title: Release of phospholipids from colloidal particles to polymeric surfaces.
abstract: This study presents a small-scale polymerization of high molecular weight methyl methacrylate/n-butyl acrylate (MMA/n-BA) colloidal particles that are synthesized in an aqueous environment in the presence of phospholipid hydrogenated soybean phosphatidylcholine (HSPC) molecules that also serve as the particle stabilizing agents. When such particles coalesce to form polymeric films, they release phospholipids, which, in turn, form organized structures near the film-air (F-A) interface. Diffusion and mobility of phospholipid molecules are affected not only by their compatibility with colloidal particles but also by electrolyte environments of colloidal dispersions. When Na(+), K(+), and Ca(2+) counterions are added to MMA/n-BA aqueous colloidal dispersions stabilized with HSPC, and such films are coalesced, different degrees of diffusion of HSPC to the F-A interface exist, depending on the counterion, and conformational changes of HSPC result. For example, in the presence of Ca(2+), HSPC molecules collapse entropically to form random surface layers, as opposed to smaller Na(+) and K(+), which force amphiphilic HSPC ends to align preferentially parallel to the film surface. These studies show that it is possible to design stimuli-response colloidal systems triggered by chemical environments of active molecules on colloidal polymer particles.
authors.affiliation: Shelby F Thames Polymer Science Research Center, School of Polymers and High Performance Materials, The University of Southern Mississippi, Hattiesburg, Mississippi 39406, USA.
authors.forename: Ator
authors.initials: A
authors.lastname: Yacoub
authors.forename: Marek W
authors.initials: MW
authors.lastname: Urban
mesh_terms: D003102:Colloids; D008768:Methylmethacrylates / Q000737:chemistry*; D010713:Phosphatidylcholines / Q000737:chemistry*; D010743:Phospholipids / Q000737:chemistry*; D011108:Polymers; D013025:Glycine max; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties
chemical_list: D003102:Colloids; D008768:Methylmethacrylates; D010713:Phosphatidylcholines; D010743:Phospholipids; D011108:Polymers; C060877:Dakril 4B