David E. Bergbreiter

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Aqueous processes ranging from protein folding and enzyme turnover to colloidal ordering and macromolecular precipitation are sensitive to the nature and concentration of the ions present in solution. Herein, the effect of a series of sodium salts on the lower critical solution temperature (LCST) of poly(N-isopropylacrylamide), PNIPAM, was investigated with(More)
Recent developments in the preparation of polymer supports for synthesis and catalysis are reviewed. The use of insoluble supports for synthesis of one molecule per bead and chemistry leading to new ways to use insoluble supports are discussed. New routes to design soluble, high capacity supports for synthesis are highlighted and the roles of polymers in(More)
The effect of a series of sodium salts on the lower critical solution temperature (LCST) of poly(N-isopropylacrylamide), PNIPAM, was investigated as a function of molecular weight and polymer concentration with a temperature gradient microfluidic device under a dark-field microscope. In solutions containing sufficient concentrations of kosmotropic anions,(More)
Fatty acid esters have been synthesized in good yield by reaction between copper(I) ate complexes formed from methylcopper(I) and primary or secondary Grignard reagents and esters of primary iodoalkylcarboxylic acids. The synthetic method is illustrated with proced.ures for CHr:gH(CHz)rgCO2C2H5, CeHsCHzO(CH2)16COzCzHs, CH3(CH2)25CO2C2H5, CH3O2C(CH)I2CO2CHI,(More)
The preparation of polyethylene-oligomer (PE(olig))-supported N-heterocyclic carbene ligands (NHCs) and their Ru complexes is described. These complexes are structurally analogous to their low molecular weight counterparts and can serve as thermomorphic, recoverable/recyclable ring-closing metathesis (RCM) catalysts. Because of the insolubility of(More)
Surfaces with solute responsive wettability can be prepared by covalent layer-by-layer assembly of PNIPAM-c-PNASI with 10 and 100 nm diameter aminated silica nanoparticles. These surfaces are found to exhibit reversible changes in surface wetting in response to solute anion identity and concentration, allowing surfaces to be switched from hydrophilic(More)
The use of polymers other than divinylbenzene crosslinked polystyrene as supports in organic chemistry is discussed. Insoluble polymer alternatives to DVB crosslinked polystyrene discussed include porous polyethylene supports, polymer-supported functional colloids, micron and submicron-sized particles and hollow spheres and one-dimensional supports. Soluble(More)