Unique gelation and rheological properties of the cellulose/CO2-based reversible ionic liquid/DMSO solutions

Lihua Zhang; Wentao Shi; Junqin Wang; Longming Jin; Gang Hu; Qiang Zheng; Haibo Xie; Peng Chen

doi:10.1016/j.carbpol.2019.115024

Unique gelation and rheological properties of the cellulose/CO₂-based reversible ionic liquid/DMSO solutions

Carbohydr Polym. 2019 Oct 15:222:115024. doi: 10.1016/j.carbpol.2019.115024. Epub 2019 Jun 25.

Authors

Lihua Zhang¹, Wentao Shi², Junqin Wang¹, Longming Jin¹, Gang Hu¹, Qiang Zheng¹, Haibo Xie³, Peng Chen⁴

Affiliations

¹ Department of Polymer Materials and Engineering, College of Materials and Metallurgy, Guizhou University, Guiyang, 550025, China.
² Zhejiang Key Laboratory of Bio-Based Polymeric Materials Technology and Application, Ningbo Key Laboratory of Polymer Materials, Ningbo Institute of Materials Technology and Engineering (NIMTE), CAS, Ningbo, 315201, China.
³ Department of Polymer Materials and Engineering, College of Materials and Metallurgy, Guizhou University, Guiyang, 550025, China. Electronic address: hbxie@gzu.edu.cn.
⁴ Zhejiang Key Laboratory of Bio-Based Polymeric Materials Technology and Application, Ningbo Key Laboratory of Polymer Materials, Ningbo Institute of Materials Technology and Engineering (NIMTE), CAS, Ningbo, 315201, China. Electronic address: pchen@nimte.ac.cn.

PMID: 31320088
DOI: 10.1016/j.carbpol.2019.115024

Abstract

Gelation and rheological behaviors of cellulose/CO₂-based reversible ionic liquid (RIL)/DMSO solutions were investigated. The exponents of specific viscosity η_sp versus concentration c were determined for wood pulp (WP) and microcrystalline cellulose (MCC) solutions. The complex viscosity acquired using oscillatory shear closely follows the steady shear viscosity, thus revealing the applicability of Cox-Merz rule. The influence of RIL content in the solvent on apparent viscosities, activation energy, intrinsic viscosities, specific viscosity-c[η] master curve, and relaxation time were also investigated. Gelation occurred in this cellulose solution system due to thermal-induced CO₂ release from the decomposition of the CO₂-based reversible ionic liquid. The formed gel was stable in air, but re-dissolved when exposed to CO₂, indicating the switch-on and switch-off effects of CO₂ in cellulose dissolution and gelation.

Keywords: CO(2); Cellulose; Reversible ionic liquid; Rheological properties; Viscoelasticity.