Publication Details (including relevant citation information): Steinbacher, Jeremy L., Moy, Rebecca W. Y., Price, Kristin E., Cummings, Meredith A., Roychowdhury, Chandrani, Buffy, Jarrod J., Olbricht, William L., Haaf, Michael, McQuade, D. Tyler, J. Am. Chem. Soc., 2006, 128 (29), pp 9442-9447
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.
Address (URL): http://dx.doi.org/10.1021/ja0612403