The thermal durability of the SiO 2 -modified papers and photodegradation study of coated curcumin dye

Cellulose is modified by many organic and inorganic substances in order to improve the quality like smoothness, whiteness and mechanical strength. These substances can help improve cellulose deterioration towards biodegradation, photodegradation, acid hydrolysis and oxidation. In this research, filter paper, a representative of cellulose fiber, was coated by SiO 2 to improve fiber thermal durability and coated natural dye photo-stability. The surface of the cellulose was initially modified by various methods as follows:1. esterification by polycarboxylic acids like tartaric acid (TA) and butanetetra-carboxylic acid (BTCA) to obtain Fil-TA and Fil-BTCA respectively. 2. etherification by sodium monochloroacetate to obtain Fil-MCAA.3. coating by carboxymethylcellulose to obtain Fil-CMC.