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In this study, composite hydrogels with interpenetrated polymer networks (IPNs), based on bacterial cellulose (BC) and poly(acrylic acid-co-N,N′-methylene-bis-acrylamide) (PAA) were synthesized by radical polymerization.

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New microfiltration and ultrafiltration membranes were obtained using acrylonitrile‐vinyl acetate copolymers in mixture with poly(vinyl alcohol) (PVA). Thus, a blend polymer solution was prepared in dimethylsulfoxide (DMSO) and used to obtain bicomponent polymer membranes by phase inversion. The rheological behavior of the DMSO polymer solutions was, mostly, dilatant at low shear gradients and pseudo plastic with quasi Newtonian tendency at higher gradients. Membranes were characterized by Fourier transform infrared spectrometry (FTIR), optical microscopy, atomic force microscopy, thermal gravimetric analysis‐differential thermal gravimetry, and pure water flux (PWF). FTIR spectra displayed the characteristic bands for acrylonitrile, vinyl acetate, and PVA. The morphology and the porosity can be tailored by the preparation conditions. PVA allows controlling the size of the pores and enables, in principle, to use the resulted membranes as supports for enzyme immobilization. PVA content influences the thermal stability. PWF values depend on the copolymer, on the content in PVA, but also on the coagulation bath composition. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41013.

Hydrogels based on polyacrylic and polymethacrylic acids were synthesized using two variants of redox initiating systems and three crosslinking agents in various ratios to the monomer. The chemical structure of these hydrogels was extensively studied by Fourier transform infrared (FTIR) spectrometry and Raman spectrometry. These hydrogels were also characterized by other techniques, namely thermo gravimetric analysis (TGA), differential thermal gravimetry, differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). The hydrogel ability to immobilize enzymes through covalent bonds was studied by FTIR and Raman spectrometry and by analyzing the SEM images before and after enzyme immobilization. The enzyme influence on the thermal behavior of the hydrogel biocomposite was investigated by DSC and TGA, too. The methacrylic acid leads to more thermo stable hydrogels formation than acrylic acid. Acrylic and methacrylic hydrogels are able to covalently immobilize enzymes. This is proved by the important changes which occur in the chemical composition, the thermal behavior and the morphology of hydrogels after immobilization stage. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

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New nanocomposites were synthesized by the reaction between a polyhedral oligomeric silsesquioxane (POSS) with eight epoxy groups (epoxy-POSS) and diglycidyl ether of bisphenol A (DGEBA) using Jeffamine D230 as curing agent. The reactivity of the systems was extensively studied by Raman spectroscopy. The hybrid materials were characterized by different techniques like thermogravimetric analysis, dynamical mechanical analysis, X-ray photoelectron spectroscopy, differential scanning calorimetry, and scanning electron microscopy. The "Si-O-Si" cages of the POSS component form aggregates, which was shown by the conversion data obtained from the Raman spectra and confirmed by the DSC curves, XPS spectra, and SEM images.