Synthesis of nanometer-sized silica by controlled hydrolysis in reverse micellar systems

F. J. Arriagada, Kwadwo Asare Osseo-Asare

Research output: Chapter in Book/Report/Conference proceedingChapter


The synthesis of nanometer-sized silica particles by the base-catalyzed, controlled hydrolysis of tetraethoxysilane (TEOS) in a nonionic reverse micellar system is described. Spectrofluorometric techniques were used to characterize the reverse micellar solutions. Particle characterization was conducted by transmission electron microscopy. The effect of the water-to-surfactant molar ratio (R) on particle size and size distribution was investigated over a wide range of R values (0.50 to 3.54). Stable dispersions of amorphous silica with mean particle diameters in the range of 46 to 68 nm were produced. Small (46 nm) and extremely monodisperse particles (polydispersity below 4%) were obtained at intermediate R values (1.4), whereas both particle size and polydispersity increased at lower and higher R values. The effects of R on particle size and size distribution are discussed in terms of water “reactivity” (i.e., proportion of bound to free water), concentration of reverse surfactant aggregates, distribution of hydrolyzed TEOS molecules among aggregates, and dynamics of intermicellar matter exchange. A mechanistic model for particle nucleation and growth in these systems is proposed.

Original languageEnglish (US)
Title of host publicationColloidal Silica
Subtitle of host publicationFundamentals and Applications
PublisherCRC Press
Number of pages9
ISBN (Electronic)9781420028706
ISBN (Print)9780824709679
StatePublished - Jan 1 2005

All Science Journal Classification (ASJC) codes

  • General Chemistry
  • General Chemical Engineering


Dive into the research topics of 'Synthesis of nanometer-sized silica by controlled hydrolysis in reverse micellar systems'. Together they form a unique fingerprint.

Cite this