We could draw some valuable conclusions about adsorption capacity, adsorption isotherm, adsorption kinetics, adsorption thermodynamics by naphthalene adsorption experiments, but the experiments could not tell us directly what the adsorption location and adsorption state are exactly on the surface of OMCs. Actually, we still don’t know the microscopic structure of OMCs very well because of the restriction of characterization technology, human factor and experimental conditions. However, molecular simulation technology could make up the disadvantages. In the work, Grand Canonical Monte Carlo method was performed for the first time to simulate the naphthalene adsorption behavior in OMCs structure model. The atomic structure model of OMCs was built firstly by using molecular modeling technique and was characterized by calculating the accessible solvent surface area, total pore volume, and small-angle X-ray diffraction patterns. The calculated results showed that the structure model of OMCs was reasonable and the structure characteristic was in agreement with experimental data. The adsorption isotherm curve is of type Langmuir IV, which was typical characteristic of ordered mesoporous materials. Also, adsorption isotherm curve revealed that the adsorption capacity of naphthalene on OMCs increased to a balance gradually, and the maximum adsorption capacity of naphthalene was 105.4 mg g–1. Additionally, the adsorption state of naphthalene were observed that from monolayer to multilayer in the mesopores with the increasing of number of naphthalene molecules.
This work deepened the understanding of the adsorption state of naphthalene for OMCs on mesoscopic level. It also demonstrated that the GCMC method is effective for studying the adsorption process and gives useful guidance on research of structure-activity relationship and performance prediction of the carbon material.