scholarly journals Low-Cost Reliable Corrosion Sensors Using ZnO-PVDF Nanocomposite Textiles

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4147
Author(s):  
Tonoy Chowdhury ◽  
Nandika D’Souza ◽  
Narendra Dahotre
Keyword(s):  
Polyvinylidene Fluoride ◽  
Electrochemical Impedance ◽  
Low Cost ◽  
Corrosion Performance ◽  
Steel Pipes ◽  
Flexible Sensor ◽  
Nanocomposite Fiber ◽  
Corrosion Sensor ◽  
Corrosion Barrier ◽  
Sensor Accuracy

Submerged steel pipes are susceptible to corrosion due to long exposure under harsh corrosive conditions. Here, we investigated the reliability and effectiveness of nonwoven zinc(II) oxide-polyvinylidene fluoride (ZnO-PVDF) nanocomposite fiber textiles as an embedded corrosion sensor. An accelerated thermal cyclic method paired to electrochemical impedance spectroscopy (EIS) was used for this purpose. Sensor accuracy and reliability were determined using the textile and instrument as reference electrodes. The results showed that the coating and the sensor improved the corrosion resistance when ZnO was added to the sensor textile and introduced into the coating. As the coating’s glass transition was approached, the corrosion performance of the coating degraded and the sensor accuracy decreased. The results suggested that the flexible sensor is reliable at both monitoring the corrosion and acting as a corrosion barrier.

scholarly journals Embedded Corrosion Sensing with ZnO-PVDF Sensor Textiles

Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3053
Author(s):  
Tonoy Chowdhury ◽  
Nandika D’Souza ◽  
Yee Hsien Ho ◽  
Narendra Dahotre ◽  
Ifana Mahbub
Keyword(s):  
Polyvinylidene Fluoride ◽  
Electrochemical Impedance ◽  
Low Cost ◽  
X Ray Diffraction ◽  
Steel Pipes ◽  
Surface Corrosion ◽  
Impermeable Barrier ◽  
Nanocomposite Fiber ◽  
Viable Solution ◽  
Metal Sensors

Corrosion in underground and submerged steel pipes is a global problem. Coatings serve as an impermeable barrier or a sacrificial element to the transport of corrosive fluids. When this barrier fails, corrosion in the metal initiates. There is a critical need for sensors at the metal/coating interface as an early alert system. Current options utilize metal sensors, leading to accelerating corrosion. In this paper, a non-conductive sensor textile as a viable solution was investigated. For this purpose, non-woven Zinc (II) Oxide-Polyvinylidene Fluoride (ZnO-PVDF) nanocomposite fiber textiles were prepared in a range of weight fractions (1%, 3%, and 5% ZnO) and placed at the coating/steel interface. The properties of ZnO-PVDF nanocomposite meshes were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) and d33 meter. Electrochemical impedance spectroscopy (EIS) testing was performed during the immersion of the coated samples to validate the effectiveness of the sensor textile. The results offer a new option for sub-surface corrosion sensing using low cost, easily fabricated sensor textiles.

Improvement of Ti/RuO2–IrO2 Anode Lifetime and Electrocatalytical Properties by Using an Eco-Friendly Thermal Decomposition Method Using Polyvinyl Alcohol as Solvent

2019 ◽  
Author(s):  
Charlys Bezerra ◽  
Géssica Santos ◽  
Marilia Pupo ◽  
Maria Gomes ◽  
Ronaldo Silva ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Polyvinyl Alcohol ◽  
High Efficiency ◽  
Electrochemical Impedance ◽  
Pechini Method ◽  
Low Cost ◽  
Charge Transfer Resistance ◽  
Transfer Resistance ◽  
Calcination Temperatures ◽  
Service Lifetime

<p>Electrochemical oxidation processes are promising solutions for wastewater treatment due to their high efficiency, easy control and versatility. Mixed metal oxides (MMO) anodes are particularly attractive due to their low cost and specific catalytic properties. Here, we propose an innovative thermal decomposition methodology using <a>polyvinyl alcohol (PVA)</a> as a solvent to prepare Ti/RuO<sub>2</sub>–IrO<sub>2</sub> anodes. Comparative anodes were prepared by conventional method employing a polymeric precursor solvent (Pechini method). The calcination temperatures studied were 300, 400 and 500 °C. The physical characterisation of all materials was performed by X-ray diffraction and scanning electron microscopy coupled with energy dispersive spectroscopy, while electrochemical characterisation was done by cyclic voltammetry, accelerated service lifetime and electrochemical impedance spectroscopy. Both RuO<sub>2</sub> and IrO<sub>2</sub> have rutile-type structures for all anodes. Rougher and more compact surfaces are formed for the anodes prepared using PVA. Amongst temperatures studied, 300 °C using PVA as solvent is the most suitable one to produce anodes with expressive increase in voltammetric charge (250%) and accelerated service lifetime (4.3 times longer) besides reducing charge-transfer resistance (8 times lower). Moreover, the electrocatalytic activity of the anodes synthesised with PVA toward the Reactive Blue 21 dye removal in chloride medium (100 % in 30 min) is higher than that prepared by Pechini method (60 min). Additionally, the removal total organic carbon point out improved mineralisation potential of PVA anodes. Finally, this study reports a novel methodology using PVA as solvent to synthesise Ti/RuO<sub>2</sub>–IrO<sub>2</sub> anodes with improved properties that can be further extended to synthesise other MMO compositions.</p>

Green water-based binders for LiFePO4/C cathode in Li-ion batteries: a comparative study

2021 ◽  
Author(s):  
Xiaojing Zhang ◽  
xinyi Ge ◽  
Zhigang Shen ◽  
Han Ma ◽  
Jingshi Wang ◽  
...  
Keyword(s):  
Comparative Study ◽  
Polyvinylidene Fluoride ◽  
Low Cost ◽  
Green Water ◽  
Li Ion Batteries ◽  
Environmental Friendliness ◽  
Water Based ◽  
Li Ion

Compared with environmentally harmful binder polyvinylidene fluoride (PVDF) in Li-ion batteries (LIBs), water-based binders have many advantages, such as low cost, rich sources and environmental friendliness. In this study, various...

scholarly journals Waterborne Polyurea Coatings Filled with Sulfonated Graphene Improved Anti-Corrosion Performance

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 251
Author(s):  
Jijia Zhang ◽  
Jihu Wang ◽  
Shaoguo Wen ◽  
Siwei Li ◽  
Yabo Chen ◽  
...  
Keyword(s):  
Composite Coating ◽  
Water Resistance ◽  
Electrochemical Impedance ◽  
Water Immersion ◽  
Doping Content ◽  
Corrosion Performance ◽  
Water Contact ◽  
Sulfonated Graphene ◽  
Long Time ◽  
Scanning Electron

In this paper, an environmentally friendly waterborne polyurea (WPUA) emulsion and its corresponding coating were prepared, which was characterized by dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), and scanning electron microscopy (SEM). To improve the performance of the coating, we doped sulfonated graphene (SG) into WPUA to prepare composite coating (SG/WPUA). SG can be uniformly dispersed in WPUA emulsion and is stable for a long time (28 days) without delamination. The water resistance of the composite coating with 0.3 wt.% SG nanofiller was improved; the water contact angle (WCA) result was SG/WPUA (89°) > WPUA (48.5°), and water absorption result was SG/WPUA (2.90%) < WPUA (9.98%). After water immersion treatment, SEM observation revealed that the SG/WPUA film only generated enlarged microcracks (100 nm) instead of holes (150–400 nm, WPUA film). Polarization curves and electrochemical impedance spectroscopy (EIS) tests show that SG nanosheets with low doping content (0.3 wt.%) are more conducive to the corrosion resistance of WPUA coatings, and the model was established to explain the mechanism.

scholarly journals Graphene oxide-based rechargeable respiratory masks

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Stelbin Peter Figerez ◽  
Sudeshna Patra ◽  
G Rajalakshmi ◽  
Tharangattu N Narayanan
Keyword(s):  
Graphene Oxide ◽  
Polyvinylidene Fluoride ◽  
Occupational Safety ◽  
Low Cost ◽  
Triboelectric Nanogenerator ◽  
Layer System ◽  
Retention Capacity ◽  
Simple Modification ◽  
Nonwoven Fabrics ◽  
Mask Design

Abstract Respiratory masks having similar standards of ‘N95’, defined by the US National Institute for Occupational Safety and Health, will be highly sought after, post the current COVID-19 pandemic. Here, such a low-cost (∼$1/mask) mask design having electrostatic rechargeability and filtration efficiency of &gt;95% with a quality factor of ∼20 kPa−1 is demonstrated. This filtration efficacy is for particles of size 300 nm. The tri-layer mask, named PPDFGO tri, contains nylon, modified polypropylene (PPY), and cotton nonwoven fabrics as three layers. The melt-spun PPY, available in a conventional N95 mask, modified with graphene oxide and polyvinylidene fluoride mixture containing paste using a simple solution casting method acts as active filtration layer. The efficacy of this tri-layer system toward triboelectric rechargeability using small mechanical agitations is demonstrated here. These triboelectric nanogenerator (TENG)-assisted membranes have high electrostatic charge retention capacity (∼1 nC/cm2 after 5 days in ambient condition) and high rechargeability even in very humid conditions (&gt;80% RH). A simple but robust permeability measurement set up is also constructed to test these TENG-based membranes, where a flow rate of 30–35 L/min is maintained during the testing. Such a simple modification to the existing mask designs enabling their rechargeability via external mechanical disturbances, with enhanced usability for single use as well as for reuse with decontantamination, will be highly beneficial in the realm of indispensable personal protective equipment.

scholarly journals A Facile and Green Synthesis of a MoO2-Reduced Graphene Oxide Aerogel for Energy Storage Devices

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 594 ◽  
Author(s):  
Mara Serrapede ◽  
Marco Fontana ◽  
Arnaud Gigot ◽  
Marco Armandi ◽  
Glenda Biasotto ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Chemical Reduction ◽  
Low Cost ◽  
Xps Analysis ◽  
3D Scaffold ◽  
Energy Storage Devices ◽  
Reduced Graphene

A simple, low cost, and “green” method of hydrothermal synthesis, based on the addition of l-ascorbic acid (l-AA) as a reducing agent, is presented in order to obtain reduced graphene oxide (rGO) and hybrid rGO-MoO2 aerogels for the fabrication of supercapacitors. The resulting high degree of chemical reduction of graphene oxide (GO), confirmed by X-Ray Photoelectron Spectroscopy (XPS) analysis, is shown to produce a better electrical double layer (EDL) capacitance, as shown by cyclic voltammetric (CV) measurements. Moreover, a good reduction yield of the carbonaceous 3D-scaffold seems to be achievable even when the precursor of molybdenum oxide is added to the pristine slurry in order to get the hybrid rGO-MoO2 compound. The pseudocapacitance contribution from the resulting embedded MoO2 microstructures, was then studied by means of CV and electrochemical impedance spectroscopy (EIS). The oxidation state of the molybdenum in the MoO2 particles embedded in the rGO aerogel was deeply studied by means of XPS analysis and valuable information on the electrochemical behavior, according to the involved redox reactions, was obtained. Finally, the increased stability of the aerogels prepared with l-AA, after charge-discharge cycling, was demonstrated and confirmed by means of Field Emission Scanning Electron Microscopy (FESEM) characterization.

scholarly journals Preparation and Chemical Protective Clothing Application of PVDF Based Sodium Sulfonate Membrane

Membranes ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 190
Author(s):  
Yue Zhao ◽  
Xinbo Wang ◽  
Deyin Wang ◽  
Heguo Li ◽  
Lei Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Polyvinylidene Fluoride ◽  
Protective Clothing ◽  
Low Cost ◽  
Chemical Warfare Agents ◽  
Contact Angles ◽  
Protective Material ◽  
Sodium Sulfonate ◽  
Vapor Permeation ◽  
Chemical Protective Clothing

Chemical protective clothing (CPC) is major equipment to protect human skin from hazardous chemical warfare agents (CWAs), especially nerve agents and blister agents. CPC performance is mainly dominated by the chemical protective material, which needs to meet various requirements, such as mechanical robustness, protective properties, physiological comfort, cost-effectiveness, and dimensional stability. In this study, polyvinylidene fluoride (PVDF) based sodium sulfonate membranes with different ion exchange capacities (IECs) are prepared simply from low-cost materials. Their mechanical properties, contact angles, permeations, and selectivities have been tested and compared with each other. Results show that membranes with IEC in the range of 1.5–2 mmol g−1 have high selectivities of water vapor permeation over CWA simulant vapor permeation and good mechanical properties. Therefore, PVDF-based sodium sulfonate membranes are potential materials for CPC applications.

scholarly journals Electrodeposition of Iridium-Nickel Thin Films on Copper Foam: Effects of Loading and Solution Temperature on HER Performance of Electrocatalyst in Alkaline Water

2020 ◽  
Author(s):  
Jianwen Liu ◽  
Wangping Wu ◽  
Xiang Wang
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Hydrogen Evolution ◽  
Electrocatalytic Activity ◽  
Electrochemical Impedance ◽  
Low Cost ◽  
Solution Temperature ◽  
High Deposition Rate ◽  
Hydrogen Energy ◽  
Copper Foam

Developing novel hydrogen evolution reaction (HER) catalysts with high activity, high stability and low cost is of great importance for the applications of hydrogen energy. In this work, iridium-nickel (Ir-Ni) thin films were electrodeposited on a copper foam as electrocatalyst for HER, and electrodeposition mechanism of Ir-Ni film was studied. The morphology and chemical composition of thin films were determined by scanning electron microscopy and energy-dispersive spectroscopy, respectively. The electrocatalytic performances of the films were estimated by linear sweep voltammograms, electrochemical impedance spectroscopy and cyclic voltammetry. The results show that Ir-Ni thin films were attached to the substrate of porous structure and hollow topography. The deposition of Ni was preferable in the electrolyte without the addition of additives, and Ir-Ni thin film was alloyed, resulting in high deposition rate for Ir42Ni58 thin film, and subsequently an increase of Ir content in the thin films of Ir80Ni20 and Ir88Ni12. Ir-Ni thin films with Tafel slopes of 40-49 mV·dec-1 exhibited highly efficient electrocatalytic activity for HER. The electrocatalytic activity of Ir-Ni thin films showed a loading dependence. As the solution temperature raised from 20 oC to 60 oC, the hydrogen evolution performance of Ir-Ni thin films improved. The apparent activation energy value of Ir88Ni12 film was 7.1 kJ·mol-1. Long-term hydrogen evolution tests exhibited excellent electrocatalystic stability in alkaline solution.

scholarly journals The influence of chromium as a diffusive additive in the boronizing treatment of AISI 4140 steel on the corrosion resistance of the coating evaluated by Electrochemical Impedance Spectroscopy (EIS)

2020 ◽  
Vol 318 ◽  
pp. 01040
Author(s):  
Dimitrios I. Zagkliveris ◽  
Azarias Mavropoulos ◽  
Efstathios Ntovinos ◽  
Georgios K. Triantafyllidis
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Low Cost ◽  
Industrial Applications ◽  
Pack Cementation ◽  
Boride Phase ◽  
Corrosion Resistant ◽  
Aisi 4140 Steel ◽  
Aisi 4140

A large variety of protective coating is being used in industrial applications to improve the resistance of the metallic substrates against corrosion. The pack-cementation method for boronizing and borochromizing is effective to produce extremely hard and corrosion resistant thick coatings and, additionally, is a low-cost and simple technique. In the present study, AISI 4140 steel specimens underwent boronizing and afterwards chromizing by the pack-cementation method using B4C as boron source and Fe-Cr as chromium source, respectively. In both treatments the appropriate activators were used. After chromizing the boronized substrate, a mixed boride phase FeCrB was formed, as it was confirmed by X-ray Diffractometry (XRD). The boronized and the borochromized specimens were subjected to Electrochemical Impedance Spectroscopy (EIS). From the analysis of the frequency response of the coating systems (Bode and Nyquist display), the conclusion that the borochromized specimens were significantly more corrosion resistant was extracted. Finally, data of optical and electron microscopy contribute to the validity of the conclusions.

scholarly journals Dependence of Capacitive Properties of an EDLC on Exfoliation Time of Graphite Electrodes

2021 ◽  
Author(s):  
Dinithi S. K. Rajaguru ◽  
Kamal Vidanapathirana ◽  
Kumudu S. Perera
Keyword(s):  
Electrochemical Impedance ◽  
Low Cost ◽  
Gel Polymer Electrolyte ◽  
Storage Device ◽  
Graphite Electrodes ◽  
Discharge Capacitance ◽  
Capacitive Properties ◽  
Device Applications ◽  
Specific Discharge ◽  
Electrochemical Double Layer

Abstract The scientific focus has been directed through the production and application of ‘wonder material- graphene’ after its discovery in 2004. But the mass production cost has become a huge disadvantage towards commercializing graphene based manufactures. As alternative low cost material, exfoliated graphite (EG) has emerged to be a novel nanostructured carbon material with a potential for electrochemical energy storage device applications owed to its unique characteristics similar to graphene. In this study a series of EG samples were prepared by a surfactant mediated liquid phase exfoliation method by changing the exfoliation time. Electrochemical double layer capacitors (EDLCs) were fabricated using different EG samples as an electrode material and a gel polymer electrolyte (GPE). They were characterized by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and galvanostatic charge discharge (GCD) techniques. EDLC having EG electrodes of 10 h exfoliation time showed the highest results with single electrode specific capacitance (Csc) of 4.12 F g− 1, single electrode specific discharge capacitance (Csd) of 1.10 F g− 1 and relaxation time of 0.22 s from CV, GCD and EIS respectively.

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