System for adsorption isotherm studies of porous carbon materials down to 4.5 k

In order to characterize different type of adsorbents for cryopumping specific application at low temperature down to 4.5 K, a facility for adsorption study (FADS) is set up at Institute for plasma research (IPR). This system comprises of a standard micro-pore analyser for sample characterization at 77 K and a GM cryocooler with sample holder cell for sample analysis at a temperature < 77 K. The use of temperature control unit enables to study the porous characteristics of adsorbents at any temperature between 4.5 K and 77 K. Using this system various activated carbons were characterized by studying their adsorption isotherms for nitrogen and helium gas. The surface area of the activated carbons were found to be varied from ∼ 1000 m²/s to ∼ 3000 m²/s for temperature range 77 K to 4.5 K. A complete detail of the system and the results of experimental studies on some specific adsorbents