Preparation of CMC-PVA/PAN-FePc(COOH)8/CS-PVA Bipolar Membrane and its Application in Electro-Oxidized Synthesis of Dialdehydle Starch

2015 ◽  
Vol 1120-1121 ◽  
pp. 141-147
Author(s):  
Zhong Gui Li ◽  
Ting Jin Zhou ◽  
Ri Yao Chen ◽  
Xiao Chen ◽  
Xi Zheng ◽  
...  
Keyword(s):  
Polyvinyl Alcohol ◽  
Current Efficiency ◽  
Current Density ◽  
Cell Voltage ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Experimental Results ◽  
Bipolar Membrane ◽  
Electrospinning Technique ◽  
A Current

The polyacrylonitrile (PAN)-iron octocarboxyphthalocyanine (FePc(COOH)8) nanofibers were prepared using electrospinning technique and introduced into the interlayer of a carboxymethyl cellulose (CMC)-polyvinyl alcohol (PVA)/chitosan (CS)-polyvinyl alcohol bipolar membrane (BPM), which was characterized using SEM, contact angle measurement, current-voltage characteristics, AC impedance spectroscopy and so on. The experimental results showed that after modification by PAN-FePc(COOH)8 nanofibers, the membrane impedance of the BPM and its cell voltage were decreased. That indicated that the water splitting efficiency in the interlayer of the BPM was increased. Then the prepared CMC-PVA/PAN-FePc(COOH)8/CS-PVA BPM was used in the electro-oxidized preparation of dialdehydle starch (DAS). The experimental results indicated that a current density of 20mA·cm-2 was suitable to obtain high current efficiency. When the electrolysis time was 3h at a current density of 20 mA·cm-2 , the current efficiency of the CMC-PVA/PAN-FePc(COOH)8/CS-PVA BPM-equipped cell was as high as 67%.

Preparation and Characterization of CMC-PVA/PVA-SA-MePc (COOH)8/CS-PVA Bipolar Membrane Using Electrospinning Technique

2013 ◽  
Vol 774-776 ◽  
pp. 795-798
Author(s):  
Ting Jin Zhou ◽  
Min Lu ◽  
Ri Yao Chen
Keyword(s):  
Polyvinyl Alcohol ◽  
Water Splitting ◽  
Current Density ◽  
Voltage Drop ◽  
High Current Density ◽  
High Current ◽  
Bipolar Membrane ◽  
Electrospinning Technique ◽  
Exchange Layer

Carboxymethyl cellulose (CMC)-polyvinyl alcohol (PVA) and chitosan (CS)-polyvinyl alcohol were cross-linked by Fe3+and glutaraldehyde respectively to prepare cation exchange layer and anion exchange layer, and polyvinyl alcohol-sodium alginate (SA)-metal octocarboxyphthalocyanine (MePc (COOH)8, a kind of water splitting catalyst, here, Me stands for Fe3+or Co2+) nanofibers were prepared by electrospinning technique and introduced into the interlayer to obtain the CMC-PVA/PVA-SA-MePc (COOH)8/CS-PVA bipolar membrane (BPM). The experimental results showed that compared with the BPM without the PVA-SA-MePc (COOH)8interlayer, the water splitting efficiency at the interlayer of the CMC-PVA/PVA-SA-MePc (COOH)8/ CS-PVA BPM was obviously increased, and its membrane impedance decreased. When the concentration of FePc (COOH)8in the PVA-SA-FePc (COOH)8nanofibers was 3.0%, the trans-membrane voltage drop (IRdrop) of the CMC-PVA/PVA-SA-FePc (COOH)8/CS-PVA BPM was as low as 0.6V at a high current density of 90 mA/cm2.

CO2 electrolysis to multicarbon products in strong acid

Science ◽  
2021 ◽  
Vol 372 (6546) ◽  
pp. 1074-1078
Author(s):  
Jianan Erick Huang ◽  
Fengwang Li ◽  
Adnan Ozden ◽  
Armin Sedighian Rasouli ◽  
F. Pelayo García de Arquer ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Hydrogen Evolution ◽  
Current Density ◽  
Carbon Emissions ◽  
Active Sites ◽  
Cell Voltage ◽  
Strong Acid ◽  
Electrochemically Active ◽  
Co2 Electrolysis ◽  
A Current

Carbon dioxide electroreduction (CO2R) is being actively studied as a promising route to convert carbon emissions to valuable chemicals and fuels. However, the fraction of input CO2 that is productively reduced has typically been very low, <2% for multicarbon products; the balance reacts with hydroxide to form carbonate in both alkaline and neutral reactors. Acidic electrolytes would overcome this limitation, but hydrogen evolution has hitherto dominated under those conditions. We report that concentrating potassium cations in the vicinity of electrochemically active sites accelerates CO2 activation to enable efficient CO2R in acid. We achieve CO2R on copper at pH <1 with a single-pass CO2 utilization of 77%, including a conversion efficiency of 50% toward multicarbon products (ethylene, ethanol, and 1-propanol) at a current density of 1.2 amperes per square centimeter and a full-cell voltage of 4.2 volts.

Asymmetric supercapacitors based on carbon nanofibre and polypyrrole/nanocellulose composite electrodes

RSC Advances ◽  
2015 ◽  
Vol 5 (21) ◽  
pp. 16405-16413 ◽  
Author(s):  
Petter Tammela ◽  
Zhaohui Wang ◽  
Sara Frykstrand ◽  
Peng Zhang ◽  
Ida-Maria Sintorn ◽  
...  
Keyword(s):  
Current Density ◽  
Aqueous Electrolyte ◽  
Cell Voltage ◽  
Composite Electrodes ◽  
Asymmetric Supercapacitors ◽  
Carbon Nanofibre ◽  
Maximum Cell ◽  
A Current

Asymmetric, all-organic supercapacitors (containing an aqueous electrolyte), exhibiting a capacitance of 25 F g−1 (or 2.3 F cm−2) at a current density of 20 mA cm−2 and a maximum cell voltage of 1.6 V, are presented.

scholarly journals Investigation of Superhydrophobic/Hydrophobic Materials Properties Using Electrospinning Technique

2019 ◽  
Vol 16 (3) ◽  
pp. 0632 ◽  
Author(s):  
Jaafar Et al.
Keyword(s):  
Polymer Solution ◽  
Glass Substrate ◽  
Low Cost ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Metal Substrate ◽  
Electrospinning Technique ◽  
Electrospinning Method ◽  
Surface Alteration ◽  
Measurement Surface

     The aim of this research is to study the surface alteration characteristics and surface morphology of the superhydrophobic/hydrophobic nanocomposite coatings prepared by an electrospinning method to coat various materials such as glass and metal. This is considered as a low cost method of fabrication for polymer solutions of Polystyrene (PS), Polymethylmethacrylate (PMMA) and Silicone Rubber (RTV). Si were prepared in various wt% of composition for each solutions. Contact angle measurement, surface tension, viscosity, roughness tests were calculated for all specimens. SEM showed the morphology of the surfaces after coated. PS and PMMA showed superhydrophobic properties for metal substrate, while Si showed hydrophobic characteristics for both metal and glass substrate. Polymer solution of (15%Si/Thinner (Th)) owned best roughness for glass substrate and polymer solution of (4%PMMA/Tetrahydrofuran (THF)) owned best roughness for metal substrate.

An advanced and highly efficient Ce assisted NiFe-LDH electrocatalyst for overall water splitting

2020 ◽  
Vol 4 (1) ◽  
pp. 312-323 ◽  
Author(s):  
Harsharaj S. Jadhav ◽  
Animesh Roy ◽  
Bezawit Z. Desalegan ◽  
Jeong Gil Seo
Keyword(s):  
Water Splitting ◽  
Current Density ◽  
Room Temperature ◽  
Cell Voltage ◽  
Highly Efficient ◽  
Overall Water Splitting ◽  
A Cell ◽  
A Current

A room-temperature synthesized NiFeCe2 electrocatalyst delivered a current density of 10 mA cm−2 at a cell voltage of 1.59 V when used as the electrolyzer.

scholarly journals High Temperature Water Electrolysis Using Metal Supported Solid Oxide Electrolyser Cells (SOEC)

2010 ◽  
Vol 72 ◽  
pp. 135-143 ◽  
Author(s):  
Günter Schiller ◽  
Asif Ansar ◽  
Olaf Patz
Keyword(s):  
High Temperature ◽  
Fuel Cell ◽  
Current Density ◽  
Degradation Rate ◽  
Cell Voltage ◽  
Operating Conditions ◽  
Solid Oxide ◽  
Metallic Interconnect ◽  
A Current

Metal supported cells as developed at DLR for use as solid oxide fuel cells by applying plasma deposition technologies were investigated in operation of high temperature steam electrolysis. The cells consisted of a porous ferritic steel support, a diffusion barrier layer, a Ni/YSZ fuel electrode, a YSZ electrolyte and a LSCF oxygen electrode. During fuel cell and electrolysis operation the cells were electrochemically characterised by means of i-V characteristics and electrochemical impedance spectroscopy measurements including a long-term test over 2000 hours. The results of electrochemical performance and long-term durability tests of both single cells and single repeating units (cell including metallic interconnect) are reported. During electrolysis operation at an operating temperature of 850 °C a cell voltage of 1.28 V was achieved at a current density of -1.0 A cm-2; at 800 °C the cell voltage was 1.40 V at the same operating conditions. The impedance spectra revealed a significantly enhanced polarisation resistance during electrolysis operation compared to fuel cell operation which was mainly attributed to the hydrogen electrode. During a long-term test run of a single cell over 2000 hours a degradation rate of 3.2% per 1000 hours was observed for operation with steam content of 43% at 800 °C and a current density of -0.3 Acm-2. Testing of a single repeating unit proved that a good contacting of cell and metallic interconnect is of major importance to achieve good performance. A test run over nearly 1000 hours showed a remarkably low degradation rate.

Hydrophobicity Enhancement of the Polyvinyl Alcohol/Rice Starch/Silk Fibroin Films by Glycerol

2013 ◽  
Vol 446-447 ◽  
pp. 360-365
Author(s):  
Pusita Kuchaiyaphum ◽  
Takeshi Yamauchi ◽  
Ruangsri Watanesk ◽  
Surasak Watanesk
Keyword(s):  
Contact Angle ◽  
Polyvinyl Alcohol ◽  
Silk Fibroin ◽  
Water Solubility ◽  
Contact Angle Measurement ◽  
Contact Angles ◽  
Angle Measurement ◽  
Rice Starch ◽  
Water Contact ◽  
Degree Of Swelling

Eco-friendly films have been prepared using various biopolymers and their properties have been improved in order to meet the requirements for appropriate applications. However, the frequently encountered weakness of the properties of most biopolymer film is its water solubility. In this study, the polyvinyl alcohol/rice starch/silk fibroin (PVA/RS/SF) films were modified by the addition of glycerol aiming to increase the hydrophobicity of the films. Some properties of the modified films including water contact angle, degree of swelling and water solubility were compared with the unmodified PVA/RS/SF film. Results from the contact angle measurement showed that the films with glycerol could be transformed to be hydrophobic after soaking in ethanol medium. The increase in soaking time tends to increase the hydrophobicity of the films. However, at about 60 min soaking, the water contact angles on the films were quite constant with the values of about 107.9±5.2º comparing with 65.3±2.4º of the ethanol-untreated PVA/RS/SF films. In addition, the ethanol-treated glycerol-modified films also show higher degree of swelling with constant solubility and better mechanical properties.

scholarly journals Selective Recovery of Tellurium from the Tellurium-Bearing Sodium Carbonate Slag by Sodium Sulfide Leaching Followed by Cyclone Electrowinning

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1176
Author(s):  
Zhipeng Xu ◽  
Zoujiang Li ◽  
Dong Li ◽  
Xueyi Guo ◽  
Ying Yang ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Current Efficiency ◽  
Sodium Carbonate ◽  
Flow Rate ◽  
Current Density ◽  
Sodium Sulfide ◽  
Cell Voltage ◽  
Promising Alternative ◽  
Selective Recovery ◽  
Solid Ratio

The rigorous environmental requirements promote the development of new processes with short and clean technical routes for recycling tellurium from tellurium-bearing sodium carbonate slag. In this paper, a novel process for selective recovery of tellurium from the sodium carbonate slag by sodium sulfide leaching, followed by cyclone electrowinning, was proposed. 88% of tellurium was selectively extracted in 40 g/L Na2S solution at 50 °C for 60 min with a liquid to solid ratio of 8:1 mL/g, while antimony, lead and bismuth were enriched in the leaching residue. Tellurium in the leach liquor was efficiently electrodeposited by cyclone electrowinning without purification. The effects of current density, temperature and flow rate of the electrolyte on current efficiency, tellurium recovery, cell voltage, energy consumption, surface morphology, and crystallographic orientations were systematically investigated. 91.81% of current efficiency and 95.47% of tellurium recovery were achieved at current density of 80 A/m2, electrolyte temperature of 45 °C and electrolyte flow rate of 400 L/h. The energy consumption was as low as 1.81 kWh/kg. A total of 99.38% purity of compact tellurium deposits were obtained. Therefore, the proposed process may serve as a promising alternative for recovering tellurium from tellurium-bearing sodium carbonate slag.

scholarly journals Electrosynthesis of Ni-Co/Hydroxyapatite as a Catalyst for Hydrogen Generation via the Hydrolysis of Aqueous Sodium Borohydride (NaBH4) Solutions

2021 ◽  
Vol 15 (3) ◽  
pp. 389-394
Author(s):  
Adrian Nur ◽  
◽  
Anatta W. Budiman ◽  
Arif Jumari ◽  
Nazriati Nazriati ◽  
...  
Keyword(s):  
Current Density ◽  
Hydrogen Generation ◽  
Carbon Anode ◽  
Bipolar Membrane ◽  
Dc Power ◽  
Production Of Hydrogen ◽  
Catalyst Formation ◽  
Hydrolysis Of ◽  
Hydrolysis Of Nabh4 ◽  
A Current

To generate hydrogen from its storage as NaBH4, a catalyst was synthesized via an electrochemical method. The catalyst, Ni-Co, had hydroxyapatite as a support catalyst. The electrochemical cell consisted of a DC power supply, a carbon anode and cathode, and a bipolar membrane to separate the cell into two chambers. The current density was adjusted to 61, 91, and 132 mA/cm2. The electrolysis time was 30, 60, and 90 min. The particles produced were analyzed by XRD and SEM/EDX and tested in the hydrolysis of NaBH4 for hydrogen generation. The Ni-Co/HA catalyst test concluded that the period of time used for electrolysis during catalyst formation was positively correlated with the rate of NaBH4 hydrolysis in the production of hydrogen. The highest rate of hydrogen production was obtained using the synthesized catalyst with a current density of 92 mA/cm2. The NaBH4 hydrolysis reaction followed a first-order reaction with the rate constant of (2.220–14.117)•10-3 l/(g•min). The Arrhenius equation for hydrolysis reactions within the temperature range of 300–323 K is k = 6.5•10-6exp(-6000/T).

scholarly journals Fabrication and Evaluation of Polycaprolactone/Gelatin-Based Electrospun Nanofibers with Antibacterial Properties

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Lor Huai Chong ◽  
Mim Mim Lim ◽  
Naznin Sultana
Keyword(s):  
Drug Loading ◽  
Antibacterial Properties ◽  
Electrospun Nanofibers ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Electrospinning Technique ◽  
Water Contact ◽  
Nanofibrous Scaffolds ◽  
Model Drug

Nanofibrous scaffolds were fabricated through blending of a synthetic polymer, polycaprolactone (PCL), and a natural polymer, gelatin (GE), using an electrospinning technique. Processing and solution parameters were optimized to determine the suitable properties of PCL/GE-based nanofibers. Several characterizations were conducted to determine surface morphology by scanning electron microscopy (SEM), wettability using water contact angle measurement, and chemical bonding analysis using attenuated total reflectance (ATR) of PCL/GE-based nanofibers. Experimental results showed that 14% (w/v) PCL/GE with a flow rate of 0.5 mL/h and 18 kV demonstrated suitable properties. This nanofiber was then further investigated for itsin vitrodegradation, drug loading (using a model drug, tetracycline hydrochloride), and antibacterial testing (using zone inhibition method).

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