Solvent free biocatalytic synthesis of vinyl monomers by lipase immobilized on hydrogels

Abstract

Simple novel research plan has been employed to tailor supports for lipase immobilization. N-aminoethylacrylamide (N-AEAAm) and N-aminoethylmethacrylamide (N-AEMAAm) were crosslinked with N,N-methylene bisacrylamide (N,N-MBAAm) and consequently reacted separately with acrylic acid (AAc) and methacrylic acid (MAAc). The hydrogels thus formed, consist of both amide and carboxylic functional groups. These hydrogels were characterized by nitrogen analysis, SEM, FTIR and also by water uptake studies as a function of time, temperature, pH, and the presence of additives like sodium dodecyl sulfate (SDS) and cetyl trimethyl ammonium bromide (CTAB). These hydrogels are environmentally sensitive. In the presence of surfactants, these hydrogels show micellization and swell to the maximum at the critical micellar concentration (CMC) of the surfactants. Lipase was immobilized on these hydrogels and the one exhibiting the maximum activity was further used as biocatalyst to explore nonconventional green routes for the synthesis of some known and novel vinyl monomers. Yields obtained have been high and the immobilized lipase show high reusability.

A study in the uranyl ions uptake on acrylic acid and acrylamide copolymeric hydrogels

“…Because of the nonbiodegradable nature of most of the surfactants, these are usually present as common effluents in most of the water bodies, hence their presence affects metal ion uptake. Depending upon the structure of the hydrogels, the presence of the surfactants increase23 or decrease24 water uptake level of the hydrogels near its critical micelle concentration (cmc), i.e., reflection of the capacity of the hydrogels to partition metal ions from the solution phase. Therefore, the swelling behavior of the hydrogels was studied in the presence of SDS using its 4.05, 8.32, and 12.15 m M /L at 40°C and pH 7.0 [Fig.…”

Unsteady Flow and Heat Transfer in a Composite Porous Annulus with Time-Dependent Injection

“…The analytical solution for the study of unsteady radiation effects on natural convection MHD flow in a rotating vertical channel is examined by Chauhan and Rastogi [21]. Also Chauhan and Kumar [22] analyzed three dimensional Couette flows in a composite channel which is partially filled with a porous medium. Kuznetsov [23] considered fully developed forced convection in a parallel-plate channel partly filled with a homogenous porous material.…”