One-step preparation of uniform cane-ball shaped water-swellable microgels containing poly(N-vinyl formamide)

Study of cellulolytic enzyme immobilization on copolymers of N-vinylformamide

This study was focused on finding of effective carriers suitable for the immobilization of cellulase. Copolymers of N-vinylformamide (NFV) and divinylbenzene (DVB) were synthesized by free radical crosslinking polymerization in inverse suspension. Methyl silicone oil was used as the continuous phase. Three polymeric carriers based on P(NVF-co-DVB) with varying degrees of crosslinking and spherical particles with different grain sizes were obtained. The formamide groups in these carriers were hydrolyzed to amino groups, yielding three P(VAm-co-DVB) polymers with vinylamine units. Enzyme, cellulase (Novozym® 476), was immobilized onto carriers with vinylamine (through glutaraldehyde) and vinylformamide groups (without glutaraldehyde). The efficiency of the enzyme immobilization was determined based on the enzymatic activity of the enzyme during the catalytic reaction relative to that of the native enzyme. All tested carriers were found to be effective carriers for the immobilization of cellulase. However, the catalytic activity of cellulase immobilized on the P(VAM-co-DVB0.27)/2000/350 carrier was higher than that for the native enzyme. In addition, two molecular spectroscopy methods, Fourier-transform absorption infrared spectroscopy (FT-IR) and Fourier-transform Raman spectroscopy (FT-Raman), were used to analyze the carriers. These studies provided complete information regarding the structure of the studied copolymers.

Gel architectures and their complexity

Gels have made the transition from brittle materials with few potential applications to high performance systems with mechanical properties approaching that of rubber. They have a wide variety of structures and provide the opportunity to tailor these structures to achieve well-controlled properties over a range of length scales. In this review we consider and compare the structures and properties of a range of gels that have been studied in recent years. In comparing these gels we highlight the importance of key structural parameters in defining gel mechanical properties. It is hoped that this article will provide authors who discover new gels a resource that will easily enable them to determine the differences of their new gels to existing gels.