Multi-scale modeling and synthesis of polyester ionomers.

Simulations of microphase separation are carried out using the dissipative particle dynamics (DPD). By varying the concentration and temperature of resin solutions we explore mesomorphologies supported by the all-atom models. We found that for a low degree of functionalization the homogeneously distributed ionomers self-assemble into spherical micelles at solid loads below 31 wt%, subject to the activation energy barrier for the gradual growth of pre-micellar aggregates.

Miniaturized system of neurotrophin patterning for guided regeneration.

Understanding the fundamentals of cell behaviour is imperative for designing and improving engineering strategies for regenerative medicine. By combining the precision of confocal microscopy with photochemistry, nerve growth factor (NGF) was chemically immobilized on chitosan films either in distinct areas or as concentration gradients. Using rhodamine as a proxy for NGF, a series of immobilized concentration gradients were created, using the number of rastering scans within a defined area and the distance between each area as a way to control the resulting gradient.

Synthesis and application of poly(phenylene ethynylene)s for bioconjugation: a conjugated polymer-based fluorogenic probe for proteases.

A set of carboxylate-functionalized poly(phenylene ethynylene)s (PPEs) has been synthesized in which the carboxylic acid groups are separated from the polymer backbone by oligo(ethylene glycol) spacer units. These polymers are soluble in water and organic solvents and have photophysical properties that are sensitive to solvent conditions, with high salt content and the absence of surfactant promoting the formation of aggregates of relatively low quantum yield and long fluorescence lifetime. Quenching of these materials by the dinitrophenyl (DNP) chromophore (K(SV) approximately 10(4)) is also highly solvent-dependent.

Enhanced fluorescence quenching in receptor-containing conjugated polymers: a calix[4]arene-containing poly(phenylene ethynylene).

A fluorescent poly(phenylene ethynylene) containing calix[4]arene-based receptor units has a sensitivity to quenching by the N-methylquinolinium ion that is over three times larger than that seen in a control polymer lacking calix[4]arenes.

Dicubyl disulfide.

Dicubyl disulfide (1) has been prepared in six steps from commercially available dimethyl-1,4-cubanedicarboxylate in 47% overall yield. In the final step, the previously unknown cubanethiol 2 was oxidized to disulfide 1. X-ray crystallography for 1 reveals the shortest tetragonal C-S bond on record (1.