ模型中的普适性行为

探讨了推广EZ模型的可能性,并给出了相应的模型中人群大小分布函数的形式解.研究表明金融市场中不同大小的人群数目的交易人的数目在重新标度后将具有最广泛的普适性行为 关键词： 金融物理 人群效应 主方程     

Using a water-confined carbon nanotube to probe the electricity of sequential charged segments of macromolecules

The detection of macromolecular conformation is particularly important in many physical and biological applications. Here we theoretically explore a method for achieving this detection by probing the electricity of sequential charged segments of macromolecules. Our analysis is based on molecular dynamics simulations, and we investigate a single file of water molecules confined in a half-capped single-walled carbon nanotube (SWCNT) with an external electric charge of +e or -e (e is the elementary charge). The charge is located in the vicinity of the cap of the SWCNT and along the centerline of the SWCNT. We reveal the picosecond timescale for the re-orientation (namely, from one unidirectional direction to the other) of the water molecules in response to a switch in the charge signal, -e → +e or +e →-e. Our results are well understood by taking into account the electrical interactions between the water molecules and between the water molecules and the external charge. Because such signals of re-orientation can be magnified and transported according to Tu et al. [2009 Proc. Natl. Acad. Sci. USA 106 18120], it becomes possible to record fingerprints of electric signals arising from sequential charged segments of a macromolecule, which are expected to be useful for recognizing the conformations of some particular macromolecules.     

溶剂萃取预处理对低阶煤大分子结构的影响

为了研究溶剂预处理对低阶煤的固有大分子结构的影响,本研究对锡林郭勒褐煤（XLL）和神府次烟煤（SFC）分别进行了四氢呋喃（THF）索氏抽提、二硫化碳/N-甲基-2-吡咯烷酮（CS₂/NMP）混合溶剂抽提及热溶处理,并对所得抽余煤进行了傅里叶红外漫反射光谱分析（DRIFT）、热重分析（TGA）、压汞法分析（MI）和溶胀度测定。结果表明,溶剂抽提导致煤大分子结构重排和再缔合。其中,THF索式抽提和CS₂/NMP混合溶剂抽提可以改变非共价键交联作用,特别是氢键作用分布,从而不同程度地松弛煤大分子结构。然而,高温溶剂热溶处理主要促进了煤大分子的共价键交联,尤其是对锡林郭勒褐煤（XLL）。所有抽取煤的溶胀都受Fickian扩散控制,且所有抽取煤的溶胀活化能都低于原煤。     

Preparation of high thermal conductive aluminum nitride/cyanate ester nanocomposite using a new macromolecular coupling agent

Novel glycidyl methacrylate–butyl acrylate–maleic anhydride (GBM) terpolymers with different molecular weights were synthesized by radical polymerization and characterized using fourier transform infrared, nuclear magnetic resonance (¹H‐NMR and ¹³ C‐NMR), and gel permeation chromatography. Each GBM terpolymer was used to modify aluminum nitride (AlN), and the modified AlN, coded as AlN(GBM), was added to 2,2′‐bis(4‐cyanatophenyl)isopropylidene (CE) resin for preparing composites. Composites based on original AlN or γ‐(2,3‐epoxypropoxy)propyltrimethoxysilane‐modified AlN (AlN(K)) were also prepared for comparison. Although GBM and γ‐(2,3‐epoxypropoxy)propyltrimethoxysilane have similar reactive groups, the results indicate that GBM shows more attractive integrated advantages, reflected by the fact that CE/AlN(GBM) composites have better thermal stability, higher thermal conductivity, and higher glass transition temperature than those of CE/AlN(K). These properties result from better dispersion of fillers, improved interfacial adhesion between fillers and CE resin, and increased cross‐linking density. This study demonstrates that the nature of the coupling agents is an important factor to develop high performance composites for cutting‐edge industries. Copyright © 2011 John Wiley & Sons, Ltd.     

Improvement of Nanoprecipitation Technique for Preparation of Gelatin Nanoparticles and Potential Macromolecular Drug Loading

An optimum nanoprecipitation technique for gelatin nanoparticles is established, based on aqueous gelatin solution and ethanolic solution containing stabilizer. Crosslinking with glutaraldehyde results in stable gelatine nanoparticles. Several factors such as the surfactant concentration, type of surfactant, type of nonsolvent and gelatin concentration are evaluated. Gelatin nanoparticles with 200–300 nm can be produced using 20–30 mg mL^?1 of gelatin and a minimum of 7% w/v stabilizer (Poloxamer 407 or 188). Furthermore, methanol and ethanol are good nonsolvents, whereas other nonsolvents such as acetone, isopropyl alcohol, and acetonitrile, result in phase separation and visible precipitates. The entrapment efficiency of fluorescein‐isothiocyanate (FITC)‐dextran as model drug was determined to 50% with no substantial effect on particle size. 80% of the drug is only released after enzymatic digestion.

     

含丙磺舒高分子药物的合成与表征

非甾体抗炎药丙磺舒以酯键连接到甲基丙烯酸2-羟乙酯上得含丙磺舒单体HP，HP在偶氮二异丁腈引发下均聚、与甲基丙烯酸甲酯共聚合成了含丙磺舒的高分子药物，产物结构经IR，1HNMR和GPC表征。     

柳林3#镜煤吡啶残煤大分子结构模型及分子模拟

对柳林3^#镜煤吡啶抽提残煤(LLR)进行了¹³C CP/MAS NMR和XPS分析,结合元素分析和工业分析,构建了其大分子模型。LLR结构中芳香部分以蒽为主,脂肪结构主要以脂肪侧链的形式存在,氧原子分别以醚键、羟基和羰基形式存在,氮原子以吡咯和吡啶的形式存在。运用¹³C NMR预测软件ACD/CNMR predictor计算了大分子结构模型的¹³C化学位移。与实验¹³C NMR谱图相比较,对LLR的大分子结构模型进行了修正,获得了¹³C NMR计算谱能和实验谱图吻合较好的大分子结构模型。采用分子模拟对LLR化学结构模型进行能量优化,结果表明,大分子结构的能量按其大小排序主要为范德华能、键扭转能、键角能与键伸缩能。芳环之间的平行排列在该结构模型中占有很小的比例。最后通过添加周期性边界条件得到该煤的密度为1.22 g/cm³。量子化学半经验方法(PM 3)模拟结构表明,脂肪侧链中的C-C键较长,因而活性较高;边缘碳原子带有较多的负电荷,易于发生氧化反应;芳香碳原子所带电荷较少,稳定性很高。     

Macromolecular brushes synthesized by “grafting from” approach based on “click chemistry” and RAFT polymerization

Well‐defined macromolecular brushes with poly(N‐isopropyl acrylamide) (PNIPAM) side chains on random copolymer backbones were synthesized by “grafting from” approach based on click chemistry and reversible addition‐fragmentation chain transfer (RAFT) polymerization. To prepare macromolecular brushes, two linear random copolymers of 2‐(trimethylsilyloxy)ethyl methacrylate (HEMA‐TMS) and methyl methacrylate (MMA) (poly(MMA‐co‐HEMA‐TMS)) were synthesized by atom transfer radical polymerization and were subsequently derivated to azide‐containing polymers. Novel alkyne‐terminated RAFT chain transfer agent (CTA) was grafted to polymer backbones by copper‐catalyzed 1,3‐dipolar cycloaddition (azide‐alkyne click chemistry), and macro‐RAFT CTAs were obtained. PNIPAM side chains were prepared by RAFT polymerization. The macromolecular brushes have well‐defined structures, controlled molecular weights, and molecular weight distributions (M_w/M_n ≦ 1.23). The RAFT polymerization of NIPAM exhibited pseudo‐first‐order kinetics and a linear molecular weight dependence on monomer conversion, and no detectable termination was observed in the polymerization. The macromolecular brushes can self‐assemble into micelles in aqueous solution. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 443–453, 2010