Ms. Kristina Vetlitsyna-Novikova - Ph.D. Candidate
18.07.2024
אודיטוריום ע"ש דויד וואנג, בניין מידן, קומה 3
14:30
Macroporous polymer monoliths (polyHIPEs) can be prepared by templating within high internal phase emulsions (HIPEs). Applications often require porous polymer monoliths with high specific surface areas, SBET. PolyHIPEs, however, typically possess SBET of less than 50 m2/g. Polymers of intrinsic microporosity (PIMs), prepared using rigid, twisted monomers, exhibit SBET as high as 900 m2/g, making PIMs of interest for gas storage and adsorption.
In this research, hierarchically porous polymer monoliths were developed via the synthesis of crosslinked PIMs within oil-in-oil HIPEs. The first route involved simultaneous polymerization and crosslinking of PIM-like monomers and either a planar or a twisted crosslinking comonomer. Unfortunately, the SBET was reduced significantly by crosslinking. In addition, residual surfactant seemed to produce flexible monoliths and block access to the micropores. Promising SBET (112 m2/g) were obtained using silane-modified silica nanoparticles for stabilization (Pickering HIPEs). The second route involved synthesizing PIMs containing a crosslinkable comonomer, forming HIPEs, and then crosslinking. Unfortunately, the SBET decreased with increasing comonomer content and a relatively large amount of comonomer and crosslinker were needed. The use of rigid, twisted crosslinking comonomers, Pickering HIPEs, and crosslinkable comonomers seem to hold the most promise for achieving PIM-based microporous polyHIPEs.