scholarly journals Effect of Autoclaving Time on Corrosion Resistance of Sandblasted Ti G4 in Artificial Saliva

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4154 ◽  
Author(s):  
Bożena Łosiewicz ◽  
Patrycja Osak ◽  
Joanna Maszybrocka ◽  
Julian Kubisztal ◽  
Sebastian Stach
Keyword(s):  
Corrosion Resistance ◽  
Chemical Stability ◽  
Electrochemical Impedance ◽  
Artificial Saliva ◽  
Electron Work Function ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Oxide Layers ◽  
Average Grain Size ◽  
The Impact

Titanium Grade 4 (Ti G4) is the most commonly used material for dental implants due to its excellent mechanical properties, chemical stability and biocompatibility. A thin, self-passive oxide layer with protective properties to corrosion is formed on its surface. However, the spontaneous TiO2 layer is chemically unstable. In this work, the impact of autoclaving time on corrosion resistance of Ti G4 in artificial saliva solution with pH = 7.4 at 37 °C was studied. Ti G4 was sandblasted with white Al2O3 particles and autoclaved for 30–120 min. SEM, EDS, 2D roughness profiles, confocal laser scanning microscopy, and a Kelvin scanning probe were used for the surface characterization of the Ti G4 under study. In vitro corrosion resistance tests were conducted using open circuit potential, polarization curves, and electrochemical impedance spectroscopy measurements. It was found that Sa parameter, electron work function, and thickness of the oxide layers, determined based on impedance measurements, increased after autoclaving. The capacitive behavior and high corrosion resistance of tested materials were revealed. The improvement in the corrosion resistance after autoclaving was due to the presence of oxide layers with high chemical stability. The optimal Ti G4 surface for dentistry can be obtained by sandblasting with Al2O3 with an average grain size of 53 µm, followed by autoclaving for 90 min.

scholarly journals Effect of Sandblasting on the Long-Term Corrosion Resistance of Ti G4 in Artificial Saliva

2021 ◽  
Vol 6 (1) ◽  
pp. 5
Author(s):  
Patrycja Osak ◽  
Maciej Zubko ◽  
Julian Kubisztal ◽  
Joanna Maszybrocka ◽  
Bożena Łosiewicz
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Machine Surface ◽  
Electrochemical Impedance ◽  
Artificial Saliva ◽  
Electron Work Function ◽  
Titanium Implants ◽  
Bone Contact

Titanium Grade 4 (G4) is the most commonly used material for dental implants due to its excellent biocompatibility and mechanical properties. However, titanium implants require a rough surface that can increase the biomechanical potential of implant–bone contact and affect protein adsorption speed. In this work, the effect of sandblasting of the Ti G4 surface on the long-term corrosion resistance in artificial saliva of pH = 7.4 at 37 °C was studied. The X-ray diffraction (XRD) single-{hkl} sin2ψ method was used to measure the sandblasted Ti residual stress. In vitro corrosion resistance tests were conducted for 21 days using the open circuit potential method, polarization curves, and electrochemical impedance spectroscopy. Using the Kelvin scanning probe, the electron work function was determined. Analysis of the obtained results showed an improvement in the corrosion resistance of the sandblasted Ti G4 compared to Ti with the machine surface. The increase in corrosion resistance was related to the residual compressive stress of 324.7 MPa present in the sandblasted Ti surface. Sandblasting caused plastic deformation of the Ti surface, which resulted in the improvement in mechanical properties, as evidenced by the increase in the hardness of the sandblasted Ti compared to Ti with the machine surface.

scholarly journals Electrochemical and surface analytical techniques applied to microbiologically influenced corrosion investigation

2018 ◽  
Vol 36 (4) ◽  
pp. 349-363 ◽  
Author(s):  
László Trif ◽  
Abdul Shaban ◽  
Judit Telegdi
Keyword(s):  
Photoelectron Spectroscopy ◽  
Laser Scanning ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Analytical Techniques ◽  
Laser Scanning Microscopy ◽  
Microbiologically Influenced Corrosion ◽  
Microbial Consortia ◽  
Confocal Laser ◽  
The Impact

AbstractSuitable application of techniques for detection and monitoring of microbiologically influenced corrosion (MIC) is crucial for understanding the mechanisms of the interactions and for selecting inhibition and control approaches. This paper presents a review of the application of electrochemical and surface analytical techniques in studying the MIC process of metals and their alloys. Conventional electrochemical techniques, such as corrosion potential (Ecorr), redox potential, dual-cell technique, polarization curves, electrochemical impedance spectroscopy (EIS), electrochemical noise (EN) analysis, and microelectrode techniques, are discussed, with examples of their use in various MIC studies. Electrochemical quartz crystal microbalance, which is newly used in MIC study, is also discussed. Microscopic techniques [scanning electron microscopy (SEM), environmental SEM (ESEM), atomic force microscopy (AFM), confocal laser microscopy (CLM), confocal laser scanning microscopy (CLSM), confocal Raman microscopy] and spectroscopic analytical methods [Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS)] are also highlighted. This review highlights the heterogeneous characteristics of microbial consortia and use of special techniques to study their probable effects on the metal substrata. The aim of this review is to motivate using a combination of new procedures for research and practical measurement and calculation of the impact of MIC and biofilms on metals and their alloys.

Confocal and SEM imaging to demonstrate food pathogen- biofilm biocontrol by pyocyanin from Pseudomonas aeruginosa BTRY1

2016 ◽  
Vol 6 (01) ◽  
pp. 5218
Author(s):  
Laxmi Mohandas ◽  
Anju T. R. ◽  
Sarita G. Bhat*
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Antibiofilm Activity ◽  
Opportunistic Pathogens ◽  
Redox Active ◽  
Sem Imaging ◽  
The Impact

An assortment of redox-active phenazine compounds like pyocyanin with their characteristic blue-green colour are synthesized by Pseudomonas aeruginosa, Gram-negative opportunistic pathogens, which are also considered one of the most commercially valuable microorganisms. In this study, pyocyanin from Pseudomonas aeruginosa BTRY1 from food sample was assessed for its antibiofilm activity by micro titer plate assay against strong biofilm producers belonging to the genera Bacillus, Staphylococcus, Brevibacterium and Micrococcus. Pyocyanin inhibited biofilm activity in very minute concentrations. This was also confirmed by Scanning Electron Microscopy (SEM) and Confocal Laser Scanning Microscopy (CLSM). Both SEM and CLSM helped to visualize the biocontrol of biofilm formation by eight pathogens. The imaging and quantification by CLSM also established the impact of pyocyanin on biofilm-biocontrol mainly in the food industry.

scholarly journals The effect of the dispersion of microfibrillated cellulose on the mechanical properties of melt-compounded polypropylene–polyethylene copolymer

Cellulose ◽  
2019 ◽  
Vol 26 (18) ◽  
pp. 9645-9659 ◽  
Author(s):  
Caterina Palange ◽  
Marcus A. Johns ◽  
David J. Scurr ◽  
Jonathan S. Phipps ◽  
Stephen J. Eichhorn
Keyword(s):  
Tannic Acid ◽  
Laser Scanning ◽  
Secondary Ion Mass Spectrometry ◽  
High Surface ◽  
Microfibrillated Cellulose ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Cellulose Content ◽  
Reinforced Composites ◽  
The Impact

Abstract Microfibrillated cellulose (MFC) is a highly expanded, high surface area networked form of cellulose-based reinforcement. Due to the poor compatibility of cellulose with most common apolar thermoplastic matrices, the production of cellulose-reinforced composites in industry is currently limited to polar materials. In this study, a facile water-based chemistry, based on the reaction of MFC with tannic acid and subsequent functionalisation with an alkyl amine, is used to render the surface of the MFC fibrils hydrophobic and enhance the dispersion of the cellulose-based filler into an apolar thermoplastic matrix. The level of dispersion of the compatibilized MFC reinforced composites was evaluated using Time of Flight Secondary Ion Mass Spectrometry and multi-channel Spectral Confocal Laser Scanning Microscopy. The agglomeration of cellulosic filler within the composites was reduced by functionalising the surface of the MFC fibrils with tannic acid and octadecylamine. The resulting composites exhibited an increase in modulus at a high cellulose content. Despite the dispersion of a large portion of the functionalised filler, the presence of some remaining aggregates affected the impact properties of the composites produced.

Influence of the Electrolyte Composition on the Corrosion Behavior of Anodized AZ31B Magnesium Alloy

2020 ◽  
Vol 1012 ◽  
pp. 424-429
Author(s):  
Leandro Antonio de Oliveira ◽  
Renato Altobelli Antunes
Keyword(s):  
Magnesium Alloy ◽  
Laser Scanning ◽  
Electrochemical Impedance ◽  
Electrolyte Composition ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Mixed Solution ◽  
Protective Properties ◽  
Az31b Magnesium Alloy ◽  
Substrate Dissolution

Investigations have been performed to study the effects of the electrolyte composition on the properties of anodized films grown on AZ31B magnesium alloy. The corrosion protection ability of the oxide layers was explored by using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy. Film morphology was examined by scanning electron microscopy and confocal laser scanning microscopy. In spite of its higher roughness average, the film formed in the silicate and hydroxide mixed solution enhanced the protective properties of the anodized layer, thus reducing the substrate dissolution rate.

Surface Analysis, Microstructural Characterization and Local Corrosion Processes in Decarburized SAE 9254 Spring Steel

CORROSION ◽  
10.5006/3234 ◽  
2019 ◽  
Vol 75 (12) ◽  
pp. 1474-1486
Author(s):  
Jéssica Cristina Costa de Castro Santana ◽  
Rejane Maria Pereira da Silva ◽  
Renato Altobelli Antunes ◽  
Sydney Ferreira Santos
Keyword(s):  
Surface Chemistry ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Microstructural Characterization ◽  
Spring Steel ◽  
Laser Scanning Microscopy ◽  
Local Corrosion ◽  
Confocal Laser ◽  
X Ray ◽  
Decarburized Layer

The aim of the present work was to study the surface chemistry, microstructure, and local corrosion processes at the decarburized layer of the SAE 9254 automotive spring steel. The samples were austenitized at 850°C and 900°C, and oil quenched. The microstructure was investigated using confocal laser scanning microscopy and scanning electron microscopy. The surface chemistry was analyzed by x-ray photoelectron spectroscopy. Electrochemical impedance spectroscopy and potentiodynamic polarization were used to assess the global corrosion behavior of the decarburized samples. Scanning electrochemical microscopy was used to evaluate the influence of decarburization on the local corrosion activity. Microstructural characterization and x-ray photoelectron spectroscopy analysis indicate a dependence of the local electrochemical processes with the steel microconstituents and Si oxides in the decarburized layer.

Characterisation of electrochemical immunosensor for detection of viable not-culturable forms of Legionellla pneumophila in water samples

2015 ◽  
Vol 69 (11) ◽  
Author(s):  
Dejla Sboui ◽  
Mina Souiri ◽  
Stephanie Reynaud ◽  
Sabine Palle ◽  
Manel Ben Ismail ◽  
...  
Keyword(s):  
Legionella Pneumophila ◽  
Indium Tin Oxide ◽  
Membrane Filtration ◽  
Laser Scanning ◽  
Electrochemical Impedance ◽  
Limit Of Detection ◽  
Angle Measurement ◽  
Electrochemical Immunosensor ◽  
Laser Scanning Microscopy ◽  
Confocal Laser

AbstractLegionella pneumophila may cause a fatal pneumonia in humans known as Legionnaires’ disease (LD). The strategies of L. pneumophila to adapt to and resist stressful environmental conditions include the ability to enter into a VBNC (viable but not culturable) state. The detection of L. pneumophila in environmental samples benefits from the use of standardised methods: for detection and enumeration following membrane filtration (AFNOR T90-431, ISO 11731) and detection and quantification by polymerase chain reaction PCR (AFNOR T90-471, ISO 12869). Culture is hampered by its inability to detect VBNC forms and PCR is unable to discriminate between live and dead bacteria. The present immunosensor was obtained by the immobilisation of a monoclonal anti-L. pneumophila antibody (MAb) on an indium-tin oxide (ITO) electrode by the self-assembled monolayers (SAMs) method using an aminosilane. The immunosensor was characterised by wettability (contact angle measurement), atomic force microscopy (AFM), confocal laser scanning microscopy (CLSM), and electrochemical impedance spectroscopy (EIS). A limit of detection of 10 bacteria per mL was observed on artificial samples.

Effect of Calcium-phosphate Desensitizers on Staining Susceptibility of Acid-eroded Enamel

2019 ◽  
Vol 44 (3) ◽  
pp. 281-288 ◽  
Author(s):  
KY Kyaw ◽  
M Otsuki ◽  
MS Segarra ◽  
N Hiraishi ◽  
J Tagami
Keyword(s):  
Surface Roughness ◽  
Calcium Phosphate ◽  
Repeated Measures ◽  
Laser Scanning ◽  
Artificial Saliva ◽  
Color Difference ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Control Group ◽  
Before And After

SUMMARY Objective: To investigate the effect of calcium-phosphate–based desensitizers, Teethmate AP paste (TMAP) and Teethmate Desensitizer (TMD) (Kuraray Noritake Dental, Tokyo, Japan), on the prevention of staining on acid-eroded enamel. Methods and Materials: Forty polished enamel samples (4×4×1 mm) from bovine incisors were randomly divided into five groups (n=8). After immersion in 50 mL of 0.5% citric acid (pH 2.5) for 15 minutes to form acid-eroded surfaces, the surfaces were subjected to different treatments with TMAP, TMD, and NaF (0.21% means 950 ppm) for five minutes. Another eroded group was not treated with desensitizer. For the control group, the samples were not eroded or treated. All the samples were stored in artificial saliva (AS) at pH 7.2 for 24 hours at 37°C. The TMAP, TMD, or NaF was reapplied at eight and 16 hours during the 24 hours of storage time. The surface roughness (Sa) was evaluated following ISO 25178 for surface texture using confocal laser scanning microscopy (VK-X 150 series, Keyence, Osaka, Japan) before acid erosion, after acid erosion, and after 24 hours of incubation in AS. Afterward, the color difference was measured with a dental colorimeter (Shade Eye NCC, Shofu, Kyoto, Japan) before and after staining with tea solution. Results: One-way repeated measures analysis of variance showed that acid erosion significantly increased Sa (p<0.001). TMAP- and TMD-treated groups exhibited lower Sa values than the NaF group and the no-desensitizer treatment group. The greatest staining was observed in the NaF group and the no-desensitizer group, while the TMAP and TMD groups significantly decreased the formation of stains. Conclusions: Acid-eroded enamel increased surface roughness and tended to absorb more stains. However, the application of TMAP and TMD moderated the roughness and thus prevented the formation of extrinsic stains.

scholarly journals Effect of Hot Deformation Process Parameters on Microstructure and Corrosion Behavior of 35CrMoV Steel

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1455 ◽  
Author(s):  
Qiumei Yang ◽  
Yajun Zhou ◽  
Zheng Li ◽  
Daheng Mao
Keyword(s):  
Grain Size ◽  
Corrosion Resistance ◽  
Strain Rate ◽  
Hot Deformation ◽  
Deformation Temperature ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Rust Layer ◽  
Corrosion Morphology ◽  
Boundary Area

Hot deformation experiments of as-cast 35CrMoV steel, with strain rates of 0.01 s−1 and 10 s−1, deformation temperatures of 850, 950, and 1050 °C, and an extreme deformation reaching 50%, were carried out using a Gleeble-3810 thermal simulator. Electrochemical corrosion experiments were conducted on the deformed specimens. The microstructure was observed by optical microscope (OM), and the corrosion morphology and corrosion products of the specimens were investigated by scanning electron microscopy (SEM), energy disperse spectroscopy (EDS), confocal laser scanning microscopy (CLSM), and X-ray diffraction (XRD) techniques. The results show that the grain size increased gradually with an increase in the deformation temperature at the same strain rate, whereas the corrosion resistance deteriorated. At the same deformation temperature, the grain size becomes smaller as the strain rate increases, which enhances the corrosion resistance. This is mainly attributed to the fine grains, which can form more grain boundaries, increase the grain boundary area, and accelerate the formation of the inner rust layer at the beginning of corrosion. Moreover, fine grains can also refine the rust particles and enhance the bonding strength between the inner rust layer and the matrix. The denseness and stability of the inner rust layer increases as the corrosion process progresses, thereby improving corrosion resistance.

scholarly journals Mosaic-CLSM Assessment of Bacterial Spatial Distribution in Cosmetic Matrices According to Matrix Viscosity and Bacterial Hydrophobicity

Cosmetics ◽  
2020 ◽  
Vol 7 (2) ◽  
pp. 32
Author(s):  
Samia Almoughrabie ◽  
Chrisse Ngari ◽  
Romain Briandet ◽  
Valérie Poulet ◽  
Florence Dubois-Brissonnet
Keyword(s):  
Spatial Distribution ◽  
Laser Scanning ◽  
Rapid Assessment ◽  
Challenge Test ◽  
Surface Hydrophobicity ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Bacterial Surface ◽  
Bacterial Hydrophobicity ◽  
The Impact

The reliability of the challenge test depends, among other parameters, on the spatial distribution of microorganisms in the matrix. The present study aims to quickly identify factors that are susceptible to impair a uniform distribution of inoculated bacteria in cosmetic matrices in this context. We used mosaic confocal laser scanning microscopy (M-CLSM) to obtain rapid assessment of the impact of the composition and viscosity of cosmetic matrices on S. aureus spatial distribution. Several models of cosmetic matrices were formulated with different concentrations of two thickeners and were inoculated with three S. aureus strains having different levels of hydrophobicity. The spatial distribution of S. aureus in each matrix was evaluated according to the frequency distribution of the fluorescence values of at least 1350 CLSM images. We showed that, whatever the thickener used, an increasingly concentration of thickener results in increasingly bacterial clustered distribution. Moreover, higher bacterial hydrophobicity also resulted in a more clustered spatial distribution. In conclusion, CLSM-based method allows a rapid characterization of bacterial spatial distribution in complex emulsified systems. Both matrix viscosity and bacterial surface hydrophobicity affect the bacterial spatial distribution which can have an impact on the reliability of bacterial enumeration during challenge test.

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