Controlling particle size in the Stöber process and incorporation of calcium

• Published in: Journal of colloid and interface science Vol. 469; pp. 213 - 223
• Main Authors: Greasley, Sarah L., Page, Samuel J., Sirovica, Slobodan, Chen, Shu, Martin, Richard A., Riveiro, Antonio, Hanna, John V., Porter, Alexandra E., Jones, Julian R.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-05-2016
• Subjects: Bioactive glass; Biocompatibility; Biodegradability; Biodegradable; Calcium; Cations; Glass; Nanocomposites; Nanoparticles; Particle size; Sol–gel; Stӧber process; Nanoparticles; Bioactive glass; Stӧber process; Biodegradable; Sol–gel
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2016.01.065

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The Stӧber process is commonly used for synthesising spherical silica particles. This article reports the first comprehensive study of how the process variables can be used to obtain monodispersed particles of specific size. The modal particle size could be selected within in the range 20–500nm. There is great therapeutic potential for bioactive glass nanoparticles, as they can be internalised within cells and perform sustained delivery of active ions. Biodegradable bioactive glass nanoparticles are also used in nanocomposites. Modification of the Stӧber process so that the particles can contain cations such as calcium, whilst maintaining monodispersity, is desirable. Here, whilst calcium incorporation is achieved, with a homogenous distribution, careful characterisation shows that much of the calcium is not incorporated. A maximum of 10mol% CaO can be achieved and previous reports are likely to have overestimated the amount of calcium incorporated.