title: Polyamine-guided synthesis of anisotropic, multicompartment microparticles.
abstract: Colloidal particles that have nonuniform bulk or surface compositions are of emerging interest because of their potential applications involving advanced chemical storage and delivery and the self-assembly of novel functional materials. Experimental realization of anisotropic particles is much more difficult than that for particles with uniform bulk and surface composition, however. A new wet-chemical synthesis method to anisotropic microparticles is presented. This approach makes convenient use of the unusual observation of a salt-triggered separation of two water-solubilized polyamines into colloidal aggregates with nonuniform polymer composition. The anisotropic structure of these ionically cross-linked aggregates is explained by the difference in surface tensions of the contained single-polymer domains. Contacting the polymer aggregates with silicic acid or 13-nm silica nanoparticles leads to the charge-driven formation of solid or hollow microspheres, respectively. Depending on the poly(lysine)/poly(allylamine) ratio, the nonuniformity of the polymer aggregates translates to surface patches or internal compartments found in the resultant silica/polymer microparticles. Such hybrid materials with their unique structure could serve as a new basis for targeted chemical delivery and controlled release for potential applications in medicine, food, and cosmetics.
authors.affiliation: Department of Chemical and Biomolecular Engineering, Rice University, 6100 S. Main Street, Houston, TX 77251-1892, USA. vinit.murthy@gmail.com
authors.forename: Vinit S
authors.initials: VS
authors.lastname: Murthy
authors.forename: Shyam B
authors.initials: SB
authors.lastname: Kadali
authors.forename: Michael S
authors.initials: MS
authors.lastname: Wong
mesh_terms: D016880:Anisotropy; D003102:Colloids / Q000737:chemistry; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D008856:Microscopy, Fluorescence; D008863:Microspheres; D011073:Polyamines / Q000737:chemistry*; D011107:Polylysine / Q000737:chemistry*; D012824:Silicic Acid / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry
chemical_list: D003102:Colloids; D011073:Polyamines; D012824:Silicic Acid; D011107:Polylysine; C063994:polyallylamine; D012822:Silicon Dioxide