有机膨润土制备及性能表征

采用湿法工艺,分别用十六烷基三甲基氯化铵、十八烷基二甲基苄基氯化铵、十八烷基三甲基氯化铵与钠基膨润土,进行离子交换反应合成了有机膨润土。以红外光谱、X-ray衍射和差热分析等手段对改性膨润土进行了结构表征,讨论了不同的季铵盐对有机膨润土性能的影响。实验表明,表面活性剂离子进入膨润土晶片层间,使其晶片层间的亲水环境改变为疏水环境并增大晶片层间距离,为制备高聚物／膨润土纳米复合材料奠定基础。     

膨润土有机改性的FTIR和XRD研究

研究内容是制备有机膨润土以提高膨润土与有机相的相容性,同时观察膨润土的层状结构在有机化前后的变化情况。以钠基膨润土为原料,并用十八胺试剂作为有机插层剂取代膨润土层间的Na^＋,制得有机膨润土,且对其结构进行表征。FTIR和DTA-TG都证明有机插层剂已进入膨润土的层间;XRD表明膨润土的层间距由1．4增大到4．3nm;从实验结果可知,钠化膨润土在各种指标上都比原钙基膨润土有显著的改善,如吸蓝量、膨胀容、胶质价、阳离子交换容量等。改性后的膨润土使其晶片层间的亲水环境改变为疏水环境以及增大晶片层间距离,从而有利于制备综合性能较好的复合材料。     

CTMAB和PDMDAAC有机改性膨润土的制备及其表征

以天然膨润土为原料,进行提纯钠化,得到钠化膨润土,测定了其膨胀容、膨润值、胶质价、吸蓝量、阳离子交换容量等指标,使提纯钠化后的膨润土性能更加优越.分别以溴化十六烷基三甲基铵(CT-MAB)和聚二甲基二烯丙基氯化铵(PDMDAAC)作为有机插层剂制备了两种有机改性膨润土,通过傅里叶变换红外光谱(FTIR)、X射线衍射(X...     

新型铸造用淀粉/膨润土复合粘结剂的红外研究

以木薯淀粉为主要原料,自行研制的有机膨润土为改性剂,经过熔融和溶液插层等工艺制备木薯淀粉/膨润土复合粘结剂.采用FTIR和XRD手段表征及力学性能测试.结果表明,PVA插层改性后的有机膨润土的层间距大于有机膨润土的层间距大于Na基膨润土的层间距,膨润土的层间距越大,越有利于淀粉与膨润土的插层反应,得到的复合粘结剂的干强度也越高.该复合粘结剂具有粘结强度高、抗吸潮性好,且成本低、工艺简单和环境友好.     

CdSe量子点膨润土复合材料的制备与表征

首先以CdCl₂·2.5H₂O、SeO₂和NaBH₄为反应物,制备巯基丁二酸稳定的CdSe量子点。然后将有机膨润土与CdSe量子点溶液混合并充分搅拌,制备负载CdSe量子点的膨润土发光材料,用荧光光谱、扫描电镜和X射线粉末衍射等分析测试手段对所得材料的光谱性能与微观结构进行表征。光谱分析表明,量子点膨润土复合材料的发光颜色与量子点溶液非常一致;X射线光电子能谱分析表明,复合后的材料中含有Cd 和 Se两种元素;此外,在量子点膨润土复合材料X射线粉末衍射谱中可见CdSe量子点（111）、（220）及（331）3个晶面的衍射峰,2θ=4.3°处出现膨润土（001）衍射峰。数据表明,在制备的CdSe量子点膨润土复合材料中,量子点和膨润土的结构都没有改变。     

La/酸化膨润土吸附剂的表征与除磷性能

以酸化改性膨润土为载体,采用浸泡法制备了稀土La掺杂的La/酸化膨润土吸附剂.通过XRD和FTIR对其结构进行了表征,探讨了膨润土的改性机理,研究了该吸附剂对废水的除磷性能.结果表明：酸化过程洗掉了膨润土中的杂质和氧化铝,稀土镧的掺杂在膨润土层间及表面引入了一定数量的羟基化合物,改善了膨润土的层间结构并生成了新的La-O-Si键,实现了La与膨润土的复合,提高了膨润土的吸附性能.     

有机膨润土负载ZnO/TiO2光降解催化剂的研制及性能

以六水硝酸锌、酞酸丁酯和有机膨润土为原料,采用沉淀法制备ZnO/TiO2膨润土复合光催化材料,用IR和XRD对光催化剂的组织构造和微观结构进行表征,实验了光催化剂对亚甲基蓝废水的降解性能。结果表明：ZnO/TiO2成功负载于膨润土片层表面,ZnO的含量为有机膨润土的8%,反应温度为70℃,焙烧温度为420℃,催化剂用量为12mg/L时,亚甲基蓝废水的降解率可达97%以上。     

高压下制备的累托石/酚醛树脂复合材料微结构和热性能研究

 采用物理方法在高压下制备了酚醛树脂（PF）/累托石（REC）纳米复合材料，用X射线衍射（XRD）、透射电子显微镜（TEM）及热分析（DSC/TGA）等方法，研究了复合材料的物相、显微结构以及热学性能。结果表明，不通过层间高分子聚合反应，不预先对累托石进行有机化处理，在高压下，由聚合物分子插入粘土层间，可以形成剥离型树脂/粘土纳米复合材料，并且其热学性能发生了较大的改变。     

分光光度法研究插层膨润土对有机染料的脱色性能

以钠基膨润土为原料制备o-羧甲基壳聚糖插层膨润土,通过XRD、IR及SEM表征插层膨润土的表面性质及组织构造;用分光光度法分析插层膨润土对有机染料的脱色性能;同时探讨表面活性剂和o-羧甲基壳聚糖加料顺序、配比对脱色性能的影响。结果表明:当表面活性剂和o-羧甲基壳聚糖为2:1时,先加入表面活性剂反应一定时间再加入羧甲基壳聚糖所得的插层膨润土对亚甲基蓝和酸性蓝脱色性能最优,脱色率可达98.5%。     

萃金体系第三相的产生及其谱学研究

利用^198Au示踪法研究了十四烷基二甲基苄基氯化铵从碱性氰化液中萃取金第三相的产生过程，同时用傅里叶变换红外光谱（FTIR），核磁共振（NMR），激光光散射（DLS）等方法分析了第三相形成后上下两有机相的微观结构，结果表明，随着有机相中金浓度的增大，有机相中有纳米级的聚集体形成；当金浓度继续增大时，有机相分为上下两相，有机相中的金，磷酸三丁酯（TBP）和水主要集中在下层，下层有机相有明显的水特征吸收峰，TBP的P=O伸缩振动向低频移动，核磁共振（^31P-NMR)的化学位移明显移向高场；用激光光散射技术测定了两有机相中聚集体的大小。     

Preparation and characterization of a novel antistatic poly(vinyl chloride)/quaternary ammonium based ion-conductive acrylate copolymer composites

Antistatic poly(vinyl chloride)/quaternary ammonium salt based ion-conductive acrylate copolymer (PVC/QASI) composites were successfully prepared in a Haake torque rheometer. The surface resistivity of the PVC/QASI composites could be reduced to 10⁷ Ω sq^?1 order of magnitude when the QASI content reached 20 phr (parts per hundreds of resin). The surface resistivity of the composites was slightly sensitive to the relative humidity (RH), showing a good antistatic ability under an RH of 12%. Mechanical properties tests, differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) were also used to investigate the tensile strength, elongation at break, thermal properties, and morphology of the PVC/QASI composites, respectively.     

The relationships of catalytic activity of metal Schiff base catalysts and the Hammett constants of their anion–cationic substituents on ligand

For quaternary ammonium, pyridinium, or imidazolium anion–cationic substituents, a linear relationship can be established between the reactivity of metal Schiff base catalysts and the Hammett constants of their anion–cationic substituents with multi‐atomic anions on ligand based on the theoretical and experimental works. Copyright © 2015 John Wiley & Sons, Ltd.     

大功率远程荧光粉型白光LED散热封装设计

针对大功率远程荧光粉型白光LED存在的散热问题,研究了其封装结构的散热设计方法。在分析现有远程荧光粉型白光LED封装结构及散热特点的基础上,提出将荧光粉层与芯片热隔离的同时开辟独立的荧光粉层散热路径的热设计方法。仿真分析结果表明:新的设计能够在不增加灯珠径向尺寸的同时改善荧光粉层的散热能力。在相同边界条件下,改进设计后的荧光粉层温度较改进前降低了10.7℃,芯片温度降低了0.55℃。在芯片基座上设置热隔离槽对芯片和荧光粉层温度的影响可以忽略。为了达到最优的芯片和荧光粉层温度配置,对荧光粉层与芯片之间封装胶层厚度进行优化是必要的。新的封装方法将芯片和荧光粉层的散热问题相互独立出来,既避免了二者的相互加热问题,又增加了灯珠光学设计的自由度。     

Surfactant-assisted organic reactions in water. Effect of ultrasound on condensation reactions between active methylene compounds and arylaldehydes

A series of quaternary ammonium salts has been tested as phase transfer agents to promote condensation reactions in an aqueous solution of sodium hydroxide in the absence of any organic solvent. Methyltrioctylammonium chloride (Aliquat 336) emerges as the most efficient catalyst. Sonication of the reaction media has a poor but positive kinetic effect.     

Intermediate particles in the catalysis of radical reactions of chlorohydrocarbons

Intermediate products of radical reactions of chlorohydrocarbons catalyzed by copper chloride complexes were synthesized by the photolysis of solutions of [(C₄H₉)₃BzN⁺]₂[CuCl₄]^2? in chlorobenzene and chloroform at the wavelength corresponding to Cl → Cu charge transfer. It was shown by the EPR method that the products of photolysis were alkyl radicals formed by organic fragments of the quaternary ammonium cation and Cu(II) complexes (supposedly organocopper compounds). The total content of paramagnetic centers decreased. The mechanisms of photoreduction of quaternary ammonium tetrachlorocuprates and possible reasons for the decay of paramagnetic particles were considered.     

Ethoxylation of p-chloronitrobenzene using phase-transfer catalysts by ultrasound irradiation: a kinetic study

Ethoxy-4-nitrobenzene was synthesized by the reaction of 4-chloronitrobenzene with potassium ethoxide in a homogeneous system using benzyltriethylammonium chloride (QCl) as a phase-transfer catalyst at 50 degrees C under ultrasound irradiation conditions. The use of phase-transfer catalysts and ultrasound has been compared and demonstrated in this nucleophilic substitution reactions. The kinetics of the reaction depends on the effect of amount of catalyst, quaternary ammonium salts, agitation speed, amount of potassium hydroxide, amount of ethanol, temperature and the frequency of the ultrasound waves on the conversion of the reaction.     

Phase-transfer catalytic dichlorocyclopropanation of styrene under the influence of ultrasound conditions - A kinetic study

The kinetics for dichlorocyclopropanation of styrene with an excess of chloroform were studied under phase-transfer catalysis and ultrasound irradiation conditions using aqueous sodium hydroxide as the base and benzyltriethylammonium bromide as a catalyst. The reaction was carried out at 35°C under pseudo-first order conditions by keeping aqueous sodium hydroxide and chloroform in excess and was monitored by gas chromatography (GC). The effects of agitation speed, quaternary ammonium salts, amount of catalyst, amount of sodium hydroxide and temperature on the kinetics of the conversion were investigated.