Journal of Colloid and Interface Science, Vol.305, No.2, 256-263, 2007
Cationic latex formation by ionic modification
Stable cationic latices were prepared by charge inversion of anionic styrene-acrylic copolymer latices upon binding Al3+ and Fe3+ ions. This is achieved by stabilizing the latices with a high-HLB (hydrophile-lypophile balance) nonionic surfactant that imparts strong steric stability to the latex, even in the presence of high concentrations of multivalent counterions while these are bound to the latex anionic sites. The cationic latices thus prepared have good stability properties, and the same procedure should be applicable to essentially any latex-carrying anionic sites. Analytical ESI-TEM images show that particle-bound iron is concentrated at the particle borders, but it is also found in the particle bulk. (c) 2006 Elsevier Inc. All rights reserved.
Keywords:cationic latex;charge inversion;Fe3+ ion;Al3+ ion;anionic latices;nonionic surfactant;zeta potential;surfactant adsorption