Controlled synthesis of solvent-responsive continuous bidirectional deformation natural rubber composite films based on nano-g-C3N4 modification and epoxy natural rubber double-layer composite

Stimuli-responsive elastomeric materials, capable of controllably and reversibly changing under external stimuli, are the key materials of intellectualized and automatic system with immense transformative application potentiality. However, it remains challenging in practice for natural rubber materials. In this research, organic solvent-responsive natural rubber (NR) films with bidirectional deformation, high stability, and excellent mechanical properties were prepared by double-layer composition and nanoparticle modification method. The bidirectional deformation of double-layer composite film (ENR/NR- g -C 3 N 4 ) with asymmetric structure consisted of an epoxy NR layer and a NR- g -C 3 N 4 composite layer. The deposition and composition of nano- g -C 3 N 4 in NR layer facilitates the rapid forward deformation of ENR/NR- g -C 3 N 4 in tetrahydrofuran. The ENR layer served as the active layer, realizing the controllable reverse deformation. The compatibility of composite films was enhanced in the procedure of direct adhesion and cross-linking interactions between ENR and NR, avoiding the appearance of phase separation. The ENR/NR- g -C 3 N 4 composite films were utilized to fabricate intelligent drive devices such as intelligent mechanical claws, artificial butterflies and bionic flowers, exhibiting rapid, sensitive and controllable stimuli-responsiveness. This study provides a novel synthetic strategy for the design of intelligent NR materials and rises to the existing challenges in the field of intelligent and responsive natural rubber materials. • Asymmetric films were produced from the varying swelling of different layers. • The introduction of g-C 3 N 4 increases the initial response rate of the NR layer. • The composite film showed continuous bidirectional deformation in the THF solvent. • The mechanism of continuous bidirectional deformation was explained. • The intelligent drive devices for natural rubber were designed.