Wortmann, FJ, Jones, C, Davies, TJ orcid.org/0000-0002-2027-6237 et al. (1 more author) (2021) Perm-waved human hair: A thermo-rheologically complex, shape-memory composite. Biophysical Journal, 120 (17). pp. 3831-3840. ISSN 0006-3495
Abstract
A “permanent” bent shape can be imposed on a straight human hair by a two-stage reduction/oxidation (perm-waving) process. The process relies on the molecular level on sulfhydryl/disulfide interchange as bond exchange reaction (BER). We expected a well-documented transition temperature around 60°C to be the trigger for the shape memory (SM) process of perm-waved hair. We confirm the existence of the SM process as such and investigate its time and temperature dependence. The results show a two-stage SM behavior, implying two distinct variations of the BER. The model to fit the data contains two fractional, normalized, elastic bending rigidities, which are strictly compensatory. They show Arrhenius-type temperature dependence and a common activation energy (EA) of ∼−12 kJ/mol. The characteristic relaxation time for the first SM process shows little, if any, temperature dependence (EA = −4 ± 2.7 kJ/mol). This is in contrast to the second process (EA = −58 ± 5.5 kJ/mol) but in line with the expected properties of the suggested BERs. None of the parameters shows any sign of the expected trigger transition (∼60°C). We hypothesize that this specific transition occurs only for large tensile deformations, when specific SS bonds in the intermediate filaments of hair are activated. There is thus no specific “trigger” transition for the SM behavior of bent, perm-waved hair.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2021 Biophysical Society. This is an author produced version of an article, published in Biophysical Journal. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | human hair; permanent bending deformation; shape memory polymer; thermo-rheologically complex behaviour |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Arts, Humanities and Cultures (Leeds) > School of Design (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 17 Aug 2021 10:24 |
Last Modified: | 16 Jan 2023 16:16 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.bpj.2021.03.044 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:177117 |
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