Skip to main content Accessibility help
×
Home
Hostname: page-component-888d5979f-zxcqg Total loading time: 0.25 Render date: 2021-10-26T16:23:54.561Z Has data issue: true Feature Flags: { "shouldUseShareProductTool": true, "shouldUseHypothesis": true, "isUnsiloEnabled": true, "metricsAbstractViews": false, "figures": true, "newCiteModal": false, "newCitedByModal": true, "newEcommerce": true, "newUsageEvents": true }

Effects of Wetting and Desiccation on the Creep Properties of Spider Dragline Silk

Published online by Cambridge University Press:  01 February 2011

Joanne Ritchie
Affiliation:
Chemistry, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, Midlothian, Scotland
Christopher Smith
Affiliation:
Chemistry, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, Midlothian, Scotland
Fraser I. Bell
Affiliation:
Chemistry, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, Midlothian, Scotland
Iain J. McEwen
Affiliation:
Chemistry, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, Midlothian, Scotland
Christopher Viney
Affiliation:
School of Engineering, University of California at Merced, P.O. Box 2039, Merced, CA 95344, USA Chemistry, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, Midlothian, Scotland
Get access

Abstract

We have previously devised a simple method for quantifying the creep resistance of silk fibres – i.e. the ability of silk to maintain dimensional stability while supporting a constant load. We demonstrated (C. Smith et al., J. Arachnol. 31:421–424, 2003) that creep of spider dragline is significant at stresses that are small compared to the conventional yield strength. In addition, the existence of a limiting creep stress was revealed: if samples are loaded smoothly and quickly to a constant stress lying above the limiting creep stress, they break within a few seconds of the stress being applied. The magnitude of the limiting creep stress is equal to approximately one fifth of the fracture stress recorded in conventional constant strain rate tests (in which the stress is applied more gradually).

Here we develop the method and broaden the study of creep to investigate the effects of immersion in water and in ethanol. Experiments are conducted by attaching a small weight (an appropriate number of office staples) to an approximately 20 cm length of dragline from Nephila clavipes spiders, and monitoring extension as a function of time while the samples are suspended vertically in the liquid. The silk is previously conditioned (immersed without imposing any geometrical constraint) in the liquid, to allow it to supercontract or relax if the liquid promotes such a response. Allowance for buoyancy is made when calculating the net force applied to samples by the weight of the staples. Water is found to have a plasticizing effect; it exacerbates the rate of creep in response to a given small load, and it decreases the limiting creep stress. Ethanol, a desiccant, delays the transition from creep dominated by changes in chain conformation to creep dominated by chain slip, and increases the limiting creep stress. These results draw attention to an important limitation that must be overcome if biomimetic silk is to be used in applications where dimensional stability is required while loads are being supported for long times, especially in a wet environment. The results also point to the molecular origins of the creep sensitivity, and thus to ways of making silk and silk analogues less susceptible to creep.

Type
Research Article
Copyright
Copyright © Materials Research Society 2005

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Viney, C., J. Textile Inst. 91(3), 2, (2000).CrossRefGoogle Scholar
2. Lazaris, A., Arcidiacono, S., Huang, Y., Zhou, J.F., Duguay, F., Chretien, N., Welsh, E.A., Soares, J.W., Karatzas, C.N., Science 295, 472 (2002).CrossRefGoogle Scholar
3. Kubik, S., S., , Angew. Chem. Int. Ed. Engl. 41, 2721 (2002).3.0.CO;2-3>CrossRefGoogle Scholar
4. Smith, C., Ritchie, J., Bell, F.I., McEwen, I.J., Viney, C., J. Arachnol. 31, 421 (2003).CrossRefGoogle Scholar
5. Viney, C., Bell, F.I., Cur. Opin. Solid State Mater. Sci., 8, 165 (2004).CrossRefGoogle Scholar
6. Thiel, B., Kunkel, D., Guess, K., Viney, C., in Biomolecular Materials by Design, edited by Alper, M., Bayley, H., Kaplan, D., Navia, M., (Mater. Res. Soc. Proc. 330, Pittsburgh, PA, 1994) pp. 2130.Google Scholar
7. Foelix, R.F., Biology of Spiders, 1st ed. (Harvard University Press, Cambridge, MA, 1982).Google Scholar
8. Carmichael, S., Viney, C., J. Appl. Polym. Sci. 72, 895 (1999).3.0.CO;2-4>CrossRefGoogle Scholar
9. Bell, F.I., McEwen, I.J., Viney, C., Nature 416, 37 (2002).CrossRefGoogle Scholar
10. Eles, P.T., Michal, C.A., Macromolecules 37, 1342 (2004).CrossRefGoogle Scholar

Send article to Kindle

To send this article to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about sending to your Kindle.

Note you can select to send to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Effects of Wetting and Desiccation on the Creep Properties of Spider Dragline Silk
Available formats
×

Send article to Dropbox

To send this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Dropbox.

Effects of Wetting and Desiccation on the Creep Properties of Spider Dragline Silk
Available formats
×

Send article to Google Drive

To send this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Google Drive.

Effects of Wetting and Desiccation on the Creep Properties of Spider Dragline Silk
Available formats
×
×

Reply to: Submit a response

Please enter your response.

Your details

Please enter a valid email address.

Conflicting interests

Do you have any conflicting interests? *