Transparent and flexible high-surface area nanoporous crystalline PPO films

Abstract

Guest and processing conditions leading to high surface area (SA) nanoporous-crystalline (NC) poly(2,6-dimethyl-1,4-phenylene)oxide (PPO) films are explored. In this framework, we found crystallization conditions leading to unprecedented high-SA films (with SA up to 450 m² g⁻¹) with transparency and toughness comparable with those for amorphous PPO films. Suitable preparation procedures require (i) guest-induced co-crystallization by large uptake of a highly boiling guest molecule; (ii) guest sorption from the vapor phase at a temperature close to the guest boiling point; and (iii) subsequent guest removal by sorption/desorption of a volatile guest. This high-SA, transparent, and tough NC PPO films are expected to be suitable for organic pollution remediation, molecular separations, and molecular sensing.