Limits...
Generation of disk-like domains with nanometer scale thickness in merocyanine dye LB film induced by hydrothermal treatment.

Miura YF, Sano M, Sugimoto T - Nanoscale Res Lett (2013)

Bottom Line: The molecular order of MS in the J-aggregate is improved by the HTT process leading to the significant sharpening of the band shape together with the further red shift of the band (from 590 to 594 nm up to 597 to 599 nm).The reorganized J-band is considered to be 'apparently' isotropic owing to the random growth of the J-aggregate in the film plane.We consider that the lubrication effect by the presence of water molecules predominates in the HTT process.

View Article: PubMed Central - HTML - PubMed

Affiliation: Graduate School of Engineering, Toin University of Yokohama, 1614 Kurogane-cho, Aoba, Yokohama 225-8503, Japan. yfmiura@toin.ac.jp.

ABSTRACT
We have characterized the binary LB films of merocyanine dye (MS) and arachidic acid (C20) before and after hydrothermal treatment (HTT), which is defined as a heat treatment under relative humidity of 100%, focusing on the morphology studied by bright field (BF) microscopy and fluorescence (FL) microscopy. BF microscopy observation has revealed that the as-deposited MS-C20 binary LB film is found to emit intense red fluorescence over the whole film area by 540-nm excitation. Since the surface image is almost featureless, it is considered that the crystallite sizes of J-aggregate are less than 10 μm. Interestingly, after HTT, round-shaped domains are observed in the LB systems, and the sizes are reaching 100 μm in diameter. Crystallites of J-aggregate, which are bluish in color and emit intense red fluorescence, tend to be in the round domains. We have observed two different types of domains, i.e., blue-rimmed domains and white-rimmed domains, which are postulated to be confined in the inner layers and located at the outermost layer, respectively. The thickness of the domains is equal to or less than that of the double layer of the MS-C20 mixed LB film, which is ca. 5.52 nm. The molecular order of MS in the J-aggregate is improved by the HTT process leading to the significant sharpening of the band shape together with the further red shift of the band (from 590 to 594 nm up to 597 to 599 nm). The reorganized J-band is considered to be 'apparently' isotropic owing to the random growth of the J-aggregate in the film plane. We consider that the lubrication effect by the presence of water molecules predominates in the HTT process.

No MeSH data available.


A BF microscopy image and the FL microscopy image of the MS-C20 mixed LB film. A BF microscopy image (a) and the FL microscopy image (red fluorescent image with 540-nm excitation) (b) of the MS-C20 mixed LB film of four layers after HTT (80°C, 60 min) with the schematic layered structure (c). The surface of the MS-C20 binary LB film is covered by a double layer of cadmium arachidate.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4016519&req=5

Figure 7: A BF microscopy image and the FL microscopy image of the MS-C20 mixed LB film. A BF microscopy image (a) and the FL microscopy image (red fluorescent image with 540-nm excitation) (b) of the MS-C20 mixed LB film of four layers after HTT (80°C, 60 min) with the schematic layered structure (c). The surface of the MS-C20 binary LB film is covered by a double layer of cadmium arachidate.

Mentions: Then, we reduced the number of layers in order to further investigate the microstructure and the thickness of the round-shape domains. Figure 7 shows a BF microscopy image (a) and the FL microscopy image (red fluorescent image with 540-nm excitation) (b) of the MS-C20 mixed LB film of four layers after HTT (80°C, 60 min) together with the schematic layered structure (c). As shown in Figure 7c, the outermost layer of the MS-C20 mixed LB film is covered by a double layer of cadmium arachidate (C20) for stability. Round-shaped domains are also observed by BF microscopy and FL microscopy. However, as seen in Figure 7a, rims of the domains are featureless compared to those observed in the ten-layered MS-C20 mixed LB systems. As shown by white schematic rims drawn in Figure 7b, a twofold stack is recognized. Thus, we further estimate that the average thickness of domains corresponds to a double layer or one single monolayer, i.e., <5 to 6 nm.


Generation of disk-like domains with nanometer scale thickness in merocyanine dye LB film induced by hydrothermal treatment.

Miura YF, Sano M, Sugimoto T - Nanoscale Res Lett (2013)

A BF microscopy image and the FL microscopy image of the MS-C20 mixed LB film. A BF microscopy image (a) and the FL microscopy image (red fluorescent image with 540-nm excitation) (b) of the MS-C20 mixed LB film of four layers after HTT (80°C, 60 min) with the schematic layered structure (c). The surface of the MS-C20 binary LB film is covered by a double layer of cadmium arachidate.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4016519&req=5

Figure 7: A BF microscopy image and the FL microscopy image of the MS-C20 mixed LB film. A BF microscopy image (a) and the FL microscopy image (red fluorescent image with 540-nm excitation) (b) of the MS-C20 mixed LB film of four layers after HTT (80°C, 60 min) with the schematic layered structure (c). The surface of the MS-C20 binary LB film is covered by a double layer of cadmium arachidate.
Mentions: Then, we reduced the number of layers in order to further investigate the microstructure and the thickness of the round-shape domains. Figure 7 shows a BF microscopy image (a) and the FL microscopy image (red fluorescent image with 540-nm excitation) (b) of the MS-C20 mixed LB film of four layers after HTT (80°C, 60 min) together with the schematic layered structure (c). As shown in Figure 7c, the outermost layer of the MS-C20 mixed LB film is covered by a double layer of cadmium arachidate (C20) for stability. Round-shaped domains are also observed by BF microscopy and FL microscopy. However, as seen in Figure 7a, rims of the domains are featureless compared to those observed in the ten-layered MS-C20 mixed LB systems. As shown by white schematic rims drawn in Figure 7b, a twofold stack is recognized. Thus, we further estimate that the average thickness of domains corresponds to a double layer or one single monolayer, i.e., <5 to 6 nm.

Bottom Line: The molecular order of MS in the J-aggregate is improved by the HTT process leading to the significant sharpening of the band shape together with the further red shift of the band (from 590 to 594 nm up to 597 to 599 nm).The reorganized J-band is considered to be 'apparently' isotropic owing to the random growth of the J-aggregate in the film plane.We consider that the lubrication effect by the presence of water molecules predominates in the HTT process.

View Article: PubMed Central - HTML - PubMed

Affiliation: Graduate School of Engineering, Toin University of Yokohama, 1614 Kurogane-cho, Aoba, Yokohama 225-8503, Japan. yfmiura@toin.ac.jp.

ABSTRACT
We have characterized the binary LB films of merocyanine dye (MS) and arachidic acid (C20) before and after hydrothermal treatment (HTT), which is defined as a heat treatment under relative humidity of 100%, focusing on the morphology studied by bright field (BF) microscopy and fluorescence (FL) microscopy. BF microscopy observation has revealed that the as-deposited MS-C20 binary LB film is found to emit intense red fluorescence over the whole film area by 540-nm excitation. Since the surface image is almost featureless, it is considered that the crystallite sizes of J-aggregate are less than 10 μm. Interestingly, after HTT, round-shaped domains are observed in the LB systems, and the sizes are reaching 100 μm in diameter. Crystallites of J-aggregate, which are bluish in color and emit intense red fluorescence, tend to be in the round domains. We have observed two different types of domains, i.e., blue-rimmed domains and white-rimmed domains, which are postulated to be confined in the inner layers and located at the outermost layer, respectively. The thickness of the domains is equal to or less than that of the double layer of the MS-C20 mixed LB film, which is ca. 5.52 nm. The molecular order of MS in the J-aggregate is improved by the HTT process leading to the significant sharpening of the band shape together with the further red shift of the band (from 590 to 594 nm up to 597 to 599 nm). The reorganized J-band is considered to be 'apparently' isotropic owing to the random growth of the J-aggregate in the film plane. We consider that the lubrication effect by the presence of water molecules predominates in the HTT process.

No MeSH data available.