Azobenzene surface mass transport

It should be emphasized here that the grating schematized in Fig. 11.1 is a volume grating, that is, the index change occurs throughout the thickness direction of the film. Upon exposure to an interference pattern with no mask, a remarkable property of azobenzene polymers is the formation of surface relief grating (SRG) as a result of a mass transport triggered by the trans-cis photoisomerization (Kim et ah, 1995 Rochon et al., 1995). As reviewed in Chapters 4 and 8 there has been a... 

Fonnation of surface relief grating (SRG) by irradiation of amorphous films of azobenzene-fiinctionalized acrylate, methacrylate, and qroxy-based polymers with two coherent laser beams has been a topic of current inteiest/ SRG, which is formed by the mass transport induced by the photoismnerization of the azobenzene chromqrhore, rrtay find potential applications fw oasable and rewritable hologr hic memoy, polarization discriminators, and waveguide couplors. 

Light control of dynamic surface tension was demonstrated in a mixture of sodium dodecylsulfate and 4,4 -bis(trimethylammonium)hexyloxyazobenzene bromide. A decrease of 25 mN/m was determined on E—>Z isomerization by UV irradiation. Aggregation in the bulk and mass transport of the surfactant to the surface of the solution differ between the isomers. This phenomenon can be used to trigger the release of droplets of aqueous solutions from capillaries. Calix[4]resocinarene derivatives substituted with azobenzenes exhibited reversible precipitation/dissolution in dilute methanol solution upon alternate UV and VIS light irradiation due to the low solubility of the -trans isomer. ... 

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