Reverse osmosis separations of some organic and inorganic solutes in methanol solutions using cellulose acetate membranes

Abstract

Menzles, M. A. Can. J . Chem. Eng. 1971, 49, 407. Lenhoff, A. M.; Morarl, M. Chem. Eng. Sci. 1982, 37, 245. Null, H. R. Chem. Eng. frog. 1978. 72. 58. Rathore, R. N. S.; Van Wormer, K. A.; Powers, 0. J. AIChE J . 1974, 20, Robertson, J. C. Chem. Eng. 1974, 81, 104. Roblnscn, C. S.; ollllland, E. R. "Elements of Fractional Distillation", 4th ed.; Tyreus, 8. D.; Luyben, W. L. /fydrmrbon frocess. 1975, 54. 93.Data on the reverse osmosls separations of Inorganic electrolytes and organic nonelectrolytes from methanol solutions were generated together with corresponding liquid chromatography data. Transport equations based on the surface force-pore flow model for reverse osmosis were applied to calculate the force constants associated with steric hindrance, electrostatic repulsion, and van der Waals attraction. These constants enable prediction of the separations of inorganic and the organic solutes studled when the pore radius of a membrane Is given. The solute separations from methanol solutlons were compared with those from aqueous solutions by use of the data from membranes of nearly equal effective pore sizes. The formation of agglomerates enhances the separation from the aqueous solution, particularly In the case of hydrocarbon solutes. The interfacial solvation and the consequentlal steric repulsion at the Interface are higher for cations of higher charge densky and lower for cations of lower charge density In methanol solvent systems compared to aqueous solvent systems.

Solvent resistant nanofiltration: separating on a molecular level

“…A positive w(r) value represents a repulsive force, a negative value an attractive force. The force can be related to the distribution coefficient K 2 , 215 which can be measured by HPLC using membrane polymer as the column material 216 or by sorption experiments. 217 Whenever K 2 , 1, the solute is repelled from the membrane resulting in a high solute rejection.…”

Advances in Solvent‐Resistant Nanofiltration Membranes

“…They explained the results using the solution-diffusion model, taking into account the role of membrane swelling. On the other hand, Farnand et al 16 studied the transport behavior of polar organic solutes (dimethyl aniline, acetonitrile, etc.) in a methanol medium and used the surface force-pore flow model to explain the results.…”

Graphene‐Based Advanced Membrane Applications in Organic Solvent Nanofiltration

“…[ 31 ] Predictably, the cellulose acetate membrane remains a standard reference for the separation of organic solvents. [ 32–34 ] However, the strong adsorption of organic solvents onto polymeric membranes has hindered their applications in future industries; this is because the high sorption of organic solvents (up to 50 wt%) together with the potential membrane disintegration in organic solvents can negatively affect the overall stability of membranes. [ 29,35–39 ] Thus, efforts have been exerted to use tough glassy polymers that are composed of condensed aromatic rings (e.g., polybenzimidazoles, [ 40–42 ] polyacrylates, [ 43 ] polymers of intrinsic microporosity, [ 44–47 ] and perfluorinated polymers [ 48 ] ) to fabricate membranes.…”