Comprehensive insight of crosslinking agent concentration influence on starch‐based aerogels porous structure
Paulo Henrique Camani, Maria G. M. Gonçalo, Rennan F. S. Barbosa, Derval dos Santos Rosa
Abstract
Abstract In this work, we evaluated starch‐based aerogels prepared using freeze‐drying, and an eco‐friendly crosslinking agent (trisodium citrate), in three different concentrations: 12.8, 19.3, and 25.7 mg ml −1 . Aerogels were characterized by Fourier transform infrared spectroscopy, X‐ray diffraction, relative density, porosity percentage, scanning electron microscopy (SEM), and water uptake. The results indicated a higher reticulation and crystallinity and lower water uptake, increasing crosslinking agent concentration (Aero 1:2). SEM images revealed the prominent presence of macroporous structure (more than 50 nm) within the aerogel, containing small and large pores within the aerogel structure. The small pores were statistically similar for Aero 1:1 and Aero 1:1.5, as observed by analysis of variance analysis, but they were statistically different from Aero 1:2. The large pores diameter increased with higher crosslinking concentration and induced them as closed pores, resulting in a less porous structure. This result is directly associated with a higher reticulation degree. Overall, the influence of crosslinking agent concentration was studied and indicated that Aero 1:1.5 presented valuable properties.