title: Mechanical property of lipid-coated polyelectrolyte microcapsules.
abstract: The deformations of lipid coated polyelectrolyte capsules induced by osmotic pressure were determined in poly(styrene sulfonate, sodium salt) (PSS) solution by making use of the fact that PSS molecules with a molecular weight 70000 will not penetrate into the capsules. At a critical osmotic pressure the initial spherical capsules changed their shape and became an invagination. The measurements of single particle light scattering provided the wall thickness of the lipid-coated capsules with 25.6 nm while the thickness for pure polyelectrolyte capsules in solution is about 21.6 nm, indicating that the coating lipid layer has about 4 nm thickness. It demonstrates that DMPA forms a bilayer on the surface of polyelectrolyte capsules. With these data, that the elasticity coefficient of the lipid-coated capsules is about 426 Mpa can be obtained.
authors.affiliation: State Key Laboratory of Bioelectronics, Biological Science and Medical Engineering Department, Southeast University, Nanjing 210096, PR China.
authors.forename: Liqin
authors.initials: L
authors.lastname: Ge
authors.forename: Helmuth
authors.initials: H
authors.lastname: Möhwald
authors.forename: Junbai
authors.initials: J
authors.lastname: Li
mesh_terms: D000327:Adsorption; D002214:Capsules / Q000737:chemistry*; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D004573:Electrolytes / Q000737:chemistry*; D008027:Light; D008055:Lipids / Q000737:chemistry*; D008970:Molecular Weight; D053758:Nanoparticles / Q000737:chemistry; D036103:Nanotechnology / Q000379:methods*; D010743:Phospholipids / Q000737:chemistry; D011137:Polystyrenes / Q000737:chemistry; D011312:Pressure; D012542:Scattering, Radiation; D013499:Surface Properties
chemical_list: D002214:Capsules; D020099:Coated Materials, Biocompatible; D004573:Electrolytes; D008055:Lipids; D010743:Phospholipids; D011137:Polystyrenes; C003321:polystyrene sulfonic acid