Ultrafast layer-by-layer assembly of PDMS for boosting the H2 separation
of a P84 membrane
Abstract
BTDA-TDI/MDI (P84) has been widely applied in gas separation, however,
pinholes or defects on P84 membrane surfaces were formed in the membrane
preparation process and directly weaken its separation performance.
Herein, we developed an ultrafast polydimethylsiloxane (PDMS)
layer-by-layer assembly strategy via spraying method to heal the defects
of the P84 membrane. Firstly, a very short assembly time 20-30 s was
achieved by a UV-curing method. Secondly, both the PDMS spraying
concentration and cycle times were optimized to strengthen the healing
ability of PDMS. The P84-PDMS membrane with 3 wt % PDMS spraying
concentration and 2 spraying cycle times significantly improve the
H2/CH4 selectivity from 62.99 to 231.92 with a satisfactory H2 permeance
(20.85 GPU). The layer-by-layer PDMS assembly strategy for healing
defects of P84 membrane displays outstanding comprehensive abilities,
with an easy manufacturing based upon ultrafast curing and excellent gas
separation performance based on the defect-free membrane structure.