Abstract
Adsorption of acrylamide monomer on activated carbon has been measured in various solvents, i.e., water, methanol, chloroform and dioxane. Adsorption of n-butanol in aqueous phase has also been measured. The apparent adsorption isotherms against relative concentration belonged to the BET II type. In the case of aqueous solution, the rising portion of the isotherm was observed even within a relatively low concentration range, and lumpy polymer was observed in the sediment at 25°C in 48hrs. The yield of polymer showed the increase accompanying the increase in the amount of the activated carbon added and of the initial concentration of acrylamide. BET-type multilayer adsorption equation has been derived on the model in which the solute molecules adsorbed on the solute molecules in monolayer were regarded as the second layer molecules in adphase, etc., whilst the solvent molecules may form the only monolayer, because of the difference of structure and of potential in an adphase from those in the bulk solution phase, respectively. The reasonable agreement between the calculated and the experimental and also the reasonable surface areas were obtained in the region of the isotherm less than 0.4 in a relative concentration. These surface areas are remarkably smaller than the value obtained from the argon adsorption at 77°K. These may possibly be explained by the specificity in the structure of the activated carbon (like the turbostratic structure). Since the decrease of the surface area from the argon adsorption at 77°K has been shown by the activated carbon coexisting with the polymer as the sediment, the degree of the surface treatment of the activated carbon could be detected by measuring the surface area through the gas phase adsorption.
