微反应器的结构优化设计与仿真

设计了两步微反应器,对影响反应的几何参数进行了优化。对于微反应器的混合单元,设计了内肋型障碍物结构,用于产生混沌对流,促进样品混合。利用基于有限元原理的数值模拟软件分别对混合单元的障碍物与微通道的高宽比、障碍物宽度与间距的比值和障碍物的宽度进行设计与优化。采用蜿蜒通道作为微反应器的反应单元,研究了反应单元长度、反应时间与初始浓度对反应的影响。以葡萄糖氧化反应为例,设计了一个两步微反应器。     

毛细管电泳柱端酶微反应器研究进展

微反应器是指使物理、化学、生化等反应在微小的空间内发生的装置。微反应器能减少试剂消耗和样品污染,且反应条件易于控制,特别适合于酶促反应分析,因而多为酶微反应器。微反应器与电泳联用时,可将毛细管柱端作为微反应器,集反应与分离于一根毛细管柱上,可实现反应与分离一次性完成。根据酶微反应器制备原理的不同进行分类,综述了近2年来毛细管电泳柱端酶微反应器的研究进展。     

基于烧结微纤多孔结构材料的微反应器中的苯硝化反应

基于烧结微纤结构材料发展了一种集微混合、反应和换热于一体的微反应器,以苯硝化为模型反应考察了该微反应器用于快速、强放热的液-液两相混合反应的效果.烧结微纤材料具有大的空隙率、三维开放孔结构和大的面积与体积比,有利于传质和传热,同时微纤三维网络具有微搅拌器的作用,有利于流体的微米尺度分割和快速混合.因此,苯硝化反应得以在很短的时间内高选择性地进行完全.在一定的操作条件下,苯转化率可以达到91.7%,硝基苯选择性高达99.4%.     

微反应器中甲醇自热重整

 本文开展了在微通道反应器中甲醇自热重整反应的研究，着重考察了空速对反应转化率的影响。实验结果表明，在水醇摩尔比为1.2、氧醇摩尔比为0.3、反应温度为450℃、常压条件下，当反应空速为186,000 h-1时，甲醇转化率仍高于93%；与蜂窝陶瓷整体反应器相比，反应空速（以甲醇计）提高1个数量级，接触时间达到毫秒级（~10ms）。     

基于MCM-41微反应器的微波辅助合成新方法研究

采用微波辐射合成法合成了纳米介孔分子筛MCM-41作为微反应器.以苯并呋喃-2(3H)-酮的合成为实例,在甲苯介质中将邻羟基苯乙酸组装到MCM-41微反应器中,研究了溶液体系及微反应器中反应温度、反应时间及微波辐射时间对反应的影响.结果显示,在施加微波与不施加微波情况下,MCM-41微反应器中进行的反应较溶液体系中进行的反应产率提高了2～33与2～12倍.对于MCM-41微反应器中的反应,施加微波辐射后反应产率可进一步提高20%～100%.     

反相胶束微反应器及其制备纳米微粒的研究进展

对反相胶束微反应器的原理，模型和胶束内核水特性等方面的研究进行了评价，介绍了微反应器制备纳米微粒的研究进展。     

毛细管区带电泳用于酶微反应器酶解条件的研究

将氨基酰化酶通过戊二醛固定在毛细管内壁,制备毛细管酶微反应器,用毛细管区带电泳对毛细管酶微反应器的酶解产物进行分离,以生成物的峰面积优化底物N-乙酰-DL-蛋氨酸的酶解条件。实验结果表明,在温度37℃的条件下,10μg/mL N-乙酰-DL-蛋氨酸磷酸盐缓冲溶液(pH7.5)以4μL/min的速度通过15 cm长的毛细管酶微反应器,具有良好的酶解效果。利用毛细管酶微反应器对底物N-乙酰-DL-蛋氨酸进行酶解,每天酶解5次,10天后酶活仅下降了8.66%,说明制备的毛细管酶微反应器具有良好的稳定性。     

基于超亲水纳米通道的智能可控微反应器

对阳极氧化铝(Anodic Alumina Oxide, AAO)多孔膜进行低温空气等离子体处理得到超亲水纳米通道. 在此基础上引入油溶性铁磁流体(Ferrofluid), 通过调节外磁场的方向和强度构建出智能可控微反应器. 该智能微反应器具有多梯度门控、 高电流门控比、 长期循环稳定性的特点. 将其分别用于均相和非均相反应中, 采用荧光分光光度计和扫描电子显微镜等手段进行表征. 结果表明, 不同门控状态下反应产物具有不同的产量和结构, 在微反应器的可控反应方面具有良好的应用前景.     

纳米沸石修饰微通道反应器内固定化酶催化的水解反应动力学

通过在毛细管内层叠层组装纳米沸石并固定脂肪酶来构建纳米沸石修饰的固定化酶微反应器通道,将纳米沸石良好的生物相容性和高的酶固定能力与微反应器反应效率高、扩散传质快等优点相结合. 以对硝基苯棕榈酸酯的水解作为探针反应对该微反应器内固定化酶催化水解反应动力学进行了研究和计算,并与普通反应器内同样的反应进行比较. 通过对比米氏方程参数,证实在微反应器内酶催化水解反应效率可比普通反应器内提高3倍以上并可提高酶和反应底物的亲和能力.     

固定化酶微反应器的制备及应用

固定化酶微反应器是将生物分子固定技术与生化微反应相结合制备的一种固定化催化装置。这种微型化的反应系统由于兼具固定化酶的特异性催化、可重复利用及微分析的低消耗、易分离等优点,在生命科学如蛋白质组学、酶抑制剂的筛选、生物催化等领域具有非常重要的作用。固定化酶微反应器的性能与其制作方法关系密切。本文着重从酶与固定化载体结合方式的角度,对近年来固定化酶微反应器的各种制备方法和应用进行了较为详细的评述。重点讨论了各种方法的优缺点和最新的发展情况,并对其发展前景进行了展望。     

The preparation and reaction of enolates within micro reactors

Over the past 5 years, interest in the miniaturisation of chemical synthesis has grown rapidly, however in order to facilitate transfer of the technology from its current position as a research tool to industrial applications, a core understanding of the challenges associated with transferring reactions from the macro to the micro domain is required. This paper therefore aims to broach this problem by investigating the application of micro reactors to a range of commonly employed synthetic reactions including acylation, aldol, alkylation, 1,4-conjugate addition (Michael addition) and the Knoevenagel condensation. Comparison of the results obtained with traditional batch techniques enable us to highlight some of the advantages associated with micro reaction technology.     

Acid-catalysed synthesis and deprotection of dimethyl acetals in a miniaturised electroosmotic flow reactor

Through incorporating a series of polymer-supported acid catalysts into a miniaturised EOF-based flow reactor, we demonstrate a clean and efficient technique for the protection of aldehydes as their respective dimethyl acetal. In addition, we also report the acid catalysed deacetalisation of 11 dimethyl acetals to their respective aldehyde. In all cases, the compounds described are obtained in high yield (>95%) and excellent purity (>99%) without the need for further product purification.     

用正电子湮没谱研究聚酯型聚氨酯的微观结构和自由体积特性

用正电子湮没谱研究了两类分别由聚己二酸丁二醇酯多元醇和聚ε 己内酯多元醇合成的线型聚酯型聚氨酯 (PBU和PCU)在 140～ 36 0K温度范围内的结构转变和自由体积特性 .研究结果表明 ,两类聚氨酯(PU)在 140～ 36 0K温度范围内 ,都存在三个转变点 ,其中较低温度的转变 (约 2 0 0K)对应于PU中软段的玻璃化转变温度 (Tg) ,2 75K处的转变可能与样品吸附少量水分有关 ,较高温度的转变 (约 310K) ,对于PBU而言对应于软段结晶的熔点 ,而对于PCU则与在无序的硬段中混入一定量的软段后形成的相容区的Tg 有关 .当温度低于PU软段的Tg 时 ,两类PU的自由体积尺寸和浓度都随温度升高而增大 .当温度高于软段的Tg 但低于2 75K时 ,自由体积尺寸较快地增加 ,而自由体积浓度保持不变 .温度高于 2 75K并低于软段的熔点或硬段 软段相容区的Tg 时 ,自由体积尺寸增加速度最快 ,自由体积浓度却保持同样的数值 .当温度进一步升高时 ,自由体积尺寸和浓度都随温度增大而增加 .最后研究了这两类PU的自由体积分布与温度的关系 .所有这些实验现象均与大分子链的运动有关 ,并与通过DSC和WAXD表征的材料的形态一致     

Fluorinations, chlorinations and brominations of organic compounds in micro reactors

This paper gives an overview of the application of micro reactors for fluorination and chlorination of organic compounds supplemented by reporting about first investigations by the authors on the topic of bromination reactions in a micro reactor system. After a brief introduction illuminating the status of micro-chemical processing in general and covering the basic advantages of microstructured reactors, the different micro reactors used so far for halogenation reactions will be described with respect to fabrication, range of operation and performance. Thereafter, investigated reaction systems will be described and discussed.All the reactions have in common that halogenation is achieved by using elemental halogens. Beside one gas phase chlorination, the described fluorinations and chlorinations are gas/liquid processes investigated in specialised gas/liquid micro reactors. In contrast, bromination reactions were performed in a micro mixer/tube set-up not specially adopted e.g. to gas/liquid conditions. Phase conditions here are quite complex through evaporated bromine and gaseous hydrogen bromide formed during the reaction.The range of reactions comprises aromatic electrophilic substitutions and free radical substitutions of alkanes and in the side chain of aromatic compounds. The experimental results underpin the benefits of micro reactors for halogenation reactions as improved process control, process safety, improved selectivity and yields, shortening of syntheses and higher space-time yields. Furthermore, another aspect is the potential for an accelerated process development.     

多单体接枝聚丙烯对PBT/PP共混体系的形态结构及力学性能影响研究

研究了甲基丙烯酸缩水甘油酯 (GMA)和苯乙烯 (St)多单体熔融接枝聚丙烯 (PP g (GMA co St) )对聚对苯二甲酸丁二酯 (PBT) 聚丙烯 (PP)共混物的形态结构和力学性能的影响 .利用双螺杆挤出机对PBT PP合金进行共混挤出 ,使用DSC、FT IR和SEM、TEM等手段对共混物进行了分析和相形态观察 ,并测试了力学性能 .实验证明 ,熔融共混过程中PP g (GMA co St)的环氧基团可以与PBT的端羧基发生化学反应 ,就地生成了PBT g PP共聚物 ,该共聚物可对PBT PP合金起到良好的增容剂作用 ,使共混物的相区尺寸显著减小 ,共混物的拉伸强度和冲击强度等力学性能同时得到明显改善 ,达到了弹性体系或小分子增容所难以达到的力学性能平衡的效果 .此外 ,TEM的研究还在PBT PP g (GMA co St)共混物中发现了特殊的微相分离结构     

Asymmetric catalysis in a micro reactor—Ce, Yb and Lu catalysed enantioselective addition of trimethylsilyl cyanide to benzaldehyde

A T-shaped micro reactor was used for the optimisation of reaction conditions for the enantioselective silylcyanation of benzaldehyde catalysed by lanthanide-pybox complexes. Compared to a conventional batch procedure, higher conversion was observed within shorter reaction time. The micro reactor process involving Lu(III) afforded essentially the same enantioselectivity as the batch process (73 vs 76% ee), whereas the enantioselectivity was lower in the micro reactor for catalysts containing Yb(III) (53 compared to 72%). Ce(III) provided very low selectivity in both types of processes (1 and 11% ee, respectively). A study of the effect of additives showed that the enantioselectivity in the Yb catalysed reaction performed in the micro reactor could be increased to 66%, whereas only a minor improvement, to 78% ee, was observed in the reaction with Lu.     

Micro enzymatic assay coupled to capillary electrophoresis via liquid junction

Summary A system for capillary electrophoresis combined with enzymatic assay has been evaluated for the two enzymes glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase. Instrumentation included a post-column reactor coupled to the separation capillary by a liquid junction. A technique for generating a substrate solution flow into the reactor by utilizing two high voltage supplies is proposed. This method offers a high degree of freedom in optimizing the separation and enzymatic reaction conditions individually. Possibilities for improving the enzymatic assay sensitivity were also examined.     

CuSO4 Micro-crystal Lattice Produced by Microcontact Printing

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聚丙烯催化合金结构表征

用IR、DSC、NMR分析了聚丙烯催化合金中乙丙共聚物的微结构 ,发现在一定条件下合成的乙丙共聚物主要由两部分组成 :无规乙丙共聚物和各种不同序列长度的乙丙嵌段物组成 .加上丙烯均聚物 ,聚丙烯催化合金是一种具有多分散性结构的混合物 .这种特殊的结构是聚丙烯催化合金具有高抗冲性的主要原因