Polyelectrolyte effect and settling of alumina dispersions

Effect of Molecular Weight and Ionic Strength on the Formation of Polyelectrolyte Complexes Based on Poly(methacrylic acid) and Chitosan

“…This hypothesis has already been considered in the literature, regarding the formation of different polyelectrolyte complexes. 53,54 As a consequence, there is also the probability of formation of particles by bridging flocculation 6,48 of the negatively charged particles and soluble complex species.…”

“…Macromolecular complexes with the subsequent formation of particulate systems with micrometric and submicrometric dimensions, generally in the form of colloids or suspensions obtained by polymerization, aggregation, and/or complexation of polymers, have been reported as promising advanced functional materials . These polymer dispersions have been used in a wide variety applications, such as in the preparation of synthetic rubber, coatings, adhesives for paper and textile, , flocculants, , and rheological modifiers . They have also been increasingly used in biomedical and pharmaceutical applications, such as diagnostic tests and targeted drug delivery. − …”

Polyelectrolytes in Solution and the Stabilization of Colloids

“…The adsorption of polyelectrolytes is an important phenomenon that occurs in solid/liquid interfaces, since the stability of colloidal dispersions by electrostatic and steric interaction forces is a very important parameter due to its relevance to many industrial processes, such as the treatment of water, paper industry process, and pigment dispersions. [53,54] Determining the modes of action of polyelectrolytes and the characterization of the destabilization process in a particular situation are not easy tasks. [49 -51] Bearing in mind that polyelectrolytes are homopolymers that may be either strongly or weakly dissociated, one has two situations: in the first case, the charge on the chain does not depend on pH, while in the second case, the polymer charge will depend on it.…”

“…[54,57,88] Time-dependent models of behavior are less satisfactory and more controversial than models related to behavior dependent only on shear. [54,57,88] Time-dependent models of behavior are less satisfactory and more controversial than models related to behavior dependent only on shear.…”

Biomacromoléculas carboximetiladas: atuação como agentes de estabilização de suspensões aquosas de alumina

“…(Hirata;Nishimoto;Ishima, 1992;Zupancic;Lapasin;Kristoffersson, 1999;Guo et al, 1998;Yokosawa, 1996;Greenwood;Kendall, 2000;Vasconcelos et al, 2003;Wu et al, 2010) Na literatura, pouco constam trabalhos sobre estabilização de suspensões cerâmicas utilizando-se macromoléculas e/ou polímeros de fontes naturais, (Yokosawa;Yokosawa;Cerrutti, 2005;Cerrutti et al, 2010), a utilização dos sintéticos, como o PAA, continua sendo a opção mais utilizada. (Tallon et al, 2007;Tallon;Limacher;Franks, 2010;Wu et al, 2010;Lu;Su, 2010;Yoon et al, 2010) Em trabalhos anteriores a este, foram desenvolvidos estudos visando a obtenção de suspensões cerâmicas estáveis utilizando macromoléculas (polieletrolíticas ou não) oriundas de fontes naturais, tais como cosmédia guar (leguminosa originária da Índia), (Yokosawa, 1996) lignossulfonato de sódio, (Yokosawa;Frollini, 2002a;Yokosawa, 2002b), taninos (Mimosa Acácia) e trimetilquitosana, (Cerrutti, 2005;Cerrutti, et al, 2009).…”