Recently, we have found that the hydrothermal treatment (HTT), which is a heat treatment under relative humidity of 100%, is

effective for controlling the dye aggregation states when it is applied to the well-known MS-C20 binary LB film [16–26]. The as-deposited J-band originally located around 590 nm is reorganized by HTT to form a new phase associated with a further narrowing and a red shift of the peak [16–26]. We have already investigated kinetics of hydrothermally induced reorganization of J-aggregate in the mixed MS-C20 LB system and have pointed out that the UV-visible absorption spectra can be deconvoluted to three components: Band I (centered at 500 to 515 nm), Band II (centered at 545 to 555 nm), and Band III (centered at 590 to 598 nm) [17, 19, 22, 26]. Band I, JQ-EZ-05 purchase Lenvatinib ic50 Band II, and Band III are assigned as the blue-shifted dimer, monomer, and red-shifted J-aggregate, respectively. www.selleckchem.com/products/iwr-1-endo.html Furthermore, the HTT process consists of following two stages. The first stage is characterized by the decrease in the Band III component

associated with the increase in the Band I component, which is hypothesized as a dissociation process of the original J-aggregate (Band III centered at 590 nm) to the blue-shifted dimer (centered at 500 to 515 nm). The second stage is characterized as the reorganization of Band III (centered at 597 to 599 nm) from Band I (500 to 515 nm). Since the component of Band II (centered Demeclocycline at 545 to 555 nm) is almost unchanged throughout the whole HTT process, we have described that the growth and decay processes in the second stage are assumed to be a first-order reaction between Band I and Band III components [22, 26]. We have also reported that the HTT process induces a unique superstructure in the MS-C20 binary LB systems [18, 20–25]. Giant round-shaped domains with diameters reaching 100 μm are observed by optical microscopy. In those papers, we have touched

upon the sizes of the round-shaped domains depending on heating temperature (T H) and heating time (t H) and found that the average size of the domains tends to increase superlinearly depending on T H and t H. However, due to insufficient color sensitivity and resolution of the optical microscope used for the observation, the surface structure had not been characterized in detail [18, 20–25]. Since J-aggregate is known to emit intense fluorescence, fluorescence (FL) microscopy is considered to be a powerful tool to characterize the system. In this paper, we report on surface morphology of the MS-C20 binary LB films before and after HTT process combining bright field (BF) microscopy and FL microscopy and discuss the possible mechanisms of the J-aggregate reorganization. Methods Fabrication of the mixed LB films of Merocyanine and arachidic acid The film-forming materials, merocyanine dye (MS in Figure 1) and arachidic acid (C20 in Figure 1), were purchased from Hayashibara Biochemical Lab. Inc. (Okayama, Japan) and Fluka AG (St.