U.S. flag

An official website of the United States government

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.


Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Main content area

Choline chloride based ionic liquid analogues as tool for the fabrication of agar films with improved mechanical properties

Ana M.M. Sousa, Hiléia K.S. Souza, Nicholas Latona, Cheng-Kung Liu, Maria P. Gonçalves, LinShu Liu
Carbohydrate polymers 2014 v.111 pp. 206-214
absorption, agar, biocompatible materials, biodegradability, biodegradable products, choline, contact angle, diffusion, drying, films (materials), glycerol, hydrophilicity, ionic liquids, macroalgae, mechanical properties, microstructure, plasticizers, polymers, scanning electron microscopy, urea
In the present paper, we test the suitability of ChCl/urea (DES-U) and ChCl/glycerol (DES-G) eutectic mixtures, each one prepared at 1:2 molar ratio, for the production of agar films. A three-step process is proposed: pre-solubilization of polymer in DES followed by compression-molding and subsequent drying. The mechanical properties, water resistance and microstructure of the films were evaluated at different polymer concentrations (i.e. 2–6%, w/w). DES-U showed by far, the best film forming ability. Agreeing with the diffusion and SEM data, films with the best mechanical properties were found at the lowest and highest agar concentrations (tensile strengths of 24.2–42MPa and elongations of 15.4–38.9%). The water sorption and contact angle studies suggested increased hydrophilicity for the film containing the lowest concentration of agar. The use of choline chloride based ionic liquid analogues as solvent and plasticizer might be a promising tool for the development of new non-aqueous materials based on seaweed polysaccharides.