A2BA2-Type Amphiphilic Liquid Crystalline Block Copolymers by ATRP: Synthesis and Characterization

2010 ◽  
Vol 428-429 ◽  
pp. 154-157 ◽  
Author(s):  
Xin De Tang ◽  
Nian Feng Han ◽  
Jing Xu
Keyword(s):  
Block Copolymers ◽  
Data Storage ◽  
Liquid Crystalline ◽  
Optical Switch ◽  
Gel Permeation Chromatography ◽  
Optical Data Storage ◽  
Optical Data ◽  
Esterification Reaction ◽  
Scanning Calorimetry ◽  
Hexyl Methacrylate

A2BA2-type amphiphilic liquid crystalline block copolymers containing azobenzene were synthesized by atom transfer radical polymerization (ATRP). The macroinitiator prepared by the esterification reaction between poly(ethylene glycol) (PEG) and 2,2-dichloroacetyl chloride was used to initiate the ATRP of 6-[4-(4-ethoxyphenylazo)phenoxy]hexyl methacrylate (M6C). The resulting macroinitiator and block copolymers were characterized by 1H NMR, gel permeation chromatography (GPC). Polarizing optical microscopy (POM) and differential scanning calorimetry (DSC) preliminarily revealed the liquid crystalline property of these block copolymers. These novel amphiphilic liquid crystalline block copolymers are promising in some areas, such as optical data storage, optical switch, and molecular devices.

Novel Azobenzene Homopolymers via Atom Transfer Radical Polymerization Initiated by an Azobenzene Derivative

2010 ◽  
Vol 663-665 ◽  
pp. 92-95
Author(s):  
Xin De Tang ◽  
De Jie Zhou ◽  
Nian Feng Han
Keyword(s):  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Data Storage ◽  
Liquid Crystalline ◽  
Optical Switch ◽  
Optical Data Storage ◽  
Optical Data ◽  
Atom Transfer ◽  
Scanning Calorimetry ◽  
Crystalline Property

An azobenzene derivative substituted with a 2-bromoisobutyryl group was used as an initiator for the atom transfer radical polymerization of 2-[4-(4-ethoxyphenylazo)phenoxy]ethyl methacrylate) (MAZO). The resulting homopolymers (AZO-PMAZO) possess azobenzene moieties both in the main chain and in the side chain. Differential scanning calorimetry (DSC) and polarized optical microscopy (POM) preliminarily revealed the liquid crystalline property of these polymers. The novel liquid crystalline polymers are expected to act as the candidates in some promising areas including optical data storage, optical switch, and molecular devices.

Photoinduced Reorientation and Multiple Optical Data Storage in Photo-Cross-Linkable Liquid Crystalline Copolymer Films Using 405 nm Light

2006 ◽  
Vol 39 (9) ◽  
pp. 3245-3251 ◽  
Author(s):  
Nobuhiro Kawatsuki ◽  
Kunihisa Kato ◽  
Tomoko Shiraku ◽  
Takeshi Tachibana ◽  
Hiroshi Ono
Keyword(s):  
Data Storage ◽  
Liquid Crystalline ◽  
Optical Data Storage ◽  
Optical Data ◽  
Copolymer Films

Effect of Molecular Weight on Mesomorphic Behavior of Side-Chain Liquid-Crystalline Azopolymers

2015 ◽  
Vol 1765 ◽  
pp. 133-138
Author(s):  
Flores V. Daniela ◽  
Larios L. Leticia
Keyword(s):  
Liquid Crystalline ◽  
Gel Permeation Chromatography ◽  
Side Chain ◽  
Scanning Calorimetry ◽  
Small Shift ◽  
Molecular Weights ◽  
Chemical Structures ◽  
Vis Spectroscopy ◽  
Wide Range ◽  
Hexyl Methacrylate

ABSTRACTThree methacrylic polymers bearing (phenylene)azobenzene moieties in the side-chain were synthesized via free-radical polymerization of monomer (E)-6-(4-((3’-cyano-4’-(hexyloxy) -[1,1’- biphenyl]-4-yl) diazenyl) phenoxy) hexyl methacrylate using 1, 5 and 10 mol% of 1,1’-azobis(cyclohexanecarbonitrile) (ABCN) as initiator. The chemical structures of monomer and polymers were confirmed by 1H NMR and FT-IR spectroscopies. Analysis by gel permeation chromatography (GPC) showed average molecular weights (Mw) of 1.0x105, 7.3x104, and 4.5x104 g/mol for polymers P1%, P5%, and P10%, respectively. These results indicate a clear dependence of the Mw on the amount of initiator used; the higher the amount of ABCN, the lowest the molecular mass. Thermotropic liquid-crystalline properties were analyzed by differential scanning calorimetry (DSC) and polarized optical microscopy (POM). All polymers showed a liquid-crystalline behavior over a wide range of temperatures (>100°C) displaying smectic type mesophases. A small shift (around 8°C) upwards in the clearing temperature was observed on increasing the molecular masses from P10% to P1%. The trans-cis photo-isomerization of polymers was studied in solution and in thin films by UV-Vis spectroscopy. High cis-isomer contents in solution (>90%) were reached in relative short irradiation times.

scholarly journals Structural and optical properties of amorphous Si–Ge–Te thin films prepared by combinatorial sputtering

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
C. Mihai ◽  
F. Sava ◽  
I. D. Simandan ◽  
A. C. Galca ◽  
I. Burducea ◽  
...  
Keyword(s):  
Optical Properties ◽  
Data Storage ◽  
Optical Sensors ◽  
Material Selection ◽  
Functional Materials ◽  
Stability Study ◽  
Optical Data Storage ◽  
Optical Data ◽  
Structural And Optical Properties ◽  
Topological Constraint

AbstractThe lack of order in amorphous chalcogenides offers them novel properties but also adds increased challenges in the discovery and design of advanced functional materials. The amorphous compositions in the Si–Ge–Te system are of interest for many applications such as optical data storage, optical sensors and Ovonic threshold switches. But an extended exploration of this system is still missing. In this study, magnetron co-sputtering is used for the combinatorial synthesis of thin film libraries, outside the glass formation domain. Compositional, structural and optical properties are investigated and discussed in the framework of topological constraint theory. The materials in the library are classified as stressed-rigid amorphous networks. The bandgap is heavily influenced by the Te content while the near-IR refractive index dependence on Ge concentration shows a minimum, which could be exploited in applications. A transition from a disordered to a more ordered amorphous network at 60 at% Te, is observed. The thermal stability study shows that the formed crystalline phases are dictated by the concentration of Ge and Te. New amorphous compositions in the Si–Ge–Te system were found and their properties explored, thus enabling an informed and rapid material selection and design for applications.

scholarly journals Optical Isomerization and Photo-Patternable Properties of GeO2/Ormosils Organic-Inorganic Composite Films Doped with Azobenzene

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 818
Author(s):  
Xuehua Zhang ◽  
Qian Wang ◽  
Shun Liu ◽  
Wei Zhang ◽  
Fangren Hu ◽  
...  
Keyword(s):  
Optical Waveguide ◽  
Data Storage ◽  
Optical Switching ◽  
Sol Gel ◽  
Composite Films ◽  
Optical Data Storage ◽  
Optical Data ◽  
Single Chip ◽  
Coating Method ◽  
Inorganic Composite

GeO2/organically modified silane (ormosils) organic-inorganic composite films containing azobenzene were prepared by combining sol-gel technology and spin coating method. Optical waveguide properties including the refractive index and thickness of the composite films were characterized by using a prism coupling instrument. Surface morphology and photochemical properties of the composite films were investigated by atomic force microscope and Fourier transform infrared spectrometer. Results indicate that the composite films have smooth and neat surface, and excellent optical waveguide performance. Photo-isomerization properties of the composite films were studied by using a UV–Vis spectrophotometer. Optical switching performance of the composite films was also studied under the alternating exposure of 365 nm ultraviolet light and 410 nm visible light. Finally, strip waveguides and microlens arrays were built in the composite films through a UV soft imprint technique. Based on the above results, we believe that the prepared composite films are promising candidates for micro-nano optics and photonic applications, which would allow directly integrating the optical data storage and optical switching devices onto a single chip.

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