Polymer Gelation and Aggregation at the Liquid / Air and Solid / Air Interfaces

Orateur : Gemma NEWBY (University of Warwick)

The gelation mechanisms of polymers at interfaces are extremely important in many technological sectors [Aguilar et al. 2007]. Here, both the solid / air and liquid / air interfaces of a well known non-ionic triblock copolymer, Pluronic P85 [Mortensen et al. 1996], have been probed using Grazing Incidence Small Angle Scattering, (GISAS), and Transition Electron Microscopy, (TEM). The determined morphologies have been compared to those in the bulk studied before [Newby et al. 2009]. The findings have helped to understand the gelation mechanism and resolve certain morphologies, along with enhancing the prospective industrial applications of these remarkable set of materials. The surface morphology of selected concentrations of Pluronic P85 has been resolved and the intermediate phases between morphologies scrutinized. A variety of structures were found to be present, from correlated micelles to mesoporous arrays, as rich as in the bulk, confirming the high tunability of Pluronics. It was also observed with both neutrons and x-rays that ordered systems prevailed under particular conditions. The order that these systems produce could be extremely technologically important especially if the order is over a large area since this large domain size is desirable for many applications. One particular example being the need to produce large arrays [Searle et al. 2000] of cubic and hexagonal structures which are in high demand for protein folding applications. Pluronics can achieve such arrays.

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