Effect of Complex on Electrical Properties of Dendrimer Langmuir–Blodgett Films Containing 48 Pyridinealdoxime

Jung, Sang-Burm; Yoo, Seung-Yeop; Park, Eunmi; Kim, Chung-Kyun; Kwon, Young−Soo

doi:10.1143/jjap.41.3065

Cited by 8 publications

(5 citation statements)

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“…During the past few years there has been a considerable interest in the use of dendrimers as surface and interface active materials. The preparation of Langmuir films from amphiphilic dendrimers or monodendrons has been investigated by several research groups. − The Langmuir technique helps to access valuable information about the behavior of dendrimers at the air−water interface. Previous publications showed possible approaches to achieve surface activity for dendritic molecules, but none of them has described Langmuir films obtained from codendrimers.…”

Section: Introductionmentioning

confidence: 99%

Liquid Crystal Codendrimers with a Statistical Distribution of Phenolic and Mesogenic Groups: Behavior as Langmuir and Langmuir−Blodgett Films

et al. 2008

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The first series of carbosilane liquid crystal codendrimers with groups of different polarity has been synthesized. The chemical structure of the newly synthesized materials and the composition of the codendrimers were studied by NMR spectroscopy and MALDI-TOF MS. It was found that the codendrimers tend to form stable Langmuir films at the air-water surface. The influence of composition and generation number on surface pressure-surface area isotherms and film stability was studied. Brewster angle microscopy confirmed the different phase behavior for monolayers of different codendrimer composition and generation number. It was found that side groups of fifth-generation codendrimers do not segregate, unlike those of lower generations. Langmuir-Blodgett films on solid substrates were obtained by the vertical dipping method. X-ray diffraction showed that the codendrimers with 75% of hydrophobic mesogenic terminal groups formed ordered layers parallel to the substrate.

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Section: Introductionmentioning

confidence: 99%

Liquid Crystal Codendrimers with a Statistical Distribution of Phenolic and Mesogenic Groups: Behavior as Langmuir and Langmuir−Blodgett Films

et al. 2008

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“…The devices clearly exhibit rectifying behavior. We consider that the asymmetric structures are formed by the LB method [8]. The outmost functional groups are toward the subphase due to its flexibility at the air-water interface, because the azobenzene groups have a hydrophilic property.…”

Section: Resultsmentioning

confidence: 99%

“…The LB films were transferred onto slide glasses for the measurement of the electrical properties. For the determination of the electrical properties, an upper aluminium (Al) electrode with a diameter of 5[mm] was deposited on the film surface using the vacuum evaporation method to form an Al/dendrimer LB film/Al sandwich structure [8]. A DC power supply and an HP 3458A multimeter were used to measure current-voltage (I-V) characteristics.…”

Section: Experimentalsmentioning

confidence: 99%

“…We measured the I-V characteristics firstly of its trans form and secondly of its cis form after irradiation of 365[nm] light at the same position. The calculated resistivity values of trans form and cis form of G4-48Azo dendrimer are 6.604×10 7 and 8.655×10 8 [ ], respectively. The difference was originated from photo-isomerization of the azobenzene unit in the periphery of the dendrimer.…”

Section: Materials Science Forum Vols 449-452mentioning

confidence: 99%

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Electrical Properties of G4-48azo Dendrimer Containing Azobenzene Functional Groups

Jung

Yang²,

Yoo

et al. 2004

MSF

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In this study, we attempted to fabricate dendrimer Langmuir-Blodgett (LB) films functionalized with azobenzene groups in their periphery. It is well known that azoenzene-type compounds undergo an efficient and fully reversible photo-isomerization reaction. We investigated monolayer behavior and its characteristics at air-water interface by LB method. Then the molecular behavior shift of the monolayer by 365[nm] light irradiation was also measured because of the isomerization of azobenzene group in periphery. The electrical properties of G4-48Azo dendrimer were compared with between trans form and cis form using metal/dendrimer LB film/metal (MIM)structure and using STM system.

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“…[1][2][3][4][5] In particular, -conjugated dendrimers are one of the most promising materials because they show multi-functional properties such as electrical-and/or optical-properties, and high solubility with one molecule. [6][7][8][9][10][11][12] The dendrimer consists of a core, dendrons (branches), and surface groups. The core and the dendron define the key electrical-or opticalproperties such as carrier transport or light emission.…”

mentioning

confidence: 99%

Photocarrier Transport Property of Phenylene-vinylene Dendrimer Studied by Time-of-Flight Method

Mizusaki¹,

Yamahara²,

Yamada³

et al. 2009

Polym. J.

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The photocarrier transport property of the three-generation dendrimer, which is composed of phenylene-vinylene as the dendron group and triphenylamine as the surface group G3D3-PV(TPA), was studied by the time of flight (TOF) method using a sandwich-type cell of indium-tin-oxide (ITO)/G3D3-PV(TPA)/Mg-Al. The photocurrent decay shows that hole transport occurs stronger than electron transport, and dispersive transport is observed in the dendrimer film. The mobility at 25 C exhibits negative electric field dependence, and the intrinsic mobility at zero electric field is 7:1 Â 10 À5 cm 2 /(VÁs). This is faster than that of linear poly(p-phenylene-vinylene). Besides this, the result is one order smaller than that of poly(3-hexylthiophene), but faster than those of poly(3-dodecylthiophene) and poly(3-octadecylthiophene). The result indicates that one of the important parameters for the carrier transport is the average distance between -conjugated molecules. The fact that the carrier hopping of the G3D3-PV(TPA) dendrimer occurs effectively implies the structure would be a disk shape since the phenylene-vinylene dendron sites of the different dendrimer molecule are estimated to be close to each other. Recently, -conjugated polymer materials have attracted much interest as potential candidates for use in electro-optical devices, since they exhibit unique features such as flexibility, solubility, and easy film preparation with uniform thickness in large area.

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Effect of Complex on Electrical Properties of Dendrimer Langmuir–Blodgett Films Containing 48 Pyridinealdoxime

Cited by 8 publications

References 0 publications

Liquid Crystal Codendrimers with a Statistical Distribution of Phenolic and Mesogenic Groups: Behavior as Langmuir and Langmuir−Blodgett Films

Liquid Crystal Codendrimers with a Statistical Distribution of Phenolic and Mesogenic Groups: Behavior as Langmuir and Langmuir−Blodgett Films

Electrical Properties of G4-48azo Dendrimer Containing Azobenzene Functional Groups

Photocarrier Transport Property of Phenylene-vinylene Dendrimer Studied by Time-of-Flight Method

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