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Ciencia de las fibras: esfuerzo de supercontracción en dragline de araña húmeda
Fraser I Bell1, Iain J McEwen, Christopher Viney
1Department of Chemistry, Heriot-Watt University, Edinburgh EH14 4AS, UK. c.viney@hw.ac.uk
Nature
|March 8, 2002
Resumen
La seda de araña se contrae cuando está mojada, reduciéndose significativamente. Una nueva investigación muestra que estas tensiones de contracción son transitorias y más altas de lo esperado, lo que potencialmente limita la seda.
Área de la Ciencia:
- Ciencia de los biomateriales ciencia de los biomateriales.
- Ciencia de los materiales ciencia de los materiales.
- La ciencia textil es la ciencia de los textiles.
Sus antecedentes:
- La seda de dragline de araña exhibe un fenómeno único de "supercontracción" cuando se expone a la humedad.
- Esta supercontracción implica cambios significativos en la longitud y el diámetro de la seda.
- Investigaciones anteriores han explorado las implicaciones de este fenómeno para la funcionalidad de la tela de araña.
Objetivo del estudio:
- Para cuantificar las tensiones transitorias de supercontracción en la seda de dragline de araña al mojarse inicialmente.
- Reevaluar el papel de la supercontracción en el mantenimiento de la tensión de la red en condiciones húmedas.
- Evaluar el impacto de la supercontracción en la capacidad de carga de la seda y sus análogos sintéticos.
Principales métodos:
- Pruebas mecánicas de las fibras de seda de dragline de araña.
- Exposición controlada a la humedad para inducir la supercontracción.
- Medición de la generación de estrés transitorio durante la fase inicial de humedecimiento.
Principales resultados:
- La seda de dragline de araña sufre una reducción significativa de la longitud y un aumento del diámetro al mojarse.
- Las tensiones de supercontracción son transitorias, lo que significa que disminuyen con el tiempo.
- Las tensiones medidas son mayores de lo estimado previamente, lo que desafía las hipótesis existentes.
- Los hallazgos sugieren que la supercontracción puede no ayudar a mantener la tensión de la red cuando está mojada.
Conclusiones:
- La magnitud transitoria y alta de las tensiones de supercontracción en la seda de araña cuestiona su papel en la tensión de la tela húmeda.
- Estos hallazgos pueden limitar las aplicaciones potenciales de los materiales naturales y sintéticos a base de seda en escenarios de carga.
- Se necesitan más investigaciones para comprender completamente el comportamiento mecánico de la seda bajo diferentes condiciones de humedad.
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