Polymer Brushes on Planar TiO2 Substrates

A facile and universal method is presented for the preparation of polymer brushes on amorphous TiO₂ film. Homogeneous and stable poly(methyl methacrylate), polystyrene, poly(4‐vinylpyridine), and poly(N‐vinyl imidazole) (PNVI) brushes up to 550 nm are directly created onto TiO₂ via UV‐induced photopolymerization of corresponding monomers. Kinetic studies reveal a linear increase in thickness with the polymerization time. Characterization of the resulting polymer brushes by FTIR spectroscopy, X‐ray photoelectron spectroscopy, contact angle, and atomic force microscopy (AFM) indicates an efficient UV‐grafting reaction. Finally, we have demonstrated the possibility in converting the PNVI brushes to poly(vinyl imidazolium bromide), i.e., poly(ionic liquid) brushes by polymer–analogous reactions.

     

Inequalities for the Polar Derivative of a Polynomial

Let P(z) be a polynomial of degree at most n. We consider an operator D _?? which maps a polynomial P(z) into D _?? P(z) :=?nP(z)?+?(?? ? z)P??(z) and prove results concerning the estimates of |D _?? P(z)| on the disk |z|?=?R??? 1, and thereby obtain extensions and generalizations of a number of well-known polynomial inequalities.     

蒙脱石修饰碳糊电极测定氨基酸的研究：Ⅰ.色氨酸的测定

本文用含10％蒙脱石的修饰碳糊电极研究了测定色氨酸的方法。发现在0.001mol/L KCl-HCl(pH=2.0)溶液中富集、介质交换后用微分脉冲伏安法测定,于+0.75V出峰,在20.～10.0μg/ml范围内有线性。相对标准偏差为2.60％。检测限为70ng/ml,该电极具有很强的抗干扰能力。用此方法直接测定氨基酸药物样品中的色氨酸,结果良好。     

Some results concerning growth of polynomials

In this paper, we establish inequalities for polynomials with restricted zeros, which in particular yields interesting generalizations of some Zygmund type inequalities for polynomial.     

Electrochemical degradation of bromophenol blue on porous PbO2–ZrO2 composite electrodes

Research on Chemical Intermediates - The electrochemical performance of porous PbO2–ZrO2 composite electrode was studied with bromophenol blue (BPB) as the simulated pollutant. In the process...     

Synthesis and biological activity of phospholipase C-resistant analogues of phosphatidylinositol 4,5-bisphosphate

The membrane phospholipid phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2) is an important regulator in cell physiology. Hydrolysis of PtdIns(4,5)P2 by phospholipase C (PLC) releases two second messengers, Ins(1,4,5)P3 and diacylglycerol. To dissect the effects of PtdIns(4,5)P2 from those resulting from PLC-generated signals, a metabolically stabilized analogue of PtdIns(4,5)P2 was required. Two analogues were designed in which the scissile O-P bond was replaced with a C-P bond that could not be hydrolyzed by PLC activity. Herein we describe the asymmetric total synthesis of the first metabolically stabilized phospholipase C-resistant analogues of PtdIns(4,5)P2. The key transformation was a Pd(0)-catalyzed coupling of a H-phosphite with a vinyl bromide to form the desired C-P linkage. The phosphonate analogues of PtdIns(4,5)P2 were found to be effective in restoring the sensitivity of the TRPM4 channel to Ca2+ activation.     

Fabrication and photoluminescent properties of ZnO/mesoporous silica composites templated by a chelating surfactant

A novel anionic surfactant-templated synthesis of ZnO/mesoporous silica nanocomposites has been carried out by using N-hexadecylethylenediamine triacetate (HED3A), a triprotic surfactant, as the structure-directing agent. The chelating template can capture zinc ions in solution and then direct the mesophase formation, enabling an amount of zinc oxide to be embedded in the porous silica matrix during calcination. With variation of the molar ratio of Zn(2+) to HED3A in the template, a series of composites with different doping amounts were obtained after the removal of organic components. The variation of the zinc ion concentration in the initial template solution induces an evolution of the silica mesophase, presumably due to the change in electronegativity of the HED3A headgroup caused by the chelating effect. Spectroscopic studies show a strong host-guest interaction between the silica pore walls and ultrafine ZnO nanoparticles. The photoluminescence properties of the resulting composites exhibit a size-dependent light emission and quantum-confinement effect of ZnO, accompanied by an infrequent violet emission originating from the ZnO-SiO(2) interface.