Encapsulation of emulsion droplets by organo–silica shells

Fabrication of hollow silica spheres using droplet templates derived from a miniemulsion technique

“…Thus, hollow silica spheres could be obtained directly since the miniemulsion droplets of octane could be evaporated very easily during the reaction or the drying process; neither additional dissolution nor a calcination process or additional surface modification of the templates were needed. In fact, several researchers have focused on the techniques of using oil as templates, but their surfactant concentration was above CMC [43][44][45][46][47][48]. Recently, Imhof et al [49] used low-molecular-weight PDMS silicone oil-inwater droplets as template without any surfactant and successfully synthesized monodisperse, micro-sized, hollow silica particles by the hydrolysis and condensation of TEOS.…”

Ultrabubble: A Laminated Ultrasound Contrast Agent with Narrow Size Range

“…Hollow-capsule synthesis has been studied for various polymeric and silica materials, using methods such as osmotic swelling, [12] emulsion droplets (that were demonstrated to produce near-monodispersed silica hollow particles [2,11,13] ), layer-by-layer and sacrificial core-template, etc. [14] The resulting capsules have found applications across fields ranging from toners, inks, architecture coatings, to medical imaging and drug delivery.…”

“…[12] However, the properties of the hollow particles, such as stiffness and structure, as well as size, will govern whether such particles may be ultrasound sensitive. [3,13] Silica has been suggested in the literature to be biocompatible, [15,16] and composite sol-gel coatings have been proposed as protective bioactive coatings. [17,18] The preliminary study reported herein is based on a core-shell method adapted from Lu et al [14] To create an ultrasound-sensitive particle, a polystyrene (PS) core was solvent etched to produce hollow capsules laminated with thin layers of silica-based materials.…”

Micro- and nanospheres from preceramic polymers: process parameters and size control

“…Hollow as well as porous ceramic spheres may be, due to their attractive properties (high specific surface area, low density, high thermal stability) useful for a wide range of technological applications such as light weight fillers, coatings, shock absorbers, catalytic substrates and thermal insulation [1][2][3]. Manufacturing of spheres can be carried out by a great variety of processes.…”