posted on 2018-03-16, 00:00authored byBabloo Sharma, Susanne Striegler
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 × 105-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.