环氧氯丙烷与环氧乙烷及环氧丙烷的三元共聚

研究了用三异丁基铝-磷酸-含氮含硫给电子化合物作为催化剂使环氧氯丙烷、环氧乙烷及环氧丙烷三元共聚的行为。结果指出,作为催化剂第三组分以二甲基苯胺的效果最好。催化体系中存在与磷酸相等克分子的水时催化活性较高。酸铝比在0.25及胺铝比在0.2时活性最高。三异丁基铝用量占总单体重量的2.5％,70℃,4小时聚合转化率可达95％左右,共聚物的η_i达到2附近。通过共聚物氯含量的测定及利用核磁共振波谱仪测定环氧丙烷链节含量,求得共聚过程中各单体组分的变化。固定单体中环氧氯丙烷配比,改变环氧丙烷及环氧乙烷配比,则随环氧丙烷比例增加,所得共聚物η_i下降,T_g呈现最小值的变化。     

锌银电池中氧化银电极的光电化学研究

用光电化学方法研究棒状和多孔氧化银电极在阳极极化过程中的光响应规律可以得到许多信息。最大光响应出现在电极表面的AgO被充分地还原为Ag_2O以及Ag结晶即将生成瞬间, 多孔电极和实体电极开路光电位ΔV_(ph,oc)之比有助于对多孔电极孔结构的了解, 首次观测到n-p-n光响应波形的转化。     

纳米氧化镍、氧化锌的合成新方法

以草酸和醋酸盐为原料,用室温固相化学反应首先合成出前驱配合物二水合草酸镍和二水合草酸锌,进而二水合草酸镍和二水合草酸锌分别在380℃和460℃热分解2 h,得到产物纳米氧化镍和氧化锌。用X-射线粉末衍射、透射电镜对产物的组成、大小、形貌进行表征。结果表明,产物纳米氧化镍为球形立方晶系结构,平均粒径均为40 nm左右,产物氧化锌为粒度分布均匀的球形六角晶系结构,平均粒径约为20 nm。     

二氧化钛、二氧化锆的合成及其催化酯化反应

M.Hino和K.Arata于1979-1980年曾报道将四氯化钛、二氯氧锆分别用氨水水解,用0.5mol硫酸处理,然后在空气中煅烧所得的二氧化钛、二氧化锆,可以催化烷烃的异构化反应。我们参考文献合成了TiO_2和ZrO_2,并发现当热处理温度为425℃(TiO_2),575℃(ZrO_2)时,它们对醋酸和脂肪醇的酯化反应,具有催化作用。     

FORMATION OF MOLYBDENUM OXIDE NANOSTRUCTURES CONTROLLED BY POLY(ETHYLENE OXIDE)

Polymeric systems have played an important role as structure-directing agents and in the control of nucleation and growth of crystals.This article reviews the work of our research group in the field of the polymer-assisted crystallization of inorganic materials,mainly focused on the formation of highly ordered,porous molybdenum oxide nanostructures.Different experimental parameters including the influence of poly(ethylene oxide)-containing polymers on the morphology and structure of the products obtained...     

FORMATION OF MOLYBDENUM OXIDE NANOSTRUCTURES CONTROLLED BY POLY(ETHYLENE OXIDE)

 Polymeric systems have played an important role as structure-directing agents and in the control of nucleation and growth of crystals. This article reviews the work of our research group in the field of the polymer-assisted crystallization of inorganic materials, mainly focused on the formation of highly ordered, porous molybdenum oxide nanostructures. Different experimental parameters including the influence of poly(ethylene oxide)-containing polymers on the morphology and structure of the products obtained from peroxomolybdate solutions are examined. Our electrochemical investigations on molybdate species are also briefly described. Finally, the importance of the precursor species in the formation of the final product is discussed.     

甲烷在含有氧缺陷的钙钛矿型复合氧化物上的低温加压氧化偶联反应

用Ｍｇ＾２＋部分置换ＳｒＴｉＯ３中的Ｔｉ＾４＋，由于Ｍｇ＾２＋与Ｔｉ＾４＋的电荷差异而在晶格中生成了氧缺陷，通过氧缺陷上吸附的活性氧物种，在低于６００℃温度范围内甲烷可以进行氧化偶联反应。由于吸附的活性氧物种随着反应的进行被消耗掉的同时，生成的水吸附在氧缺陷中抑制了气相氧的吸附。当提高反应压力时，氧缺陷中吸附的氧物种不断补充，使甲烷的氧化偶联反应可以进行。     

活性炭表面含氧基团的生成及对NO的还原作用

活性炭表面含氧基团的生成及对ＮＯ的还原作用＊高志明杨向光吴越＊＊（中国科学院长春应用化学研究所，长春１３００２２）关键词活性炭，一氧化氮，氧化铜，还原，氧化近几年，随着环保研究的开展，活性炭被用于同时脱硫脱硝反应［１］．活性炭的表面化学性质就成为需要...     

RANDOM COPOLYMER OF PROPYLENE OXIDE AND ETHYLENE OXIDE PREPARED BY DOUBLE METAL CYANIDE COMPLEX CATALYST

Copolymerization of propylene oxide (PO) and ethylene oxide (EO) using double metal cyanide (DMC) complexas the catalyst was carried out. The structure of random copolymers was confirmed by ~(13)C-NMR and IR spectra. ~1H-NMRanalysis shows that the EO content in the copolymer is the same as that in the initial monomer feed. Moderate molecularweight copolymers with various EO content were obtained and their values of molecular weigh distribution (MWD) fell inthe range of 1.21-1.55. It was found that the molecular weight of copolymers is controlled by the mass ratio of EO + PO toinitiator moles used. The reaction rate as well as polymer yield decrease with increasing EO content in the feed composition.     

铈铁复合氧化物阴离子吸附剂的表面酸碱特性研究

研究了用于水体砷等有害阴离子去除的稀土铈铁复合氧化物吸附剂的表面酸碱特性。利用电位滴定实验求定了铈铁复合氧化物吸附剂、铁氧化物和铈氧化物的表面质子电荷密度s0、零电荷点pHzpc (分别为5.8,6.2和6.8),表明特性吸附在砷等的去除中起主要的作用,铈铁复合氧化物吸附剂的表面总吸附位NS为4.1×10-3mol/L,运用表面络合恒定容量模式求算此复合氧化物吸附剂的表面固有酸度常数pKa1和pKa2,为进一步研究有害阴离子与去除材料的表面络合作用机制提供了重要参数。