Effect of Molecular Structure and Thermal Treatment on Photo-optical Properties of Photochromic Azobenzene-containing Polymer Films

2010 ◽  
Vol 212 (4) ◽  
pp. 342-352 ◽  
Author(s):  
Alexey Bobrovsky ◽  
Valery Shibaev ◽  
Alexej Bubnov ◽  
Vĕra Hamplová ◽  
Miroslav Kašpar ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Optical Properties ◽  
Thermal Treatment ◽  
Polymer Films

scholarly journals Vertical Orientation of Liquid Crystal on 4-n-Alkyloxyphenoxymethyl-Substituted Polystyrene Containing Liquid Crystal Precursor

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 736
Author(s):  
Kyutae Seo ◽  
Hyo Kang
Keyword(s):  
Molecular Structure ◽  
Liquid Crystal ◽  
Surface Energy ◽  
Polymer Films ◽  
Ultraviolet Irradiation ◽  
Molar Fraction ◽  
Side Chain ◽  
Polymer Modification ◽  
Vertical Orientation ◽  
Surface Energies

We synthesized a series of polystyrene derivatives that were modified with precursors of liquid crystal (LC) molecules, such as 4-ethyloxyphenol (homopolymer PEOP and copolymer PEOP#; # = 20, 40, 60, and 80, where # indicates the molar fraction of 4-ethyloxyphenoxymethyl in the side chain), 4-n-butyloxyphenol (PBOP), 4-n-hexyloxyphenol (PHOP), and 4-n-octyloxyphenol (POOP), via polymer modification reaction to investigate the orientation of LC molecules on polymer films, exhibiting part of the LC molecular structure. LC molecules showed a stable and uniform vertical orientation in LC cells fabricated with polymers that have 4-ethyloxyphenoxymethyl in the range of 40–100 mol%. In addition, similar results were obtained in LC cells fabricated with homopolymers of PEOP, PBOP, PHOP, and POOP. The vertical orientation of LC molecules in LC cells fabricated with polymer films correlated to the surface energy of polymer films. For example, vertical LC orientation was observed when the total surface energies of the polymer films were lower than approximately 43.2 mJ/m2. Good alignment stabilities were observed at 150 °C and 20 J/cm2 of ultraviolet irradiation for LC cells fabricated with PEOP film.

On the effects of thermal treatment on the composition, structure, morphology, and optical properties of hydrogenated amorphous silicon-oxycarbide

2009 ◽  
Vol 24 (8) ◽  
pp. 2561-2573 ◽  
Author(s):  
Spyros Gallis ◽  
Vasileios Nikas ◽  
Eric Eisenbraun ◽  
Mengbing Huang ◽  
Alain E. Kaloyeros
Keyword(s):  
Optical Properties ◽  
Thermal Treatment ◽  
Amorphous Silicon ◽  
Hydrogenated Amorphous Silicon ◽  
Effective Cross Section ◽  
Silicon Oxycarbide ◽  
Nuclear Reaction Analysis ◽  
Structure Morphology ◽  
Composition Structure ◽  
Hydrogenated Amorphous

The composition, structure, morphology, and optical characteristics of hydrogenated amorphous silicon-oxycarbide (a-SiCxOyHz) materials were investigated as a function of experimental processing conditions and post-deposition thermal treatment. Thermal chemical vapor deposition (TCVD) was applied to the growth of three different types of a-SiCxOyHz films, namely, SiC-like (SiC1.08O0.07H0.21), Si-C-O (SiC0.50O1.20H0.22), and SiO2-like (SiC0.20O1.70H0.24). The resulting films were subsequently annealed at temperatures ranging from 500 °C to 1100 °C for 1 h in an argon atmosphere. The composition, structure, and morphology of as-deposited and post-annealed films were characterized by Fourier transform infrared spectroscopy (FTIR), x-ray photoelectron spectroscopy (XPS), Rutherford backscattering spectroscopy (RBS), nuclear-reaction analysis (NRA), and scanning electron microscopy. Corresponding optical properties were assessed by spectroscopic ultraviolet-visible ellipsometry (UV-VIS-SE). These studies led to the identification of an optimized process window for the growth of Er doped silicon oxycarbide (SiC0.5O1.0:Er) thin film with strong room-temperature photoluminescence emission measured around 1540 nm within a broad (460 nm to 600 nm) wavelength band. Associated modeling studies showed that the effective cross section for Er excitation in the SiC0.5O1.0:Er matrix was approximately four orders of magnitude larger than its analog for direct optical excitation of Er ions.

Evolution of optical properties and molecular structure of PCBM films under proton irradiation

2021 ◽  
Author(s):  
Guodong Xiong ◽  
Huiping Zhu ◽  
Lei Wang ◽  
Bo Li ◽  
Fazhan Zhao ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Optical Properties ◽  
Proton Irradiation

Optical properties of polymer films for transparent insulation

2002 ◽  
Vol 181 (1) ◽  
pp. 399-410 ◽  
Author(s):  
Gernot M. Wallner ◽  
Reinhold W. Lang ◽  
Werner Platzer ◽  
Christian Teichert
Keyword(s):  
Optical Properties ◽  
Polymer Films
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