scholarly journals A Comparative Study of Multifunctional Coatings Based on Electrospun Fibers with Incorporated ZnO Nanoparticles

Coatings ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 367 ◽  
Author(s):  
Pedro J. Rivero ◽  
Alvaro Iribarren ◽  
Silvia Larumbe ◽  
José F. Palacio ◽  
Rafael Rodríguez
Keyword(s):  
Corrosion Resistance ◽  
Comparative Study ◽  
Zno Nanoparticles ◽  
Corrosion Current ◽  
Deposition Process ◽  
Electrospun Fibers ◽  
Scanning Calorimetry ◽  
Average Roughness ◽  
Electrospinning Technique ◽  
Step Over

In this work, polymeric fibers of polystyrene (PS) with incorporated ZnO nanoparticles have been deposited onto an aluminum alloy substrate (6061T6) by using the electrospinning technique. In order to optimize the deposition process, the applied voltage and flow rate have been evaluated in order to obtain micrometric electrospun fibers with a high average roughness and superhydrophobic behavior. Thermogravimetric analysis (TGA) has also been employed in order to corroborate the amount of ZnO incorporated into the electrospun fibers, whereas differential scanning calorimetry (DSC) has been performed in order to determine the glass transition temperature (Tg) of the polymeric electrospun fibers. In addition, a specific thermal treatment (Tg + 20 °C) of the synthesized electrospun fibers has been evaluated in the resultant corrosion resistance. A comparative study with previously reported results corresponding to polyvinyl chloride (PVC) fibers is carried out along this paper to show the changes in behavior due to the different compositions and fiber diameters. The coating has produced an important reduction of the corrosion current of the aluminum substrate in two orders of magnitude, showing also an important enhancement against pitting corrosion resistance. Finally, this deposition technique can be used as an innovative way for the design of both superhydrophobic and anticorrosive surfaces in one unique step over metallic substrates with arbitrary geometry.

scholarly journals Functionalized Electrospun Fibers for the Design of Novel Hydrophobic and Anticorrosive Surfaces

Coatings ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 300 ◽  
Author(s):  
Pedro Rivero ◽  
David Yurrita ◽  
Carlos Berlanga ◽  
José Palacio ◽  
Rafael Rodríguez
Keyword(s):  
Corrosion Resistance ◽  
Metal Oxide Nanoparticles ◽  
Chemical Vapor ◽  
Electrospinning Process ◽  
Electrospun Fibers ◽  
Electrospinning Technique ◽  
Water Contact ◽  
Force Microscopy ◽  
Hydrophobic Molecule ◽  
High Degree

In this work, a novel coating was deposited on aluminum alloy samples by using a combination of electrospinning and chemical vapor deposition (CVD-silanization) techniques in order to create a functionalized film with an enhancement of both corrosion resistance and hydrophobicity. The electrospinning technique makes the fabrication of highly crosslinked electrospun fibers possible by the combination of both poly(acrylic acid) and β-cyclodextrin, respectively, which can be easily functionalized in a further step by using the CVD-silanization process due to the evaporation of a hydrophobic molecule such as 1H,1H,2H,2H-Perflurodecyltriethoxysilane. In addition, the resultant electrospun fibers with a high degree of insolubility have been successfully fabricated and metal oxide nanoparticles (TiO2NPs) have been incorporated into the electrospun polymeric solution in order to improve the corrosion protection. The surface morphology has been determined by using light optical microscopy, atomic force microscopy, scanning electron microscopy, and water contact angle (WCA) measurements. The corrosion resistance has been evaluated by using both potentiodynamic polarization and pitting corrosion tests. Finally, the results related to WCA measurements after CVD-silanization corroborate that the surfaces have been successfully functionalized with a hydrophobic behavior in comparison with the electrospinning process, showing a considerable difference in the roughness.

scholarly journals Modeling Experimental Parameters for the Fabrication of Multifunctional Surfaces Composed of Electrospun PCL/ZnO-NPs Nanofibers

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4312
Author(s):  
Pedro J. Rivero ◽  
Juan P. Fuertes ◽  
Adrián Vicente ◽  
Álvaro Mata ◽  
José F. Palacio ◽  
...  
Keyword(s):  
Contact Angle ◽  
Corrosion Resistance ◽  
Surface Morphology ◽  
Water Contact Angle ◽  
Solution Concentration ◽  
Electrospun Fibers ◽  
Operational Parameters ◽  
Zno Nps ◽  
Electrospinning Technique ◽  
Water Contact

In this work, a one-step electrospinning technique has been implemented for the design and development of functional surfaces with a desired morphology in terms of wettability and corrosion resistance by using polycaprolactone (PCL) and zinc oxide nanoparticles (ZnO NPs). The surface morphology has been characterized by confocal microscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM) and water contact angle (WCA), whereas the corrosion resistance has been evaluated by Tafel polarization curves. Strict control over the input operational parameters (applied voltage, feeding rate, distance tip to collector), PCL solution concentration and amount of ZnO NPs have been analyzed in depth by showing their key role in the final surface properties. With this goal in mind, a design of experiment (DoE) has been performed in order to evaluate the optimal coating morphology in terms of fiber diameter, surface roughness (Ra), water contact angle (WCA) and corrosion rate. It has been demonstrated that the solution concentration has a significant effect on the resultant electrospun structure obtained on the collector with the formation of beaded fibers with a higher WCA value in comparison with uniform bead-free fibers (dry polymer deposition or fiber-merging aspect). In addition, the presence of ZnO NPs distributed within the electrospun fibers also plays a key role in corrosion resistance, although it also leads to a decrease in the WCA. Finally, this is the first time that an exhaustive analysis by using DoE has been evaluated for PCL/ZnO electrospun fibers with the aim to optimize the surface morphology with the better performance in terms of corrosion resistance and wettability.

scholarly journals Evaluation of the Photocatalytic Activity and Anticorrosion Performance of Electrospun Fibers Doped with Metallic Oxides

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2011
Author(s):  
Ainhoa Albistur ◽  
Pedro J. Rivero ◽  
Joseba Esparza ◽  
Rafael Rodríguez
Keyword(s):  
Titanium Dioxide ◽  
Photocatalytic Activity ◽  
Corrosion Protection ◽  
Electrospun Fiber ◽  
Corrosion Current ◽  
High Water ◽  
Electrospun Fibers ◽  
Electrospinning Technique ◽  
Electrochemical Tests ◽  
Crosslinking Process

This paper reports the development and characterization of a multifunctional coating that combines anticorrosion and photocatalytic properties, deposited by means of the electrospinning technique. In the first step, a functional electrospun fiber mat composed of poly(acrylic acid) (PAA) and β-cyclodextrin (β-CD) was obtained, showing high water insolubility and great adhesion increased by means of a thermal crosslinking process (denoted as PAA + β-CD). In the second step, the fibers were doped with particles of titanium dioxide (denoted as PAA + β-CD/TiO2) and titanium dioxide plus iron oxide (denoted as PAA + β-CD/TiO2/Fe2O3). The morphology and fiber diameter of the electrospun mats were evaluated by using confocal microscopy, whereas the presence of the metal oxides in the electrospun fibers was corroborated by scanning electron microscopy (SEM) and X-ray fluorescence (XRF), respectively. In addition, electrochemical tests in saline solution revealed that the sample composed of PAA + β-CD/TiO2/Fe2O3 showed the highest corrosion protection efficiency of all the samples, which was directly associated to lower corrosion current density and higher corrosion potential. Furthermore, the paper reports a novel approach to in situ determination of methylene blue (MB) degradation onto the coating. The results revealed complete degradation of MB, which is perfectly appreciated by total discoloration of the film in the irradiated zone (from bluish to a white spot). The main conclusions of this research are the efficiency of the electrospun system PAA + β-CD/TiO2/Fe2O3 for developing photocatalytic activity and corrosion protection and the utility of the dry MB discoloration tests to evaluate photocatalytic activity.

Role of Aluminium on the Microstructure and Corrosion Behaviour of Magnesium Prepared by Powder Metallurgy Method

2020 ◽  
Vol 17 (3) ◽  
pp. 8206-8213
Author(s):  
J. Alias
Keyword(s):  
Corrosion Resistance ◽  
Powder Metallurgy ◽  
Corrosion Behaviour ◽  
Corrosion Current ◽  
Optical Microscope ◽  
High Reactivity ◽  
Aluminium Content ◽  
Powder Metallurgy Method ◽  
X Ray Diffraction ◽  
Promising Development

Much research on magnesium (Mg) emphasises creating good corrosion resistance of magnesium, due to its high reactivity in most environments. In this study, powder metallurgy (PM) technique is used to produce Mg samples with a variation of aluminium (Al) composition. The effect of aluminium composition on the microstructure development, including the phase analysis was characterised by optical microscope (OM), scanning electron microscopy (SEM) and x-ray diffraction (XRD). The mechanical property of Mg sample was performed through Vickers microhardness. The results showed that the addition of aluminium in the synthesised Mg sample formed distribution of Al-rich phases of Mg17Al12, with 50 wt.% of aluminium content in the Mg sample exhibited larger fraction and distribution of Al-rich phases as compared to the 20 wt.% and 10 wt.% of aluminium content. The microhardness values were also increased at 20 wt.% and 50 wt.% of aluminium content, comparable to the standard microhardness value of the annealed Mg. A similar trend in corrosion resistance of the Mg immersed in 3.5 wt.% NaCl solution was observed. The corrosion behaviour was evaluated based on potentiodynamic polarisation behaviour. The corrosion current density, icorr, is observed to decrease with the increase of Al composition in the Mg sample, corresponding to the increase in corrosion resistance due to the formation of aluminium oxide layer on the Al-rich surface that acted as the corrosion barrier. Overall, the inclusion of aluminium in this study demonstrates the promising development of high corrosion resistant Mg alloys.

scholarly journals Corrosion Behavior and Osteogenic Activity of a Biodegradable Orthopedic Implant Mg–Si Alloy with a Gradient Structure

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 781
Author(s):  
Weiyan Jiang ◽  
Wenzhou Yu
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Polarization Resistance ◽  
Corrosion Current Density ◽  
Corrosion Current ◽  
Gradient Structure ◽  
Orthopedic Implant ◽  
Biological Functions ◽  
Alloy Matrix ◽  
Osteogenic Activity

A gradient Mg-8 wt % Si alloy, which was composed of the agglomerated Mg2Si crystals coating (GMS8-1) and the eutectic Mg–Si alloy matrix (GMS8-2), was designed for biodegradable orthopedic implant materials. The bio-corrosion behavior was evaluated by the electrochemical measurements and the immersion tests. The results show that a significant improvement of bio-corrosion resistance was achieved by using the gradient Mg–Si alloy, as compared with the traditional Mg-8 wt % Si alloy (MS8), which should be attributed to the compact and insoluble Mg2Si phase distributed on the surface of the material. Especially, GMS8-1 exhibits the highest polarization resistance of 1610 Ω, the lowest corrosion current density of 1.7 × 10−6 A.cm−2, and the slowest corrosion rate of 0.10 mm/year. In addition, GMS8-1 and GMS8-2 show better osteogenic activity than MS8, with no cytotoxicity to MC3T3-E1 cells. This work provides a new way to design a gradient biodegradable Mg alloys with some certain biological functions.

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.

scholarly journals Preparation and Properties of Mo Coating on H13 Steel by Electro Spark Deposition Process

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3700
Author(s):  
Wenquan Wang ◽  
Ming Du ◽  
Xinge Zhang ◽  
Chengqun Luan ◽  
Yingtao Tian
Keyword(s):  
Corrosion Resistance ◽  
Service Life ◽  
Deposition Time ◽  
Deposition Process ◽  
H13 Steel ◽  
Carbide Phases ◽  
Metallurgical Bonding ◽  
Wear And Corrosion ◽  
Deposition Power ◽  
Wear And Corrosion Resistance

H13 steel is often damaged by wear, erosion, and thermal fatigue. It is one of the essential methods to improve the service life of H13 steel by preparing a coating on it. Due to the advantages of high melting point, good wear, and corrosion resistance of Mo, Mo coating was fabricated on H13 steel by electro spark deposition (ESD) process in this study. The influences of the depositing parameters (deposition power, discharge frequency, and specific deposition time) on the roughness of the coating, thickness, and properties were investigated in detail. The optimized depositing parameters were obtained by comparing roughness, thickness, and crack performance of the coating. The results show that the cross-section of the coating mainly consisted of strengthening zone and transition zone. Metallurgical bonding was formed between the coating and substrate. The Mo coating mainly consisted of Fe9.7Mo0.3, Fe-Cr, FeMo, and Fe2Mo cemented carbide phases, and an amorphous phase. The Mo coating had better microhardness, wear, and corrosion resistance than substrate, which could significantly improve the service life of the H13 steel.

scholarly journals Sputter-Deposited Ag Nanoparticles on Electrospun PCL Scaffolds: Morphology, Wettability and Antibacterial Activity

Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 345
Author(s):  
Daniele Valerini ◽  
Loredana Tammaro ◽  
Roberta Vitali ◽  
Gloria Guillot ◽  
Antonio Rinaldi
Keyword(s):  
Ag Nanoparticles ◽  
Food Packaging ◽  
Antimicrobial Agents ◽  
Antimicrobial Properties ◽  
Deposition Process ◽  
Polymer Fibers ◽  
Antibacterial Action ◽  
Porous Scaffolds ◽  
Electrospinning Technique ◽  
Sputtering Deposition

Porous scaffolds made of biocompatible and environmental-friendly polymer fibers with diameters in the nano/micro range can find applications in a wide variety of sectors, spanning from the biomedical field to textiles and so on. Their development has received a boost in the last decades thanks to advances in the production methods, such as the electrospinning technique. Conferring antimicrobial properties to these fibrous structures is a primary requirement for many of their applications, but the addition of antimicrobial agents by wet methods can present a series of drawbacks. In this work, strong antibacterial action is successfully provided to electrospun polycaprolactone (PCL) scaffolds by silver (Ag) addition through a simple and flexible way, namely the sputtering deposition of silver onto the PCL fibers. SEM-EDS analyses demonstrate that the polymer fibers get coated by Ag nanoparticles without undergoing any alteration of their morphological integrity upon the deposition process. The influence on wettability is evaluated with polar (water) and non-polar (diiodomethane) liquids, evidencing that this coating method allows preserving the hydrophobic character of the PCL polymer. Excellent antibacterial action (reduction > 99.995% in 4 h) is demonstrated against Escherichia coli. The easy fabrication of these PCL-Ag mats can be applicable to the production of biomedical devices, bioremediation and antifouling systems in filtration, personal protective equipment (PPE), food packaging materials, etc.

PVD Coated Bipolar Plates for PEM Fuel Cells

2005 ◽  
Vol 2 (4) ◽  
pp. 290-294 ◽  
Author(s):  
Shuo-Jen Lee ◽  
Ching-Han Huang ◽  
Yu-Pang Chen ◽  
Chen-Te Hsu
Keyword(s):  
Corrosion Resistance ◽  
Fuel Cells ◽  
Fuel Cell ◽  
Physical Vapor Deposition ◽  
Corrosion Current ◽  
Pem Fuel Cells ◽  
Bipolar Plates ◽  
Coating Materials ◽  
Pvd Coating ◽  
Simulated Fuel

Aluminum was considered a good candidate material for bipolar plates of the polymer electrolyte membrane (PEM) fuel cells due to its low cost, light weight, high strength and good manufacturability. But there were problems of both chemical and electrochemical corrosions in the PEM fuel cell operating environment. The major goals of this research are to find proper physical vapor deposition (PVD) coating materials which would enhance surface properties by making significant improvements on corrosion resistance and electrical conductivity at a reasonable cost. Several coating materials had been studied to analyze their corrosion resistance improvement. The corrosion rates of all materials were tested in a simulated fuel cell environment. The linear polarization curve of electrochemical method measured by potentiostat instrument was employed to determine the corrosion current. Results of the corrosion tests indicated that all of the coating materials had good corrosion resistance and were stable in the simulated fuel cell environment. The conductivities of the coated layers were better and the resistances changed very little after the corrosion test. At last, single fuel cells were made by each PVD coating material. Fuel cell tests were conducted to determine their performance w.r.t. that was made of graphite. The results of fuel cell tests indicated that metallic bipolar plates with PVD coating could be used in PEM fuel cells.

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