Study On Construction And Performance Of Optical/Actuating Responsive Films With Predefined Shapes

Smart response materials can reversibly change the physicochemical properties of structures,colors,shapes,etc.,when externally stimulated.Among them,moisture sensitive actuators have attracted much attention due to their ease of preparation and maneuverability.Most of the current water-responsive actuators can only be simply displaced or deformed,and predefined shape cannot be made to produce more complex motions.Research on predefined shapes actuators is critical to achieving precise control of complex motions.In this work,we used a chiral nematic structure formed by cellulose nanocrystals(CNCs)as a template to prepare a novel single-layer driver material containing phenol-formaldehyde resin(PFR)and graphene oxide(GO).The so-obtained PFR/GO films have a unimorph structure with an asymmetric distribution of GO across the film.They exhibit synchronous responses of both photonic properties and actuation to humidifying/dehumidifying.In particular,by aldehyde treatment under certain conditions,the PG film can be forged into various desired shapes,and thereby are able to produce complex movements.In addition,the objects with predetermined shapes show good shape recovery capability upon many wetting–drying cycles,especially through the treatment with formaldehyde.A mechanism model for shape predetermination by aldehyde treatment is suggested based on experimental details.We also used aldehyde treatment of PG film to design several actuators with specific shapes,showing a more complex motion response.The preparation of this driving material is of great significance for achieving complex optical/driving intelligent response.