PREPARATION AND CHARACTERIZATION OF A SPHERICAL GEL FROM A LOW-COST MATERIAL

Spherical gel particles have been prepared by the digestion of rice husk with concentrated HNO3. The colloidal portion of the digestion product was washed, dried and aged at standard conditions to initiate particle formation. The organic composition of the husk and residue were analysed by chemical methods. Thermal decomposition of the gel has been investigated by thermogravimetry (TG) and isothermal heating. The observed thermal behaviour of the gel is characteristic decomposition of cellulose and hemicellulose which are believed to be the main components of the gel. Morphological features of the gel before and after heating were examined by scanning electron microscopy. The crystallinity of the gel was determined by X-ray diffraction analysis.