葡萄糖在聚对苯二胺/铜修饰电极上的电化学行为及测定

在静态法合成聚对苯二胺纳米片的基础上,经一步水热将铜微球均匀锚定于其上,成功合成了具有良好导电性、大比表面积、大孔径和孔容的铜/聚对苯二胺(Cu/Pp PD)复合物,其独特的结构有利于电子的转移、活性位点的充分利用以及反应物、电解质等的输运。复合物对葡萄糖氧化表现出很高的电催化活性,在最优测试条件下,所构建的葡萄糖无酶传感器响应时间短(达到稳定电流的95%所需时间小于3 s)、线性范围宽(0.003~6.44 mmol/L)、灵敏度高(929μA·mmol-1·L·cm-2)、检出限低(4.48×10-7mol/L)、重现性和选择性好,对血清样品进行检测,回收率为99.5%~101.1%。所制备Cu/Pp PD复合物能实现对葡萄糖的简单、快速、灵敏、准确无酶检测,在临床医学上糖尿病人的早期诊断和治疗监测领域具有很好的应用前景。     

In situ synthesis of molecularly imprinted polymers on glass microspheres in a column

A facile method to fabricate molecularly imprinted polymers (MIPs) on glass microspheres in a column was developed. The column was prepacked with glass microspheres, and then the prepolymerization mixture was injected into the interstitial volume of the column. The polymerization took place in situ and the column could be directly used for high-performance liquid chromatography after the template had been removed. The template consumption was reduced greatly because the prepolymerization mixture just filled the interstitial volume between the glass microspheres in the column. The MIPs obtained exhibited better kinetic properties, higher efficiency, and low back pressure of the column. Emodin imprinted polymers were prepared by this method and were used for solid-phase extraction.     

LINEAR AND NONLINEAR SEMICLASSICAL THEORY OF WHISPERING-GALLERY-MODE MICROSPHERE LASER

A complete whispering-gallery-mode microsphere laser theory is developed, which combines usual laser semiclassical theory with Lorenz-Mie theory. The linear and nonlinear problems of the microsphere lasing are dealt with in the universal mode picture. The threshold condition, average amplitude of the steady state and frequency effect are obtained. A comparison between the theory and experiments is also made.     

ICF氘代固体靶的研制

 以自制全氘代苯乙烯单体(氘代率99%)为原料, 以偶氮二异丁腈为引发剂, 经自由基本体聚合反应, 先制得全氘代聚苯乙烯, 最后采用乳液微封装技术制得了直径150～450μm、壁厚2～15μm、球形度≥99.5%、同心度95%～98%、表面粗糙度＜30nm的ICF固体靶用空心微球。介绍了制备工艺,并对全氘代聚笨乙烯分子量及其分布的控制,微球壁内气泡形成机理,微球储存稳定性等进行了初步探讨。     

薄壁玻璃微球壳的热扩散充气

 导出了热扩散一步充气法和分步充气法充气时,薄壁玻璃微球壳的内压变化,及其在空气中的气体渗漏速率和保气半寿命的表达式,提出了确定分步充气过程操作参数的约束条件。D₂气体通过薄壁玻璃微球壳的扩散速率与分步法充D₂气体时其内压的实验测量值与计算值相符合。     

相分离聚合法:(Ⅱ)二乙氨基乙基型共聚功能微球的合成

<正> 随着生物工程高技术的发展,功能高分子微球作为一类新的功能高分子材料已得到十分广泛的应用。然而关于最难以合成的粒径在微米级、粒度分布窄的高分子微球合成的报道至今仍很少。本文报道了用相分离法(即静止的分散聚合法)合成含有DEAE基团的高分子微球的研究。探讨了单体、交联剂、引发剂及聚合温度、聚合时间等聚合条件对生成微球的影响。相分离聚合法的特点是利用了随着在聚合过程中单体的逐渐聚合,分子量长大,聚合体与反应体系间相容性变差而最终分相成球的原理,因而所形成的微球粒度圆,粒径比较均一。与一般的分散聚合法相比不仅生成微球的粒径较大,且不需要搅拌,使反应装置得以简化。     

“Continuous” emulsifier‐free emulsion polymerization for the synthesis of monodisperse polymeric latex particles

A “continuous” emulsifier‐free emulsion copolymerization (CEFEP) of styrene and divinylbenzene (DVB) or methyl methacrylate (MMA) and ethylene glycol dimethacrylate (EGDMA) has been devised to produce uniform polymeric microspheres of narrow size distribution from 74 nm to 2 μm, depending on reaction time. Monomer and crosslinker vapors were fed continuously into a small reactor. We suggest that after initial nucleation, subsequent CEFEP proceeds near the surfaces of growing particles in a monomer‐swollen outer shell. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 3181–3187, 2000     

Synthesis of microspheres with microphase‐separated shells

Novel structural microspheres of the Janus type, with microphase‐separated polystyrene (PS) and poly(tert‐butyl methacrylate) (PBMA) shells and crosslinked poly(2‐vinyl pyridine) (PVP) cores, were synthesized with the crosslinking of PVP spherical domains in poly(styrene‐block‐2‐vinyl pyridine‐block‐tert‐butyl methacrylate) ABC triblock terpolymer film with PS/PBMA lamellae–PVP spherical structures. For the formation of lamellae‐sphere structures, toluene, which was a selective solvent for the ABC triblock terpolymer, was used. With the crosslinking of PVP spheres in the microphase‐separated film with 1,4‐diiodobutane gas, the microphase structure of the terpolymer was fixed, and microspheres composed of microphase‐separated PS and PBMA shells and P2VP cores were obtained. The size distribution of the purified microspheres was narrow. The characteristics of the microspheres and their aggregation behaviors in selective solvents were investigated by transmission electron microscopy and light scattering methods. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2091–2097, 2000     

New sulfonated engineering polymers via the metalation route. II. Sulfinated/sulfonated poly(ether sulfone) PSU Udel and its crosslinking

New mixed sulfinated/sulfonated polysulfone PSU Udel has been produced by partial oxidation of sulfinated PSU with NaOCl. From the mixed sulfinated/sulfonated PSU, thin crosslinked polymer films have been produced by S-alkylation of the residual sulfinate groups with α,ω-diiodoalkanes having 4–10  (CH₂) units. The advantages of the partial oxidation process using NaOCl are as follows: (1) The desired oxidation degree can be adjusted finely. (2) No side reactions take place during oxidation. (3) The partially oxidized polymers is stable at ambient temperature. By variation of the oxidation degree of the sulfinated/sulfonated prepolymer and by variation of the chain length of the diiodo crosslinker, crosslinked membranes with a large range of properties in terms of ionic conductivity, swelling, and permselectivity have been produced. The partially oxidized polymers have been characterized by redox titration, ¹H-NMR, and FTIR. The crosslinked membranes have been characterized in terms of ionic conductivity (resistance), permselectivity, and swelling in dependence on ion-exchange capacity and oxidation degree of the prepolymers. In addition, the thermal stabilities of the membranes have been determined by TGA, and FTIR spectra have been recorded on the crosslinked films. Selected membranes show low ionic resistances, low swelling, and good temperature stability which makes them promising candidates for application in (electro)membrane processes. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1441–1448, 1998     

Porous monodisperse poly(divinylbenzene) microspheres by precipitation polymerization

The precipitation polymerization of commercial divinylbenzene in acetonitrile containing up to 40 vol. % toluene or other cosolvents is shown to produce novel porous monodisperse poly(divinylbenzene) microspheres. These microspheres have diameters between 4 and 7 μm, total pore volumes of up to 0.52 cm³/g, and surface areas of up to 800 m²/g. As no surfactant nor stabilizer was used in the preparation of these particles, their surfaces are free of any such residues. The particles were slurry-packed into stainless steel columns for size exclusion chromatography evaluation, and the results show an exclusion limit at molecular weights of 500 g/mol. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1543–1551, 1998