Homeotropic orientation of nematic liquid crystals induced by dissolving polypropyleneimine dendrimer having peripheral mesogens

Haba, Osamu; Hiratsuka, Daigo; Shiraiwa, Takenori; Funakoshi, Nami; Asanuma, Hiroshi; Koda, T.; Takahashi, Tatsuhiro; Yonetake, Koichiro; Kwak, Musun; Momoi, Yuichi; Kim, Nakwon; Hong, Sangpyo; Kang, Dongwoo; Choi, Youngseok

doi:10.1364/ome.4.000934

Cited by 33 publications

(18 citation statements)

References 24 publications

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“…Research groups from academic to business proposed recently different types of VA‐LCD self‐alignment . Jeng et al successfully fabricated VA‐LCDs without PI alignment layers by using LC‐mixture with silica‐based nanoparticles, polyhedral oligomeric silsesquioxanes (POSS) .…”

Section: Other Alignment Technologymentioning

confidence: 99%

“…Research groups from academic to business proposed recently different types of VA-LCD selfalignment. [246][247][248][249][250][251][252]255,256 Jeng et al successfully fabricated VA-LCDs without PI alignment layers by using LCmixture with silica-based nanoparticles, polyhedral oligomeric silsesquioxanes (POSS). 247 They found that the POSS modified by phenethyl groups induced vertical LC-alignment because of the interaction of phenethyl groups with the LC molecules.…”

Section: Latest Alignment Technologiesmentioning

confidence: 99%

“…251,252,256 Research for a homogeneous self-alignment has also started in the past few years. The reason is that IPS/FFS-LCD operating modes are mostly chosen for mobile, tablet, Light transmission type 244,245 Self-alignment VA 0.1~2 wt% Unpolarized UV irradiation Light transmission type [246][247][248][249][250][251][252] Self-alignment HA 0.1~2 wt% Polarized UV irradiation Light transmission type 253,254 and PC applications. These in-plane type homogeneouslyaligned (HA) modes are characterized by a wide viewing angle and high transmittance.…”

Section: Latest Alignment Technologiesmentioning

confidence: 99%

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Alignment control technology of liquid crystal molecules

Ishihara

Mizusaki

2019

J Soc Info Display

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Liquid crystal displays are now indispensable in everyday life. The display characteristics considerably depend on the configuration of liquid crystal (LC) molecules and interactions between the LC molecules and an alignment film surface. In this paper, we introduce various methods to control parameters that dominate the LC alignment. These parameters include order parameters, the pretilt angle, the director direction, and surface anchoring strength. We also introduce their evaluation methods. In particular, recent alignment film‐free technology is explained in detail. In addition, details of how these parameters are related to the display characteristics, particularly wide viewing angles and fast response characteristics, are described primarily with reference to recent technologies.

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Section: Other Alignment Technologymentioning

confidence: 99%

Section: Latest Alignment Technologiesmentioning

confidence: 99%

Section: Latest Alignment Technologiesmentioning

confidence: 99%

See 1 more Smart Citation

Alignment control technology of liquid crystal molecules

Ishihara

Mizusaki

2019

J Soc Info Display

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“…However, other researchers assign this peak to n = 1 [16] and the periodicity is concluded to a half the stretched molecular length. Hence, the surface structure could be Figure 4(b) [17] or Figure 4(c) [18]. Additional important information for the surface structure is that the surface with azodendrimers is optical second-harmonic generation (SHG) active.…”

Section: Application For Liquid Crystal Alignmentmentioning

confidence: 99%

Azodendrimers as a Functional Material

Takezoe¹,

Haba²

2018

Dendrimers - Fundamentals and Applications

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Dendrimers can behave as active functional materials, if they are substituted at their tail ends by azo groups. The dendrimers we developed spontaneously attach to interfaces or surfaces, providing us with a variety of functions. After describing the synthesis of dendrimers and azodendrimers, we first review functions for static uses; alignment surface for liquid crystals (LCs). Then, a major part of this review is devoted to the introduction for dynamic uses. Because of photo-induced trans-cis isomerization, the azodendrimers act as a command surface, which enables us to control LC orientation. Azodendrimer layers were formed at glass substrates, LC droplets in polymers, and surfaces of microparticles in LCs. Photo-controlled trans-and cis-forms, respectively, provide homeotropic and planar orientations of LCs. The photo-irradiation induces dewetting of dendrimer layers as well. Photo-induced orientation changes of LCs provide us with various applications and novel phenomena; photo-controlled macroscopic physical properties such as thermal transport, defect structure changes in LC colloids and LC systems with microinclusions, and even dynamics of inclusions in LCs.

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“…Self-alignment technologies without using conventional alignment layer materials have an advantage for fabrication process of liquid crystal displays (LCDs). The preparation of conventional alignment layers produced from polyimide (PI) films usually requires large quantities of solvents, heating process such as rubbing or UV exposure [1]. Moreover, adhesive force between the PI film and sealant is considerably weak [2].…”

Section: Introductionmentioning

confidence: 99%