Seminar: Prof Hyacinthe Randriamahazaka - From Surface Modification to Electrochemical Devices

Wednesday, 20 September 2017 - 12:00pm – Wednesday, 20 September 2017 - 1:00pm  |  Chem Sci M11

Speaker: Prof Hyacinthe Randria

Applications regarding energy harvesting, electrochemical energy storage, biomaterials, chemical sensors, biosensors, and (photo)catalysis summarize most of the fields in which the surface chemistry plays an essential role. Then, the ability to control, to tune, and to investigate interfacial properties is crucial for the development of various devices. We will combine both theoretical and experimental approaches to investigate the interfacial properties by means of various techniques such as electrochemical impedance spectroscopy (EIS), scanning electrochemical microscopy (SECM), and intensity modulated photocurrent spectroscopy (IMPS). Because of the great interest in the potential of ionic liquids as alternative materials in diverse electrochemical applications, studies on the properties of molecular assemblies of ionic liquids have become important. Herein, we will report the surface modification by means of electrografting. Electrochemical processes based on oxidative or reductive grafting have been used for the attachment of organic molecules, such as redox active ionic liquids, onto various electrode surfaces providing new and special properties to the interfaces. The immobilization of redox active poly(ionic liquid) by surface-initiated atom transfer radical polymerization SI-ATRP process onto electrode surfaces has been investigated. The surface and electrochemical properties of these modified surfaces were investigated by combining different techniques (XPS, AFM, ellipsometry, and contact angle). We will show the use of redox active poly(ionic liquid) polymer brush as electrochemically reversible tunable surface wettability system. These immobilized redox active compounds are also interesting for various systems such as organic battery, supercapacitor, and photoelectrochemical systems. Herein, we will report our recent results on these topics.