Cellulosic Hydrogels: A Greener Solution of Sustainability

Abstract

Hydrogels are insoluble three-dimensional cross-linked polymeric network that swells in presence of water and other fluids. They can hold plenty of water compared to its own mass. The absence of dissolution attraction toward water is due to hydrophilic nature of the polymeric chain. Hydrophilicity arises because of holding hydrophilic functional groups in the chain. Highest portion of the world production of hydrogels is petrochemical based which is neither renewable nor biocompatible. In spite of some drawbacks like nondegradability, synthetic hydrogels are superior to natural one in water absorbency, diversification in chemicals, and longer service life. Taking into consideration sustainability factor, scientists are interested in preparation of hydrogels from renewable cellulosic sources. As cellulose possesses intrinsic nature of degradability, biocompatibility, and nontoxicity, also available in nature, and some cellulose derivatives show smart behavior, cellulose-based hydrogels can be an alternative to synthetic petrochemical-derived hydrogels. Numerous research articles concerning the synthesis and utilization of hydrogels in different fields have been published, and still restless labor is giving for the betterment of the product quality. It is a crying need to make available and adequate information on synthesis and characterization of cellulosic hydrogels for individual researchers. For this the specific aim of this paper is to accumulate some crucial information which will cover synthesis, detailed classification, characterization, and technological feasibility of application about hydrogels of renewable source. As of consequence, the research on hydrogel concerning current environmental issues will reach to its target of making the greener solution of sustainability. In addition, recent trend of hydrogel research is also discussed in this review.