Sol-gel derived carbon ceramic electrode containing methylene blue-intercalated α-zirconium phosphate micro particles

Methylene blue-intercalated alpha-zirconium phosphate (MBZrP) micro particles in deionized water were deposited onto the surface of graphite powder to prepare graphite powder-supported MBZrP, which was subsequently dispersed into methyltrimethoxysilane-derived gels to yield a conductive composite. The composite was used as electrode material to fabricate a surface-renewable, rigid, leak-free carbon ceramic composite electrode, bulk-modified with methylene blue (MB). In the configuration, alpha-zirconium phosphate was employed as a solid host for MB, which acted as a catalyst. Graphite powder ensured conductivity by percolation, the silicate provided a rigid porous backbone and the methyl groups endowed hydrophobicity and thus limited the wetting section of the modified electrode. Peak currents of the MBZrP-modified electrode were surface-confined at low scan rates but diffusion-controlled at high scan rates. Square-wave voltammetric study revealed that MBZrP immobilized in carbon ceramic matrix presented a two-electron, three-proton redox process in acidic aqueous solution with pH ranged from 0.44 to 2.94. In addition, the chemically modified electrode showed an electrocatalytic activity toward nitrite reduction at +0.15 V ( vs. Ag/AgCl) in acidic aqueous solution (pH=0.44). The linear range and detection limit are 1x10(-6)-4x10(-3) mol x L(-1) and 1.5x10(-7) mol x L(-1), respectively.     

纳米级NiTiO3粉体的合成

以Ｈ２ＴｉＯ３，Ｈ２Ｏ２及ＮｉＣｌ２为主要原料，用化学共沉淀法制备了纳米级ＮｉＴｉＯ３。确定了反应物Ｈ２ＴｉＯ３，Ｈ２Ｏ２，ＮＨ３的最佳摩尔比为１：８：２，用不同的退火温度和退火时间对样品处理得到相应粒径的纳米级粉体。     

A metallo-capped polyrotaxane containing calix[4]arenes and cyclodextrins and its highly selective binding for Ca2+

A water-soluble nanometer-scale metallocapped polyrotaxane has been prepared by the inclusion complexation of azo-calixarenes with metallo-bridged bis(beta-CD)s, displaying highly selective binding for Ca(2+).     

聚醚氨酯的氧化及其接枝共聚合的研究

本文研究了在聚醚氨酯表面上进行接枝共聚合的新方法。首先在聚醚氨酯薄膜上通过过氧化氢光氧化引入过氧化氢基,然后在还原剂亚铁盐或N,N-二甲基对甲苯胺的作用下引发丙烯酰胺接枝共聚合,反应具有低温快速的特点。产物经吸水性实验及扫描电子显微镜观察均证实了是一接枝共聚物。通过模型化合物的研究证明,接枝反应具有较高的选择性,接枝共聚占优势地发生在聚醚软段上,接枝地点很可能就在醚键旁的α-碳原子上。     

Infrared and electronic spectra of copper (II) complex of maleonitriledithiolate and 4,4'-dimethyl-2, 2'-bipyridine and their theoretical studies

The molecular structure and binding, as well as infrared and electronic spectroscopic properties for the title complex Cu(mnt)(dmbpy)(mnt(2-)=maleonitriledithiolate, dmbpy=4,4'-dimethyl-2,2'-bipyridine) were studied in this paper. With semi-empirical PM3 and non-empirical DFT (B3LYP/6-311G*) methods, the molecular geometry of the complex was optimized and corresponding vibrational spectra in the gaseous state were obtained. The calculated results derived from DFT were more reasonable than those from PM3. The point group of Cu(mnt)(dmbpy) in isolated gaseous state was C(2), in which Cu(II) adopted a distorted tetrahedral geometry and the dihedral angle between the N(2)Cu and S(2)Cu planes was about 29.814 degrees. And a complete assignment to the IR spectra of such a complicated molecule was exhibited. With ZINDO/S method an electronic spectrum was calculated. The results showed that the calculated values generally agreed with the observed ones. And a detailed explain was made on its electronic spectra.     

端羟丁腈聚氨酯/聚甲基丙烯酸甲酯互穿网络高聚物的T_g和形态研究——Ⅰ.组分比和交联程度的影响

用同步法合成了端羟丁腈聚氨酯/聚甲基丙烯酸甲酯互穿网络高聚物[PU(HTBN)/PMMA-IPN]。用动态力学方法和透射电镜研究了它们的T_(?)转变行为和形态。理论计算和实验结果表明,样品具有两个明显相互分离但又各自连续的相结构,呈现出分属于组分聚合物的两个Tg转变(Tg_1,Tg_2)。在全IPN中,PMMA相区的尺寸(1000—2000?),比在接枝共聚物(3000—6000?)和半IPN(—3000?)中的明显变小。适当的交联程度可使相区进一步变小,变均匀,相连续性增加。这是网络互穿造成的“强迫互容”所致。部分丁腈羟(HTBN)分子同PMMA的反应,使一些样品出现了Tg_2升高的现象。