|报告题目:||Accessing Innovative Porous Polymers through Emulsion Templating|
|报 告 人:||Prof. Michael S. Silverstein（Sherman–Gilbert Chair in Energy ）|
Porous polymers exploit the ease of processability associated with polymers for the production of monoliths, films, beads, and powders that can possess well--defined and tailor‐made porous architectures with multiple functionalities. The recent surge in porous polymer research and development reflects the added-‐value anticipated for the numerous applications, high-‐tech and low-‐tech, that include: biomedical devices, membranes, supports, and packing; Lightweight foams; microelectronics and optics; responsive/smart materials; and precursors for porous ceramics and carbons. There are several templating methods that can be used to produce porous polymers: block copolymer templating, particle templating, and emulsion templating.
Emulsion--‐templated porous polymer are typically synthesized through polymerization within the external phases of a high internal phase emulsions (HIPEs), emulsions containing more than 74% internal phase (individually dispersed droplets). Typically, emulsion templating generates macroporous structures with voids (in place of the droplets), ranging in size from a few micrometers to hundreds of micrometers (see figures), that are highly interconnected through holes in the polymer walls. Originally, emulsion templating was used to synthesize porous, hydrophobic, crosslinked polymers within surfactant--‐stabilized water--‐in--‐oil HIPEs using free radical polymerization. Now, myriad porous polymer systems are being designed using the wide variety of emulsion templating approaches currently available. The advantages of emulsion--‐templated porous polymers include: the highly interconnected micrometer--‐scale porous structures (typically 90% porosity) through which liquids can be pumped with relative ease; the ability to rapidly absorb large quantities of liquids through capillary action; the facility with which specific shapes and sizes can be produced; the availability of abundant surface functionalization routes; and the wide--‐ ranging design flexibility and versatility accessible within a relatively simplistic synthesis platform.
Recent advances in emulsion--‐templated polymers include innovations in the emulsion stabilization strategy, the polymerization chemistry, the nature of the monomers, the crosslinking strategy, the macromolecular structure, the porous architecture, and the functionality. The resulting novel emulsion--‐templated polymer systems include: hydrophilic--‐hydrophobic bicontinuous polymers, shape-‐memory polymers, stimulus-‐response polymers, superabsorbent polymers, contaminant--absorbing polymers, polymers with hierarchical porosities, polymer precursors for microporous carbons, and even, polymers for droplet encapsulation. Future research and development will be able to access novel families of innovative porous polymers with unique properties using these advances in emulsion--‐templating.
Prof. Michael S. Silverstein
Sherman–Gilbert Chair in Energy
Department of Materials Science and Engineering
Technion–Israel Institute of Technology
Professor Michael S. Silverstein holds the Sherman–Gilbert Chair in Energy at the Department of Materials Science and Engineering, Technion – Israel Institute of Technology, and is the Chairman of the Technion's Interdepartmental Program in Polymer Engineering. Silverstein is presently investigating a plethora of novel emulsion--‐?templated porous polymers and has recently developed several extraordinary materials, highly porous superabsorbent hydrogels, liquid--‐? droplet--‐?filled monoliths for the storage of either aqueous liquids or organic liquids, and porous shape memory polymers. Silverstein, has co--‐?edited the book "Porous Polymers", has organized nine highly successful "Porous Polymers" symposia over the past 10 years, has edited two Special Issues of the journal POLYMER on “Porous Polymers”, and is an associate editor for Polymer International.
Silverstein has been interested in the field of polymeric materials since his Honours BASc in Engineering Science at the University of Toronto. He followed with a DSc in the field of polymers at the Technion before joining the Department of Materials Engineering, Technion, in 1989. He has published over 100 papers in international reviewed journals, has over 160 international conference contributions, and has mentored over 40 graduate students.