A Physicochemical Study of the Process of Modification of Carbon Sorbents with Lactic Acid

Abstract

With the aim of creating new adsorbing materials with biospecific properties for applications in medicine (obstetrics and gynecology), a technique for the chemical modification of a molded carbon sorbent with lactic acid by polycondensation of the latter on the surface of the former without catalysts is proposed. The completeness of the process of polycondensation of lactic acid on a molded carbon sorbent was controlled by physicochemical methods (low-temperature nitrogen absorption and thermal analysis). The amount of the deposited modifier (lactic acid oligomer) is a determining factor of the completeness of the modification process, which is determined from the results of thermogravimetric analysis of samples. The optimal conditions of the impregnation and thermal processing of a molded carbon sorbent, under which the amount of the deposited modifier reaches the maximum value and equals 7.2–10.5 wt %, have been chosen on the basis of the results of studies. The elemental composition and the content of surface functional groups of the two most promising samples of modified molded carbon sorbents are analyzed. These modified samples are of interest for further analyses and a study of their adsorption properties.