Anna Merrit
B.S., Chemical Engineering, Colorado School of Mines, 2002
The molecular sieving properties of carbon membranes coupled with their
thermal and chemical stability make them promising candidates for
a variety of separation and reaction engineering applications. This
research presents a new approach to improve the performance of nanoporous
carbon membranes by virtue of a supported composite membrane. It
is seen that incorporation of silica nanoparticles in nanoporous
carbon membranes increases the single gas permeance by two orders
of magnitude as compared to conventional carbon membranes at similar
ideal selectivity.
In addition to permeance, the presence of silica nanoparticles allows production of membranes in fewer coating steps. It is theorized that nanoparticles fill the porous support, preventing intrusion of the selective layer into the support as well as decreasing the support surface roughness. Modification of supports allows a defect free coating to be synthesized with fewer coating steps and thus selective layers are orders of magnitude thinner than in pure carbon membranes. Current work is focused on developing a general methodology for effective support modification as a function of support pore size and nanoparticle size and volume fraction.