Aumaitre, E. and Knoche, S. and Cicuta, P. and Vella, D. (2012) Wrinkling in the deflation of elastic bubbles. EPL . (Submitted)

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Abstract
The protein hydrophobin HFBII selfassembles into very elastic films at the surface of water; these films wrinkle readily upon compression. We demonstrate and study this wrinkling instability in the context of nonplanar interfaces by forming HFBII layers at the surface of bubbles; the interfaces are then compressed by deflating the bubble. By varying the initial concentration of the hydrophobin solutions, we are able to show that buckling occurs at a critical packing fraction of protein molecules on the surface. Independent experiments show that at this packing fraction the interface has a finite positive surface tension, and not zero surface tension as is usually assumed at buckling. We attribute this nonzero wrinkling tension to the finite elasticity of these interfaces. We develop a simple geometrical model for the evolution of the wrinkle length with further deflation, and show that wrinkles start close to the needle used for deflation and grow rapidly towards the midplane of the bubble. This geometrical model yields predictions for the length of wrinkles in good agreement with experiments, independently of the rheological properties of the adsorbed layer.
Item Type:  Article 

Subjects:  D  G > General 
Research Groups:  Oxford Centre for Collaborative Applied Mathematics 
ID Code:  1571 
Deposited By:  Peter Hudston 
Deposited On:  27 Jul 2012 07:35 
Last Modified:  29 May 2015 19:16 
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