In an effort to develop biomimetic glycosyl transfer catalysts, a polymerization protocol was developed that is applicable to the synthesis of crosslinked microgels via UV-initiated free radical polymerization of miniemulsions at ambient temperature and below. The catalytic activity of the microgels derived from butyl acrylate, EGDMA, and a catalyst-precursor ligand was established using the hydrolysis of 4-methylumbelliferyl β-d-galactopyranoside as a model reaction. The microgel-catalyzed hydrolysis was up to 3 × 10-fold accelerated over the background reaction and notably 38-fold faster than the hydrolysis catalyzed by its low molecular weight analog. Dynamic light scattering analysis demonstrated mean hydrodynamic diameters of the particles between 210 and 280 nm and chemical stability of the particles in aqueous solution between pH 1 and 13. A bell-shaped correlation between catalytic proficiency and material rigidity was observed that peaks at 40 mol % of crosslinking content of the microgel.

Microgels with embedded binuclear copper­(II) complex were prepared in the presence of galactose and mannose as biomimetic catalysts for the hydrolysis of glycosidic bonds. The study was designed to elucidate matrix effects responsible for the high catalytic proficiency (k cat/K M × k non) of the microgels that reaches up to 1.7 × 106 upon hydrolysis of 4-methylumbelliferyl-β-d-mannopyranoside. The experimental results reveal differences of sugar coordination to the binuclear copper­(II) complex in coordination sites, binding strength, overall geometry, and binding energies that differ by 7.1 kcal/mol and are based on experiments using UV–Vis spectroscopy and isothermal titration calorimetry. Accompanying computational analyses, based on density functional theory (DFT) at the B3LYP/m6-31G­(d) level of theory, further support the experimental results of sugar coordination by suggesting plausible binding sites of sugar coordination and providing additional insight into the cause of substrate discrimination during microgel-catalyzed glycoside hydrolyses. Subsequent kinetic analyses correlate the catalytic proficiency of the microgels with contributions of the metal complex core, the surrounding cross-linked matrix, and strongly binding mannose; however, the data reveal minor contributions of a templating effect to the overall catalytic performance of the water-dispersed microgel catalysts.

A unique class of aromatic ether polymers containing perfluorocyclopentenyl (PFCP) enchainment was prepared from the simple step growth polycondensation of commercial bisphenols and octafluorocyclopentene (OFCP) in the presence of triethylamine. Model studies indicate that the second addition/elimination on OFCP is fast and polycondensation results in linear homopolymers and copolymers without side products. The synthesis of bis(heptafluorocyclopentenyl) aryl ether monomers and their condensation with bisphenols further led to PFCP copolymers with alternating structures. This new class of semifluorinated polymers exhibit surprisingly high crystallinity in some cases and excellent thermal stability.

Ultra low dielectric constant (k ¼ 1.53) materials with self-cleansing properties were synthesized via incorporation of fluorodecyl-polyhedral oligomeric silsesquioxane (FD-POSS) into recently synthesized perfluorocyclopentenyl (PFCP) aryl ether polymers. Incorporation of fluorine rich, high free volume, and low surface energy POSS into a semifluorinated PFCP polymer matrix at various weight percentages resulted in a dramatic drop in dielectric constant, as well as a significant increase in hydrophobicity and oleophobicity of the system. These ultra-low dielectric self-cleansing materials (q tilt ¼ 38 ) were fabricated into electrospun mats from a solvent blend of fluorinated FD-POSS with PFCP polymers.

In a proof of concept study, a series of nonionic surfactant blends derived from Tween 80 and Span 80 were used to prepare catalytic microgels from stabilized droplets in miniemulsions. The goal of this study is to optimize the catalytic efficiency of microgels by decreasing their particle size with surfactants that are custom-made for the respective prepolymerization mixture. The effectiveness of the approach is examined by evaluating the catalytic efficiency of the resulting microgels in comparison to their counterparts made in the presence of ionic sodium dodecyl sulfate (SDS) solution. Spherical particles with hydrophilic−lipophilic balance (HLB) value dependent mean hydrodynamic diameters between 99 and 200 nm are obtained. Addition of Cu(II) ions and selected other transition metal ions activated the dormant catalysts for cleavage of glycosidic bonds in 2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic acid (HEPES) buffer at pH 7.00 and 37 °C using a fluorescent model substrate. The highest proficiency for the catalytic hydrolysis was observed for Cu(II)-containing microgels (k cat / K M × k non = 870 000) with the lowest diameter indicating an almost twofold better stabilization of the transition state compared to a microgel prepared in the presence of ionic SDS solution. The study establishes a correlation of the HLB value of the nonionic surfactant blend used during material synthesis to the particle size and catalytic performance of the resulting microgels.