Assembly of sodium soap fibers and fibrillar particles triggered by dissolution of sodium chloride crystals

作者：Zawko Scott A; Schmidt Christine E^*

来源：Soft Matter, 2010, 6(14): 3289-3297.

DOI：10.1039/c002084b

Fatty acids in the presence of sodium ions are known to self-assemble into sodium soap fibers. Previous work has yielded these fibers only in the form of randomly entangled gels. Here, for the first time, we demonstrate a method to create discrete fibrillar particles from sodium soap fibers. Immersion of sodium chloride crystals in solutions of neutralized fatty acids causes the crystals to dissolve and release sodium ions. Release of sodium triggers the nucleation and assembly of fibers in the solution surrounding the dissolving crystal. This process ultimately yields fibrillar particles with brush layers of sodium soap fibers. The fibers are flexible ribbons that are 1 mm in width, 3 mm in height, and hundreds of microns in length. We extended our method to polystyrene microspheres by encapsulating them with thin shells of sodium chloride microcrystals. Microspheres coated with sodium chloride shells triggered the assembly of encapsulating fibrillar brush layers. Microspheres with such brush layers have dramatically increased surface areas and this property may be applicable to oral drug delivery systems.

• 出版日期2010