Synthesis and properties of temperature-resistant and salt-tolerant tetra-acrylamide copolymer

Abstract

The acrylamide copolymer with acrylamide as its main monomer is a modified polyacrylamide. In addition, the acrylamide copolymer is generally to dissolve or swell in water and can be used as thickener, dispersant, flocculant and so on. Therefore, using Acrylamide AM, 2-acrylamide-2-methyl propanesulfonic acid AMPS, dimethyldodecyl (2-acrylamidoethyl) ammoniumbromide AQ₁₂ and vinyltriethoxysilane VTEO as raw materials so that a series of four-membered acrylamide copolymers are prepared in aqueous solution polymerization. The amphoteric structure in the polymer has a unique anti-polyelectrolyte behavior when it is electrically neutral, which can significantly improve the salt resistance of the aqueous polymer. In addition, the hydrolysis of the vinyltriethoxysilane containing silicon structure by hydrophobic association can improve the temperature resistance of the polymer. The optimal reaction conditions were determined by orthogonal experiment: the reaction temperature was 10?°C; the initiator concentration was 0.05?mol%; the monomer concentration was 25?wt% and the pH was 7. Properties of polymer solution indicated that the series of tetra-copolymer possessed salt-tolerant and heat-resisting performances. As an oil displacing agent, it can significantly improve the efficiency of oil displacement, and particularly highlights the effect of 4-member copolymer as an oil displacing agent.     

C28X4（X=H,Cl）,CX4（X=H,Cl）的结构和电子光谱的理论研究

用ＩＮＤＯ法对Ｃ２８Ｘ４（Ｘ＝Ｈ，Ｃｌ）和ＣＸ４（Ｘ＝Ｈ，Ｃｌ）进行几何构型优化，得到Ｔｄ对称性的构型Ｃ２８Ｘ４有４种键、４种不等同原子，基态为稳定的闭壳层分子，以此构型为基础计算了上述分子的电子光谱，并预测Ｃ２８Ｘ４的电子光谱。     

C~6~0^2^-单态和三态的结构和光谱性质

用INDO系列方法对C~6~0^2^-单态和三态分别进行了几何构型优化, 得到D~2~h对称性的构型, 表明C~6~0^2^-确实发生了Jahn-Teller畸变, 导致双键变长, 形成15种键, 9种不等同碳原子, 其额外负电荷主要分布在赤道附近, 以此构型为基础,计算了C~6~0^2^-的电子光谱, 与实验值基本一致, 对光谱进行了理论指认, 说明了光谱红移的原因。     

新型10-取代小檗碱衍生物的合成

2-羟基-3-甲氧基苯甲醛在酸性条件下脱除甲基制得2,3-二羟基苯甲醛（2）;在不同碱作用下,2与卤代烷烃选择性反应生成邻、间烷氧基单取代中间体（3和4）,经二次烷基化反应制得2-甲氧基-3-烷氧基、2-烷氧基-3-丁氧基苯甲醛（5a~5f）; 5a~5f与3,4-亚甲二氧基苯乙胺经脱水缩合生成席夫碱中间体,再依次经硼氢化钠还原生成胺,并与乙二醛水溶液发生双重环合反应,合成了一系列10-位非甲基取代的小檗碱衍生物（9a~9f）,其中5b~5e和9a~9f为新化合物,其结构经¹H NMR、¹³C NMR和HR-MS(ESI)表征。     

CO2 and photo-controlled reversible conversion of supramolecular assemblies based on water soluble pillar[5]arene and coumarin-containing guest

In this communication,a new supramolecualr amphiphile was successfully constructed based on water soluble pillar[5]arene and a unique guest which contain a CO₂ responsive tertiary amine unit and a UV responsive coumarin group.When guest molecule 1 dispersed in water,it self-assembled into sheet-like structures.Upon bubbling CO₂,1 transformed into 1 H due to the tertiary amine unit was protonated,accompany the nano-sheets transformed into vesicles.Further irradiation of 1 H with 365 nm light for 3 h,the coumarin group reacted with each other to form bola-type amphiphie 2 H.In this case,vesicles collapsed and re-assembled into nano-tubes.However,when addition of WPS into the solution of 1 H,the vesicles transformed into micelles,this is due to the formation of supramolecular amphiphile WP5&1 H.Upon irradiation of WP5&1 H with 365 nm light for 3 h,nano-ribbons observed instead of micelles in the solution.Notably,nanotubes from 2 H could also transform into nano-ribbons after adding WPS.The selfassembly process and the resultant assemblies were characterized by TEM,SEM,DLS,SAXS and NMR technologies.Due to both CO₂ and light are "green" for living organisms,we anticipated our system can offer the possibilities in "on demand" drug absorption and release.     

Stabilities and Electronic Spectra for C78O2 Isomers

1 INTRODUCTION Functional derivatives of fullerenes have aroused chemists’ interest and monofunctional products are accompanied by difunctional derivatives[1～3]. Diede- rich[1] prepared and detected C70O2 by the FAB mass spectrum. Kalsbeck[2] synthesized C60On (n = 1～4) by electrochemical oxidation of C60. Wood[3] investi- gated photolysis of a crude fullerene mixture and obtained C60On (n = 2～5) and C70O2. Menon[4] stu- died the optimized structures and electronic proper- ties o…     

交联壳聚糖树脂对部分尿毒症毒物的吸附性能研究

用反向悬浮的方法制备了戊二醛交联壳聚糖树脂吸附剂,并对制得的球形吸附剂用NaBH4进行了氢化还原处理,以提高其在使用环境下的化学稳定性。扫描电子显微镜(SEM)分析表明,吸附剂的表面形态构成了吸附的微观基础。通过对部分尿毒症毒性物质的吸附研究发现,本文研制的壳聚糖吸附剂对这些目标物均产生了一定的吸附作用,吸附平衡时间符合临床要求,其对3种小分子尿毒症毒性物质的吸附能力依肌酐、尿酸、尿素的次序递增,而对促皮质素(ACTH)的吸附量则达到了13.04mg/g,显示了该类吸附剂应用于临床治疗的潜在价值     

Apicidin选择性抑制ClassⅠ HDACs分子动力学研究

采用模拟方法研究组蛋白脱乙酰酶抑制剂(Apicidin)选择性抑制组蛋白去乙酰化酶(Histone deacetylases, HDACs)中的HDAC1和HDAC8. 通过HDAC8晶体结构同源模建HDAC1三维结构模型, 将Apicidin分别与HDAC1和HDAC8对接并进行分子动力学模拟, 结果表明, HDAC1活性口袋入口处的Arg270是Apicidin-HDAC1形成稳定结构的重要因素; HDAC1中Tyr303及His178与Apicidin形成2个持续存在的氢键, 而在HDAC8中未发现, 这是Apicidin选择性抑制HDAC1高于HDAC8的另一重要原因.     

红外光谱结合线阵列检测技术研究聚合物分散液晶膜分子取向

采用偏振红外光谱和变温红外光谱研究聚合物分散液晶膜中液晶分子取向随外加电场及温度的变化.利用线阵列检测技术表征了聚合物与液晶界面处的成分分布.结果表明,线阵列检测技术能够快速而直观地给出成分分布图,通过该成分分布图可以解释PDLC在温度场作用下分子取向的变化.     

绿色荧光蛋白质——2008年诺贝尔化学奖成果介绍

介绍了2008年诺贝尔化学奖得主下村修、马丁.查尔菲和钱永健3位科学家在绿色荧光蛋白质的发现和开发方面的卓越贡献,阐述了绿色荧光蛋白质的结构、性质以及应用等。