Loget G., Roche J., Gianessi E., Bouffier L., Kuhn A.,
J. Am. Chem.Soc. 2012, 134, 20033-20036.

Based on the principles of bipolar electrochemistry, localized pH gradients are generated at the surface of conducting particles in solution. This allows the toposelective deposition of inorganic and organic polymer layers via a pH-triggered precipitation mechanism. Due to the intrinsic symmetry breaking of the process, the concept can be used to generate in a straightforward way Janus particles, with one section consisting of deposits obtained from non-electroactive precursors. These indirect electrodeposits, such as SiO2, TiO2, or electrophoretic paints, can be further used as an immobilization matrix for other species like dyes or nanoparticles, thus opening promising perspectives for the synthesis of a variety of bifunctional objects with a controlled shape.

 

JACS2012 p20033 TOC

Fattah Z., Garrigue P., Lapeyre V., Kuhn A., Bouffier L.,
J. Phys. Chem. C 2012, 116, 22021-22027.

Asymmetric particles of various chemical compositions have attracted great attention because of their application potential in different areas, ranging from photosplitting of water to autonomous swimmers. In this context, the spatial arrangement of the different components can be of major importance. We report here a bulk procedure based on bipolar electrochemistry that allows generating asymmetric particles with a highly controlled spatial orientation of a metal deposit on a carbon substrate. Two fundamentally different topologies of the metal deposit can be obtained as a function of controllable experimental parameters like the orientation and amplitude of the electric field as well as the viscosity of the medium.

 

JPhysChemC2012 p22012 TOC

Sentic M., Loget G., Manojlovic D., Kuhn A., Sojic N.,
Angew. Chem. Int. Ed. 2012, 51, 11284–11288.

Swimmer in the dark: Propulsion of a conducting object is intrinsically coupled with light emission using bipolar electrochemistry. Asymmetric redox activity on the surface of the swimmer (black bead; see picture) causes production of gas bubbles to propel the swimmer in a glass tube with simultaneous electrochemiluminescence (ECL) emission to monitor the progress of the swimmer.

 

AngewChem2012 p11284 TOC

 

Video:

Zigah D., Rodriguez-Lopez P., Bard A. J.,
Phys. Chem. Chem. Phys. 2012, 14, 12764-12772.

Asymmetric particles of various chemical compositions have attracted great attention because of their application potential in different areas, ranging from photosplitting of water to autonomous swimmers. In this context, the spatial arrangement of the different components can be of major importance. We report here a bulk procedure based on bipolar electrochemistry that allows generating asymmetric particles with a highly controlled spatial orientation of a metal deposit on a carbon substrate. Two fundamentally different topologies of the metal deposit can be obtained as a function of controllable experimental parameters like the orientation and amplitude of the electric field as well as the viscosity of the medium.

 

PhysChemChemPhys2012 p12764 TOC