铝支撑酸化蒙脱土的表征及催化性能

通过ＸＲＤ、脱吸附分析、ＦＴＩＲ、骨架振动红外光谱等手段表征了铝支撑酸化蒙脱土。结果表明：经酸化后的蒙脱土再进行铝交联，具有较强的固体酸性，对柴油转化为汽油和联二苯丙烯烷基化反应都有较高的催化活性。本文也讨论了固体酸对催化活性的影响。     

铝交联蒙脱土结构影响因素的研究

利用电镜、比表面仪和X射线衍射分析方法表征了制备的铝交联蒙脱土。结果表明,OH^-与Al^3+物质的量比、焙烧温度和酸化浓度对交联蒙脱土结构有一定影响,交联剂陈化时间对酸化交联蒙脱土的收率也有影响,最佳条件:n(OH^-)∶n(Al³⁺)=2.2,焙烧温度65 ℃,酸化浓度5%～20%,交联剂陈化时间1.5天。     

三聚阳离子表面活性剂改性蒙脱土的制备与表征

合成了一种含六氢三嗪的新型三聚季铵盐阳离子表面活性剂T16,以13C NMR和ESI-MS表征其结构,并作为有机插层剂应用于蒙脱土的改性。红外光谱(FTIR)、热重分析(TGA)表明,T16已插层到蒙脱土片层间。X射线粉末衍射(XRD)表明,T16改性后蒙脱土层间距从原来的1.486 nm增加到3.324 nm。沉降实验表明,改性后蒙脱土在苯乙烯和甲苯中形成凝胶体系,表现出很好的相容性和分散性,有利于聚合物或其单体进入蒙脱土层间形成纳米复合材料。     

三元柱交联蒙脱土的合成及其催化性能的研究

采用共混法制备了一系列三元柱交联蒙脱土,并以偏三甲苯和甲醇的烷基化及均四甲苯的异构化作为探针反应考察其催化活性,找出金属离子的种类和预处理温度对偏三甲苯、偏四甲苯转化率及均四甲苯收率的影响。结果发现,少量二价离子的引入能提高三元柱交联蒙脱土的活性,但大量二价离子的引入反而会降低其活性。催化剂最适宜的预处理温度为500～550 ℃,同时以偏三甲苯-甲醇烷基化反应对催化剂的失活进行了考察。结果表明,催化剂经20多个脉冲后仍能保持较好的活性。     

铝交联蒙脱土催化合成环己酮乙二醇缩酮

以临安钠基蒙脱土为原料制备了铝交联蒙脱土催化剂,进行了X射线衍射和比表面积分析,将其用于环己酮和乙二醇反应,合成环己酮乙二醇缩酮。系统研究了催化剂用量、酮醇物质的量比、带水剂用量及反应时间等因素对产品收率的影响。结果表明,在n(环己酮)∶n(乙二醇)=1∶1.5、反应时间1 h,催化剂和带水剂环己烷用量分别为反应物料总质量的2%和20%条件下,环己酮乙二醇缩酮收率可达74.0%。     

双子阳离子表面活性剂改性蒙脱土的制备与表征

合成了新型双子阳离子表面活性剂Gemini-16,并用其对钠基蒙脱土进行改性。红外光谱(FTIR)、热重(TGA)分析表明,Gemini-16已插层到蒙脱土片层间。X射线衍射(XRD)表明,改性后蒙脱土层间距从1.47 nm增加到3.48 nm。分散性实验表明,经Gemini-16改性的蒙脱土在液体石蜡中表现出很好的相容性和分散性,改性效果优于目前常用的CTAB处理效果,更有利于聚合物单体进入蒙脱土层间形成聚合物/蒙脱土纳米复合材料。     

铁铝柱撑酸化蒙脱土催化剂的表征及催化性能

为改善柱撑蒙脱土的催化活性,对蒙脱土进行酸预处理,并采用离子交换法制备铁铝柱撑酸化蒙脱土(Fe-Al-酸化土)催化剂,通过XRD、BET、ICP和FI-IR对其进行表征。结果表明,蒙脱土经酸化预处理制备Fe-Al酸化土催化剂比表面积为157.3 m~2·g~(-1),层间距d001为1.787 nm,铁铝柱撑剂进入酸化蒙脱土层间域形成均一稳定的Si—O—Fe结构,在2 930 cm-1处出现尖锐的吸收峰,在协同过氧化氢降解废水实验中表现出较高的活性和稳定性。     

无机交联蒙脱土在催化反应中的应用

对近年来Al、Ti、Fe、Zr-交联蒙脱土用于烷烃芳构化、酯化、选择还原NOx、光催化氧化分解有机污染物、Friedel-Crafts反应和醇胺化等反应的研究结果进行了综述。为进一步提高蒙脱土的热稳定性和催化性能，在单一交联蒙脱土研究的基础上，制备多元交联蒙脱土将成为今后的研究重点。     

贫燃条件下铜离子改性铝交联蒙脱土汽车尾气净化催化剂的研制

以铝交联蒙脱土为载体,研制铜离子改性铝交联蒙脱土催化剂,在贫燃条件下考察其选择性还原NO的催化活性,并与Cu/ZSM-5做了比较。结果表明:采用浸渍法Cu2+负载量以w(Cu2+)=3%为最佳,可使NO转化率达52 25%;采用SO2-4改性能较大幅度提高催化活性,使NO转化率提高15 42%,同时能使操作温度范围更宽,500℃NO转化率仍达到22 16%,优于Cu/ZSM-5。     

铁镧交联蒙脱土的合成及催化氧化性能

以临安钠基蒙脱土为原料,制备了铁交联和铁镧复合交联蒙脱土催化剂,利用物理吸附(BET)、扫描电镜(SEM)和X-射线衍射(XRD)对催化剂进行表征,并以铁镧复合交联蒙脱土(Fe/La-PILC)为催化剂,质量分数为30%的过氧化氢水溶液为氧化剂,考察反应时间、催化剂用量和过氧化氢用量对苯甲醇催化氧化制苯甲醛的影响.结果表明:铁镧复合交联蒙脱土形成了比较均一的中孔骨架结构;当苯甲醇与过氧化氢物质的量之比为1:2,Fe/La(200)-PILC(Fe与La物质的量之比为200)质量分数为4%,反应5 h时,苯甲醇转化率和苯甲醛选择性分别为62.1%和86.4%.研究铁镧交联蒙脱土催化剂的催化氧化机理,发现Fe/La-PILC催化氧化苯甲醇的活性氧来自于Fe/La-PILC所吸附的氧.     

交联聚乙烯料加工设备的选型分析

通过多年从事硅烷交联聚乙烯料的实践和研究,就交联料生产的主要影响因素,即加工设备进行了剖析,对使用的几种机型的工作原理、运动方式、混炼效果、接枝反应时间、优缺点等问题进行了较深入的说明和比较,提出了自己的看法。     

(Meth)acrylic Cross‐Linked Polymer Microparticles: Synthesis by Dispersion Polymerization and Particle Characterization

(Meth)acrylic cross‐linked polymer microparticles have been synthesized by dispersion polymerization in organic media. They were produced by radical copolymerization of mono(meth)acrylate monomers with a certain concentration of a diacrylate as cross‐linker, in a mixture of two organic solvents, heptane and propan‐2‐ol. The reactive surfactant (“surfmer”) was a low solubility parameter acrylate monomer, based on an aliphatic ester group (generally C₁₈) or an isobornyl cycle, which gave auto‐dispersing character to the microparticles. By using glycidyl methacrylate in the monomer mixture, oxirane groups were introduced in the particles. The influence of the major synthesis parameters such as solvent composition, monomer composition and concentration, and initiator concentration has been investigated regarding the size and the molar mass of the cross‐linked polymer microparticles. The study was completed with the influence of the nature and the concentration of the surfmer, the concentration of cross‐linking agent and the composition of monomers feed. Stable cross‐linked microparticles ranging from z‐average radius of gyration, R_z = 20 nm to R_z > 60 nm were obtained by varying the synthesis conditions. The smallest microparticles were prepared with a blend of heptane and propan‐2‐ol in the 50/50 ratio by weight. Increasing the surfmer concentration or reducing the monomer concentration in the reaction mixture usually led to smaller microparticles. The longer the aliphatic chain of the surfmer, the smaller the microparticles. Minimum sizes were obtained for cross‐linking agent concentrations between 5 and 7.5 mol‐%, depending on monomers composition. For higher concentrations, macrogelation may occur during the synthesis.     

Cross‐Linked Enzyme Aggregates of Chloroperoxidase: Synthesis,Optimization and Characterization

In this study we have optimized the conditions to precipitate and cross‐link the enzyme chloroperoxidase (EC 1.11.1.10) from Caldariomyces fumago (CPO) using 1,2‐dimethoxyethane as the precipitating agent. The coprecipitation of the enzyme with albumin and pentaethylenehexamine was needed for optimum results, presumably due to the low number of lysines available in CPO. The enzyme was immobilized with an activity recovery of 68%. The cross‐linked enzyme aggregate showed higher temperature and pH stability, and better hydrogen peroxide tolerance than the free enzyme.     

镱改性对铬掺杂的介孔氧化铝催化性能的影响

以溶胶凝胶法合成镱改性的铬掺杂的介孔氧化铝催化剂Yb-Cr/Al2O3,通过X-射线衍射（XRD）、N2吸附-脱附等温线（BET）、程序升温还原（TPR）、透射电镜（TEM）等现代分析手段对制备的催化剂的结构进行表征。结果表明,稀土镱的引入使铬负载的介孔氧化铝表面更规整,结构更稳定。将催化剂用于以过氧化氢为氧化剂的苯氧化反应进行催化剂活性评价,Yb-Cr/Al2O3比Cr/Al2O3表现出了更高的苯转化率和苯酚选择性。     

交联壳聚糖树脂制备与吸附低浓度盐酸的研究

通过壳聚糖与铜离子作用得到模板壳聚糖，再用交联剂环氧氯丙烷交联后将铜离子洗脱制得交联壳聚糖树脂，研究了不同交联度的交联壳聚糖树脂的物理特性与吸附低浓度盐酸的特性。     

光照及需氧条件下Al2O3-AlBrx催化醇的选择性氧化反应

以脱脂棉为模板制备了多孔管状结构的Al2O3材料,用不同浓度的氢溴酸对多孔管状结构的Al2O3材料进行化学剪裁,制备了活性量可控,比表面积可调,不同形貌的负载型催化剂Al2O3-AlBr x。采用电场发射扫描电镜(SEM)和X射线衍射仪(XRD)对催化剂进行了表征。结果表明,该催化剂较好地复制了棉纤维的宏观和微观结构,呈现出明显的生物形貌特征。在光照条件下以空气为氧化剂的醇的选择性氧化反应中,发现催化剂Al2O3-AlBr x-3可以高选择性地将醇氧化为相应的醛、酮或酸,并对反应机理进行了探讨。该催化剂循环使用3次仍保持较高的催化活性。     

电导法研究交联壳聚糖树脂吸附低浓度酸

利用电导实验技术,跟踪交联壳聚糖树脂吸附游离酸的行为,研究吸附体系的性质对吸附的影响。实验结果表明,表观吸附速率常数随外加盐离子强度和吸附质浓度的增大而降低,交联壳聚糖树脂吸附游离酸的行为遵循单分子层吸附机制。     

多孔碳化硅表面改性及其生物相容性的研究

采用浸渍提拉的方法将聚乙烯醇、硅溶胶、海藻酸钙等涂敷于多孔碳化硅板上对其进行改性,并通过SEM观察改性后多孔碳化硅的生物相容性,并对其处理COD的能力进行测定。实验表明:聚乙烯醇和硅溶胶可以对多孔碳化硅进行改性,改性后多孔碳化硅板的生物相容性提高,微生物负载量增大,处理COD的能力明显提高。反应5d后,PVA改性的多孔碳化硅板COD去除率由改性前的15%提高到80%;硅溶胶改性的多孔碳化硅板COD去除率由改性前的15%提高到78%。     

Mechanical and Rheological Behavior of Hybrid Cross‐Linked Polyacrylamide/Cationic Micelle Hydrogels

In this work, a hybrid cross‐linked polyacrylamide (PAM)/cationic micelle hydrogel is fabricated by introducing the cationic micelles into the chemically cross‐linked PAM network. The cationic micelles act as the physical cross‐linking points through the strong electrostatic interaction with anionic initiator potassium persulfate. Thereafter, in situ free radical polymerization is initiated thermally from the cationic micelle surface to form the hybrid cross‐linked network. The synergistic effect between chemical and physical cross‐link endows the hydrogel with excellent mechanical and recoverable properties. The resulting hydrogel exhibits tensile stress of 481 kPa and fracture toughness of 1.65 MJ m⁻³. It is found that the chemical cross‐linking can inhibit the hysteresis of the hybrid hydrogel, exhibiting good elasticity in the tensile loading–unloading test. Moreover, dynamic rheological measurements show that the hybrid hydrogels possess fewer defects of network and exhibit excellent self‐recovery behavior. Thus, this investigation provides a different view for the design of new high elastic and tough hydrogels containing hybrid physical and chemical cross‐linking networks.