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31.
《Composite Interfaces》2013,20(5-7):453-465
Diimides 4,4′-oxydiphenylene diphthalylimide (PT-ODA-PT) and diphenylbiphenyltetracarboxyimide (A-BPDA-A) of an evident affinity to polyimides have been dispersed in a matrix of poly(4,4′-oxydiphenylene biphenyltetracarboxyimide) (BPDA-ODA). Changes in thermal and mechanical properties of BPDA-ODA films modified by diimides have been found to depend on the amount of diimide added and the conditions of film preparation (stretching). It has been established that diimides can play two different roles. When dissolved in polyimide, they act as plasticizers improving the segment mobility of BPDA-ODA chains, which may be critically needed to achieve the better molecular packing. The films plasticized by diimides show lower T g and the order–disorder transition temperature; the unstretched films exhibit better tensile properties, compared to unmodified films. However, dispersed beyond the limit of solubility in polyimides, diimides have detrimental effects on mechanical properties of the films. Though changes of the thermal properties of compositions derived from BPDA-ODA polyimide and microparticular diimides are less expressed than those of polyimide films plasticized by diimides, the compositions have poorer ultimate strength and shorter elongation at break. The conclusion may be drawn that the mechanical properties of the films modified by microparticular diimide are mainly controlled not by the interfacial interaction matrix–microparticles, but more likely by the much stronger macromolecular chain–chain interaction. 相似文献
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PCVD法制备ZrO~2和YSZ薄膜 总被引:7,自引:0,他引:7
以金属β-二酮类有机螯合物Zr(DPM)~4和Y(DPM)~3为挥发性源物质, 采用微波等离子体化学气相淀积法于较低的温度下(420~560℃)成功地在多孔α-Al~2O~3陶瓷,非晶玻璃等衬底上制备出致密的ZrO~2和YSZ薄膜材料.XRD分析结果表明,纯ZrO~2薄膜中除了单斜相外还存在着亚稳态的四方相.当掺入的Y~2O~3 摩尔百分含量大于或等于7%时,ZrO~2完全被稳定成立方相.SEM观察表明, 在等离子体内的不同区域中生成的薄膜形貌有所不同.XPS检测了YSZ薄膜中Zr3d~5~/~2和Zr3d~3~/~2 的电子结合能,发现较ZrO~2的标准值低0.7eV.由TEM观察和由XRD衍射峰半宽度计算, 所制备的ZrO~2和YSZ薄膜中微晶粒径在10nm左右 相似文献
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电化学控制释放三磷酸腺苷 总被引:3,自引:0,他引:3
在含有甲苯磺酸钠和吡咯的水溶液中电化学合成聚吡咯膜.当膜在三磷酸腺苷(ATP)的溶液中氧化时,ATP掺入膜内;当膜还原时ATP从膜中释放出来, 释放出的ATP的量可由紫外可见光谱法测定. 相似文献
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基于等离子体聚合膜的日本血吸虫压电免疫传感器的研究 总被引:2,自引:0,他引:2
提出了一种测定日本血吸虫抗体的可逆压电免疫传感器。先在石英晶振上沉积正丁胺等离子体聚合膜,再自组装聚电解质,用以静电吸附固定日本血吸虫抗原。然后采用BSA和NRS作封闭剂,以封闭晶振上非特异必吸附位点,实现对日本血吸虫感染兔血清的测定。探讨了聚电解质(PSS和AASS)自组装、抗原包被和免疫反应等实难条件的影响;考察了该传感器的响应特性与再生性能,并与采用戊二醛共价键合固定法进行比较。发现该传感器具有灵敏度高、重现性好、非物异性吸附低、再生简便等优点。将它用于测定一系列不同感染程度的兔血清样本,结果表明,该传感系统是临床定性和定量诊断日本血吸虫病的一种有效工具。 相似文献
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《Composite Interfaces》2013,20(5-7):581-594
In the course of film coat preparation it is very important to carry out preformulation investigations. The film formed by Metolose® SM-4 polymer containing Macrogol 2000 (polyethylene glycol) as plasticizer showed structure changes depending on the concentration of the plasticizer during storage. This could be explained by the fact that the small quantity of plasticizer can be built in among the methyl cellulose molecules more easily, while the greater amount of plasticizer forms a separate phase in the beginning and can be built in into the film structure only later. On the other hand, the water bound by the hygroscopic property of the plasticizer can further influence the properties of the film as water also serves to function as a plasticizer. The increase in the quantity of the plasticizer enhanced the tensile strength of the film: the resulting film was less breakable and easier to handle mechanically. The studied films proved to be suitable for forming a protective coat of different solid dosage forms (pellets, tablets). 相似文献
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利用Gibbs吸附公式处理了硅胶自四氯化碳和环己烷中吸附脂肪醇、环己醇、苯甲醛、苯甲醚、乙酸丙酯的实验结果,得到吸附膜的表面压(π)和分子面积(A)的关系曲线,这些曲线均可用描述不溶物液态扩张膜的Smith方程描述。文中对所得结果给出了初步的解释。 相似文献
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Hua-xinSun SongWang He-sunZhu. 《高分子科学》2004,(4):399-403
In order to improve the blood compatibility of silk fibroin (SF), poly(ethylene glycol) macromer (PEGM) in different amounts was added to the SF film to incorporate C=C group into the surface of blend films which were then modified by SO2 gas plasma treatment. ATR-FITR and XPS were used to analyze the chemical change which had occurred on the film‘s surface. When the content of sulfur on the surface of blend films surpasses 1.59%, the antithrombogenicity of plasma treated films increases remarkably due to surface sulfonation. This result implies that SF with blend of PEGM after SO2 plasma treatment have potential use for making blood-contacting biomaterials. 相似文献