INTERFACIAL MECHANICAL PROPERTIES AT EQUILIBRIUM OF FUNCTIONALIZED ZnO QUANTUM DOTS MONOLAYERS AT THE AIR/WATER INTERFACE

We report the structure and Young's modulus of switchable films formed by peptide self-assembly at the air–water interface. Peptide surfactant AM1 forms an interfacial film that can be switched, reversibly, from a high- to low-elasticity state, with rapid loss of emulsion and foam stability. Using neutron reflectometry, we find that the AM1 film comprises a thin (approx. 15 Å) layer of ordered peptide in both states, confirming that it is possible to drastically alter the mechanical properties of an interfacial ensemble without significantly altering its concentration or macromolecular organization. We also report the first experimentally determined Young's modulus of a peptide film self-assembled at the air–water interface ( E =80 MPa for AM1, switching to E <20 MPa). These findings suggest a fundamental link between E and the macroscopic stability of peptide-containing foam. Finally, we report studies of a designed peptide surfactant, Lac21E, which we find forms a stronger switchable film than AM1 ( E =335 MPa switching to E <4 MPa). In contrast to AM1, Lac21E switching is caused by peptide dissociation from the interface (i.e. by self-disassembly). This research confirms that small changes in molecular design can lead to similar macroscopic behaviour via surprisingly different mechanisms.

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Characterization and 2D Self-Assembly of CdSe Quantum Dots at the Air−Water Interface

Journal of the American Chemical Society ◽

10.1021/ja0514848 ◽

2005 ◽

Vol 127 (42) ◽

pp. 14640-14646 ◽

Cited By ~ 70

Author(s):

Kerim M. Gattás-Asfura ◽

Celeste A. Constantine ◽

Matthew J. Lynn ◽

Daniel A. Thimann ◽

Xiaojun Ji ◽

...

Keyword(s):

Quantum Dots ◽

Self Assembly ◽

Cdse Quantum Dots ◽

Water Interface ◽

Air Water Interface

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CdSe magic-sized quantum dots incorporated in biomembrane models at the air–water interface composed of components of tumorigenic and non-tumorigenic cells

Biochimica et Biophysica Acta (BBA) - Biomembranes ◽

10.1016/j.bbamem.2016.04.009 ◽

2016 ◽

Vol 1858 (7) ◽

pp. 1533-1540 ◽

Cited By ~ 6

Author(s):

Thiago E. Goto ◽

Carla C. Lopes ◽

Helena B. Nader ◽

Anielle C.A. Silva ◽

Noelio O. Dantas ◽

...

Keyword(s):

Quantum Dots ◽

Water Interface ◽

Air Water Interface ◽

Tumorigenic Cells

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Linear and nonlinear microrheology of lysozyme layers forming at the air–water interface

Soft Matter ◽

10.1039/c4sm00484a ◽

2014 ◽

Vol 10 (36) ◽

pp. 7051-7060 ◽

Cited By ~ 22

Author(s):

Daniel B. Allan ◽

Daniel M. Firester ◽

Victor P. Allard ◽

Daniel H. Reich ◽

Kathleen J. Stebe ◽

...

Keyword(s):

Mechanical Properties ◽

Water Interface ◽

Nonlinear Mechanical ◽

Air Water Interface ◽

Linear And Nonlinear

Microrheology tracks the evolution in the linear and nonlinear mechanical properties of layers of the protein lysozyme adsorbing at the air–water interface as the layers undergo a viscoelastic transition.

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