Engineering Commons^™

Sequence And Entropy-Based Control Of Complex Coacervates, Li-Wei Chang, Tyler K. Lytle, Mithun Radhakrishna, Joel J. Madinya, Jon Vélez, Charles E. Sing, Sarah L. Perry

Chemical Engineering Faculty Publication Series

Biomacromolecules rely on the precise placement of monomers to encode information for structure, function, and physiology. Efforts to emulate this complexity via the synthetic control of chemical sequence in polymers are finding success; however, there is little understanding of how to translate monomer sequence to physical material properties. Here we establish design rules for implementing this sequence-control in materials known as complex coacervates. These materials are formed by the associative phase separation of oppositely charged polyelectrolytes into polyelectrolyte dense (coacervate) and polyelectrolyte dilute (supernatant) phases. We demonstrate that patterns of charges can profoundly affect the charge–charge associations that drive this …

Patterned Well-Ordered Mesoporous Silica Films For Device Fabrication, Todd A. Crosby

Masters Theses 1911 - February 2014

Developing effective methods of generating thin metal oxide films are important for sensing and separations applications. An obstacle to device fabrication is controlling the size and spatial orientation of domain level pores while retaining the ability to generate arbitrary device level patterns. Well-ordered hexagonally packed cylindrical pores were created by taking advantage of block copolymer self-assembly followed by selective condensation of silica precursors using supercritical carbon dioxide as the solvent. It was possible to control the pore size by choosing PEO-PPO-PEO (Pluronic® series) triblock copolymers of differing molecular weights.

These processes were then incorporated with conventional lithographic techniques to generate …

Synthesis And Adsorption Studies Of The Micro-Mesoporous Material Sba-15, Eunyoung You

Masters Theses 1911 - February 2014

Over the past decades, there have been worldwide efforts to synthesize new types of ordered porous materials for catalysis, separations, etc. Among those, mesoporous material with microporous walls are promising in a sense that while mesopores act as channels for the reactant transport with little diffusion limitation, micropores in the wall act as active sites for reactions or storage of the molecules. In this study, we focused on the SBA-15 material, which is a highly ordered mesoporous silica material with micropores present in the wall. We have studied the synthesis of the material by manipulating various factors that are known …