Matsuura, Takeshi,Brinza, Daniel L.2009-03-232009-03-2320002000Source: Masters Abstracts International, Volume: 39-05, page: 1414.9780612584440http://hdl.handle.net/10393/8496http://dx.doi.org/10.20381/ruor-7339Membrane forming properties of two natural, microporous clay minerals, montmorillonite and sepiolite, were investigated. The research presented in this work was exploratory in nature and had two distinct parts: montmorillonite as a gas separation membrane material and sepiolite as an ultrafiltration membrane material. The pore size of montmorillonite was modified by pillaring with an aluminum hydroxy cation; sepiolite was only purified from its natural state. By employing the sol-gel method, with various amounts of the inorganic polymer boehmite as a binder, unsupported membranes were cast, calcined and tested under different configurations and permeating species. The membranes made of 60% pillared montmorillonite and 40% boehmite showed permeability ratios higher than 200 between gases with small molecular size (helium, hydrogen) and gases with bulkier molecules (propane, nitrogen). Preparation of composite membranes consisting of a thin layer of pillared clay/boehmite mixture on inorganic supports with different pore sizes was also attempted. The sepiolite membranes displayed a sharp pore size distribution centered around 9.3 nm radius and good results in ultrafiltration experiments using dilute aqueous solutions of macromolecules of various molecular weights. A mathematical model was attempted for the sepiolite membrane, linking pore size distribution with the experimental permeation data.91 p.Engineering, Chemical.Thesis