Abstract

This article describes nanocomposite films with separately grown protein nanofibrils (PNFs) in a nonfibrillar protein matrix from the same protein starting material (whey). Tensile tests on the glycerol-plasticized films indicate an increased elastic modulus and a decreased extensibility with increasing content of PNFs, although the films are still ductile at the maximum PNF content (15 wt %). Infrared spectroscopy confirms that the strongly hydrogen-bonded beta-sheets in the PNFs are retained in the composites. The films appear with a PNF-induced undulated upper surface. It is shown that micrometer-scale spatial variations in the glycerol distribution are not the cause of these undulations. Instead, the undulations seem to be a feature of the PNF material itself. It was also shown that, apart from plasticizing the protein film, the presence of glycerol seemed to favor to some extent exfoliation of stacked beta-sheets in the proteins, as revealed by X-ray diffraction.

Keywords

Protein fibrils; Whey; Nanocomposite; Protein structure; Mechanical properties

Published in

ACS Sustainable Chemistry and Engineering
2018, Volume: 6, number: 4, pages: 5462-5469
Publisher: AMER CHEMICAL SOC

SLU Authors

• Langton, Maud

  • Department of Molecular Sciences, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Nano-technology
Polymer Technologies


Publication identifier

DOI: https://doi.org/10.1021/acssuschemeng.8b00330

Permanent link to this page (URI)

https://res.slu.se/id/publ/94987