Extraction of silica from cassava periderm using modified sol-gel method
Cassava peridem wastes are generated and disposed indiscriminately or burnt due to zero economic value. In this study, modified sol-gel synthesis of amorphous silica nanoparticles from cassava periderm (CP) was investigated. The wastes were pretreated with HCl to remove soluble metallic impurities. Both treated and untreated CP flakes were calcined at 700 oC to obtain their respective ashes. The ashes were leached with HCl to remove soluble metallic oxides and thereafter sol-gelled to obtain silica gel modified with ethylene glycol. The gel was dried at 80 oC for 18 hours and then characterized using SEM, EDX, XRD, FT-IR, Raman, TEM and PSA. The SEM micrographs showed that silica modified with ethylene glycol is less agglomerated with higher silica yield and lower particle sizes. All the silica produced showed similar functional groups and non-crystallinity. The silica nanoparticles could be used as starting materials for synthesis of silicon nanoparticles.
Keywords: agricultural waste, cassava periderm, amorphous silica, agglomeration, sol-gel