Alcohol induced gelation of TEMPO-oxidized cellulose nanofibril dispersions

被引：0

作者：

Da Silva M.A. ^{[1
]}

Calabrese V. ^{[1
]}

Schmitt J. ^{[1
]}

Celebi D. ^{[1
,2
]}

Scott J.L. ^{[1
,2
]}

Edler K.J. ^{[1
]}

机构：

[1] Department of Chemistry, University of Bath, Claverton Down, Bath

[2] Centre for Sustainable Chemical Technologies, University of Bath, Claverton Down, Bath

来源：

Da Silva, Marcelo A. (m.alves.da.silva@bath.ac.uk) | 2018年 / Royal Society of Chemistry卷 / 14期

基金：

英国工程与自然科学研究理事会;

关键词：

The authors thank EPRSC for funding this project (grant EP/N033310/1). V. Calabrese thanks the University of Bath for supporting his PhD. We thank the Diamond Light Source for access to beamline I22 (SM16364-1) that contributed to the results presented here; and we would like to thank Dr N. Terrill and Dr A. Smith for their assistance with the experiment on beamline I22;

D O I：

10.1039/C8SM01815D

中图分类号：

学科分类号：

摘要：

Solvent-induced physical hydrogels of TEMPO-oxidized cellulose nanofibrils (OCNFs) were obtained from aqueous/alcoholic dispersions of fibrils in lower alcohols, namely, methanol, ethanol, 1-propanol and 2-propanol. The sol-gel transition occurs above a critical alcohol concentration of ca. 30 wt% for all alcohols tested. The rheological properties of the hydrogels depend on the nature of the alcohol: for ethanol, 1-propanol and 2-propanol the magnitude of the shear storage modulus follows the alcohol hydrophilicity, whilst methanol produces the weakest gels in the group. Above a second critical concentration, ca. 60 wt% alcohol, phase separation is observed as the gels undergo syneresis. Analysis of small-angle X-ray scattering data shows that the OCNFs may be modelled as rigid rods. In the presence of lower alcohols, attractive interactions between nanofibrils are present and, above the alcohol concentration leading to gelation, an increase of the OCNF cross-section is observed, suggesting alcohol induced aggregation of nanofibrils. © The Royal Society of Chemistry.

引用

页码：9243 / 9249

页数：6