【作者】 韦文波；

【导师】 文纲要；

【作者基本信息】 哈尔滨理工大学 ， 材料学， 2009， 硕士

【摘要】 两亲性嵌段共聚物因其优良的自组装性能,国内外众多学者已将其应用到LB膜的研究中,通过调控其微区结构,极大地提高了LB超薄膜的机械和化学性能,但其复杂的溶解和表面行为过程,以及丰富的聚集形态和成因,一直是人们研究的热点。本文主要利用Langmuir技术和原子力显微镜(AFM)研究了选择性溶剂对嵌段共聚物PS-b-PEO(SEO)的Langmuir单层及其LB膜的影响。同时考察了亚相温度、溶液滴加体积和沉积压力的影响。通过样品Langmuir单层的π-A等温曲线、滞后曲线及其LB膜的AFM图像的对比分析,可以看出选择性溶剂对样品的铺展效果有一定的影响,SEO等温曲线的平台高度随着温度的升高而依次上升;等温线的趋势不受滴加体积的影响;沉积压力的增加使胶束尺寸增大,颗粒更稠密。氯仿使胶束粒子铺展得更为均匀,而甲苯则可使胶束表面铺展更平整。对于SEO要想有好的成膜效果,亲油链段PS的分子量至少应大于10000或者PS的百分含量应高于50%。此外,我们对SEO与PS的共混体系(PS/SEO) Langmuir单层及其LB膜进行了研究,以氯仿为铺展溶剂,主要考察SEO对成膜效果欠佳的PS的改善情况,并观察是否有项链网络结构的产生。结果发现,随着均聚物PS的增加,共混物LB膜中的胶束由岛状胶束逐步变为规则的圆形胶束,密度也随之增大。SEO9500可改善PS的成膜效果,但由于PEO的阻挠作用仍较明显,PS/SEO9500体系中没有出现项链网络结构;而在PS/SEO5000体系中,当PS含量达到80%,滴加体积为20μl,沉积压力为1、2和7mN/m时,均出现了新颖的项链网络结构,在7mN/m时的效果最好。更多还原

【Abstract】 Due to the excellent self-assembling property of amphiphilic block copolymer, many scholars at home and abroad have applied it to the research of LB films. The mechanical and chemical properties of the LB ultrathin films can be improved a lot by regulating the micro-structures. But it is difficult to explain the processes of solution and surface behavior as well as the abundant aggregation morphologies and their reasons, which have been the research focuses.The effect of the selective solvent on the Langmuir monolayer and LB film of block copolymer PS-b-PEO（SEO） was studied by using of Langmuir technology and atomic force microscopy（AFM）. The effects of subphase’s temperature, dropping volumn and deposited pressure were also considered. According to the analyses of theπ-A isotherms, hysteresis curves of the monolayers and the images of LB films, we found that there were certain effects of selective solvent on the spreading impact of the samples, the position of the isotherm’s plateau region rised gradually with the increase of temperature, the dropping volume didn’t play a function on the trends of isotherms. The micelle grains became densers and grew as the deposited pressures increased. The samples spread with CHCl3 could disperse evenly, but the surface planeness wasn’t as good as the ones spread with C7H8. In order to get a better pattern of LB films for SEO, the molecular weight of hydrophobic chain PS must be at least 10000 or the content of PS is more than 50%.The blend system of SEO and PS, spread with CHCl₃, has also been investigated to improve the film forming effect of PS with SEO, which has not a good film forming effect as SEO, and to find the necklace-network structure. It was shown that, with the increase of homopolymer, the island micelles turned into regular circular micelles gradually as the density became more bigger. The film forming effect of PS could be improved by SEO, but for the sake of the hindering effect of PEO, the necklace-network structures haven’t been found in the system of PS/SEO9500. For the system of PS/SEO5000, when the content of PS is up to 80%, the dropping volumn is 20μl, finally the novel necklace-network structrues were discovered at the deposited pressures 1, 2 and 7 mN/m, especially good for the one at 7mN/m.更多还原