Dissolution of cellulose with ionic liquids and its application: a mini-review

TLDR

Cellulose can be dissolved directly in certain hydrophilic ionic liquids, enabling green processing for fractionation, derivative, and composite production, and recent commercialization has advanced these applications. This review surveys the dissolution of cellulose with ionic liquids and its applications. The authors review the dissolution process of cellulose in ionic liquids and its subsequent applications. Microwave heating accelerates dissolution, and cellulose can be regenerated with water, ethanol, or acetone, after which the ionic liquids can be recovered and reused.

Abstract

Dissolution of cellulose with ionic liquids allows the comprehensive utilization of cellulose by combining two major green chemistry principles: using environmentally preferable solvents and bio-renewable feed-stocks. In this paper, the dissolution of cellulose with ionic liquids and its application were reviewed. Cellulose can be dissolved, without derivation, in some hydrophilic ionic liquids, such as 1-butyl-3-methylimidazolium chloride (BMIMCl) and 1-allyl-3-methylimidazolium chloride (AMIMCl). Microwave heating significantly accelerates the dissolution process. Cellulose can be easily regenerated from its ionic liquid solutions by addition of water, ethanol or acetone. After its regeneration, the ionic liquids can be recovered and reused. Fractionation of lignocellulosic materials and preparation of cellulose derivatives and composites are two of its typical applications. Although some basic studies, such as economical syntheses of ionic liquids and studies of ionic liquid toxicology, are still much needed, commercialization of these processes has made great progress in recent years.