Influence of functional group on the electrification of organic pigments

Abstract

Electrification of phthalocyaninatocopper derivative-powders was investigated based on the measurement of contact potential difference (CPD) between the powder and reference gold electrode. The powder-introduced halogen substituents in the end group show negative CPD values. The value of CPD increases negatively as the number of chlorine substituents increases, while the value increases negatively as the number of bromine substituents increases. Powders having hydrogens in the end groups are initially positively electrified and tend to their respective CPD values as time elapses, while powders fully substituted by halogens are negatively electrified. It is found that the charge decay data are well represented by a sum of two exponential functions. Charge-decay speed depends greatly on the number of substituents. Molecular orbital calculation has showed that the measured contact potential difference changes linearly with the calculated Fermi level.