Fabrication of poly(PEGMA) surface with controllable thickness gradient and its mediation on the gradient adhesion of cells

The gradient surface shows enormous potential in the development of tissue engineering, biosensor, microfluidic control, and particle sorting. In this work, a poly(polyethyleneglycol methacrylate) (poly(PEGMA)) gradient surface was prepared through surface-initiated activators regenerated by electron transfer atom transfer radical polymerization (SI-AGRET ATRP). The effect of various parameters on the thickness growth of poly(PEGMA) film were analyzed, among which the excessive reducing agent was utmost important. The reducing agents supported the regeneration of Cu^I and eliminated the disturbance of air, maintaining the "living polymerization" of poly(PEGMA) up to 73.1 nm under tested conditions. The physicochemical properties of the fabricated surfaces were characterized by ellipsometry, X-ray photoelectron spectroscopy, water contact angle. The thickness slope of gradient poly(PEGMA) was controllable in a nanoscale range. The gradient surface was further grafted with CRGD (Cys-Arg-Gly-Asp) peptides onto the poly(PEGMA-co-[glycidyl methacrylate]) blocks via the ring-opening reaction between epoxy and amino groups, which showed a gradient change in water contact angle and adhesion of endothelial cells.     

浅谈浙江省涂料企业技工人才存在的问题及对策

对浙江省部分涂料企业技工人才现状及原因进行了分析,就企业如何培训和留住技工人才提出了一些对策和建议。     

微波合成阿司匹林的工艺研究

本论文采用微波方法合成阿司匹林，用无水碳酸钠作催化剂量，研究了微波在有机合成中的应用及其他加热原理。利用了交互的正交试验方法，在反应物配比、微波功率，辐射时间和催化剂用量这四个因素中寻找出最佳合成工艺条件，从而提高了阿司匹林的产率，实现了有效地利用微波技术促进有机合成反应。     

界面改性剂对PP/滑石粉形态结构和性能影响

用在50L固相接枝反应器中合成的等规聚丙烯接枝马来酸酐(PP-g—MAH)作界面改性剂，制备了PP—g—MAH／PP／滑石粉复合材料。研究了PP—g—MAH／PP／滑石粉复合材料的形态结构和力学性能。结果表明，PP—g—MAH对PP／滑石粉复合物的缺口冲击强度、弯曲强度和拉伸强度均有增强作用；PP—g—MAH对PP／滑石粉复合物表观粘度几乎没有影响。SEM观察发现PP—g—MAH对PP／滑石粉复合物相界面有明显的改善。     

新型光化学反应器及二氧化碳光解反应研究

研究设计了可产生波长小于200 nm真空紫外光的光化学反应器,首次利用该波段的光在该反应器中进行了CO2光解反应的研究。用氮气为发光介质对其进行光强标定,实验表明主要产生120、149、174 nm波长的光(N原子谱线);实验条件下CO2光解后生成产物CO,结果表明光源电流一定时产生CO的量与光源工作气体的压力有关,在CO2和N2反应物系中,光源内发光介质N2的压力在2 500 Pa左右时CO的产率最大,而在该反应物系中加入甲烷后,CO的产率明显增大。     

有机磷化物制备羟基磷灰石工艺条件的探讨

探索用有机磷化物制备羟基磷灰石的工艺条件：采用硝酸钙、氨水、磷酸三丁酯为原料进行正交对比研究，优化得到了制备较佳羟基磷灰石的工艺条件。优化的工艺条件为：原料中Ca／P（molar ratio）1．67；Ca（NO3）2、4H2O／NH3H2O（g／g）为0.99；烧结温度为850℃：恒温时间为5h，并对合成的样品进行了化学和红外光谱的分析。     

Humidity sensitivity of polypyrrole and polypyrrole/SBA‐15 host–guest composite materials

Polypyrrole (PPY) and PPY/SBA‐15 host–guest composite materials have been prepared using chemical synthesis route and characterized by XRD, IR, N₂ adsorption–desorption isotherms, and SEM. The humidity sensitive properties (HSP) of this kind of materials have been studied by analyzing the variation curve of impedance as a function of relative humidity. It was found that the PPY/SBA‐15 host–guest composites materials exhibit better HSP than that of the corresponding pure PPY. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3301–3305, 2006     

对国际原油价格持续走高的几点看法

分析了2005年上半年国际原油价格持续走高的原因，对下半年油价走势进行了预测。     

Na2S-SO2反应体系中H2S产生的过饱和态分析

向Na2S溶液中通入低浓度SO2气体以生成H2S，H2S从液相中逸出时，存在一突跃现象。本文根据这一现象，结合Y．T．Shah等提出的吸收－反应－解吸体系中过饱和态存在的条件，通过理论分析，得出在Na2S-SO2-H2S4反应体系中H2S解吸存在过饱和现象。