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.
Schumacher
Heloisa Cajon
HC
Instituto de Química, Universidade Estadual de Campinas, Caixa Postal 6154, 13084-971 Campinas, SP, Brazil.
Alves
Marilene
M
Leite
Carlos Alberto Paula
CA
Santos
Juliane Pereira
JP
Neto
Erico Teixeira
ET
Murakami
Mauro Makoto
MM
Galembeck
Fernando
F
do Amaral
Marcelo
M