scholarly journals Direct mass analysis of water absorption onto ceria thin films

MRS Advances ◽  
2017 ◽  
Vol 2 (12) ◽  
pp. 649-654
Author(s):  
D. Laventine ◽  
R. Wilbraham ◽  
C. Boxall ◽  
R. Taylor ◽  
R. Orr.
Keyword(s):  
Thin Films ◽  
Water Absorption ◽  
Crystal Surface ◽  
Precursor Solution ◽  
Storage Conditions ◽  
Waste Streams ◽  
Gravimetric Measurement ◽  
Nuclear Fuel Waste ◽  
Closed Reactor ◽  
Comprehensive Study

ABSTRACTPlutonium oxide (PuO2) is one of the most highly radioactive components of nuclear fuel waste streams and its storage poses particular challenges due to the high temperatures produced by its decay and the production of gases (particularly H2and steam). Its high radiotoxicity necessitates the use of analogues, such as CeO2, to allow the comprehensive study of its interaction with water under storage conditions.We have developed a method which enables direct gravimetric measurement of water adsorption onto CeO2thin films with masses in the microgram region. Porous CeO2films were fabricated from a surfactant based precursor solution. The absorption of water onto the CeO2coating at different relative humidities was studied in a closed reactor. Quartz Crystal Microbalance (QCM) gravimetry was used as a signal transducer, as changes in crystal resonant frequency due to absorbed mass are directly and linearly related to mass changes occurring at the crystal surface. Using this method, we have determined the enthalpy of absorption of water onto CeO2to be 49.7 kJmol–1at 75°C, 11 kJmol-1greater than the enthalpy of evaporation. This enthalpy is within the range predicted for the absorption of water onto PuO2, indicating this method allows for investigation of water absorption using microgram samples.

scholarly journals Stability and Influence of Storage Conditions on Nanofibrous Film Containing Tooth Whitening Agent

Pharmaceutics ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 449
Author(s):  
Siriporn Okonogi ◽  
Adchareeya Kaewpinta ◽  
Pisaisit Chaijareenont
Keyword(s):  
Water Absorption ◽  
Storage Condition ◽  
Storage Conditions ◽  
Scanning Calorimetry ◽  
Adhesive Properties ◽  
Tooth Whitening ◽  
Electrospinning Technique ◽  
Long Term Storage ◽  
Whitening Agent ◽  
Nanofibrous Structure

Carbamide peroxide (CP), a tooth whitening agent, is chemically unstable. The present study explores stability enhancement of CP by loading in a nanofibrous film (CP-F) composed of polyvinyl alcohol/polyvinylpyrrolidone/silica mixture, using an electrospinning technique. Kept at a temperature range of 60–80 °C for 6 h, CP in CP-F showed significantly higher stability than that in a polymer solution and in water, respectively. Degradation of CP in CP-F could be described by the first order kinetics with the predicted half-life by the Arrhenius equation of approximately 6.52 years. Physicochemical properties of CP-F after long-term storage for 12 months at different temperatures and relative humidity (RH) were investigated using scanning electron microscopy, X-ray diffractometry, differential scanning calorimetry, and Fourier transform infrared spectroscopy. It was found that high temperature and high humidity (45 °C/75% RH) could enhance water absorption and destruction of the nanofibrous structure of CP-F. Interestingly, kept at 25 °C/30% RH, the nanofibrous structure of CP-F was not damaged, and exhibited no water absorption. Moreover, the remaining CP, the mechanical properties, and the adhesive properties of CP-F were not significantly changed in this storage condition. It is concluded that the developed CP-F and a suitable storage condition can significantly improve CP stability.

Sol-gel synthesis of textured lanthanum titanate thin films

2003 ◽  
Vol 18 (2) ◽  
pp. 357-362 ◽  
Author(s):  
Mary M. Sandstrom ◽  
Paul Fuierer
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Precursor Solution ◽  
Solution Concentration ◽  
Optical Measurements ◽  
Layered Perovskite ◽  
Orientation Factor ◽  
Anisotropic Structures ◽  
Sol Gel Films ◽  
Sol Gel Synthesis

Control over crystallographic orientation in thin films is important, particularly with highly anisotropic structures. Because of its ferroelectric nature, the layered perovskite La2Ti2O7 has interesting piezoelectric and electrooptic properties that may be exploited when films are highly textured. Sol-gel films with an orientation factor of greater than 95% were fabricated without relying on epitaxial (lattice-matching) growth from the substrate. Film orientation and crystallization were confirmed by x-ray diffraction, scanning electron microscopy, atomic force microscopy, and optical measurements. The particle sizes in all precursor solutions were measured by dynamic light scattering experiments. Experimental results indicate that film orientation is a function of precursor solution concentration, size of the molecular clusters in the solution, and film thickness.

A Comprehensive Study on the Activity and Deactivation of Immobilized Lecitase Ultra in Esterifications of Food Waste Streams to Monoacylglycerols

ChemSusChem ◽  
2013 ◽  
Vol 6 (5) ◽  
pp. 872-879 ◽  
Author(s):  
Karen M. Gonçalves ◽  
Felipe K. Sutili ◽  
Ivaldo I. Júnior ◽  
Marcella C. Flores ◽  
Leandro Soter de Mariz e Miranda ◽  
...  
Keyword(s):  
Food Waste ◽  
Waste Streams ◽  
Lecitase Ultra ◽  
Comprehensive Study

ITO Thin Films on Silicon Buffer by Sol Gel Method

2006 ◽  
Vol 514-516 ◽  
pp. 1155-1160 ◽  
Author(s):  
Talaat Moussa Hammad
Keyword(s):  
Thin Films ◽  
Indium Tin Oxide ◽  
Optical Transmission ◽  
Sol Gel ◽  
Precursor Solution ◽  
Charge Carriers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ito Thin Films ◽  
Uv Visible

Sol gel indium tin oxide thin films (In: Sn = 90:10) were prepared by the sol-gel dipcoating process on silicon buffer substrate. The precursor solution was prepared by mixing SnCl2.2H2O and InCl3 dissolved in ethanol and acetic acid. The crystalline structure and grain orientation of ITO films were determined by X-ray diffraction. The surface morphology of the films was characterized by scanning electron microscope (SEM). Optical transmission and reflectance spectra of the films were analyzed by using a UV-visible spectrophotometer. The transport properties of majority charge carriers for these films were studied by Hall measurement. ITO thin film with electrical resistivity of 7.6 ×10-3 3.cm, Hall mobility of approximately 2 cm2(Vs)-1 and free carrier concentration of approximately 4.2 ×1020 cm-3 are obtained for films 100 nm thick films. The I-V curve measurement showed typical I-V characteristic behavior of sol gel ITO thin films.

Effect of Precursor Sol Ageing on Sol-Gel Derived Ruthenium Oxide Thin Films

1999 ◽  
Vol 606 ◽  
Author(s):  
S. Bhaskar ◽  
S. B. Majumder ◽  
P. S. Dobal ◽  
R. S. Katiyar ◽  
A. L. M. Cruz ◽  
...  
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Ruthenium Oxide ◽  
Precursor Solution ◽  
Silicon Substrates ◽  
Solution Deposition ◽  
Precursor Material ◽  
Afm Analysis

AbstractIn the present work we have optimized the process parameters to yield homogeneous, smooth ruthenium oxide (RuO2) thin films on silicon substrates by a solution deposition technique using RuCl3.×.H2O as the precursor material. Films were annealed in a temperature range of 300°C to 700°C, and it was found that RuO2 crystallizes at a temperature as low as 400°C. The crystallinity of the films improves with increased annealing temperature and the resistivity decreases from 4.86µΩ-m (films annealed at 400°C) to 2.94pµΩ (films annealed at 700°C). Ageing of the precursor solution has a pronounced effect on the measured resistivities of RuO2 thin films. It was found that the measured room temperature resistivities increases from 2.94µΩ-m to 45.7µΩ-m when the precursor sol is aged for aged 60 days. AFM analysis on the aged films shows that the grain size and the surface roughness of the annealed films increase with the ageing of the precursor solution. From XPS analysis we have detected the presence of non-transformed RuCl3 in case of films prepared from aged solution. We propose, that solution ageing inhibits the transformation of RuCl3 to RuO2 during the annealing of the films. The deterioration of the conductivity with solution ageing is thought to be related with the chloride contamination in the annealed films.

scholarly journals Morphological and Structural Evolution of Chemically Deposited Epitaxially LaNiO3 Thin Films

Coatings ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1376
Author(s):  
Mircea Nasui ◽  
Ramona Bianca Sonher ◽  
Ecaterina Ware ◽  
Andrada Daniel ◽  
Traian Petrisor ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Analyses ◽  
Structural Evolution ◽  
Precursor Solution ◽  
Solution Deposition ◽  
Chemical Solution Deposition Method ◽  
Out Of Plane ◽  
Optimal Surface ◽  
Decomposition Behavior ◽  
Surface Morphologies

We report the preparation and characterization of epitaxial LaNiO3 (LNO) thin films by chemical solution deposition method using lanthanum and nickel acetylacetonates as starting reagents dissolved in propionic acid. In order to obtain further information regarding the decomposition behavior of the film, the precursor solution was dried to obtain the precursor powder, which was investigated by thermal analyses and X-ray diffraction measurements (XRD). The LNO perovskite thin films were deposited by spin coating on SrTiO3(100) single crystal substrates. A detailed study with different crystallization temperatures (600–900 °C) at two different heating ramps (5 and 10 °C/min) was performed. Oriented LaNiO3 thin films with good out-of-plane textures were obtained with optimal surface morphologies.

scholarly journals Influence of Ag-Dopant on Structural Optical and Electrical Properties of Cu(1-x)AgxO Thin Films Prepared By Chemical Spray Pyrolysis Technique

2018 ◽  
Vol 4 (5) ◽  
pp. 542-545 ◽  
Author(s):  
R. Shabu ◽  
A. Moses Ezhil Raj
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Spray Pyrolysis ◽  
Optical Band Gap ◽  
Spray Pyrolysis Technique ◽  
Precursor Solution ◽  
Oxide Semiconductor ◽  
Chemical Spray Pyrolysis ◽  
Chemical Spray Pyrolysis Technique ◽  
Chemical Spray

As major attention has been paid to transition metal oxide semiconductor suitable for solar cell, photo detector and gas sensor, present study embark on the structural, optical and electrical characterization of Ag doped CuO thin films prepared using chemical spray pyrolysis technique at the constant substrate temperature of 350 �C. For Ag doping, various concentrations of silver acetate (0.5-3.0 wt.%) was used in the sprayed precursor solution. Confirmed monoclinic lattice shows the tenorite phase formation of CuO in the pure and Ag doped films. The optical band gap of the films was in the range of 2.4 -3.4 eV. A minimum resistivity of 0.0017x103 ohmcm was achieved in the 0.5 wt.% Ag doped film, and its optical band gap was 2.74 eV.

A comprehensive study of SHI irradiated fullerene C 60 thin films: Polymerization to amorphization

2017 ◽  
Vol 227 ◽  
pp. 93-99 ◽  
Author(s):  
P. Sharma ◽  
R. Singhal ◽  
R. Vishnoi ◽  
M.K. Banerjee ◽  
D.K. Avasthi
Keyword(s):  
Thin Films ◽  
Comprehensive Study
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