scholarly journals Synthesis and Deposition of Thermochromic VO2 Thin Films from Peroxide-based Chemical Solutions

2021 ◽  
Author(s):  
Matthias Van Zele ◽  
Hannes Rijckaert ◽  
Davy Deduytsche ◽  
Christophe Detavernier ◽  
Isabel Van Driessche ◽  
...  
Keyword(s):  
Coating Thickness ◽  
Optical Transmission ◽  
Solar Modulation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Thermochromic Properties ◽  
Chemical Solutions ◽  
Vo2 Thin Films

In this paper, a novel synthesis for a chemical precursor for nanocrystalline VO2 coatings is elaborated. The compatibility of the precursor towards the substrate is optimized for spin coating. This is done by subjecting multiple solvents to contact angle measurements. A suitable thermal treatment is developed to densify the coating and to induce crystallization. Afterwards the microstructure of the coating is investigated using X-Ray diffraction, electron microscopy and ellipsometry techniques. To assess the thermochromic properties of the fabricated device, optical transmission experiments were conducted both at room temperature and at elevated temperature. A correlation between these thermochromic properties and coating thickness was investigated in order to obtain an optimized thermochromic device, where both high visual transparency and prominent thermochromic switching abilities are aimed for. In this work, an optimal coating thickness is proposed for a thermochromic coating with high switching ability and solar modulation.

scholarly journals Synthesis and Deposition of Thermochromic VO2 Thin Films from Peroxide-based Chemical Solutions

2021 ◽  
Author(s):  
Matthias Van Zele ◽  
Hannes Rijckaert ◽  
Davy Deduytsche ◽  
Christophe Detavernier ◽  
Isabel Van Driessche ◽  
...  
Keyword(s):  
Coating Thickness ◽  
Optical Transmission ◽  
Solar Modulation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Thermochromic Properties ◽  
Chemical Solutions ◽  
Vo2 Thin Films

In this paper, a novel synthesis for a chemical precursor for nanocrystalline VO2 coatings is elaborated. The compatibility of the precursor towards the substrate is optimized for spin coating. This is done by subjecting multiple solvents to contact angle measurements. A suitable thermal treatment is developed to densify the coating and to induce crystallization. Afterwards the microstructure of the coating is investigated using X-Ray diffraction, electron microscopy and ellipsometry techniques. To assess the thermochromic properties of the fabricated device, optical transmission experiments were conducted both at room temperature and at elevated temperature. A correlation between these thermochromic properties and coating thickness was investigated in order to obtain an optimized thermochromic device, where both high visual transparency and prominent thermochromic switching abilities are aimed for. In this work, an optimal coating thickness is proposed for a thermochromic coating with high switching ability and solar modulation.

Effect of electron irradiation on the Crystallite size, Grain size and Contact angle of electrodeposited Cadmium Telluride thin films

2015 ◽  
Vol 8 (2) ◽  
Author(s):  
S. A. Gangawane ◽  
V. P. Malekar ◽  
V. J. Fulari
Keyword(s):  
Thin Films ◽  
Contact Angle ◽  
Grain Size ◽  
Electron Beam Irradiation ◽  
Crystal Size ◽  
X Ray Diffraction ◽  
X Ray ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Cdte Thin Films

In this paper, the effects of electron beam irradiation on the CdTe thin films are studied. The CdTe thin films are characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and contact angle measurements for different bath concentration. The thin film layers are subjected to irradiation of 6 MeV electrons. Finally the effect of irradiation is correlated to crystal size, grain size and contact angle measurements of the CdTe thin films

Preparation of N, O-Carboxymethyl Chitosan with Different Substitutional Degree and its Application for Hemostasis

2013 ◽  
Vol 798-799 ◽  
pp. 1061-1066 ◽  
Author(s):  
Yan Wei Zhao ◽  
Lu Liu ◽  
Xiang Han ◽  
Jing Guan
Keyword(s):  
Carboxymethyl Chitosan ◽  
X Ray Diffraction ◽  
Clotting Time ◽  
X Ray ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Ft Ir ◽  
Ubbelohde Viscometer

We prepared N, O-carboxymethyl chitosans (CMCSs) with different substitutional degrees (SDs) to evaluate their effects of hemostasis, and provided experimental basis on biomedical materials. Chloroethanoic acid was used to synthesize CMCSs. The structure were characterized by Fourier transform infrared (FT-IR) and wide-angle X-ray diffraction (WXRD). Potentiometric titration and Ubbelohde viscometer were adopted to determine the SD and intrinsic viscosity of CMCSs. Contact angle measurements were investigated to determine surface wettability. Method of dynamic clotting time and coagulation test in vivo were used to evaluate their effects of hemostasis. SDs of CMCSs were from 50% to 110%. As the SD increased, molecular weight decreased. CMCS powder with SD 63% possessed excellent hemostasis both in vitro and in vivo. CMCS powder owned hemostatic capability prior to CS. CMCS powder with SD 63% (neither too high, nor too low) possessed excellent hemostasis both in vitro and in vivo.

Surface Treatments of Titanium Alloy for Preparing Laminated Composite Material

2015 ◽  
Vol 1101 ◽  
pp. 229-232 ◽  
Author(s):  
Svetlana Vladimirovna Sibileva ◽  
Andrey Leonidovich Botanogov ◽  
Nikolay Vadimovich Trofimov ◽  
Ludmila Viktorovna Zaharova
Keyword(s):  
Titanium Alloy ◽  
Laminated Composite ◽  
Adhesive Bond ◽  
X Ray Diffraction ◽  
X Ray ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Alloy Vt20 ◽  
Before And After ◽  
Laminated Composite Material

In this investigation surface treatment of titanium alloy VT20 is carried out by phosphating and anodization in order to increase the adhesive bond strength. The surfaces were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), profilometry, contact angle measurements. The joined titanium specimens were shear tested before and after exposure to high humidity to a period of three months.

Nanotubes Growth on Ti-15Mo Alloys by Anodization at Low Voltage

2016 ◽  
Vol 869 ◽  
pp. 924-929 ◽  
Author(s):  
André Luiz Reis Rangel ◽  
Guilherme Rogeri Moreira Santos ◽  
Ana Paula Rosifini Alves Claro
Keyword(s):  
Positive Characteristic ◽  
Low Voltage ◽  
Ammonium Fluoride ◽  
X Ray Diffraction ◽  
X Ray ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Biological Environment ◽  
Post Implantation ◽  
Microscopy Images

Surface modification by nanotubes growth is an efficient technique to improve the interaction between implant and biological environment. Several studies indicate who low voltages anodizations are able to generate nanotubes with smaller diameters, positive characteristic for the post-implantation cell growth. The aim of this study was to characterize the morphology of the nanotubes formed on Ti-15Mo surfaces applying 5 or 10 V as anodizing voltage. For both conditions were used glycerol based electrolyte with ammonium fluoride and the anodization time was 24 hours. The samples were cleaned in an ultrasonic bath and annealed at 450 ° for 1 hour after anodization. In order to characterize the surfaces were performed scanning electron microscopy images, contact angle measurements and X-ray diffraction analysis. The results confirmed the formation of nanotubes evenly distributed on the surfaces and a direct relation between anodizing voltage and nanotubes diameters.

scholarly journals Strongly Selective Polymer Membranes Modified with Heteroarm Stars for the Ethylene Glycol Dehydration by Pervaporation

Membranes ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 86 ◽  
Author(s):  
Valeriia Rostovtseva ◽  
Alexandra Pulyalina ◽  
Daria Rudakova ◽  
Ludmila Vinogradova ◽  
Galina Polotskaya
Keyword(s):  
Ethylene Glycol ◽  
Membrane System ◽  
Butyl Methacrylate ◽  
Strong Increase ◽  
Separation Performance ◽  
Intrinsic Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Angle Measurements ◽  
Contact Angle Measurements

Hybrid membranes based on poly (2,6-dimethyl-1,4-phenylene oxide) modified with heteroarm stars (HAS) were developed to separate ethylene glycol/water mixtures by pervaporation. The HAS consist of a small branching center fullerene C 60 and twelve arms of different nature, six arms of nonpolar polystyrene and six arms of polar poly-tert-butyl methacrylate. The changes of structure and physical properties with HAS inclusion were systematically studied using SEM, X-ray diffraction analysis, TGA, and contact angle measurements. Mass transfer of ethylene glycol and water through membranes was studied by sorption and pervaporation tests. It was found that the growth of HAS content up to 5 wt% in the membrane leads to an increase in the total flux and a strong increase in the separation factor. To evaluate intrinsic properties of the penetrant–membrane system, permeability and selectivity were calculated. Overall, utilizing star-shaped macromolecules as a filler can be a promising way to improve the separation performance of diffusion membranes.

Contact Angle Measurements of Wetting In Pristine and Ion Implanted High Modulus Benzene Derived Graphite Fibers

1984 ◽  
Vol 40 ◽  
Author(s):  
O. C. de Hodgins ◽  
M. S. Dresselhaus ◽  
D. Uhlmann
Keyword(s):  
Contact Angle ◽  
Carbon Fibers ◽  
Structural Disorder ◽  
Contact Angles ◽  
X Ray Diffraction ◽  
Three Solutions ◽  
X Ray ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Graphite Fibers

AbstractMeasurements are reported of the contact angles of benzene-derived carbon fibers with de-ionized water, aminopropyltriethoxy silane and du Pont 5878 polyimide solutions. Both pristine fibers and fibers implanted with 5×1012 cm-2 and 1×1015 cm-2 fluences of 31p ions were investigated. Such implantation was observed to decrease the contact angle in all three solutions. The ion implantation had no significant effect on tensile strength, but did result in increased structural disorder (as reflected in the width of the main wide angle X-ray diffraction peak) and increased surface roughness. The increased disorder and roughness are believed to be principally responsible for the observed change in wetting angle.

scholarly journals Electrochemical Aspects of a Nitrogen-Doped Pseudo-Graphitic Carbon Material: Resistance to Electrode Fouling by Air-Aging and Dopamine Electro-Oxidation

2020 ◽  
Vol 6 (4) ◽  
pp. 68
Author(s):  
Kailash Hamal ◽  
Jeremy May ◽  
Haoyu Zhu ◽  
Forrest Dalbec ◽  
Elena Echeverria ◽  
...  
Keyword(s):  
Pyrolytic Graphite ◽  
X Ray Diffraction ◽  
Water Contact ◽  
X Ray ◽  
Nitrogen Doped ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Electro Oxidation ◽  
The University ◽  
University Of Idaho

The nitrogen-doped form of GUITAR (pseudo-Graphite from the University of Idaho Thermalized Asphalt Reaction) was examined by X-ray photoelectron, Raman, and X-ray diffraction spectroscopies and cyclic voltammetry (CV). Electrochemical studies indicate that N-GUITAR exhibits significant resistance to fouling by adsorption and by passivation. Unlike other carbon materials, it maintains fast heterogenous electron transfer (HET) kinetics with Fe(CN)63−/4− with exposure to air. The CV peak potential separation (ΔEp) of 66 mV increased to 69 mV in 3 h vs. 67 to 221 mV for a highly oriented pyrolytic graphite (HOPG) electrode. Water contact angle measurements indicate that N-GUITAR was able to better maintain a hydrophilic state during the 3-h exposure, going from 55.8 to 70.4° while HOPG increased from 63.8 to 80.1°. This indicates that N-GUITAR better resisted adsorption of volatile organic compounds. CV studies of dopamine also indicate N-GUITAR is resistant to passivation. The ΔEp for the dopamine/o-dopaminoquinone couple is 83 mV indicating fast HET rates. This is reflected in the peak current ratios for the oxidation and reduction processes of 1.3 indicating that o-dopaminoquinone is not lost to passivation processes. This ratio along with the minimal signal attenuation is the best reported in literature.

scholarly journals Investigation of the Orientation of Ions in the Interlayer of CTAB Pillared Montmorillonite

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Semra Karaca ◽  
Ahmet Gürses ◽  
Mehtap Ejder Korucu
Keyword(s):  
Clay Mineral ◽  
Interlayer Space ◽  
Contact Angles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pillared Montmorillonite ◽  
Zeta Potentials ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Scanning Electron

The orientation of CTA+in the interlayer of organic pillared montmorillonite prepared by adding different amounts of surfactant corresponding to the CEC of the pristine clay mineral has been studied using X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) spectra. Morphology of the samples was examined by scanning electron microscopy (SEM). The results are supported by the measurements of zeta potentials and contact angles of pristine clay and organoclay samples. From the XRD results, a series of arrangement models of CTA+in the interlayer of montmorillonite have been proposed as lateral-bilayer, pseudotrilayer, paraffin-type-monolayer and pseudotrilayer, paraffin-type-bilayer and pseudotrilayer for 0.5, 1, 1.5, and 2.0 CEC, respectively. FTIR spectrum and contact angle measurements of pristine montmorillonite and organoclays indicated the incorporation of surfactant and the changing of hydrophility in the different OMts. This study demonstrates that not only the arrangement model of surfactant, but also the morphology of organoclay strongly depends on the surfactant packing density within the montmorillonite interlayer space. In addition, it can be also proposed that, the magnitude of surface charge or its distribution on clay mineral might be an important factor for expansion characteristics of organoclay.

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