Scalable techniques for the formation of polymer-nanoplatelet hybrid membranes and characterization thereof

Membrane technology has become an essential alternative for efficient gas separation processes versus traditional thermally-driven processes. Although polymeric membranes have received the most attention, researchers have found that combining highly separation selective inorganic, metal-organic (MOFs) or carbon molecular sieving materials with polymeric materials can improve membrane performance. These multi-component membranes are often referred to as mixed matrix or hybrid membranes. Traditional hybrid membrane filler materials have size and aspect ratio characteristics that are less favorable for the production of asymmetric membranes that utilize a thin (∼100nm) permselective layer. Recent developments have considered high aspect ratio sieving materials (i.e. flakes or platelets) as alternative inorganic fillers in hybrid membrane systems. Polymer-nanoplatelet hybrid membranes show promise as the next generation of membranes, but in order to make these realizable, methods to produce these materials on a large scale are necessary. In this study it was our objective to develop scalable techniques for creating polymer-nanoplatelet membranes.;Dense film membrane studies were used to prove the effectiveness of our exfoliation and dispersion process developed for this work. Permeation measurements showed the hybrid membranes have desirable transport properties that are on par with mathematical model predictions. Additionally, TEM characterization provided strong evidence supporting the efficacy of our preparation procedures to produce an exfoliated system of nanoplatelets. We also showed that these procedures are applicable to different polymer systems (cellulose acetate and TorlonRTM) of commercial relevance. Demonstrating the successful production of dense films set the stage for asymmetric hollow fiber membrane formation. We report the first production of asymmetric hollow fiber membranes containing nanoplatelet fillers; indicating that the process can be applied in a realistic membrane formation platform. These accomplishments serve as the groundwork for future nanocomposite formation. We believe that the results from this work strongly indicate that the methods are flexible, diverse and scalable.;There has been extensive research in the area of these hybrid materials. Moreover, many authors have been successful at producing gas separation membranes. Typically these reports have utilized melt blending, in situ polymerization or solution blending. Few, however, have utilized solution blending for creating membranes via phase inversion. And to date, there have not been any reports regarding the fabrication of asymmetric membranes containing nanoplatelet filler materials. In this work we have developed a solution-based procedure for the formation of hybrid polymer-nanoplatelet dopes for dense film and asymmetric hollow fiber membrane formation. To our knowledge, we are the first to report the formation of successful polymer-nanoplatelet membranes containing unmodified filler materials.