Smart free-standing film force-assembled by Ti 3 C 2 T x /CNC with high sensitivity to humidity and near-infrared light

Smart films that can specifically recognize the outer surrounding change and make rapid motion behavior, have presented their potential application in composing intelligent actuators. Herein, we have prepared a hydrophilic free-standing film with the nacre-like layered and directional aligned structure by vacuum-filtering the mixed suspension of Ti 3 C 2 T x nanosheets and cellulose nanocrystal (CNC). Because of the axial Young’s modulus from the oriented arrangement of CNC and Ti 3 C 2 T x, the assembled hybrid film can achieve fast and directed humidity-driven performance, and obtain a specific bending angle by controlling the asymmetric humidity value. Besides, the introduction of CNC also increased the surficial roughness of the hybrid film compared to the pure Ti 3 C 2 T x film, which lengthened the light propagation path. Based on the good photothermal conversion ability of Ti 3 C 2 T x nanosheets around the NIR region, the hybrid film presented ultra-high NIR conversing efficiency that can rapidly heat up to 178.2 °C only under the NIR (808 nm) power of 0.45 W/cm 2. Therefore, by depositing thermochromism materials with different color change points, the composited film can realize visual temperature detection. This TC/CNC film with the ability of humidity and NIR sensing will satisfy the further demand for designing smart equipment.