Preparation of anionic ion exchange latex particles via heteroaggregation

Abstract

To prepare relatively large negatively charged polymer particles in a size range from 0.3 μm to 0.5 μm, having high surface charge densities, the heteroaggregation of small (50–100 nm), highly charged (185 and 421 μeq/g) anionic polystyrene particles onto the surface of larger (317–466 nm) poly(vinylbenzyl choride)‐based cationic (10, 614, and 830 μeq/g) particles was carried out. As a result, particles with different surface charges, having a core‐shell structure, were successfully prepared. First, aggregated particles were formed via heteroaggregation of the lowest surface charge density anionic particles (185 μeq/g) with the lowest surface charge density cationic particles (10 μeq/g). However, the anionic particles in the shell layer desorbed with time owing to the relatively weak interaction between the two particles. Second, aggregated particles comprised of the highest surface charge density cationic (830 μeq/g) and anionic latex particles (421 μeq/g) were formed. However, to prepare a stable system, an excess of the small anionic particles was required, leaving a large number of small particles present in the aqueous phase, which proved difficult to remove. Finally, aggregated particles were formed by heteroaggregation of cationic particles with an intermediate surface charge density (614 μeq/g) with the highest surface charge anionic particles (421 μeq/g). As a result, not only were core‐shell particles formed, but few free small anionic particles remained in the aqueous phase. In this article, the preparation and characterization of each of these aggregates are discussed in terms of particle size, morphology, and extent of incorporation of the functional groups. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Modification of Physicochemical Properties by Heteroaggregation of Oppositely Charged Lactoferrin and Soybean Protein Isolate Coated DHA Emulsion Droplets

“…This confirmed that LF-coated and SPI-coated DHA droplets electrostatically interacted with each other. Similar results regarding the formation of microclusters of LF droplets and β-lactoglobulin droplets through electrostatic charges have been reported. , …”

Hematite/Polystyrene Raspberry‐Like Microcomposites as Stable Support for Silver Nanoparticle Immobilization

“…The main strategies for the preparation of raspberry‐like composite microparticles are as follows: polymerization processes, [ 21–23 ] linking of nanoparticle to the core surface, [ 24,25 ] seed growth process, [ 26,27 ] reduction of ions precursors in the presence of core particles [ 28,29 ] and electrostatically driven immobilization of nanoparticles at the surface of microparticles, which is also referred to as heterocoagulation or heteroaggregation. [ 30–34 ] Because of its universality, the electrostatically driven deposition of metal, [ 35,36 ] oxide, [ 37–39 ] and polymer nanoparticles [ 40,41 ] has attracted a special attention of the scientific community. Among the variety of oxide nanoparticles utilized in this approach, due to their well‐known catalytic properties, hematite nanoparticles (HNPs) seem to be especially attractive.…”