Diacetylenes multilayer assemblies

Table 3. List of dyes used as sensitizers for photopolymerization of diacetylene multilayer assemblies. (R —(CH2)S- CH3 the counterion was I ) and their absorption maxima...

Fig. 20. Comparison between UV-absorption spectra of a paraffinsubstitiled diacetylene (m = 8, n = 8) incorporated in a multilayer assembly and the action spectrum of photopolymerization (from Ref.

The range of potential sensitizers for photopolymerization of diacetylenes widened considerably when Wegner and coworkers discovered sensitized photopolymerization in LB-multilayer systems doped with certain dyes. It is known for long that dye molecules carrying long aliphatic substituents can easily be incorporated into LB-multilayer assemblies without destroying the sample architecture Therefore, the topotactic requirements for the polymerization reaction to proceed are retained. 

A modification of the sequential polyelectrolyte multilayer fabrication strategy uses small molecule bipolar amphiphiles in place of polymers [53,74-76]. Many tens of layers of small molecules can be stacked by alternate adsorption, approaching total layer thicknesses between 150 and 200 nm. Organization in these multilayers is reduced over that observed in polyelectrolyte multilayers. This order as well as stability can be improved by hybrid structures comprising alternating bipolar am-phiphile and polyelectrolyte charged layers [53], Bipolar diacetylenes can also be utilized [77, 78], providing interlayer stabilization via photopolymerization after multilayer assembly. 

Saremi, F., et al.. Self-assembled alternating multilayers built-up from diacetylene... 

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