IN SITU SYNTHESIS AND STUDY OF TWO-PHASE HYBRID HYDROGELS OF β-CYCLODEXTRIN/CELLULOSE BY SCANNING ELECTRON MICROSCOPY AND FTIR SPECTROSCOPY

Abstract

Two-phase hybrid hydrogels from powder cellulose (PC) and/or microcrystalline cellulose (MCC) and biologically active natural cyclic oligosaccharide β-cyclodextrin (β-CD) were obtained by combining them in the solvent N,N-dimethylacetamide/LiCl and regenerating the hydrogels from the solutions. Cellulose-cyclodextrin hybrid hydrogels were synthesized for the first time without use of cross-agents and/or other gel-promoting components, and without precipitants and anti-solvents under atmospheric conditions. The properties of the composites depended on the type of pristine cellulose and the method of combining the components. Optimally, composite hydrogels were obtained by combining a 1–3 wt.% solution of PC in DMAA/LiCl followed by the addition of β-CD powder to the solution. The water-retention capacity of MCC/β-CD hydrogel was 48.8 g g-1, that of deciduous and flax PC/β-CD hydrogels 62.9 and 55.5 g g-1 respectively. The morphology of the hybrid gels was characterized by scanning electron microscopy (SEM) and the functional content was determined by Fourier transform IR spectroscopy. It was shown that the hydrogels seem to be two-phase interpenetrating systems that interact at the interface. Both phases coexist as a monolithic agglomerate stabilized additionally by hydrogen bonds. Each phase has an individual shape and morphological structure. The results allow the use of cellulose-containing materials, including waste materials, in the elaboration of new hybrid materials to be predicted.