Hydrogel

from Wikipedia, the free encyclopedia
Hydrogel of a superabsorbent

A hydrogel is a water-containing but water-insoluble polymer whose molecules are chemically, e.g. B. by covalent or ionic bonds, or physically, e.g. B. by entangling the polymer chains are linked to form a three-dimensional network. Due to built-in hydrophilic polymer components, they swell in water with a considerable increase in volume, but without losing their material cohesion.

Due to their biocompatibility and tissue-like mechanical properties, hydrogels are gaining in importance in the biomedical field. Well-known examples are soft contact lenses (invented by the Czech chemist Otto Wichterle ), intraocular lenses and plastic implants .

In the treatment of wounds , in particular for moisturizing or for rehydration dry wounds, hydrogels as compresses or in the form of Tubengelen used. The latter are also used in the context of debridement to promote wound cleansing. By releasing water, the hydrogels support the body's own processes in softening and flushing out necroses and deposits.

So-called smart hydrogels have enormous development potential in technology because they have integrated actuator-sensor properties.

These are then disperse systems of at least two components, which mostly consist of a solid substance (gelling or thickening agent) and water as a dispersing agent .

The swelling behavior of hydrogels is often described with the help of (modified) Flory-Rehner models , which are based on the Flory-Huggins model .

Individual evidence

  1. ↑ Entry on hydrogels. In: Römpp Online . Georg Thieme Verlag, accessed on June 14, 2014.
  2. ↑ Enas M. Ahmed: Hydrogel: Preparation, characterization, and applications: A review. In: Journal of Advanced Research. Volume 6, Issue 2, 2015, pp. 105–121, doi : 10.1016 / j.jare.2013.07.006 .
  3. ↑ A fabric stronger than steel on Spektrum.de, accessed on March 17, 2017.
  4. ^ Kerstin Protz: Modern wound care 8th edition, Elsevier Verlag, Munich 2016, ISBN 978-3-437-27885-3 , page 36
  5. ^ Paul J. Flory, John Rehner: Statistical Mechanics of Cross ‐ Linked Polymer Networks II. Swelling . In: The Journal of Chemical Physics . tape 11 , no. November 11 , 1943, ISSN  0021-9606 , p. 521-526 , doi : 10.1063 / 1.1723792 ( scitation.org [accessed November 17, 2019]).