期刊
LANGMUIR
卷 25, 期 2, 页码 1196-1209出版社
AMER CHEMICAL SOC
DOI: 10.1021/la803182n
关键词
-
资金
- [NSF-DMR-0756273]
- [NSF-NIRT 0650705]
- Division Of Materials Research
- Direct For Mathematical & Physical Scien [0756273] Funding Source: National Science Foundation
This study probes the behavior of two series of organic-functionalized core-shell silsesquioxane (POSS-M)p-(x/y) derivatives with various hydrophobic-hydrophilic terminal group compositions in the bulk state and within mono- and multilayered films at the air-water interface and on solid surface. POSS-M refers to mixed silsesquioxane cores, in contrast to the geometrically specific POSS compounds. It is composed of polyhedra, incompletely condensed polyhedra, ladder-type structures, linear structures, and all the possible combinations thereof and attracts great interest because of its facile preparation, low polydispersity, high yield, and low cost. The two series of (POSS-M)p-(x/y) molecules are different in hydrophobic-hydrophilic balance of their terminal groups, with x and y respectively referring to the molar percent of -OCONH-C18H37 tails and -OH for p = 1 and the percent of -OCONH-C18H37 tails and -OCO-C6H4COOH terminal groups for p = 2. In the bulk state, the presence of aromatic rings in (POSS-M)2-(x/y) series resulted in a lower symmetry crystal structure than the (POSS-M)1-(x/y) series. Moreover, the (POSS-M)p-(x/y) molecules that contain a sufficient amount of -OCONH-C18H37 tails exhibit double endothermic transition, which attributed to the melting of alkyl chains followed by the melting of the unit cells of (POSS-M) cores. The surface morphologies for the various hydrophobic-hydrophilic combinations at surface pressure p = 0.5 mN/m are similar to that observed for the classical amphiphilic star polymers. However, at higher surface pressure (p >= 5 mN/m), the POSS-M compounds with lower content of hydrophilic groups form a uniform monolayer.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据