双膜式和多管式磺化反应器传质系数的比较

通过对双膜和多管膜式磺化反应器传质系数的计算与分析比较，表明传质系数的决定性因素是三氧化硫的扩散距离，其传质系数与实际情况较接近。又根据传质系数建立了反应高度与反应率的关系，分析了产品质量差异的原因，以及多管膜式磺化反应器和双膜式磺化反应器差异的原因。     

δ-层状结晶二硅酸钠合成

本文概述了6一层状结晶：二硅酸钠的性能、用途及发展趋势，对烧碱法制备层状结晶二硅酸钠工艺进行了探讨。固碱与石英在80-860℃反应0.5h埋合成水玻璃，在660-70℃锻烧固体硅酸网袋10-30min,使其发生晶型转化，得到钙，镁离子交换量大的δ晶型层状结晶二硅酸钠。     

气液传质对PX液相催化氧化反应的影响

提出了适合Amoco工艺的PX工业氧化反应体系的kLa和εg的计算关联式,判断了工业氧化反应器中反应与传质的相对大小,并对不同传质系数时反应结果进行了模拟。结果表明:气液传质过程不是Amoco工艺PX氧化反应过程的控制步骤,但对氧化过程有影响;增加搅拌功率对于改善反应效果不明显,工业上合适的搅拌输入功率为2.9～4.8kW/m3。     

硅钼杂多酸合成工艺研究

研究了用硅酸钠和钼酸钠制取12－硅钼杂多酸,其适宜的工艺条件为：硅酸钠与钼酸钠的摩尔比为0．1,反应温度为85－90℃,用盐酸调节反应液pH值为1－2,反应4h,反应完毕冷至室温,再加乙醚萃取分离硅钼酸,减压蒸馏回收乙醚,真空干燥得纯品,产品收率（以钼酸钠化学计量数计）为78．5％,纯度为99％。     

低模数硅酸钠溶液的结构及其键合反应特性

采用IR,^29Si NMR手段对低模数硅酸钠溶液结构进行研究。采用硅酸钠溶液与偏高岭石的固化键合反应所得到的固体产物的抗压强度表征其键合反应的程度,并对不同模数的硅酸钠溶液条件下获得的矿物聚合材料的强度进行了测试。结果表明：低模数硅酸钠溶液中的低聚硅氧四面体基团的存在直接与固化键合反应进行的程度相关,硅酸钠溶液中的低聚硅氧四面体基团浓度越高,键合反应进行得越彻底。     

一步法工艺合成十二烷基糖苷过程中的液固传质

为了考察葡萄糖与脂肪醇一步法制备烷基糖苷工艺中反应和液固传质的耦合过程,从单个颗粒的液固传质模型出发,推导出了固体颗粒群与脂肪醇之间的液固传质模型。实验考察了粒径分布、搅拌速度及温度对传质过程的影响,关联实验数据得到了不同条件下的模型参数。结果表明,此模型能准确预测葡萄糖与正十二醇之间的液固传质过程,此模型及其计算结果可以应用于一步法工艺中传质速率和反应速率相对大小的判断,确定反应过程的控制步骤,具有较大的应用价值。     

撞击流反应-沉淀法制备超细白炭黑

在浸没循环撞击流反应器中,以工业硫酸和液体硅酸钠为原料,采用反应-沉淀法制备超细白炭黑.研究了各种因素对产品粒径的影响;确定适宜工艺条件为:硅酸钠溶液中二氧化硅的含量35 kg/m3,反应温度40℃,转速1000 rpm,硫酸溶液浓度9 mol/L.优化条件下制得产品用FAM激光粒度测量仪测定其产品平均粒径为2.1微米.     

层状硅酸钠的制备及插层性能的研究进展

从晶体结构、制备工艺、插层改性和应用的角度,对层状硅酸钠的研究进行较全面阐述。介绍了层状硅酸钠存在的多种晶相及结构特点;指出了喷雾干燥结晶法或水热合成工艺在制备结晶层状硅酸钠中存在的技术问题;从反应类型的角度详细介绍了层状硅酸钠的插层改性技术和赋予改性层状硅酸钠丰富的功能性;分析了层状硅酸钠的不同晶相或改性技术在实际应用中的研究思路和存在问题,为层状硅酸钠的深度研究与开发指出方向。     

聚碳酸酯非光气法合成工艺研究进展

综述了近年来聚碳酸酯的酯交换法合成工艺的研究进展,着重阐述了其预聚反应动力学,介绍了该工艺中传热传质等因素对聚合过程的影响以及国内外相关研究现状和研究前景。     

热液生产硅酸钠溶液

研究了用石英砂与氢氧化钠水溶液反应形成SiO2对Na2O摩尔比低于2.9：1的硅酸钠水溶液，再用此硅酸钠水溶液为半成品与于l100℃～其熔点老化过的石英反应，热液生产高模数硅酸钠溶液的方法。     

Establishment of nucleation and growth model of silica nanostructured particles and comparison with experimental data

A mathematical model is developed for the calculation of the nucleation and growth process of silica nanostructured particles prepared by using the drop-by-drop method, and the calculation results of the proposed model is compared with the experimental value obtained from SAXS data. The model provides a non-ideal improvement in the supersaturation calculation and considers the impact of both mass transfer and surface reaction on the particle growth rate. The nucleation and growth rates are coupled depending on the change in monomer concentration over time, based on which the particle size and distribution are calculated. The growth curve of the silica particles from 3 nm to 20 nm and the change in particle number from 0 to over 10²⁰ are calculated, which are consistent with the experimental values, establishing the reliability of the model. The calculations of the growth rate reveal that mass transfer controls the growth of silica particles before 10 min and the surface reaction is the rate-determining step after 10 min. The changes in the model parameters obtained by fitting with the SAXS data under different reaction conditions indicate the sensitivity of the corresponding process to different conditions. Moreover, the relationship between the particle growth rate and monomer concentration change is analyzed using the proposed model.     

溶胶-凝胶包埋固定化酶的研究

介绍了溶胶-凝胶(sol-gel)包埋法制备固定化酶的基本过程和影响因素,着重论述了S iO2、有机改性硅胶和有机/无机杂化硅胶三类溶胶-凝胶基质材料制备固定化酶的特性和在催化反应中的应用,对溶胶-凝胶包埋法制备高性能固定化酶的发展前景予以展望。     

Influence of unlimited 3-membered ring cyclization on a multiscale dynamic Monte Carlo/continuum model of drying and curing in sol–gel silica films

The coating process of sol–gel silica films involves multiple length and time scales ranging from molecular to macroscopic. At the molecular scale, cyclization during polymerization is so extensive that it cannot be neglected or treated statistically. Here we present a multiscale model of a 1D sol–gel drying process coupled to a Monte Carlo polymerization model with unlimited cyclization. Because our model allows cyclic and cage–like siloxanes to form, it is better able to predict the silica gelation conversion than any other reported kinetic model. By studying the competition between molecular growth and cyclization, and the competition between mass transfer (drying) and reaction (gelation) on the drying process of the sol–gel silica film, we observe that cyclization delays the gelation, shrinks the molecular size, increases the likelihood of literal skinning, and leads to a molecular structure gradient inside the film. Although for simplicity our model just considers the possibility of forming 3-membered ring, it is the first multiscale model to couple unlimited cyclization in polycondensation with a continuum mass transfer process. Also it is the first model that can predict structure gradients caused by drying in sol–gel silica films.     

Similar effect of carbon and silica catalyst support on the hydrogenation reaction rate in organic slurry reactors

This paper investigates the influence of the catalyst support type on mass transport and reaction rate for the case of hydrogenation of α-methylstyrene to cumene in a gas inducing stirred slurry reactor and in a slurry bubble column. The reaction is carried out in the presence of 3% Pd/carbon and 3% Pd/silica catalyst particles. The lyophobicity of the two catalyst supports in the cumene slurry is found to be similar. The overall rate of the hydrogenation reaction is described by the classical transport and reaction resistances-in-series model. The rate of gas-to-liquid mass transfer is somewhat larger during reaction than without reaction. This enhanced mass transfer points to particle-to-bubble adhesion as a result of the relative affinity of both catalyst supports to the gas phase. The observed reaction enhancements are similar for both Pd/carbon and Pd/silica catalyst/cumene slurries.     

Preparation of doubly responsive polymer functionalized silica hybrid nanoparticles via a one‐pot thiol‐isocyanate click reaction at room temperature

Well‐defined poly(N‐isopropylacrylamide) and poly(2‐(diethylamino) ethyl methacrylate) were synthesized first by a reversible addition‐fragmentation chain transfer process. These polymers were then reduced to generate an end thiol group to react with isocyanate groups on the surface of silica nanoparticles, which were pretreated with toluene‐2,4‐diisocyanate, by a one‐pot “click” reaction to prepare temperature and pH responsive polymer functionalized hybrid silica nanoparticles. The polymer functionalized silica hybrid nanoparticles were characterized by a range of techniques such as Fourier transform infrared spectroscopy and dynamic light scattering. The doubly responsive polymer functionalized silica hybrid nanoparticles show both temperature and pH responsive behavior and their solution properties were dependent on the ratio of the two polymers on the surface of silica. Covalent functionalization of the silica nanoparticle with well‐defined temperature and pH responsive polymers was accomplished via a one‐pot thiol‐isocyanate click reaction. This reaction was found to be extremely efficient in producing doubly responsive polymer functionalized silica hybrid nanoparticle, even at relatively low reaction temperature and short reaction time. Thermogravimetric analysis indicated that the same ratio of poly(N‐isopropylacrylamide) and poly(2‐(diethylamino)ethyl methacrylate) functionalized silica hybrid nanoparticle consisted of 42.46 wt% polymer. POLYM. COMPOS., 38:1454–1461, 2017. © 2015 Society of Plastics Engineers     

二氧化硅微球负载钌催化剂的制备及其在苯乙酮不对称氢转移反应中的应用

采用一步原位聚合诱导沉淀法制得了形貌多样、结构复杂的二氧化硅介孔微球,将其与Noyori配体RuCl(p-cymene)[(R,R)-Ts-DPEN]络合制得负载型钌催化剂并应用于苯乙酮不对称氢转移反应。利用场发射扫描电镜和氮气等温吸脱附手段证明了二氧化硅微球和负载型钌催化剂的微球型介孔结构,结合透射电镜表明了钌元素均匀分布在二氧化硅微球上;通过红外光谱显示该催化剂与反应底物之间存在氢键作用;在此基础上考察了载体孔结构,反应条件等因素对催化性能的影响。研究结果表明,钌配体负载到具有小孔径、高比表面积的二氧化硅微球上有利于苯乙酮的不对称氢转移反应,由此引出介孔氧化硅微球的孔道限域效应对不对称催化反应的活性和光学选择性存在明显的促进作用。在40℃、0.2ml苯乙酮的条件下反应16h,负载型钌催化剂用于苯乙酮不对称转移加氢反应其转化率和对映选择性最高可分别达到64.1%和93.4%。     

光伏压延玻璃硅珠结石产生机理与分析

利用岩相分析、电子探针和光学显微镜,对光伏压延玻璃生产线产生的玻璃硅珠结石缺陷进行分析,鉴别出硅珠类结石为单质硅结石,来源于玻璃液中二氧化硅与杂质铝反应生成,同时伴随气泡产生,并对玻璃硅珠结石缺陷问题提出了有效的解决方法,为全氧燃烧窑炉压延玻璃生产提供了技术参考。     

Deposition of silica from geothermal waters on heat transfer surfaces

Extended tests in specially designed equipment have been carried out on deposition from hot geothermal water from two different locations in Iceland, onto cooled heat exchanger surfaces. It is concluded that the deposition process is diffusion controlled followed by a dehydration reaction at the surface. The deposits consisted of a complex combination of elements with silica being the predominant compound. The solubility of amorphous silica may be influenced by the presence of cations. The nature of the surface of the scale appears to be related to the hydrodynamic conditions, a distinct “rippled” surface being obtained at one location.Due to the increased turbulence generated by the rough scale surface an initial enhancement of heat transfer was obtained, but as deposition continued, gradually increasing resistance to heat transfer was observed. Even over long periods (up to 2000 hours) no “equilibrium” value for the fouling resistance was obtained.     

Cationic Graft Polymerization onto Silica Nanoparticle Surface in a Solvent-Free Dry-System

For the purpose of the prevention of the environmental pollution and the simplification of reaction process, the scale-up synthesis of polymer-grafted silica nanoparticle by surface initiated cationic ring-opening graft polymerization of 2-methyl-2-oxazoline (MeOZO) in a solvent-free dry-system was investigated. The introduction of iodopropyl groups onto the silica surface as initiating group was carried out by the reaction of silanol groups with 3-iodopropyl- trimethoxysilane in a solvent-free dry-system. The graft polymerization of MeOZO onto silica nanoparticle surface in a solvent-free dry-system was initiated by spraying the monomer onto the surface having iodopropyl groups and the polymerization was conducted in powder fluid system under nitrogen. After the polymerization, unreacted MeOZO was readily removed under high vacuum. It was found that the cationic ring-opening polymerization of MeOZO was successfully initiated in the solvent-free dry-system to give polyMeOZO-grafted silica nanoparticles. The maximum grafting of polyMeOZO obtained from the polymerization initiated by iodopropyl groups on the surface reached 47.7 %. The percentage of grafting and grafting efficiency during the cationic ring-opening graft polymerization in the solvent-free dry-system were considerably larger than those in solution system. This suggests that chain transfer reaction from surface growing cation to monomer was effectively inhibited in the solvent-free dry-system.     

电磁场作用下的强化传质研究进展

总结了电场、磁场和电磁场作用下强化传质的一些实验与理论工作,分析了3种强化传质方式在传质对象和传质机理方面的一些不同.进行比较后显示,电磁场强化传质的应用更加广泛,其强化传质机理可解释为:电磁场与物质的相互作用改变了物质的活性,降低了传质过程的活化能,从而使扩散得到增强.最后介绍了微波非热效应的一些实验与理论研究进展.研究表明,一些化学反应、陶瓷烧结和萃取等过程的传质得到强化确实是由于微波非热效应的作用.