Physical and mechanical properties of the fully interconnected chitosan ice-templated scaffolds

Abstract

Porous chitosan scaffolds were prepared with a freeze-casting technique with different concentrations, 1.5 and 3 wt %, and also different cooling rates, 1 and 4C/min. The pore morphology, porosity, pore size, mechanical properties, and water absorption characteristics of the scaffolds were studied. Scanning electron microscopy images showed that the freeze-cast scaffolds were fully interconnected because of the existence of pores on the chitosan walls in addition to many unidirectionally elongated pores. Increases in the chitosan concentration and freezing rate led to elevations in the thickness of the chitosan walls and reductions in the pores size, respectively. These two results led to the enhancement of the compressive strength from 34 to 110 kPa for the scaffolds that had 96-98% porosity. Also, augmentation of the chitosan concentration and decreases in the freezing rate led to the reduction of the number of pores on the chitosan walls. Furthermore, the volume of water absorption increased with a reduction in the chitosan concentration and cooling rate from 690 to 1020%.