(675f) Ordered Mesoporous Carbon as An Efficient and Reversible Adsorbent for the Adsorption of Fullerenes

It is found that fullerenes has installed in scientists a variety of application hopes, such as superconductors, large-scale industrial catalysts, and perhaps even antiviral agents. Because the preparation of pure fullerene compounds on a large scale is very difficult, the number of their successful applications is still limited. This academic interest and enthusiasm in fullerene science has prompted us to develop a safe, fast, effective, and inexpensive method for the separation and purification of fullerenes, which can produce large quantities of pure C60 and C70, the most popular members of the fullerene family.

In this study, an ordered mesoporous carbon, CMK-3, was synthesized using mesoporous siliceous material, SBA-15, as the template. The CMK-3 was characterized and used for the adsorption of fullerenes, C60 and C70. It was found that the adsorption capacity of CMK-3 is four times higher than that of activated carbon (AC), while the other two adsorbents being investigated, alumina and silica gel, have little adsorption capacity for fullerenes. A detailed study was undertaken to determine the adsorption equilibrium isotherms of C60 and C70 on CMK-3 for both single and binary systems. The reversibility of fullerene adsorption on CMK-3 was also studied. It was found that nearly 24 % adsorbed C60 and 8 % adsorbed C70 can be desorbed from CMK-3 within 10 minutes at 25 °C when a volume of 200 ml pure toluene is used to desorb 25 mg of pre-saturated adsorbent in a batch desorption process. The effects of time, volume of toluene, and temperature on the desorption of fullerenes from CMK-3 were examined. It was shown that the volume of toluene and the temperature are two important factors for fullerenes, especially for C70, to be desorbed from CMK-3. Increasing the volume and the temperature will help C70 to be desorbed from CMK-3. The above results indicate that CMK-3 is an efficient and reversible adsorbent for the separation of fullerenes by adsorption.