Cationic colloidal unimolecular polymer (CUP) particles were prepared by using a lower concentration of the quaternary ammonium functional copolymers during the process of water reduction. True nanoscale (diameter 3-9 nm), zero-volatile organic content (VOC), spheroidal CUP particles, and self-stabilized via electro-repulsion of surface cationic groups were obtained. the viscosity of the cationic CUP systems was influenced by the electroviscous effects arising from the surface charge and the associated surface water layer. the density of surface water was 1.6 % greater than the bulk water density which was attributed to the structuring of water around charged quaternary ammonium groups. the equilibrium surface tension values decreased linearly with increasing concentration and surface charge density of CUP particles due to a greater reduction in surface energy. the rate of surface tension reduction determined by maximum bubble pressure method decreased with increasing concentration and the molecular weight of the CUP due to diffusion effects.