Study on solubility and biopersistance of SAS

Subject of investigation

The solubility behavior of synthetic amorphous silica in liquids such as occur in biological systems. This allows clarification of whether silica is biopersistent or is degraded in organisms.

Core statement

Silica nanoparticles have high solubility in media such as are found in biological systems.

The substance

The synthetic amorphous silicas investigated were pyrogenically or wet-chemically produced products from various companies.

Results in detail

  • Small quantities of silica nanoparticles quickly dissolve in a biological milieu such as extracellular lung fluid. A buffer solution of similar pH, buffering capacity, and osmotic pressure served in the experiments to simulate the relevant properties of the extracellular lung fluid.
  • It is theoretically verifiable and experimentally confirmed that silica nanoparticles, due to their large specific surface areas, go into solution faster and in greater quantities than larger units of silica particles.

Type of the study

Experimental work; in addition, a numerical model allowed prediction of the variation of silica concentration with time in the tests.

About the authors

At the time of publication of the study the two authors were employees of the Institute for Physical Chemistry of Friedrich-Schiller-Universität Jena, Wolfram Vogelsberger as Professor and Frank Roelofs as research assistant.

Original publication:

Frank Roelofs und Wolfram Vogelsberger, J. Phys. Chem. B (2004), DOI 10.1021/jp048767r