Cell adhesion mechanisms on laterally mobile polymer films.

In contrast with the majority of substrates used to study cell adhesion, the natural extracellular matrix (ECM) is dynamic and remodeled over time. Here we use amphiphilic block copolymers to create self-assembled supported films with tunable lateral mobility. These films are intended to serve as partial mimics of the ECM in order to better understand cell adhesion responses, specifically in the context of dynamic substrates.

Surfactant-mediated ion exchange and charge reversal at ionic liquid interfaces.

Room-temperature ionic liquids (ILs) exhibit a unique set of properties due to their charged character, presenting opportunities for numerous applications. Here, we show that the combination of charged surfactants with ILs leads to rich interfacial behavior due to the interplay between electrostatic and surface forces. Using traditional measures of surface activity and X-ray photoelectron spectroscopy (XPS), we find that sodium alkyl sulfates and alkyl trimethylammonium bromides are, indeed, surface-active at the air-IL interfaces of both [EMIM][EtSO(4)] and [BHEDMA][MeSO(3)].

Controlled interfacial assembly and transfer of brushlike copolymer films.

The self-assembly and compression of polybutadiene-bpoly(ethylene oxide) (PBd-PEO) at the air/water interface enables control over surface density, height, and film structure. Interfacial transfer was performed by a combination of Langmuir-Blodgett (LB) and Langmuir-Schaefer (LS) techniques, resulting in monolayer and bilayer films. Ellipsometry and wettability results were used to characterize the efficiency of transfer and to determine the properties of the resulting films, confirming a brushlike monolayer.