After 60 min of soaking, the swollen membrane was sandwiched between two glass
sheets and cured with the same UV lamp setup for 45min. The cover glass was then removed.
The IPN membrane was post-cured on a hot plate at 130 for 60min. The resulting membrane,
PTBA-IPN-50, was allowed to cool down to room temperature, and then peeled off of the glass
substrate as a freestanding thin rigid sheet. The fabricated films are referred to as PTBA-IPN-X,wherein X is the parts by weight of toluene in the second monomer solution relative to 100 parts
of tert-butyl acrylate.