Layer-by-layer (LbL) assembled films of poly[bis(methoxyethoxyethoxy) phosphazene] (MEEP) and poly (acrylic acid) (PAA) are demonstrated by utilizing the hydrogen bonding between these two polymers. These films show controlled thickness growth, high ionic conductivity, and excellent hydrolytic stability. The ionic conductivity of these films is studied by changing the assembly pH of initial polymer solutions and thereby controlling the hydrogen bonding characteristics. MEEP/PAA LbL films assembled at higher pH values have enhanced water uptake and transport properties, which play a key role in increasing ion transport within the films. At fully humidified conditions, the ionic conductivity of MEEP/PAA is 7 × 10-4 S cm-1, more than 1 order of magnitude higher than previously studied hydrogen-bonded LbL systems. Finally, free-standing films are isolated from lowenergy surface substrates, which allows for bulk characterization of these thin films.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)
- Materials Chemistry