The structures and photoreactions of the Langmuir and LB films of an amphiphilic spiropyran, 1′,3′-dihydro-3′,3′-dimethyl-6-nitro-1′-octadecyl-8-(docosanoyloxymethyl)spiro[2H-1-benzopyran-2,2′-(2H)-indole] (SP) are investigated. A chloroform solution of SP at a concentration of 0.1 mM is spread on the water surface. When the Langmuir film of SP is compressed on a subphase at 30°C and a phase transition takes place, the monolayer changes into a mosaic structure where bilayer domains are buried in the monolayer. When the Langmuir films are illuminated with UV light, SP is isomerized to merocyanine (MC). J-aggregates of MC are formed at high temperatures and at high surface pressures where the bilayer domains are formed. The Langmuir films of SP are transferred as LB films onto solid substrates at 30°C. The LB films consist of the bilayer domains with a diameter of 10 to 20 µm and a height of 4 to 5 nm. Three-dimensional structures are present in almost all the bilayer domains. Room-temperature illumination of the LB films with UV light produces the J-aggregation of MC with the development of dendritic structures starting from the three-dimensional structures in the domains. These dendrites consist of the J-aggregates. Molecules are aligned radially in the dendrites. When the LB film is illuminated at 7°C, the J-aggregation of MC does not proceed. All these results indicate that the criteria of the J-aggregation of MC in the Langmuir and LB films are the presence of the bilayer domains and the nucleation sites with the mobility of the molecules large enough for the morphological change necessary for the J-aggregation.

Highly conductive hybrid Langmuir-Blodgett (LB) films of MoS 2 and amphiphilic compounds such as alkylammonium halides and alkylamines were fabricated. The interlayer spacing of the LB films depended on the organic species. The lateral conductivity of 10layer LB films was in the range of 10 1 to 10 2 S cm -1 and decreased with an increase in interlayer spacing. The conductivity of 10 2 S cm -1 is the highest value for LB films reported so far. The conductivity of the LB films increased with the layer number and became constant when the layer number was sufficiently large. The conductivity was stable at room temperature even for single-layer LB films and decreased by less than an order of magnitude during four months.

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