Cellulose-Based Metallogels-Part 1: Raw Materials and Preparation

Metallogels are a class of materials produced by the complexation of polymer gels with metal ions that can form coordination bonds with the functional groups of the gel. Hydrogels with metal phases attract special attention due to the numerous possibilities for functionalization. Cellulose is preferable for the production of hydrogels from economic, ecological, physical, chemical, and biological points of view since it is inexpensive, renewable, versatile, non-toxic, reveals high mechanical and thermal stability, has a porous structure, an imposing number of reactive OH groups, and good biocompatibility. Due to the poor solubility of natural cellulose, the hydrogels are commonly produced from cellulose derivatives that require multiple chemical manipulations. However, there is a number of techniques of hydrogel preparation via dissolution and regeneration of non-derivatized cellulose of various origins. Thus, hydrogels can be produced from plant-derived cellulose, lignocellulose and cellulose wastes, including agricultural, food and paper wastes. The advantages and limitations of using solvents are discussed in this review with regard to the possibility of industrial scaling up. Metallogels are often formed on the basis of ready-made hydrogels, which is why the choice of an adequate solvent is important for obtaining desirable results. The methods of the preparation of cellulose metallogels with d-transition metals in the present state of the art are reviewed.

Automated summary

Metallogels are materials formed by complexing polymer gels with metal ions that can coordinate with the gel's functional groups. Hydrogels made of cellulose are of particular interest due to their low cost, renewable nature, versatility, non-toxicity, mechanical and thermal stability, porous structure, reactive OH groups, and biocompatibility. Various techniques exist for preparing hydrogels from non-derivatized cellulose, including plant-derived cellulose and cellulose wastes. This review discusses the advantages and limitations of solvent use in industrial scaling up, as well as the methods for preparing cellulose metallogels with d-transition metals.