A New Method for the Preparation of Monoporous Hollow Microspheres

• Published in: Langmuir Vol. 26; no. 7; pp. 5115 - 5121
• Main Authors: Chang, Ming-Wei, Stride, Eleanor, Edirisinghe, Mohan
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 06.04.2010
• Subjects: Chemistry; Colloidal state and disperse state; Exact sciences and technology; Fluorocarbons - chemistry; General and physical chemistry; Materials: Nano-and Mesostructured Materials, Polymers, Gels, Liquid Crystals, Composites; Microscopy, Electron, Scanning; Microspheres; Organosilicon Compounds - chemistry; Polymers - chemistry; Porosity; Porous materials; Surface physical chemistry; Scanning electron microscopy; Flow rate; Microsphere; Surfactant; Volatiles; Porous material; Particle; Liquid; Additive; Pore size; Pore; Preparation; Models; Atomization; Diameter; Electrohydrodynamics
• ISSN: 0743-7463; 1520-5827; 1520-5827
• DOI: 10.1021/la903592s

The feasibility of producing a hollow microsphere with a single hole in its shell by coaxial electrohydrodynamic atomization (CEHDA) is demonstrated. Polymethylsilsesquioxane (PMSQ) was used as a model shell material encapsulating a core of a volatile liquid, perfluorohexane (PFH), which was subsequently evaporated to produce the hollow microspheres. The diameters of the microspheres and of the single surface pore were controlled by varying the flow rate of the components, the concentration of the PMSQ solution, and the applied voltage in the CEHDA process. The particles were characterized by scanning electron microscopy, and the ranges obtained were 275−860 nm for the microsphere diameter and 35−135 nm for the pore size. The process overcomes several of the key problems associated with existing methods of monoporous microsphere formation including removing the need for elevated temperatures, multiple processing steps, and the use of surfactants and other additives.