Mass transport during coagulation of cellulose-ionic liquid solutions in different non-solvents
Artikel i vetenskaplig tidskrift, 2019

Cellulose can be regenerated from cellulose-ionic liquid (IL) solutions by immersion in water or alcohols. These compounds are potent non-solvents due to their proton-donating ability in hydrogen bonds to IL anions. Although they share this fundamental way of reducing IL solvent quality, coagulation in water is distinctly different from coagulation in alcohols with regard to the microstructures formed and the mechanisms that generate the microstructures. In this study, the possibility of mass-transport effects on microstructures was investigated. The mass-transport of all components: non-solvent (EtOH, 2PrOH), IL ([C2mim][OAc]), and a co-solvent (DMSO), during coagulation was studied. The data was compared to previous data with water as the non-solvent. Results showed that diffusion is essentially limited to a continuous non-solvent-rich phase that is formed during phase separation in all non-solvents. There were also significant differences between non-solvents. For instance, [C2mim][OAc] diffusion coefficients were 6–9 times smaller in 2PrOH than in water, and there were apparent effects from cellulose concentration in 2PrOH that were not observed in water. The differences stem from the interactions between solvent, non-solvents, and cellulose, which can be both mutual and competitive. Weaker [C2mim][OAc]-non-solvent interactions with alcohols give more persistent [C2mim][OAc]-cellulose interactions than with water as the non-solvent, which has consequences for mass-transport. Graphic abstract: [Figure not available: see fulltext.].

Coagulation

Ionic liquids

Alcohol

Mass transport

Non-solvent

Precipitation

Water

Cellulose

Författare

Artur Hedlund

Swerea IVF AB

Hans Theliander

Chalmers, Kemi och kemiteknik, Kemiteknik, Kemisk reaktionsteknik

Tobias Köhnke

Swerea IVF AB

Cellulose

0969-0239 (ISSN)

Vol. 26 16 8525-8541

Ämneskategorier

Polymerkemi

Fysikalisk kemi

Vattenteknik

DOI

10.1007/s10570-019-02649-w

Mer information

Senast uppdaterat

2019-11-08