Electromechanical polyaniline–cellulose hydrogels with high compressive strength

Usually, it is very difficult to fabricate hydrogels from hydrophobic polyaniline (PANI). In the present work, an electromechanical PANI–cellulose hydrogel, for the first time, was prepared from a PANI–cellulose transparent solution dissolved in a NaOH–urea aqueous system at low temperature by cross-linking with epichlorohydrin. The composite hydrogels displayed a homogeneous macroporous structure, good miscibility, and excellent mechanical strength, as a result of the association of the PANI chains with the cellulose crosslinked networks held together by noncovalent interactions. Moreover, the hydrogels exhibited a continuous and linear crawling motion under a low applied electric field. The motion of the composite hydrogels was an acceleration process, reflecting the characteristics of a rapid electrical response. This work shows the great potential of a smart hydrogel for applications in the field of biomimetic materials.