scholarly journals Linearly Polarized UV Light-Induced Optical Anisotropy of PVA Films and Flexible Macrocycle Schiff Base Ni(II), Cu(II), Zn(II) Dinuclear Complexes

Symmetry ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 760
Author(s):  
Masahiro Takase ◽  
Shiomi Yagi ◽  
Tomoyuki Haraguchi ◽  
Shabana Noor ◽  
Takashiro Akitsu
Keyword(s):  
Optical Anisotropy ◽  
Molecular Orientation ◽  
Soft Matter ◽  
Uv Light ◽  
Polarized Light ◽  
X Ray ◽  
Crystallographic Symmetry ◽  
Linearly Polarized ◽  
Dinuclear Metal Complexes ◽  
Crystal Structural

Three dinuclear metal complexes (comprised of six-coordinated nNi2L and five-coordinated nCu2L and nZn2L) were confirmed by means of elemental analysis, UV-vis and IR spectra, and single X-ray crystal structural analysis in a spectroscopic study. The stable structures of these nNi2L, nCu2L, and nZn2L complexes in poly(vinylalcohol) (PVA) films were analyzed using UV-vis spectra. The molecular orientation of hybrid PVA film materials after linearly polarized light irradiation was analyzed to obtain the polarized spectra and dichroic ratio. Among the three materials, nNi2L and nZn2L complexes indicated an increasing optical anisotropy that depended on the flexibility of the complexes. We have included a discussion on the formation of the pseudo-crystallographic symmetry of the components in a soft matter (PVA films).

scholarly journals Ultrafast isomerization-induced cooperative motions to higher molecular orientation in smectic liquid-crystalline azobenzene molecules

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Masaki Hada ◽  
Daisuke Yamaguchi ◽  
Tadahiko Ishikawa ◽  
Takayoshi Sawa ◽  
Kenji Tsuruta ◽  
...  
Keyword(s):  
Molecular Orientation ◽  
Soft Matter ◽  
Liquid Crystalline ◽  
Laser Polarization ◽  
Time Resolved ◽  
Cooperative Motion ◽  
Subsequent Response ◽  
Molecular Dynamics Calculations ◽  
Polarization Axis ◽  
Linearly Polarized

Abstract The photoisomerization of molecules is widely used to control the structure of soft matter in both natural and synthetic systems. However, the structural dynamics of the molecules during isomerization and their subsequent response are difficult to elucidate due to their complex and ultrafast nature. Herein, we describe the ultrafast formation of higher-orientation of liquid-crystalline (LC) azobenzene molecules via linearly polarized ultraviolet light (UV) using ultrafast time-resolved electron diffraction. The ultrafast orientation is caused by the trans-to-cis isomerization of the azobenzene molecules. Our observations are consistent with simplified molecular dynamics calculations that revealed that the molecules are aligned with the laser polarization axis by their cooperative motion after photoisomerization. This insight advances the fundamental chemistry of photoresponsive molecules in soft matter as well as their ultrafast photomechanical applications.

scholarly journals Influence of Molecular Orientation on the Melting Behavior of Poly(phenylene sulfide) Fibers

2013 ◽  
Vol 8 (3) ◽  
pp. 155892501300800
Author(s):  
Prabhakar Gulgunje ◽  
Gajanan Bhat ◽  
Joseph Spruiell
Keyword(s):  
Differential Scanning Calorimetry ◽  
Molecular Orientation ◽  
Polarized Light ◽  
Melting Behavior ◽  
Probable Mechanism ◽  
Wide Angle ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Phenylene Sulfide

The influence of molecular orientation on the melting behavior of draw-annealed poly(phenylene sulfide) fibers is investigated in the present paper. Tools used to probe the investigation were differential scanning calorimetry, polarized light optical microscopy, wide angle X-ray diffraction, and small angle X-ray diffraction. It is shown that molecular orientation in the crystalline and amorphous regions play a key role in crystal rearrangement during melting. A probable mechanism by which amorphous orientation influences crystal rearrangement is also discussed.

scholarly journals Molecular orientation in soft matter thin films studied by resonant soft x-ray reflectivity

2011 ◽  
Vol 83 (15) ◽  
Author(s):  
Markus Mezger ◽  
Blandine Jérôme ◽  
Jeffrey B. Kortright ◽  
Manuel Valvidares ◽  
Eric M. Gullikson ◽  
...  
Keyword(s):  
Thin Films ◽  
Molecular Orientation ◽  
Soft Matter ◽  
X Ray

Properties of Epitaxial ZnO Thin Films for GaN and Related Applications

1998 ◽  
Vol 537 ◽  
Author(s):  
H. Shen ◽  
M. Wraback ◽  
J. Pamulapati ◽  
S. Liang ◽  
C. Gorla ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Anisotropy ◽  
Polarized Light ◽  
Chemical Vapor ◽  
Zno Thin Films ◽  
Organic Chemical ◽  
Zno Films ◽  
Light Modulator ◽  
Cross Sectional ◽  
Linearly Polarized

AbstractIn this paper, we present a detailed study of high quality (110) ZnO films, epitaxially grown on R-plane sapphire substrates by metal-organic chemical vapor deposition (MOCVD). The epitaxial relationships are (1120) ZnO//(0112) Al2O3 and {0001} ZnO//[0111] A12O3 as confirmed by X-ray diffraction (θ-2θ, and φ-scan) and high-resolution cross-sectional transmission electron microscopy (HR-TEM). Low temperature photoluminescence (PL) indicates the ZnO thin films are almost strain free. Optical absorption and reflection measurements with linearly polarized light indicate a strong optical anisotropy. The polarization rotation towards the C-axis associated with the optical anisotropy is utilized to demonstrate an optically addressed ultra-fast, ultraviolet light modulator.

Bistable Characteristics of Liquid Crystal Devices with Patterned Alignment Films

2011 ◽  
Vol 264-265 ◽  
pp. 1752-1757 ◽  
Author(s):  
Jais Bin Lias ◽  
Munehiro Kimura ◽  
Tadashi Akahane
Keyword(s):  
Liquid Crystal ◽  
Uv Light ◽  
Polarized Light ◽  
Mechanical Damage ◽  
Single Step ◽  
Patterned Substrate ◽  
Electrostatic Charges ◽  
Linearly Polarized ◽  
Polyimide Coating ◽  
Homeotropic Alignment

The photoalignment technology for the alignment of liquid crystal molecules has lately gathered much attention because its advantages over the conventional rubbing of polyimide coating and several different approaches for the realization of photoalignment have been presented. Due to its non-contact nature, a photoalignment eliminates generation of dust and electrostatic charges as well as mechanical damage to the surface. Up to now, the study of the photoalignment effect has been focused mostly on uniform substrates through linearly polarized light. With the aim to achieve such a bistable liquid crystal device by means of unpolarized UV light, we have proposed a single-step laser patterning on a photoalignment layer using a photomask to achieve an equilibrium configuration of LC molecules in contact with a periodically patterned substrate. The patterns were formed by stripes of alternating random planar and homeotropic anchoring in a sub-micron scale on the order of 0.5 micron. We proposed two possible configurations of bistable LC cells that can be obtained by combination of micro-patterned surface formed with alternating random planar alignment with either planar alignment or homeotropic alignment surfaces. In this study, we have investigated the alignment properties and switching behaviours of both proposed models.

Anisotropic Molecular Orientation of Poly [4, 4'-oxydiphenylene- 1, 2, 3, 4-cyclobutanetetracarboximide] Films Irradiated by Linearly Polarized UV Light

1999 ◽  
Vol 38 (Part 2, No. 12A) ◽  
pp. L1435-L1438 ◽  
Author(s):  
Kenji Sakamoto ◽  
Kiyoaki Usami ◽  
Takeshi Araya ◽  
Sukekatsu Ushioda
Keyword(s):  
Molecular Orientation ◽  
Uv Light ◽  
Linearly Polarized

Characterization and photoinduced properties of photo chromic polymers. 1. Polyesterimides with 4-amino 4´-nitro azobenzene moieties

e-Polymers ◽  
2006 ◽  
Vol 6 (1) ◽  
Author(s):  
Ewa Schab-Balcerzak ◽  
Beate Sapich ◽  
Joachim Stumpe ◽  
Anna Sobolewska ◽  
Andrzej Miniewicz
Keyword(s):  
Optical Anisotropy ◽  
Polarized Light ◽  
Ethyl Benzene ◽  
H Nmr ◽  
Azobenzene Group ◽  
Vis Spectroscopy ◽  
Different Types ◽  
Linearly Polarized ◽  
Kinetics Of ◽  
Dsc Thermograms

AbstractNovel photochromic polyesterimides (PEIs) with two different types of azobenzene units as side groups have been synthesized from 2,2’-{4-[(4- nitrophenyl)-azo} phenyl]iminobis(ethyl benzene-1,2-dicarboxylic acid anhydride-4- carboxylate) and diamines: 2,4-diamino-4’-methylazobenzene and 2,4-diamino-4’- (trifluoromethoxy)azobenzene. An analogous polyesterimide with one azobenzene group based on 1,3-phenylendiamine has been prepared to compare with these PEIs. Molecular structural characterization for these polymers has been achieved by FTIR, 1H NMR and UV-Vis spectroscopy. These amorphous polyesterimides are thermally stable up to 260°C as follows from the thermogravimetric analysis (TGA). The glass transition temperatures (Tg) for the resulting polyimides have been determined from DSC thermograms and are in the range of 141-210°C. The irradiation with linearly polarized light of an Ar+ laser results in the induction of optical anisotropy within the initially isotropic films. Light induced optical anisotropy in polymer films has been studied by examining the value of generated dichroism using Ar+ laser (λ = 488 nm) and by holographic polarization grating recording performed at λ = 514.5 nm. The value of photoinduced dichroism is in the range of 0.15-0.26. The induction of dichroism and kinetics of grating inscription have been investigated in relation to the presence of the second type of azobenzene group in the polymer and its substitution.

Nematic Liquid Crystals (NLC) Alignment by the Oriented Nanopatterns of some Polymers Functionalized with Monochlorotriazinyl-β-Cyclodextrin

2012 ◽  
Vol 20 ◽  
pp. 117-128
Author(s):  
Ana Maria Grigoriu ◽  
Constantin Luca ◽  
Aurelia Grigoriu ◽  
Cristina Racu ◽  
Gabriela Hitruc ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Uv Light ◽  
Nematic Liquid Crystals ◽  
Polarized Light ◽  
Hydroxyl Groups ◽  
Nanostructured Surfaces ◽  
Dichroic Dye ◽  
Vis Spectroscopy ◽  
Linearly Polarized ◽  
Ft Ir

This paper presents the practical strategies of obtaining the oriented nanostructured surfaces of some polymers functionalized with monochlorotriazinyl-β-cyclodextrin (MCT-β-CD) by two techniques: uniaxial rubbing or linearly polarized UV light (LPUVL) irradiation. We have chosen for the present study polymers and copolymers with exotic behavior with hydroxyl groups allowing the grafting of the reactive product monochlorotriazinyl-β-cyclodextrin or whose pyridinic nuclei can be complexated with MCT-β-CD. The obtained oriented nanostructures align colourless nematic liquid crystals (NLC) or NLC coloured with a dichroic dye. The orientation of NLC has been studied by means of polarized light FT-IR spectroscopy (IR dichroism) and polarized light UV-VIS spectroscopy (VIS dichroism). The initial polymers as well as the chemically modified products have an exotic behavior with regard to the ability of orientating the NLC. The polymers functionalized with MCT-β-CD orientate the NLC perpendicularly to the rubbing direction (or, for photopolymers, perpendicularly to the electrical vector of LPUVL).

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