Abstract: Hydrogel products made up of a group of polymeric materials, the hydrophilic structure of which renders them capable of holding large amounts of water in their three-dimensional networks. Extensive application of these products in a number of industrial and environmental areas of application is considered to be of prime importance. As expected, natural hydrogels were gradually replaced by artificial types due to their higher water absorption capacity, long service life, and wide varieties of raw chemical resources. Literature on this subject was found to be expanding, especially in the scientific fields of research. However, a number of publications and technical reports dealing with hydrogel products from the engineering points of view were examined to overview technological aspects covering this growing multiple professional fields of research. The primary objective of this article is to review the literature concerning classification of hydrogels on different bases, physical and chemical characteristics of hydrogel, and technical feasibility of their utilization. An innovated category of recent generations of hydrogel materials was also presented in some detail.

Keywords: Hydrogel preparation, processing, application