Surface graft polymerization acrylic acid onto bamboo charcoal and to improve ammonia adsorption

Abstract

Bamboo charcoal is a kind of bioinert material with porous structure which provides surface area about 1,500 m2/g. However, the adsorption ability of polar ammonia gas is still undefined. In this study, the ammonia adsorption ability of bamboo charcoal was significantly enhanced by surface modification. The bamboo charcoal was first silicone oxide modified by hexa-methyldisilazane (HMDSZ) plasma to protect the bulk property and the surface was then oxidized by O2 plasma. The hydrophilic bamboo charcoal was next titanium oxide treated by sol-gel method and following grafted acrylic acid under UV light to immobilize acid group on the surface and make the treated bamboo charcoal being able to absorb the ammonia. The property of the modified bamboo charcoal was characterized by SEM, weight measurement, wettability, ammonia adsorption test and electron spectroscopy for chemical analysis (ESCA) for surface functionalization, respectively. The ammonia adsorption of bamboo charcoal grafted with 10% acrylic acid, compared with untreated sample, was found improved from 61% to 98%.