scholarly journals In-situ monitoring by thermal lens microscopy of a photocatalytic reduction process of hexavalent chromium

2018 ◽  
Vol 64 (5) ◽  
pp. 507
Author(s):  
E Cedeño ◽  
J. Plazas-Saldaña ◽  
F. Gordillo-Delgado ◽  
A. Bedoya ◽  
Ernesto Marin
Keyword(s):  
Calibration Curve ◽  
Thermal Lens ◽  
Sol Gel ◽  
Colorimetric Method ◽  
Reduction Process ◽  
Dip Coating ◽  
In Situ Monitoring ◽  
Probe Laser ◽  
A Cell

In this work, we describe the application of a micro-spatial thermal lens spectroscopy setup (thermal lens microscope, TLM) with coaxial counter-propagating pump and probe laser beams and an integrated passive optical Fabry-Perot to quantify the Cr-VI concentration in water during a photocatalytic reaction in-situ. A series of test samples was analyzed using the 1,5 diphenil carbazide colorimetric method. A calibration curve was obtained by plotting of the TLM signal as a function of the concentration of Cr(VI) in a range between 0 and 10 μg/L (1 μg/L = 1 ppb, part per billion), with a detection limit of 53 ng/L (1 ng/L = 1 ppt, part per trillion). A solution of 10 μg/L Cr(VI) in distillated water was placed into a cell in contact with an iron-incorporated titanium dioxide film, which was previously grown onto a 1 mm thick glass microscope slide by the sol-gel dip-coating technique. The TLM signal was registered as a function of the photocatalysis time measured from the beginning of the process, radiating the film with UV-violet light. The Cr(VI) concentration was determined with the calibration curve and after the first 50 minutes a reduction of 95 % of Cr(VI) was observed, being the chemical reaction kinetic described by a potential time decreasing function.

In-Situ Study of NiO Growth on Textured Nickel Tape Using Environmental Scanning Electron Microscope (ESEM) and Hot Stage

2001 ◽  
Vol 7 (S2) ◽  
pp. 1276-1277
Author(s):  
Y. Akin ◽  
R.E. Goddard ◽  
W. Sigmund ◽  
Y.S. Hascicek
Keyword(s):  
Buffer Layer ◽  
Lattice Mismatch ◽  
Sol Gel ◽  
Surface Oxidation ◽  
Dip Coating ◽  
Buffer Layers ◽  
Superconducting Film ◽  
Environmental Scanning ◽  
Cold Rolling And Annealing

Deposition of highly textured ReBa2Cu3O7−δ (RBCO) films on metallic substrates requires a buffer layer to prevent chemical reactions, reduce lattice mismatch between metallic substrate and superconducting film layer, and to prevent diffusion of metal atoms into the superconductor film. Nickel tapes are bi-axially textured by cold rolling and annealing at appropriate temperature (RABiTS) for epitaxial growth of YBa2Cu3O7−δ (YBCO) films. As buffer layers, several oxide thin films and then YBCO were coated on bi-axially textured nickel tapes by dip coating sol-gel process. Biaxially oriented NiO on the cube-textured nickel tape by a process named Surface-Oxidation- Epitaxy (SEO) has been introduced as an alternative buffer layer. in this work we have studied in situ growth of nickel oxide by ESEM and hot stage.Representative cold rolled nickel tape (99.999%) was annealed in an electric furnace under 4% hydrogen-96% argon gas mixture at 1050°C to get bi-axially textured nickel tape.

scholarly journals Effect of Preparation Condition of Ti Film and Experimental Condition on C Reduction Performance of Ti Photocatalyst Membrane Reactor

2011 ◽  
Vol 2011 ◽  
pp. 1-14 ◽  
Author(s):  
Akira Nishimura ◽  
Yuki Okano ◽  
Masafumi Hirota ◽  
Eric Hu
Keyword(s):  
Membrane Reactor ◽  
Sol Gel ◽  
Reduction Process ◽  
Dip Coating ◽  
Preparation Condition ◽  
Circulation Type ◽  
Reduction Experiment ◽  
Separation Membrane ◽  
Coating Method ◽  
Dip Coating Method

It was previously reported that CO2could be reduced into CO, CH4, and so forth, which can be used as fuels, by TiO2as the photocatalyst under UV radiation. To increase the concentration of fuel and improve CO2reduction performance on TiO2photocatalyst, a membrane reactor composed of TiO2and gas separation membrane prepared by sol-gel and dip-coating method has been built. Factors such as rising speed (RS) in the dip-coating process and the timing and amount of water injected in the membrane reactor in CO2reduction experiment have been investigated. As a result, the largest amount of TiO2film is obtained for  mm/s among various RS conditions investigated in this study. According to CO2reduction experiment by gas circulation type reactor, too much water which cannot be consumed in CO2reduction process would not help improving the CO2reduction performance.

Low Concentration Synthesis of Super-Amphiphilic Nanoflake ZSM-5 Film with Adjustable Property

NANO ◽  
2020 ◽  
Vol 15 (10) ◽  
pp. 2050124
Author(s):  
Fei Tong ◽  
Jie Gong ◽  
Hengfei Qin ◽  
Jinlong Jiang ◽  
Lixiong Zhang
Keyword(s):  
Sol Gel ◽  
Dip Coating ◽  
Hydrophobic Property ◽  
Low Concentration ◽  
Silica Source ◽  
High Silica ◽  
Slide Show ◽  
Zeolite Films ◽  
Synthesis Solution

High silica zeolite ZSM-5/glass film was successfully synthesized by an in-situ sol–gel dip-coating process combined with the steam-assisted conversion (SAC) technique with low concentration of the synthesis solution. The resulting zeolite films grown on the glass slide show amphiphilic properties. The growing process and the effect of the concentration of SiO2 in the silica source were examined. The mechanism of the formation of the nanoflake crystals and their wetting behavior was investigated. By simply adding fluorescein in the synthesis solution during the preparation, ZSM-5 films showing luminescence property can be obtained. Furthermore, these ZSM-5 zeolite films are easily modified to exhibit hydrophobic property.

In situ monitoring the sol–gel transition for polyacrylamide gel

2006 ◽  
Vol 46 (5) ◽  
pp. 595-600 ◽  
Author(s):  
Loredana Elena Niţă ◽  
Aurica P. Chiriac ◽  
Maria Bercea ◽  
Iordana Neamţu
Keyword(s):  
Sol Gel ◽  
Polyacrylamide Gel ◽  
In Situ Monitoring ◽  
Sol Gel Transition ◽  
Gel Transition

scholarly journals FLUORESCENCE STUDIES FOR IN SITU MONITORING OF THE HYDROLYSIS AND POLYMERIZATION REACTIONS OF ORGANICALLY –MODIFIED TETRAMETHYLORTHOSILICATE

2010 ◽  
Vol 5 (3) ◽  
pp. 290-294
Author(s):  
Eko Sri Kunarti
Keyword(s):  
Condensation Reaction ◽  
Sol Gel ◽  
In Situ Monitoring ◽  
Condensation Polymerization ◽  
Surrounding Water ◽  
Fluorescence Studies ◽  
Hydrolysis And Condensation ◽  
Organically Modified ◽  
Kinetics Of

Monitoring of hydrolysis and condensation polymerization reactions of tetramethylorthosilicate-organosiloxane have been carried out. Proton transfer from the excited state of 8-hydroxy-1,3,6-pyrenetrisulfonic acid trisodium salt (pyranine) to surrounding water molecules was used as a sensitive fluorescence method for following the kinetics of water consumption during the early stages of the sol-gel polymerisation process. Changes in water/silane ratio, type of organosiloxane, mol ratio of organosiloxane to silica precursor and pH affected markedly the kinetic behavior of the hydrolysis and condensation reaction of tetramethylorthosilicate.   Keywords: hydrolysis, polymerisation, fluorescence, pyranine, tetramethylorthosilicate, organosiloxane.

scholarly journals Applicability of the Electrochemical Oxygen Sensor for In-Situ Evaluation of MgO Solubility in the MgF2–LiF Molten Salt Electrolysis System

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 906 ◽  
Author(s):  
Youngjae Kim ◽  
Junsoo Yoo ◽  
Jungshin Kang
Keyword(s):  
Oxygen Sensor ◽  
Reduction Process ◽  
Monitoring And Evaluation ◽  
In Situ Monitoring ◽  
Calibration Line ◽  
Molten Salt Electrolysis ◽  
Molten Fluoride ◽  
Measurement And Evaluation ◽  
Electrochemical Oxygen

The measurement and evaluation of MgO solubility in the molten fluoride system is of significant importance in the recently proposed magnesium electrolysis reduction process. In the present study, an in-situ quantitative method of evaluating the concentration of dissolved MgO in molten fluoride is proposed. The MgO solubility in the 32.8MgF2–67.2LiF system was measured at 1083 and 1123 K using a combustion analyzer. MgO saturation was achieved in under 2 h, and higher solubilities were observed as the temperature increased. Thermodynamic assessment was carried out in order to ascertain the applicability of the electrochemical oxygen sensor, which indicated that the logarithm of oxygen concentration in molten fluoride has a linear relationship with the measured electromotive force (EMF) potential. The EMF potential of the controlled MgO concentration was measured, and a straight calibration line was obtained, describing the relationship between the measured EMF and the logarithm of MgO concentration. From the obtained calibration line, MgO concentration in the 0.4 wt% MgO was calculated. The calculated value was 0.44 wt% that was in excellent accordance with the controlled MgO concentration of 0.4 wt%, verifying the practical applicability of electrochemical oxygen for the in-situ monitoring and evaluation of MgO solubility in the electrolysis magnesium reduction process.

Sign in / Sign up

Export Citation Format

Share Document