Hydrophilic nanoporous polystyrenes and 1,2-polybutadienes

Nanoporous polymers from ordered block copolymers having hydrophilic cavity surfaces were successfully prepared by two methodologies: ' 1. Nanoporous polystyrenes fromPtBA-b-PS diblock or PDMS-b-PtBA-b-PS triblock copolymer precursors by atom transfer radical polymerization (ATRP), or combination of living anionic polymerization~ and ATRP r~spectively. The one, PtBA block, can be modified to the hydrophilic PAA, where the dther, polydimethysiloxane (PDMS) block, can be fully degraded. Deprotection of the tert-butyl groups in PtBA and the selective etching of PDMS· chains were accomplished by applying HF or TFA in one step. Thus both the di- and triblock copolymers after such a treatment resulted. in nanoporous polystyrenes with hexagonal cavities of different nanosizes (6-11 nm, Figure 1). 2. Nanoporous I,2-polybutadienes (I,2-PB) by grafting various acrylic monomers onto the pore. surfaces via surface-initiated ATRP. The nanoporous 1,2-PB precursor with gyroid morphology was prepared from the diblock copolymer 1,2-PB-b-PDMS after cross-linking the major 1,2-PB .. block, and etching the minor PDMS block. Then a bromoester i~itiator for ATRP was immobilized onto the pore walls using different pathways for the conversion of the double bonds of 1,2-PB to bromoisobutyrate by using one to three steps chemical modification. Grafting polyacrylate layers of PPEGMA, PHEMA etc. onto themon