scholarly journals Physico-Chemical and Light-Induced Properties of Quinoline Azo-dyes Polymers

2020 ◽  
Vol 21 (16) ◽  
pp. 5755
Author(s):  
Dariusz Chomicki ◽  
Oksana Kharchenko ◽  
Lukasz Skowronski ◽  
Jolanta Kowalonek ◽  
Anna Kozanecka-Szmigiel ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Stability ◽  
Optical Properties ◽  
Azo Dyes ◽  
Side Chain ◽  
Photochromic Properties ◽  
Scanning Calorimetry ◽  
Dsc Measurements ◽  
Physico Chemical ◽  
Thermal Stability Of

We present investigation of optical and photochromic properties as well as of surface quality of thin films of novel methacrylic polymers with 8-hydroxyquinoline azo-dyes in side-chain. Additionally, thermal stability of polymer powders was examined and their glass transition temperature was determined. Optical properties (extinction coefficient and refractive index) were determined by spectroscopic ellipsometry (SE) combined with absorbance measurements. Photoresponsive behavior was investigated by determination of photoisomerization rates under irradiation with unpolarized 365 nm light, as well as by conduction of holographic grating inscription experiment. Thin film quality was determined by atomic force microscopy (AFM) measurements. Thermal analysis was performed by thermogravimetric (TG), derivative thermogravimetric (DTG) and differential scanning calorimetry (DSC) measurements. We found that optical properties as well as photoisomerization rates of investigated polymers are dependent on the substituent in the para position of the phenyl ring. Surface relief grating inscription was successfully generated only for materials with chromophores containing dimethylamino (N(CH3)2) and methyl (CH3) substituents, but all materials exhibited birefringence grating in the bulk. Surface of most thin films was very smooth, but its quality was impaired by neutral (H) as well as carboxyl (COOH) substituent. Thermal stability of copolymers with side-chain chromophores was improved compared to pure poly(methyl methacrylate) (PMMA).

Medium-term thermal stability of amorphous Ge2Sb2Te5 flash-evaporated thin films with regards to change in structure and optical properties

2009 ◽  
Vol 517 (16) ◽  
pp. 4694-4697 ◽  
Author(s):  
T. Wagner ◽  
J. Orava ◽  
J. Prikryl ◽  
T. Kohoutek ◽  
M. Bartos ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Stability ◽  
Optical Properties ◽  
Medium Term ◽  
Thermal Stability Of

Thermal stability of the optical properties of plasma deposited diamond-like carbon thin films

2005 ◽  
Vol 14 (11-12) ◽  
pp. 1795-1798 ◽  
Author(s):  
Daniel Franta ◽  
Vilma Buršíková ◽  
Ivan Ohlídal ◽  
Lenka Zajíčková ◽  
Pavel St′ahel
Keyword(s):  
Thin Films ◽  
Thermal Stability ◽  
Optical Properties ◽  
Diamond Like Carbon ◽  
Carbon Thin Films ◽  
Thermal Stability Of

Microstructure, optical properties and thermal stability of ZrB2 and Zr–B–N thin films as high-temperature solar selective absorbers

2014 ◽  
Vol 4 (3) ◽  
pp. 205-212 ◽  
Author(s):  
Yaoming Sun ◽  
Xiudi Xiao ◽  
Guanqi Chai ◽  
Gang Xu ◽  
Bin Xiong ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Stability ◽  
Optical Properties ◽  
High Temperature ◽  
Thermal Stability Of

scholarly journals The influence of ageing on the morphological and optical properties of thin TPD films

2011 ◽  
Vol 65 (1) ◽  
pp. 9-13
Author(s):  
Sasa Trifunovic ◽  
Dejan Milicevic ◽  
Maja Micic ◽  
Tihana Mudrinic ◽  
Edin Suljovrujic
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Growth Dynamics ◽  
Distribution Profile ◽  
Scanning Calorimetry ◽  
Spatially Correlated ◽  
Silica Substrate ◽  
Dsc Measurements ◽  
Organic Electroluminescent ◽  
Strongly Connected

This paper presents the influence of ageing on the morphological and optical properties of TPD (N, N? - Bis (3 - methylphenil) - N, N? diphenylbenzidine) thin films. Understanding of the nucleation mechanism and growth dynamics of molecular thin films is pivotal for controlling their morphology and the film interfacial properties, while the influence of ageing is essential for the potential commercial utilization. Initially, thin films were prepared using a combinatorial physical vapour deposition (CPVD) method, following a cosine-like distribution profile of thickness along monocrystal silica substrate. Morphology of thin films was investigated by using optical (OM) and atomic force microscopy (AFM). The link between optical properties and the resulting thin film morphology was made by spatially correlated morphological (AFM and OM) and optical (absorption and photoluminescence) measurements. The changes in the absorption and photoluminescence spectra are strongly connected to the ageing-induced changes in the microstructure of thin films. Regardless of morphological and differences in the film thickness (two orders of magnitude), all films show amorphous arrangement just after the deposition. Ageing of these films in regular atmosphere conditions results in morphological and changes in optical properties induced by the crystallization. The crystallization of initially amorphous samples was also confirmed by the differentional scanning calorimetry (DSC) measurements. All results indicate the limited possibility of using TPD films in organic electroluminescent devices.

Preparation and properties of fluorosilicone and fluorosilicone elastomer with various contents of trifluoropropyl groups

e-Polymers ◽  
2011 ◽  
Vol 11 (1) ◽  
Author(s):  
Yan Cui ◽  
Wenge Jiang ◽  
Dongmei Li ◽  
Chengqun Niu ◽  
Shengyu Feng ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Ring Opening ◽  
Gel Permeation Chromatography ◽  
Scanning Calorimetry ◽  
Solvent Resistance ◽  
Glass Transition Temperatures ◽  
Methyl Vinyl ◽  
Dsc Measurements ◽  
Gel Permeation ◽  
Thermal Stability Of

AbstractPoly(dimethyl-methyltrifluoropropyl-methylvinyl)siloxanes (PFMVS) with various contents of trifluoropropyl groups were prepared by ring-opening copolymerization of 2,4,6-trimethyl-2,4,6-tris(3,3,3-trifluoropropyl) cyclotrisiloxane (D3F), octamethylcyclotetrasiloxane (D4) and 1,3,5,7-tetramethyl tetravinylcyclotetrasiloxane (D4Vi). All the polymers were characterized by IR, 1HNMR, 29SiNMR, gel permeation chromatography (GPC), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) measurements. The results show that methyltrifluoropropyl-siloxane units in the copolymer can disrupt the molecular regularity and lead to noncrystalline copolymers with low glasstransition temperatures. Moreover, the onset temperatures of thermal degradation and the glass transition temperatures of polymers decrease gradually with the content of trifluoropropyl groups increasing. Then the thermal stability and solvent resistance of elastomers based on PFMVSs were measured. The data of TGA indicate that the thermal stability of fluorosilicone elastomers are less than conventional methyl vinyl silicone rubber (MVQ), but the fluorosilicone elastomers have outstanding solvent resistance. The content of the trifluoropropyl groups influences the performances of elastomer to a certain degree.

scholarly journals Influence of Alumina Addition on the Optical Properties and the Thermal Stability of Titania Thin Films and Inverse Opals Produced by Atomic Layer Deposition

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1053
Author(s):  
Martin Waleczek ◽  
Jolien Dendooven ◽  
Pavel Dyachenko ◽  
Alexander Y. Petrov ◽  
Manfred Eich ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Stability ◽  
Optical Properties ◽  
Low Temperature ◽  
Photonic Crystals ◽  
Atomic Layer ◽  
Inverse Opal ◽  
Tio2 Thin Films ◽  
Layer Deposition ◽  
Thermal Stability Of

TiO2 thin films deposited by atomic layer deposition (ALD) at low temperatures (<100 °C) are, in general, amorphous and exhibit a smaller refractive index in comparison to their crystalline counterparts. Nonetheless, low-temperature ALD is needed when the substrates or templates are based on polymeric materials, as the deposition has to be performed below their glass transition or melting temperatures. This is the case for photonic crystals generated via ALD infiltration of self-assembled polystyrene templates. When heated up, crystal phase transformations take place in the thin films or photonic structures, and the accompanying volume reduction as well as the burn-out of residual impurities can lead to mechanical instability. The introduction of cation doping (e.g., Al or Nb) in bulk TiO2 parts is known to alter phase transitions and to stabilize crystalline phases. In this work, we have developed low-temperature ALD super-cycles to introduce Al2O3 into TiO2 thin films and photonic crystals. The aluminum oxide content was adjusted by varying the TiO2:Al2O3 internal loop ratio within the ALD super-cycle. Both thin films and inverse opal photonic crystal structures were subjected to thermal treatments ranging from 200 to 1200 °C and were characterized by in- and ex-situ X-ray diffraction, spectroscopic ellipsometry, and spectroscopic reflectance measurements. The results show that the introduction of alumina affects the crystallization and phase transition temperatures of titania as well as the optical properties of the inverse opal photonic crystals (iPhC). The thermal stability of the titania iPhCs was increased by the alumina introduction, maintaining their photonic bandgap even after heat treatment at 900 °C and outperforming the pure titania, with the best results being achieved with the super-cycles corresponding to an estimated alumina content of 26 wt.%.

Thermal Stability of N-Heterocycle-Stabilized Iodanes – A Systematic Investigation

2019 ◽  
Author(s):  
Andreas Boelke ◽  
Yulia A. Vlasenko ◽  
Mekhman S. Yusubov ◽  
Boris Nachtsheim ◽  
Pavel Postnikov
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Thermogravimetric Analysis ◽  
Systematic Investigation ◽  
Scanning Calorimetry ◽  
Thermal Stability Of

<p>The thermal stability of pseudocyclic and cyclic <i>N</i>-heterocycle-stabilized (hydroxy)aryl- and mesityl(aryl)-l<sup>3</sup>-iodanes (NHIs) through thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) is investigated. NHIs bearing <i>N</i>-heterocycles with a high N/C-ratio such as triazoles show among the lowest descomposition temperatures and the highest decomposition energies. A comparison of NHIs with known (pseudo)cyclic benziodoxolones is made and we further correlated their thermal stability with reactivity in a model oxygenation. </p>

scholarly journals The role of the substrate on the mechanical and thermal stability of Pd thin films during hydrogen (de)sorption

2021 ◽  
Vol 46 (5) ◽  
pp. 4137-4153
Author(s):  
Neha Verma ◽  
Rob Delhez ◽  
Niek M. van der Pers ◽  
Frans D. Tichelaar ◽  
Amarante J. Böttger
Keyword(s):  
Thin Films ◽  
Thermal Stability ◽  
Thermal Stability Of
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