The CO permeability and selectivity of CHA-type zeolite membranes in the separation of a CO/CH mixture gas at high pressure were evaluated using non-equilibrium molecular dynamics (NEMD). It was found that in a perfectly crystalline, defect-free CHA membrane, the adsorption of CH, which diffuses slowly in the pores, hinders CO permeation. Therefore, an increase in the amount of CH adsorbed at high pressure decreases the CO permeability and significantly reduces the CO selectivity of the CHA membrane.
View Article and Find Full Text PDFAdsorption properties of organoclay have been investigated for decades focusing on the morphology and physicochemical properties of two-dimensional interlayers. Experimental studies have previously revealed that the adsorption mechanisms depend on the molecular species of the organocation and adsorbate, making it difficult to estimate the adsorbed amount without experiments. Considering that the adsorption of aromatic compounds has been reported by using various clays, organocations, and adsorbates, machine learning is a promising method to overcome the difficulty.
View Article and Find Full Text PDFIntercalation of phenol in montmorillonite, a representative layered material, has historically been investigated, and modification of the interlayer with methylviologen (Mont-MV) results in color change due to formation of a charge-transfer complex. Its detailed nanostructure, however, has yet been revealed owing to its small gallery height and poor crystallinity. In the present study, we performed molecular dynamics simulation to investigate structural changes in Mont-MV by the intercalation of phenol.
View Article and Find Full Text PDFThe modification of an interlayer of layered materials by intercalation with an organoammonium ion has been a promising method to control the polarity of the two-dimensional nanospace. Montmorillonite is one of the best-known examples, and the modification with octadecyltrimethylammonium ion (Mont-C) results in adsorption of anthracene and pyrene together with specific excimer emission, while the nanostructure is yet to be uncovered at the molecular level because the gallery height is only ca. 27 Å.
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