Synthesis and characterization of transparent poly(2-methyl-2-oxazoline) (POZO)-vanadium oxide (V2O5) hybrids with reversible formation

Optically transparent and homogeneous polymer hybrids of poly(2-methyl-2-oxazoline) (POZO) and vanadium oxide (V2O5) can be prepared by utilizing the hydrogen bonding interactions between the amide groups of POZO and V-OH groups formed in the hydrolysis of vanadium(V) oxytripropoxide (TPVO). POZO acts as a stabilizer in the sol-gel reaction of TPVO, since this sol-gel reaction is too fast to obtain a transparent film without POZO. The amorphous state of the POZO-V2O5 hybrid was confirmed by DSC, SEM, and XRD. The polymer hybrids obtained can be reversibly dissolved in the solvents and cast again because of the amorphous state of vanadium(V) oxide. Moreover, the solubility of the polymer hybrids was dramatically changed by the reduction of V2O5 from V(V) to V(IV).