Role of polymer network and gelation kinetics on the mechanical properties and adsorption capacity of chitosan hydrogels for dye removal. Issue 24 (25th September 2017) - Salzano de Luna, Martina
ABSTRACT: Chitosan (CS) hydrogels are receiving growing attention as adsorbents for water purification purposes. The conditions of preparation of this class of materials play a crucial in the determination of their performances; however, this aspect is often neglected in the literature. In this study, we deal with this issue, focusing on the structure‐property relationships of CS hydrogels obtained by phase inversion method. We show that the concentration of the starting solution determines the density and strength of intermolecular interactions, and that the gelation kinetics dictates the hydrogel structure at the microscale. Consequently, even subtle changes in the preparation protocol can cause significant differences in the performances of CS hydrogels in terms of mechanical properties and dye adsorption capacity. The observed trends are often neither trivial nor monotonic. Nonetheless, we demonstrate that they can be interpreted looking at the CS network structure, which can be inferred by rheological measurements. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys.2017, 55, 1843–1849 Abstract : The preparation conditions of chitosan (CS) hydrogels intended for dye removal significantly affect their mechanical strength and dye adsorption capacity. This research combines rheological analyses, confined compression tests, and batch adsorption experiments to investigate the effects of two processing parameters: (i) polymer concentration in the starting solution and (ii) gelation kinetics. The former determines the density and the strength of the interactions at the molecular scale, while the latter dictates the hydrogel assembly at the micron‐scale.