Six types of spherical colored methylmethacrylate particles that have a particle diameter of 2, 3, 4, 5, 6, and 7 μm were prepared by seed polymerization. Obtained particles were completely separated mono-dispersed particles having a uniform diameter. The amount of tribo-charge q/m generated by mixing with reference particles having an irregular or a spherical shape was measured. The amount of q/m in-creased in proportion to the increase of the specific area of the mono-dispersed particles at a restricted particle concentration. With the combination of the spherical monodispersed particles and spherical reference particles, the tribo-charging characteristics can be measured reproducibly even when small mono-dispersed particles having a diameter of 2 μm are used. The combination can be used as an ideal standard mixture for the tribo-charge measurements.
Takahide Mizawa, Yoosuke Nakata, Yusuke Mizuno, Toshihiko Oguchi, "Charging Characteristics of Spherical Mono-dispersed Particles" in Proc. IS&T Int'l Conf. on Digital Printing Technologies (NIP19), 2003, pp 107 - 110, https://doi.org/10.2352/ISSN.2169-4451.2003.19.1.art00026_1