能源与催化讲座系列

Title: Characterization of Carbon Nanotubes By Base Titration and Point of Zero Charge

Speaker: Prof. Gary L. Haller

　　　　 Department of Chemical and Environmental Engineering, Yale University, USA.

Time: 10:00am- 11:30am, (Fri.) 22, March 2013

Venue: Room 468, Lee Hsun Building

Welcome to attend!

报告简介：

In its simplest form, the point of zero charge (PZC), or the isoelectric point, is defined as that solution pH in contact with a carbon surface that results in a neutral surface. At a pH below the PZC, the surface will charge positively by protonation of surface hydroxyls (or equivalent groups) and adsorb anions and at a pH above the PZC the surface will charge negatively by dissociation of surface hydroxyls (or equivalent groups) and adsorb cations. This information can be used to predict the electrostatic adsorption of different metal precursors. Here we also describe the use of PZC to quantify the degree of oxidation of CNT as a function of time and concentration of nitric acid treatment, the effectiveness of different oxidation or reduction agents, and effectiveness of thermal treatment in inert gas at different temperatures, to remove functional groups. Principle component analysis of the titration curves provide a method to estimate the distribution of oxygen functional groups.