PatrycjaFastyn, WojciechKornacki, Tomasz Gierczak, JanuszGawlowski and Jan Niedzielski in research, They study The water uptake by carbon molecular sieves (CMS) and graphitized carbons, all of which are used to determine volatile organic compounds in air, was investigated using a direct experimental approach. CMS, e.g. Carboxen 1002, Carboxen 1003 and Anasorb CMS adsorb substantial amounts of water, in the range 400 to 450 mg per gram of adsorbent. Graphitized carbons, e.g. Carbrogaph 5TD and Carbopack X show low water trapping, less than 30 mgg−1 and Carbopack Y as little as 5mg g−1 or less. It is find that the water sorption capacity for graphitized carbons is strongly dependent on the relative humidity (RH). The change of RH from 95 to 90% .adsorption on polar centers and micropore volume filling. For graphitized carbons and CMS at low RH, adsorption on polar centers is involved. For CMS, once the threshold value of relative humidity (RHth) is surpassed, micropore volume filling becomes predominant. RHth is 44±3 and 42±3% for Carboxen 1002 and 1003, respectively, and 32±3% for Anasorb CMS. The CMS mass in the trap was found not to affect the mass of retained water under condition of incomplete saturation of adsorbent bed with water.
Xiongce Zhao in research he studied adsorption isotherms of water on graphite using grand canonical Monte Carlo simulations combined with multiple histogram re weighting, based on the empirical potentials of SPC/E for water, the 10-4-3 van der Waals model, and a recently developed induction and multipolar potential for water and graphite. Our results show that wetting transition of water on graphite occurs at 475-480 K, and the prewetting critical temperature lies in the range of 505-510 K. The calculated wetting transition temperature agrees quantitatively with a previously predicted value using a simple model. The observation of the coexistence of stable and metastable states at temperatures between the wetting transition temperature and prewetting critical temperature indicates that the transition is first order.