Poly(aniline-co-p-phenylenediamine) cryogels stabilized by poly(vinyl alcohol) were prepared by one-step oxidative cryocopolymerization. Composite cryogels have macroporous structure with pore sizes up to tens of micrometers; however, copolymer cryogels have smaller pores compared to homopolymer cryogels.
The cryogels containing 70 mol% and 80 mol% of aniline have the smallest pores and have the highest mechanical stability. The decrease in aniline fraction led to decrease of conductivity from 5 x 10(-2) S cm(-1) for polyaniline-based cryogel to < 1 x 10(-11) S cm(-1) for poly(p-phenylenediamine) analogue.
The cryogel with 80 mol% of aniline, which already had improved mechanical integrity, possesses only moderately decreased conductivity up to 5 x 10(-4) S cm(-1) compared with polyaniline-based cryogel. The corresponding changes in the molecular structure of the composite cryogels are reflected in their infrared and Raman spectra using 633 and 785 nm laser excitation.