Rapid self-assembly of core-shell organosilicon microcapsules within a microfluidic device.
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.
Steinbacher
Jeremy L
JL
Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853-1301, USA.
Moy
Rebecca W Y
RW
Price
Kristin E
KE
Cummings
Meredith A
MA
Roychowdhury
Chandrani
C
Buffy
Jarrod J
JJ
Olbricht
William L
WL
Haaf
Michael
M
McQuade
D Tyler
DT