From Basic Principles of Protein–Polysaccharide Association to the Rational Design of Thermally Sensitive Materials
-
1.
California Institute of Technology
Abstract
Biology resolves design requirements toward functional materials by creating nanostructured composites, where individual components are combined to maximize the macroscale material performance. A major challenge in utilizing such design principles is the trade-off between the preservation of individual component properties and emerging composite functionalities. Here, polysaccharide pectin and silk fibroin were investigated in their composite form with pectin as a thermal-responsive ion conductor and fibroin with exceptional mechanical strength. We show that segregative phase separation occurs upon mixing, and within a limited compositional range, domains ∼50 nm in size are formed and distributed homogeneously so that decent matrix collective properties are established. The composite is characterized by slight conformational changes in the silk domains, sequestering the hydrogen-bonded β-sheets as well as the emergence of randomized pectin orientations. However, most dominant in the composite’s properties is the introduction of dense domain interfaces, leading to increased hydration, surface hydrophilicity, and increased strain of the composite material. Using controlled surface charging in X-ray photoelectron spectroscopy, we further demonstrate Ca ions (Ca2+) diffusion in the pectin domains, with which the fingerprints of interactions at domain interfaces are revealed. Both the thermal response and the electrical conductance were found to be strongly dependent on the degree of composite hydration. Our results provide a fundamental understanding of the role of interfacial interactions and their potential applications in the design of material properties, polysaccharide–protein composites in particular.
Acknowledgement
© 2024 The Authors. Published by American Chemical Society. This publication is licensed under CC-BY 4.0.
Acknowledgement
The authors are grateful to Dr. Anna Kossoy and Dr. Yishay (Isai) Feldman, Powder Diffraction Laboratory, Department of Chemical Research Support Faculty of Chemistry, Weizmann Institute of Science Rehovot, Israel, for performing WAXD and XRD measurements. The authors are grateful to Steve Manch for editing the manuscript.
Funding
U.S. and C.D. thank Schwartz/Reisman for supporting the CalTech-WIS collaborative research. U.S. acknowledges financial support from the Gruber Foundation, the Nella and Leon Benoziyo Center for Neurological Diseases. In addition, U.S. thanks the Perlman family for funding the Shimanovich Lab at the Weizmann Institute of Science, Israel: “This research is made possible in part by the historic generosity of the Harold Perlman Family”. This work was also supported by a research grant from the Anita James Rosen Foundation, the Weizmann Institute of Science, Israel. The authors acknowledge partial support from the GMJ Schmidt Minerva Centre of Supramolecular Architectures at the Weizmann Institute, Mondry Family Fund for University of Michigan/Weizmann collaboration, Gerald Schwartz and Heather Reisman Foundation, and WIS Sustainability and Energy Research Initiative (SAERI). H.D.W. is the recipient of the Livio Norzi Professorial Chair in Materials Science.
Contributions
A.R. and A.S. contributed equally. H.C., D.E., I.K., O.B., A.K., and L.W. carried out experiments. A.R., A.S., H.C., D.E., I.K., O.B., A.K., L.W., H.D.W., C.D., and U.S. analyzed the data. A.S., H.C., C.D., and U.S. designed research. A.R., A.S., H.C., I.K., H.D.W., C.D., and U.S. wrote the paper.
Conflict of Interest
The authors declare no competing financial interest.
Data Availability
Schemes of film fabrication; full FT-IR spectra of the films; XPS spectra of the materials; rheological analysis of the liquid materials; ζ-potential measurements of the liquid materials; contact angle measurements; thermogravimetric analysis of the films; schemes of the electrical measurements; changes of the electrical properties of the films at different conditions of humidity and temperature; XPS spectra of pure pectin; and time-dependent XPS spectra of the films (PDF)
Files
| Name | Size | Download all |
|---|---|---|
|
md5:b7ac92d559514a6474d61ef963228d5c
|
2.8 MB | Preview Download |
|
md5:42339ada70985049351096b66a7c607b
|
10.2 MB | Preview Download |
Additional details
- ISSN
- 1944-8252
- PMCID
- PMC10895586
- California Institute of Technology
- Weizmann Institute of Science
- Gruber Foundation
- Anita James Rosen Foundation
- Council for Higher Education