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Osmotic Effects

  1. Domenico Larobina1,
  2. Luigi Sanguigno2

Published Online: 20 JUL 2012

DOI: 10.1002/9781118097298.weoc166

Wiley Encyclopedia of Composites

Wiley Encyclopedia of Composites

How to Cite

Larobina, D. and Sanguigno, L. 2012. Osmotic Effects. Wiley Encyclopedia of Composites. 1–5.

Author Information

  1. 1

    Institute of Composite and Biomedical Materials, National Research Council, Naples, Italy

  2. 2

    Institute of Italian Technology, Naples, Italy

Publication History

  1. Published Online: 20 JUL 2012


When a solvent, usually water, is allowed to diffuse into a composite structure and a soluble solute is present therein, an osmotic pressure sets in at the composite interface drawing more solvent into the structure. The phenomenon is of particular importance in composite materials since dramatic structural effects can develop. In this article, after a brief description of the osmotic phenomenon and the thermodynamic variables affecting it (e.g., concentration and pressure), we turn our attention to the more practical problem of how osmosis occurs inside a composite, particularly in glass-reinforced polymers. Then, we continue our description exploring the consequence of osmosis in a composite: this is a well-known technological problem referred to in the literature as blistering. We conclude the article by giving some hints on how to prevent blistering inside a composite.


  • osmosis;
  • composites;
  • water diffusion;
  • blistering;
  • debonding