Gerald Fuller
Publication Details
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Influence of phase transition and photoisomerization on interfacial rheology.
Phys Rev E Stat Nonlin Soft Matter Phys. 2003; (4 Pt 1): 041601
This paper presents the shear responses and interfacial rheology of photosensitive monolayers. Langmuir films of a fatty acid containing an azobenzene moiety that can undergo trans-cis photoisomerization have been investigated for their structural and dynamical properties. The cis conformation produces a structureless, Newtonian film that cannot be oriented by surface flows. Transforming the molecule to the trans configuration produces a well-packed film that responds to flow with an anisotropic and non-Newtonian character. The trans state supports two separate phases, a low-pressure phase where the azobenzene group is free to rotate, and a high-pressure phase where this moiety is frozen in place.
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