A GCMC simulation and experimental study of krypton adsorption/desorption hysteresis on a graphite surface

作者：Prasetyo Luisa; Horikawa Toshihide; Phadungbut Poomiwat; Tan Shiliang; Do D D; Nicholson D

来源：Journal of Colloid and Interface Science, 2016, 478: 402-412.

DOI：10.1016/j.jcis.2016.06.033

• Adsorption
• Hysteresis
• Graphite
• Condensation
• Isosteric heat
• Monte Carlo

Adsorption isotherms and isosteric heats of krypton on a highly graphitized carbon black, Carbopack F, have been studied with a combination of Monte Carlo simulation and high-resolution experiments at 77 K and 87 K. Our investigation sheds light on the microscopic origin of the experimentally observed, horizontal hysteresis loop in the first layer, and the vertical hysteresis-loop in the second layer, and is found to be in agreement with our recent Monte Carlo simulation study (Diao et al., 2015). From detailed analysis of the adsorption isotherm, the latter is attributed to the compression of an imperfect solid-like state in the first layer, to form a hexagonally packed, solid-like state, immediately following the first order condensation of the second layer. To ensure that capillary condensation in the confined spaces between microcrystallites of Carbopack F does not interfere with these hysteresis loops, we carried out simulations of krypton adsorption in the confined space of a wedge-shaped pore that mimics the interstices between particles. These simulations show that, up to the third layer, any such interference is negligible.

• 出版日期2016-9-15