静电喷涂法制备具有低吸附力的超疏水性聚苯乙烯膜

采用聚苯乙烯的N,N-二甲基甲酰胺溶液为原料, 通过静电喷涂的方法制备了具有微-纳米复合结构的聚苯乙烯膜. 通过调节溶液浓度, 得到了不同的结构、浸润性及吸附性的表面. 当聚苯乙烯的质量分数为5%、分子量为25000时, 得到的表面与水的接触角达到167°, 吸附力达到15 μN, 表明该膜表面具有超疏水性的同时对水滴具有很低的吸附力. 此外, 分子量的大小也对静电喷涂膜表面形貌的变化起重要的作用.     

获得高性能电致变色薄膜的ITO表面修饰方法

氧化铟锡玻璃(ITO)以其优良的导电性能和透过率以及相对低的反应活性使其在显示器和电致变色器件中有广泛的应用. 然而, ITO表面的金属氧化物基团也带来了一些问题, 如通过物理方法沉积的电致变色薄膜易从ITO基底上脱离, 从而降低器件寿命, 此种问题在使用液体电解质时显得尤为突出. 为此, 我们利用有机酸小分子对ITO基底表面进行修饰, 继而利用电化学沉积的方法制备聚3,4-(2,2-二甲基丙烯二氧基)噻吩电致变色薄膜. XPS结果表明基底与修饰物间以化学键结合, 超声波处理可以看出电致变色薄膜在修饰后的基底上有更好的稳定性. 本研究提供了一种简单易行的方法来获得高性能的高分子电致变色薄膜.     

凹槽铜基底表面与单层石墨烯的相互作用特性研究

基于石墨烯二维材料的诸多应用需要将其大面积、高质量地转移到目标基底上,迫切需要了解石墨烯在剥离和转移过程中与基底之间的相互作用特性.本文采用经典分子动力学方法探索了铜基底表面凹槽的几何特征尺寸对石墨烯吸附和剥离过程中凹槽基底对石墨烯吸附作用的影响机理和规律.结果表明:对于固定边界条件下的单层石墨烯,当基底表面的凹槽宽度固定不变时,吸附过程中基底对石墨烯的吸附力随二者间距的减小,呈现先增大后减小的趋势;其最大吸附力随凹槽深度的增加而增大,而当凹槽深度继续增大至石墨烯未能吸附进入凹槽底部的临界值时,吸附力迅速减小;剥离过程中,石墨烯完全剥离的临界作用力随凹槽深度的增加同样呈现先增大后减小的趋势,且与剥离前石墨烯与凹槽基底的相互作用面积有关;当基底表面凹槽的深度固定不变时,吸附和剥离过程中石墨烯-基底之间的吸附力随间距的变化规律取决于石墨烯在基底凹槽处的稳态吸附构型.     

仿生柔性表面的结构设计及吸附力试验分析

模仿昆虫脚上光滑型吸附垫表面的结构设计,选用具有黏弹性的硅胶板,分别测试了光滑、带凹槽、带凹坑试样在干的和湿的玻璃表面上的水平摩擦力和垂直吸附力.结构表明在干玻璃表面非光滑结构的接触面积比光滑的要小,具有减粘降阻的作用;而在有一层厚液体膜作媒介时,摩擦力比光滑的要大.有液体时,水平摩擦力是凹槽型的最大,垂直吸附力是凹坑型的最大.有一薄层液体时的湿吸附能力比干吸附大,且液体粘性越大吸附能力越强.这些研究为仿生爬壁机器人的足掌设计提供了有价值的参考.     

PREPARATION AND ADSORBABILITY OF DEXTRAN MICROSPHERES WITH UNIFORM DIAMETER

The method of preparing uniform dextran microspheres with a narrow diameter distribution was introduced and the adsorbability of these microspheres was evaluated. The microspheres were prepared in W/O microemulsion using 0.5% dextran solution as the aqueous phase and n-hexane as the oil phase. Characteristics of the prepared dextran microspheres were examined with laser light blocking technique, optical microscope and ultraviolet spectrometer. The results show that the prepared dextran microspheres have uniform morphology and narrow diameter distribution, nearly 92% of them having a diameter of 56.6μm. In vitro evaluation of adsorbability, wet dextran microspheres have good adsorption of 98.32mg/g of model drug methylene blue in 20.86mg/L methylene blue solution at 25℃, The adsorption of dried dextran microspheres under the same condition is 132.15mg/g, which is even higher. And the adsorbability of dextran microspheres has significant relationship with the concentration of methylene blue and temperature. The adsorbability is better at lower temperature and higher concentration of methylene blue.     

超疏水性聚二甲基硅氧烷膜的制备及其表面吸附性研究

采用简单的激光刻蚀方法制备了具有类“菜花”状多级结构的粗糙聚二甲基硅氧烷(PDMS)膜, 并用CCD与高敏感性微电力学天平观察和测量PDMS表面对水的吸附情况. 结果表明, 该膜表面具有超疏水性, 同时对水滴具有超低的吸附力. 还对其表面特殊多级结构产生的机理进行了分析, 并探讨了在化学组成和表面结构对超疏水性以及吸附性产生的影响.     

Theoretical Studies on Interaction Between Methanol and Functionalized Single-Walled Carbon Nanotubes

We study the adsorption of a methanol molecule on single-walled carbon nanotubes (SWCNTs) with various diameters and chiral angles by using the density functional theory based calculations. We find that methanol prefers to be adsorbed physically on the exterior surface of chiral nanotubes in comparison to the armchair and zigzag tubes with binding energy of about-2.76 kcal/mol, which is consistent with recent experimental andtheoretical investigation results. We further consider the adsorption of methanol on the exterior surface and edge site of functionalized SWCNTs. The obtained results indicate that the binding energy of methanol is significantly increased for adsorption on the sidewall of functionalized nanotubes. It is also found that the adsorption of methanol at the edge site of both functionalizedand pristine SWCNT is remarkably different (chemisoption process) incomparison to the exterior sidewall of the tubes. Furthermore, the electronic structures and Mulliken charge population of the considered complexes at their ground state are discussed within the context.