MORPHOLOGICAL AND SURFACE ASPECTS OF CELLULOSE-LIGNIN HYDROGELS

Cellulose-lignin hydrogels (CL), prepared by a two-step procedure consisting in dissolving the cellulose in an alkaline solution at low temperature, followed by the crosslinking reaction with lignin in the presence of epichlorohydrin, were subjected to experimental approaches, additional to those reported before, for their in-depth characterization. Thus, the morphology was examined by optical and scanning electron microscopy (SEM), while some surface properties (surface area, average pore size, and sorption capacity) were estimated by dynamic water vapor sorption (DVS) analysis. The changes in crystalline structure of the samples were confirmed by X-ray diffractometry (XRD). It has been found that these characteristics are influenced by the lignin whose presence leads to increased porosity of the material.