Novel Quaternary Ammonium Derivatives Based on Apple Pectin.

New quaternary ammonium derivatives (quats) based on apple pectin (PA) were synthesized by the chemical modification of native polysaccharides with various quaternization mixtures containing epichlorohydrin (ECH) and a tertiary amine. Pectin derivatives (QPAs) were studied by elemental analysis, conductometric titration, Fourier-transform infrared spectroscopy (FTIR), and C nuclear magnetic resonance (C NMR). Viscosity measurements enabled the evaluation of the viscosity average molar mass (M) for the unmodified polysaccharide, as well as its intrinsic viscosity ([η]) value.

Application of some cationic pullulan and curdlan derivatives as flocculants in fungicides-containing wastewater purification.

The ability of some cationic pullulan (TMAP-P) and curdlan (TMAP-C) derivative to remove different fungicide particles from synthetic wastewater has been studied. Commercial fungicides formulations of different type, Bordeaux mixture (BM), Dithan M45 (Dt) and Melody Compact49 WG (MC) have been used. The influence of some parameters related to the dispersion characteristics (suspension pH and salinity) and the polysaccharide derivatives (polymer dose, the ionic groups content, flexibility) on the separation process have been assessed.

Chitosan/Poly(maleic acid--vinyl acetate) Hydrogel Beads for the Removal of Cu from Aqueous Solution.

Covalent cross-linked hydrogels based on chitosan and poly(maleic acid--vinyl acetate) were prepared as spherical beads. The structural modifications of the beads during the preparation steps (dropping in liquid nitrogen and lyophilization, thermal treatment, washing with water, and treatment with NaOH) were monitored by FT-IR spectroscopy. The hydrogel beads have a porous inner structure, as shown by SEM microscopy; moreover, they are stable in acidic and basic pH due to the covalent crosslinking.

Antimicrobial Hydrogels Based on Cationic Curdlan Derivatives for Biomedical Applications.

Hydrogels based on biocompatible polysaccharides with biological activity that can slowly release an active principle at the wound site represent promising alternatives to traditional wound dressing materials. In this respect, new hydrogels based on curdlan derivative with 2-hydroxypropyl dimethyl octyl ammonium groups (QCurd) and native curdlan (Curd) were obtained at room temperature by covalent cross-linking using a diepoxy cross-linking agent. The chemical structure of the QCurd/Curd hydrogels was investigated by Fourier transform infrared spectroscopy (FTIR) spectroscopy.