title: Rapid self-assembly of core-shell organosilicon microcapsules within a microfluidic device.
abstract: The preparation of hierarchically structured organosilicon microcapsules from commercially available starting materials is described. Using a microfluidic device, an emulsion of dichlorodiphenylsilane is formed in a continuous phase of aqueous glycerol. The silane droplets undergo hydrolysis, condensation, and crystallization within minutes to form self-assembled, core-shell microcapsules. The microparticles have been characterized with light and electron microscopy, nuclear magnetic resonance spectroscopy (NMR), diffusion-ordered NMR spectroscopy (DOSY), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and powder X-ray diffraction (XRD). The characterization data show that the microcapsule walls consist of amorphous, oligomeric poly(diphenylsiloxane) surrounded by a spiny layer of crystalline diphenylsilanediol. Glycerol is occluded within the wall material but is not covalently bound to the silicon components. Glycerol is a crucial element for producing low-dispersity microcapsules with well-ordered surface spines, as the use of methyl cellulose as viscomodifier yields amorphous surfaces.
authors.affiliation: Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853-1301, USA.
authors.forename: Jeremy L
authors.initials: JL
authors.lastname: Steinbacher
authors.forename: Rebecca W Y
authors.initials: RW
authors.lastname: Moy
authors.forename: Kristin E
authors.initials: KE
authors.lastname: Price
authors.forename: Meredith A
authors.initials: MA
authors.lastname: Cummings
authors.forename: Chandrani
authors.initials: C
authors.lastname: Roychowdhury
authors.forename: Jarrod J
authors.initials: JJ
authors.lastname: Buffy
authors.forename: William L
authors.initials: WL
authors.lastname: Olbricht
authors.forename: Michael
authors.initials: M
authors.lastname: Haaf
authors.forename: D Tyler
authors.initials: DT
authors.lastname: McQuade