Light‐Activated Active Colloid Ribbons. Issue 43 (25th September 2017)

• Record Type: Journal Article
• Authors: Lin, Zhihua; Si, Tieyan; Wu, Zhiguang; Gao, Changyong; Lin, Xiankun; He, Qiang
• Is Part Of: Angewandte Chemie international edition. Volume 56:Issue 43(2017)
• Page Start: 13517
• Page End: 13520
• Publication Date: 2017-09-25
• Subjects: colloids -- dynamic assembly -- nanomotors -- nonequilibrium processes -- self-propulsion; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201708155
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: We report a dynamic self‐organization of self‐propelled peanut‐shaped hematite motors from non‐equilibrium driving forces where the propulsion can be triggered by blue light. They result in one‐dimensional, active colloid ribbons with a positive phototactic characteristic. The motion of colloid motors is ascribed to the diffusion‐osmotic flow in a chemical gradient by the photocatalytic decomposition of hydrogen peroxide fuel. We show that self‐propelled peanut‐shaped colloids readily form one‐dimensional, slithering ribbon structures under the out‐of‐equilibrium collisions. This self‐organization intrinsically results from the competition among the osmotically driven motion, the phoretic attraction and the inherent magnetic moments. The giant size number fluctuation in colloid ribbons is observed above a critical point 4.1 % of the surface density of colloid motors. Such phototactic colloid ribbons may provide a model system to understand the emergence of function in biological systems and have potential to construct bioinspired active materials based on different active building blocks. Abstract : Dynamic assembly : Peanut‐shaped hematite colloid motors activated by light can readily be organized into one‐dimensional colloid ribbons, which exhibit a positive phototactic behavior. The direction, speed, and size of as‐formed active colloid ribbons can be modulated by using light and surface fraction of colloidal suspensions.