Dielectric Spectroscopy Research Papers - Academia.edu (original) (raw)

2025, Eskişehir Technical University Journal of Science and Technology A - Applied Sciences and Engineering

Heat shock proteins are produced when the organisms are exposed to various environmental stress conditions such as temperature, light, toxins. It is a known fact that in bacteria, which has the HSP gene, antibiotics can trigger the expression of the heat shock protein. However, the response of heat shock protein genes to antibiotics has not been fully clarified in the literature yet, studies are still ongoing. In this study, a novel way for the detection heat shock protein65 was investigated using the electrochemical impedance spectroscopy due to its sensitivity, selectivity, low cost. To do so, heat shock protein65 probe and target were designed and the hybridization behavior of the probe with designed target was studied upon the binding onto screen-printed electrodes. Cyclic voltammetry was performed to analyze surface characterization of secreen printed electrodes and the performance of the screen printed electrodes was tested using electrocehimcal impedance spectroscopy by measu...

2025, Journal of The Electrochemical Society

The energy storage performance of one of the lightest-known MXenes, Ti 2 CT x (MX) combined with carbon nanospheres (CNS) has been investigated as a symmetric electrode system in an aqueous electrolyte (1 M Li 2 SO 4 ). The energy storage properties were interrogated using cyclic voltammetry (CV), galvanostatic cycling with potential limitation (GCPL), electrochemical impedance spectroscopy (EIS) and voltage-holding tests. The combined material (MX/CNS) demonstrated a higher specific capacity compared to each of the individual components. The material was fabricated with relatively high and low mass loadings, assembled into a symmetric device and performance compared. Specific capacitance, specific power and specific energy for the lower electrode mass loading of 180 F•g -1 , 37.6 kW•kg -1 and 14.1 W•h•kg -1 were all higher than 86 F•g -1 , 20.1 kW•kg -1 and 6.7 W•h•kg -1 for the higher mass loading. A wide voltage window of 1.5 V was obtained, but with limited long-term cycling behavior, suggesting the need for future improvement. Mathematical modelling and simulation of the supercapacitor showed good correlation with the experimental results, validating the model. The results reveal the potential of the Ti 2 CT x to be employed as a viable energy storage system for lightweight applications.

2025, Materials Science and Engineering: C

The aim of the study was to fabricate titanium (Ti) material coated with functionalized carbon nanotubes (f-CNTs) that would have potential medical application in orthopaedics as an implantable electronic device. The novel biomedical material (Ti-CNTs-H 2 O) would possess specific set of properties, such as: electrical conductivity, nontoxicity, and ability to inhibit connective tissue cell growth and proliferation protecting the Ti-CNTs-H 2 O surface against covering by cells. The novel material was obtained via an electrophoretic deposition of CNTs-H 2 O on the Ti surface. Then, physicochemical, electrical, and biological properties were evaluated. Electrical property evaluation revealed that a Ti-CNTs-H 2 O material is highly conductive and X-ray photoelectron spectroscopy analysis demonstrated that there are mainly COOH groups on the Ti-CNTs-H 2 O surface that are found to inhibit cell growth. Biological properties were assessed using normal human foetal osteoblast cell line (hFOB 1.19). Conducted cytotoxicity tests and live/dead fluorescent staining demonstrated that Ti-CNTs-H 2 O does not exert toxic effect on hFOB cells. Moreover, fluorescence laser scanning microscope observation demonstrated that Ti-CNTs-H 2 O surface retards to a great extent cell proliferation. The study resulted in successful fabrication of highly conductive, non-toxic Ti-CNTs-H 2 O material that possesses ability to inhibit osteoblast proliferation and thus has a great potential as an orthopaedic implantable electronic device.

2025, RSC Advances

End- and side-contact resistances between carbon nanotubes and contacts are easily probed in vertically aligned arrays.

2025, Corrosion Science

The influence of the electrochemical hardening treatment on the composition and structure of coloured porous films formed by triangular current scan on AISI 304 stainless steel has been examined by impedance spectroscopy and also by SEM, AES, XPS and AFM. It was observed that the films, originally consisting of a porous chromium-iron oxide, became more compact and enriched in chromium after the hardening treatment. The development of a high frequency semi-circle in the impedance spectra is explained by the formation of an outer oxide layer.

2025, Journal of the Brazilian Chemical Society

2025, Journal of steel structures & construction

The anti-corrosive properties of (E)-3-styrylquinoxalin-2(1H)-one (STQ), (E)-1-benzyl-3-(4-methoxystyryl) quinoxalin-2(1H)-one (BMQ) and (E)-3-(2-(furan-2-yl) vinyl) quinoxalin-2(1H)-one (FVQ) were analyzed by different techniques such as: potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), weight loss (WL) and molecular modeling by DFT method and Monte Carlo simulation studies. All quinoxaline derivatives showed appreciable inhibition efficiency. Among the quinoxaline derivatives studied, BMQ exhibited the best inhibition efficiency. The results from the experimental and theoretical investigations show that the order of inhibition efficiency by the quinoxaline derivatives follow the order BMQ > FVQ> STQ. The experimental results suggest that the three tested inhibitors function as mixed-type compounds and the inhibition efficiency increases with the increase in inhibitor concentration and decreased with temperature. Adsorption of the three compounds on mild steel (MS) surface obeys Langmuir's isotherm model. The theoretical study by DFT method, Monte Carlo simulation and radial distribution function (RDF) provided strong evidence that the inhibition efficiency of quinoxaline derivatives is due to their ability to adsorb strongly at the MS surfaces, which is supportive of the obtained experimental results.

2025, Moroccan Journal of Chemistry

The inhibitive action of Sodium tetra fluoroborate(NaBF 4 ) on corrosion of carbon steel (CS) in 1.0M HCl was studied by weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS). The measurements show that the inhibition efficiencies increase with the increasing of NaBF 4 concentrations but decrease with increasing of the temperatures. This reveals that the inhibitive action of the inhibitor was mainly due to the adsorption on the carbon steel surface by blocking of the active sites. The above results showed that NaBF 4 acted as a mixed-type corrosion inhibitor. The adsorption of NaBF 4 on the carbon steel surface obeyed the Langmuir adsorption isotherm. This was supported by the impedance measurements which showed a change in the charge transfer resistance and double layer capacitance, indicating the adsorption of NaBF 4 on the carbon steel surface. Thermodynamic parameters of the studied inhibitor were calculated and discussed.

2025, Applied Journal of Environmental Engineering Science

The corrosion behavior of C38 steel in Hcl solution with different concentration of 3,3'-Dimethylbiphenyl-4,4'-diamin (O.Tolidine)(OT) ,was investigated by weight loss and electrochemical measurements. The effect of temperature on the corrosion behavior with the addition of (OT) was studied in the temperature range 298-328 K. Results obtained reveal that (OT) performs excellently as good corrosion inhibitor for C38 steel in 1.0 M Hcl. Potentiodynamic polarization studies have shown that (OT) behaves as mixed-type inhibitors. The inhibition efficiencies, calculated from weight loss measurements, show the same trend as those obtained from electrochemical studies. Also, the inhibition efficiency was found to increase with increase of the inhibitor concentrations to reach 87.84 % at 10 -3 M of (OT) due to the adsorption of the inhibitor molecules on the metal surface and the adsorption follows Langmuir's adsorption isotherm. EIS spectra exhibit one capacitive loop and confirm the inhibitive ability. To elaborate the mechanism of corrosion inhibition, the kinetic and thermodynamic parameters for Carbon steel corrosion and inhibitor adsorption, respectively were determined and discussed. Double layer capacitance and charge transfer resistance values were derived from Nyquist plots obtained from impedance studies.

2025

The inhibition effect of Sulfamethoxypyridazine(SMP) against mild steel corrosion in 2.0 M H3PO4 was evaluated using weight loss and electrochemical techniques (potentiodynamic polarization and electrochemical impedance). The experimental results showed that SMP is a good corrosion inhibitor and the inhibition efficiency increased with the increase of SMP concentration, while the adsorption followed the Langmuir isotherm. Theoretical calculation was carried out to establish mechanism of corrosion inhibition for mild steel with SMP in 2.0 M H3PO4 medium. The inhibition action of the compound was assumed to occur via adsorption on the steel surface through the active centers in the molecule. The corrosion inhibition is due to the formation of a chemisorbed film on the steel surface.

2025, PALAMNEE PATHIPPAGAM

Recently, the entire world has faced three big challenges: energy demand, pollution, and health concerns. As a result, researchers from all over the world are concentrating their efforts in this area. The present conference, 2nd International Conference on Materials & Applied Science for Society (ICMASS - 2025), organized by the PG & Research Department of Physics on March 13th and 14th 2025, in association with the CSIR, New Delhi, Tamil Nadu State Council for Science and Technology (TNSCST), Raman Research Foundation, Tiruchirappalli, and BioMe (Live Analytical Centre), Karaikudi. The aim of the international conference is to provide a place for all physicists, chemists, biologists, materials scientists, technologists, and researchers to communicate their current findings and information, as well as to foster collaboration both domestically and globally.
We distributed the conference invitation via email and several social media platforms, and because of the invitation, 266 participants registered for the conference. We got 160 abstracts from all around the world, which were carefully evaluated by the expert committee and published in these proceedings. An international conference included 10 invited talks over two days. We express our heartfelt gratitude to Dr. A. Pethalakshmi, Principal of Alagappa Government Arts College, for her encouragement and advise. We are grateful to Prof. S. Subbiah, Former-Vice Chancellor, Alagappa University, Karaikudi, for his constant encouragement and his inaugural address of this international conference (ICMASS - 2025). We are grateful to Dr. M. Jothi Basu, Controller of Examinations, Alagappa University, for his excellent valedictory address. We are deeply grateful to the invited speakers and chairpersons for their assistance.
We thankfully acknowledge the service of the members of Advisory Committee without them we may not have successfully organized this international conference. We also remember and forward our sincere thanks to faculty, staff and students who volunteered and extended all possible support. We would like to express our gratitude to the Scholars from the Thin Film & Nanoscience Research Lab and express our wishes to Green and Health Physics Research Lab at Alagappa Government Arts College for their exceptional help in typesetting the conference papers for this conference. We also appreciate all writers for submitting their abstracts on time.

2025, Langmuir

Screen-printed gold (SPG, Dupont gold conductor 5734) on low-temperature co-fired ceramic (LTCC) materials (Dupont dielectric tape 951, mostly composed of alumina and silica) has been demonstrated to be a substrate for electrochemical enzyme-linked immunosorbant assays. The effect of two different cleaning treatments and the extent of nonspecific adsorption on the SPG/LTCC and plain LTCC surfaces were also evaluated. LTCC materials hold promise for constructing a new generation of devices for microelectrochemical sensing and assays. Facile fabrication in three dimensions with integrated conducting elements makes them attractive. A standard sandwich immunoassay for a model analyte, mouse IgG, was used to evaluate the LTCC materials. After the assembly of components onto chips of SPG/LTCC and plain LTCC, p-aminophenol that was generated enzymatically by the enzyme label was detected electrochemically with a separate glassy carbon electrode. Cleaning SPG/LTCC with a piranha solution (7:1 vol/vol of concentrated H 2 SO 4 /30% H 2 O 2 ), traditionally used for other gold surfaces prior to SAM assembly, resulted in a notable decrease in assay signal and an increase in nonspecific adsorption when compared to cleaning with water alone. Assay components assemble specifically on plain LTCC, with only a small percent attributed to NSA. Environmental scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy reveal the tremendous chemical heterogeneity and complexity of both SPG/LTCC and plain LTCC surfaces and aid in the explanation of assay results. A 10% acetate Tween bovine serum albumin solution and an ethanolic solution of 4 mM 1-butanol eliminate assay signals originating from plain LTCC. The outcomes of these studies can now be used to achieve miniaturized electrochemical immunoassays on LTCC materials where both plain and SPG surfaces are present.

2025, Thermal Spray 2021: Proceedings from the International Thermal Spray Conference

A typical structure of thermal spray coatings consisted of molten particles, semi-molten particles, oxides, pores and cracks. These factors caused the porosity of sprayed coatings, leading to a great influence on the coating properties, especially their wear-corrosion resistance. In this study, a post-spray sealing treatment of Cr3C2-NiCr/Al2O3-TiO2 plasma sprayed coatings was carried out, then their corrosion properties were evaluated, before and after the treatment. For sealing process, aluminum phosphate (APP) containing aluminum oxide (Al2O3) nanoparticles (~10 nm) was used. The permeability of APP into the sprayed coating was analyzed by scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS). The treatment efficiency for porosity and corrosion resistance of sprayed coatings were evaluated by electrochemical measurements, such as the potentiodynamic polarization and electrochemical impedance spectroscopy. In addition, the wear-corrosion resistance of ...

2025, Vietnam Journal of Science and Technology

As the growing interest on green corrosion inhibitors, plant extracts have gradually showed the potential in replacing the traditional hazardous chemicals due to the eco-friendly and economy characteristics. Previous study reported that rose myrtle leaf-extract (Rhodomyrtus tomentosa, Myrtaceae) was as an efficient corrosion inhibitor for rust removal process of mild steel in H2SO4 acid medium. This study presents the corrosion inhibition assessments of rose myrtle leaf-extract on mild steel surface in HCl 1M solution. The potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) methods have been used to study the corrosion behaviors of mild steel. The corrosion rate, corrosion current and corrosion potential results indicate that only small amount of the leaf-extract (2% vol.) was required for high inhibition efficiency (Hin=83.9%). By affecting on both anodic and cathodic branches of the Tafel plot, the corrosion inhibition mechanism is proposed by an adsorpti...

2025

In this study, we developed a flexible, recyclable, and adhesive conductive composite film, which shows promise as an alternative material for supercapacitor electrodes. The film was produced by using commercially available soybean protein-containing textile fibers (SPF) derived from soybean powder. The biocompatibility and multifunctionality of the film make it suitable for applications in electronics, biomedical devices, tissue engineering, drug delivery, and energy storage. To achieve this goal, lithium nitrate (LiNO 3) was incorporated into a viscous solid-liquid mixture of SPF dissolved in formic acid (FA) and 1.0 M H 2 SO 4. Aniline was then polymerized in situ as polyaniline (PAn) within this mixture using ammonium persulfate (APS), resulting in an SPF-Li + /PAn electrolyte with a heterogeneous liquid-solid composition. Additionally, a similar mixture with a composition of SPF/PAn-Li + was also prepared by polymerizing aniline in the SPF solution and then adding LiNO 3. The electrical conductivities of the composite films, prepared by casting the SPF-Li + , SPF-Li + /PAn, SPF/PAn, and SPF/PAn-Li + mixtures onto a plastic surface, varied across the (2.1-4.3) × 10-5 S cm-1 range. Structural, morphological, and surface properties were characterized by using ATR-FTIR, SEM, and water contact angle measurements, respectively. The composite film, containing Li + ions, PAn, and SPF, exhibited good adhesion and high electrochemical stability when coated onto a glassy carbon electrode (GCE) in an aqueous medium. Supercapacitive properties of SPF-Li + , SPF-Li + /PAn, SPF/PAn, and SPF/PAn-Li + coated GCEs were investigated via cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge-discharge (GCD) measurements in a 0.5 M H 2 SO 4 solution. The obtained results revealed good capacitive behavior with a long-term life cycle, suggesting the potential of the films as a viable alternative for supercapacitor electrodes.

2025, The Journal of Physical Chemistry C

The study reveals various unexplored pathways to energy storage in the parallel and curved plate supercapacitors (SCs). The spatiotemporal variations in the electric field intensity of such SCs were found to have a significant influence on their performance. The observations unearth the limitations associated with the previous theoretical models, which are routinely employed to analyze the performance of SCs by considering electrical double layers (EDLs) as capacitors near the electrodes. The time-dependent electrochemical behaviors of SCs obtained from the Nyquist and Bode diagrams of electrochemical impedance spectroscopy showed, (i) electrode polarization at the higher frequency sweeps, (ii) immobile Helmholtz layer formation at the midfrequency zone, and (iii) formation of diffuse layer of EDL at low-frequency-regime. The results suggest that charge storage of SCs heavily depend upon electrode geometry, type of electrolyte, electrolyte concentration, electrode separation, separator type, and dielectric relaxation of the electrolyte. A theoretical model composed of Poisson-Nernst-Plank equations for the electric field in electrolyte and Laplace equation for the electric field in electrodes were coupled with Navier-Stokes equations for the fluid flow was numerically solved with appropriate boundary conditions to uncover the pathways to supercapacitance during the experiments. The experimental and theoretical studies together reveal that the use of the potential drop across the EDL originating

2025, International Journal of Electrochemical Science

Organoclay nanogold composite were prepared using gold nanoparticles and the natural Cameroonian clay grafted with amino organosilane. The functionnalization of clay provided abundant amino group to assemble gold nanoparticles. A label-free electrochemical immunosensor for the sensitive determination of carcinoembryonic antigen (CEA) was fabricated by immobilizing anti-CEA onto organoclay nanogold composite film modified electrode by the cross-linking method using glutaraldehyde. In addition, the preparation procedure of the immunosensor was investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Under optimal conditions, the resulting immunosensor displayed a high sensitivity for the detection of CEA, and responded to the CEA concentration in two ranges from 0.05 to 5.0 ng/mL (R = 0.991) and from 5.0 to 120.0 ng/mL (R = 0.998) with a detection limit of 0.01 ng/mL.

2025, International Journal of Electrochemical Science

2025

The demand for secondary batteries with longer cycle life and higher power is greater now than ever. Lithium-ion batteries have emerged as the leading technology to store electrochemical energy and power our transportation needs. By employing solutionbased nanotemplating methods, new three-dimensional cell configurations can exploit the high-surface area of nanowire array electrodes. A key to the architecture is the deposition of a nanoscale solid polymer electrolyte (SPE). The non-active component must provide sufficient electrical insulation and lithium-ion conductivity between the electro-active battery electrodes. The uniform application of the polymer electrolyte is done in solution by the direct electropolymerization of electrochemically-active monomers. The first system explored was the reductive electropolymerization of a zinc vinylbipyridine complex [Zn(vbpy) 3 ] 2+ . The electrochemical synthesis covered the surface of planar and nanowire electrodes. Uniform deposition was observed by XPS and As global energy requirements increase at an alarming rate, so does the demand for safe, portable and high-energy devices to power the new-age of electronics 1 . High gravimetric and volumetric energy densities make lithium-ion (Li-ion) batteries an excellent electrochemical energy storage medium. A part of society where Li-ion batteries can make an immediate, meaningful impact is the transportation sector 2-3 . Electric vehicles require a portable, safe and rechargeable energy storage medium with high charge/discharge rates, high voltage and high capacity properties. One avenue of battery research has focused on finding new battery materials 4-6 . New electrodes with high-storage capacities and new electrolytes with fast Li-ion transport are pushing the frontier of the Li-ion battery capability. However, science has recently taken a large interest in the, sometimes radical, change in properties exhibited by physically restraining the size of known materials 4,7-9 . Nanoparticle solar cells 10 , nanowire sensors [11][12] , nanostructured electrochemical electrodes 13 and nanocrystal H 2 -storage materials 14 are promising areas of energy research. A route to improving battery performance is to transition from two-dimensional (2D) thin-film technologies to three-dimensional (3D) battery architectures. For Li-ion batteries, nanowire array (NWA) electrode materials have recently displayed capacityretention at extremely fast rates, capacity-retention at high cycle numbers and high-power capabilities [15][16][17][18][19][20][21][22] . These exciting results are due to the larger effective surface area and the short diffusion distance of Li + within the nanowires. Detrimental volume changes of the battery electrodes, or pulverization, cause a drop in capacity of thin-film batteries, but nanowires are physically less affected by the chemical intercalation/deintercaltion of Li +

2025, Journal of Electroceramics

Microsized fayalite Fe2SiO4 as anode material: the structure, electrochemical properties and working mechanism. Journal of Electroceramics.

2025

The use of mesoporous gold as electrode material for measurement of electrochemical capacitance is investigated. The electrodes possess a pore size in the range of 10 to 30 nm and are prepared by de-alloying films of AuAl x , where x≥2. Analyses conducted with X-ray photoelectron spectra (XPS) show that their surfaces are essentially pure gold, with only traces of aluminium remaining. The electrodes show near-ideal capacitor behaviour under both cyclic voltammetry and potential-step conditions. The higher capacitance of the mesoporous electrodes leads to a better dynamic range in potential-step experiments, resulting in improved accuracy of measurement. The sensitivity of the new material as a capacitive sensor is demonstrated in a milk fouling experiment, and is improved by up to 30 times compared to the control sample of ordinary planar gold. We propose that the use of mesoporous gold electrodes offer a convenient way to sensitively and accurately amplify the capacitance signal of an electrochemical sensor.

2025, Biochemistry & Analytical Biochemistry

A robust and effective nano-composite film based on nafion-CdTe quantum dots modified glassy carbon electrode was prepared by droplet casting. The fabricated nano-composite was used to construct a novel catalase biosensor for the determination of hydrogen peroxide. Direct electron transfer and electrocatalysis of catalase were investigated. A pair of quasi-reversible redox peaks of catalase was observed in 0.20 M deaerated phosphate buffer solution of pH 7.0. The nano-composite film showed a pronounced promotion of the direct electron transfer among catalase and glassy carbon electrode. The immobilized catalase exhibited an excellent electrocatalytic activity towards the reduction of H 2 O 2 . Cyclic Voltammetry (CV), Chronoamperometry (CA) and Electrochemical Impedance Spectroscopy (EIS) were used to characterize the performance of the prepared nanobiosensor. The results showed that the prepared biosensor could be used as an amperometric biosensor for H 2 O 2 detection. The system was also found well suited for the use of impedimetry as an excellent biosensing system for hydrogen peroxide. The electrochemical impedance spectroscopy measurements revealed that the charge transfer resistance decreases significantly after enzymatic reaction with hydrogen peroxide concentration, so that the proposed modified electrode can be applied as an excellent nanobiosensor to the detection of ultra-traces of H 2 O 2 (2.0 × 10 -10 -2.0 × 10 -9 M).

2025

2025, Solid State Ionics

The crystal structure of Cl-mayenite (Ca 12 Al 14 O 32 Cl 2 ) is very similar to that of the well-known oxygen ion conductor O-mayenite (Ca 12 Al 14 O 33 ), showing zeolite-type cages with partial occupancy by oxygen anions. In Clmayenite chlorine ions occupy the cage centers instead of oxygen ions, and it is of interest whether these chlorine ions are mobile and whether Cl-mayenite is a chlorine ion conductor. The answer for these questions is the focus of the paper. High temperature neutron powder experiments and impedance spectroscopy measurements were performed. For information on possible chloride migration pathways and activation energies, quantum-chemical calculations based on density-functional theory were carried out. The behavior of Cl -is in clear contrast to O 2-in O-mayenite: even at high temperatures it only shows normal harmonic thermal displacement without indications for long range diffusion between the cages. The total ionic conductivity was found to be very low with a value of σ ≈ 10 -6 S cm -1 at 1073 K. Quantum-chemical calculations result in a very high activation barrier for Cl -migration of 3.07 eV.

2025, Sensors and Actuators B: Chemical

Novel electrochemical aptasensor toward cytochrome c (Cyt c) has been developed on the base of glassy carbon electrode (GCE) modified with electropolymerized neutral red (Poly-NR) and decacarboxylated pillar[5]arene (P[5]A-COOH) bearing terminal neutral red (NR) and aminated aptamer specific to Cyt c. Addition of Cyt c resulted in decrease of the cathodic peak current of NR on cyclic voltammogram due to suppression of the electron exchange between reduced and oxidized NR forms in the surface layer. The implementation of Cyt c in the surface layer was confirmed by scanning electron microscopy (SEM), atomic force microscopy (AFM) and electrochemical impedance spectroscopy (EIS). Depending on the content of the surface layer and assembling protocol, the limits of detection (LODs) varied from 0.02 to 1.0 nM and linear range of concentrations was within three orders of magnitude. Interfering influence of some proteins and polyethylene glycol was characterized. The aptasensors developed can find application in detection of Cyt c as apoptosis agent in blood serum. This has been partially validated in model blood serum mimicking the ionic composition of the plasma.

2025

Furosemide (4-chloro-2-furan-2-ylmethylamino-5-sulfamoylbenzoic acid) was examined as an inhibitor for the corrosion of carbon steel (CS) in 1.0 M HCl. The investigation included mass loss (ML) and electrochemical techniques: potentiodynamic polarization (PP), electrochemical impedance spectroscopy (EIS), and electrochemical frequency modulation (EFM). The efficiency of inhibition rises with increasing Furosemide concentration and temperature. At 300 ppm, the IE% reached 90%. This compound's behaviour follows the Temkin isotherm with good fit. The presence of varying quantities of the substance influences both anodic metal dissolution and cathodic hydrogen evolution (i.e., mixed type). Scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FT-IR) were used to detect the effect of this compound on the CS surface. The molecular inhibitory effect of furosemide was demonstrated using qua...

2025, ACS Applied Materials & Interfaces

A combination of nanosized dielectric relaxation (BDS) and thermal spectroscopy (SHS) was utilized to characterize the dynamics of thin films of poly(vinyl methyl ether) (PVME) (thicknesses: 7-160 nm). For the BDS measurements, a recently designed nanostructured electrode system is employed. A thin film is spin-coated on an ultraflat highly conductive silicon wafer serving as the bottom electrode. As top electrode, a highly conductive wafer with nonconducting nanostructured SiO 2 nanospacers with heights of 35 or 70 nm is assembled on the bottom electrode. This procedure results in thin supported films with a free polymer/air interface. The BDS measurements show two relaxation processes, which are analyzed unambiguously for thicknesses smaller than 50 nm. The relaxation rates of both processes have different temperature dependencies. One process coincides in its position and temperature dependence with the glassy dynamics of bulk PVME and is ascribed to the dynamic glass transition of a bulk-like layer in the middle of the film. The relaxation rates were found to be thickness independent as confirmed by SHS. Unexpectedly, the relaxation rates of the second process obey an Arrhenius-like temperature dependence. This process was not observed by SHS and was related to the constrained fluctuations in a layer, which is irreversibly adsorbed at the substrate with a heterogeneous structure. Its molecular fluctuations undergo a confinement effect resulting in the localization of the segmental dynamics. To our knowledge, this is the first report on the molecular dynamics of an adsorbed layer in thin films.

2025, Chemical Physics Letters

The molecular dynamics of 4-octyl-4 X -cyanobiphenyl and 4-pentyl-4 X -cyanobiphenyl, confined to the mesopores with diameters less than 25 A of the molecular sieve AlMCM-41, was investigated over a wide temperature range using broadband dielectric spectroscopy. As expected, the phase transitions of the bulk liquid crystals cannot be detected for the confined molecules. A new, slow relaxational process occurs over the whole temperature range due to the motions of the molecules confined in the pores; the temperature dependence of the characteristic frequency obeys a Vogel-Fulcher-Tam-Ž . man VFT law associated with a glassy state. The orientational order within these small pores is mostly dominated by the local environment.

2025, Macromolecules

Broadband dielectric spectroscopy (10-2-106 Hz) is employed to study the relation between a relaxation and normal mode process for oligomeric polyisoprene samples of different molecular weights. It is shown that a relaxation and normal mode process merge above the Vogel temperature of the a relaxation. This means that the Rouse model is not applicable to the normal mode relaxation near the glass transition. Further, this result is discussed from a microscopic point of view in terms of the different temperature dependences of the two relevant length scales, the correlation length for the a relaxation 4 and the end-to-end vector of the polymer chain. A quantitative evaluation gives more evidence that there exists a characteristic length scale for the a relaxation which is in the order of magnitude of 2-3 nm a t the glass transition temperature.

2025, Journal of Physical Chemistry Letters

Photoelectrochemical impedance spectroscopy (PEIS) is a useful tool for the characterization of photoelectrodes for solar water splitting. However, the analysis of PEIS spectra often involves a priori assumptions that might bias the results. This work puts forward an empirical method that analyzes the distribution of relaxation times (DRT), obtained directly from the measured PEIS spectra of a model hematite photoanode. By following how the DRT evolves as a function of control parameters such as the applied potential and composition of the electrolyte solution, we obtain unbiased insights into the underlying mechanisms that shape the photocurrent. In a subsequent step, we fit the data to a process-oriented equivalent circuit model (ECM) whose makeup is derived from the DRT analysis in the first step. This yields consistent quantitative trends of the dominant polarization processes observed. Our observations reveal a common step for the photo-oxidation reactions of water and H2O2 in alkaline solution.

2025, Sensors

The As2S3-Cu interface was studied by dielectric spectroscopy measurements on Cu-As2S3-Cu thin film heterostructure samples to assess the charge carriers’ contribution to the electrical properties of such an interface. Three-dimensional printed masks ensured good reproducibility during the PLD deposition of heterostructure samples. The samples were tested for electrical conductivity and AC photoconductivity by dielectric spectroscopy measurements. DC bias voltages and light were applied to the samples. The electrical capacity of the thin film heterostructure can be modified electrically and optically. We observed long-term photoconductivity with a time dependency that was not exponential, and a quick change of the electrical capacity, indicating the potential of the heterostructure cells as photodetector candidates.

2025

is paper concerns the inductive experimental study of corrosion products of the medium carbon steel CK45DIN using magnetized water as hardening media, where the water has been exposed to a magnetic field of 1000 Gauss and 2000 Gauss, respectively, for time durations of 1 to 5 hours, with a volumetric flow rate of 4 gal/min. Medium carbon steel CK45DIN samples were exposed to air as corrosive environment for reasonable time interval, and the corrosion product was weighed in order to determine the loss of weight. e results showed that the corrosion rate of all samples decreased as the experiment progresses over time. Corrosion resistance of the medium carbon steel CK45DIN increased when we raised its temperature to 870 °C for 40 minutes and hardened by magnetized water applied in a magnetic field with a strength of 1000 Gauss for 3 hours as compared with the sample hardened by normal water.

2025, Briefings in Bioinformatics

Traditional approaches for genetic mapping are to simply associate the genotypes of a quantitative trait locus (QTL) with the phenotypic variation of a complex trait. A more mechanistic strategy has emerged to dissect the trait phenotype into its structural components and map specific QTLs that control the mechanistic and structural formation of a complex trait.We describe and assess such a strategy, called structural mapping, by integrating the internal structural basis of trait formation into a QTL mapping framework.Electrical impedance spectroscopy (EIS) has been instrumental for describing the structural components of a phenotypic trait and their interactions. By building robust mathematical models on circuit EIS data and embedding these models within a mixture model-based likelihood for QTL mapping, structural mapping implements the EM algorithm to obtain maximum likelihood estimates of QTL genotype-specific EIS parameters.The uniqueness of structural mapping is to make it possible to test a number of hypotheses about the pattern of the genetic control of structural components.We validated structural mapping by analyzing an EIS data collected for QTL mapping of frost hardiness in a controlled cross of jujube trees.The statistical properties of parameter estimates were examined by simulation studies. Structural mapping can be a powerful alternative for genetic mapping of complex traits by taking account into the biological and physical mechanisms underlying their formation.

2025, Thin Solid Films

The formation and quality of highly hydrophobic coatings deposited from water dispersible organosilanes onto pre-oxidized single crystal silicon were studied using atomic force microscopy, ellipsometry, dynamic contact angle measurements and electrochemical impedance spectroscopy (EIS). Highly hydrophobic films of a commercially available water dispersible silane and two different cationic alkoxysilanes were prepared by dip coating. It was found using atomic force microscopy that, in general, the structure of these highly hydrophobic films is a continuous film with some particulates attributed to bulk polymerization of the precursor molecule in water. Film defects were quantified using EIS by the value of charge transfer resistance at the hydrofluoric acidysilicon interface. Potential applications of this type of coatings include reductionyelimination of stiction in micro-electromechanical systems, contact printing in materials microfabrication, inhibition of corrosion and oxidation, prevention of water wetting, lubrication and protein adsorption.

2025, Applied Physics Letters

We experimentally demonstrate non-volatile resistive switching (RS) with a resistance window of ∼10× in oxide ion conductor BiYO3 (BYO) thin films. (111)-oriented BYO films of multiple thicknesses (20 nm–300 nm) were deposited using the pulsed laser deposition technique on a Pt/TiO2/SiO2/Si substrate. The thermal stability of BYO films in a wide temperature range (10 K–800 K) was confirmed, using temperature dependent dielectric measurements. Further, impedance spectroscopy suggests the presence of oxygen vacancies (defects) at the Au/BYO interface in the high resistance state (after forming) too. Root mean square roughness of the films varied from 1.16 nm to 2.76 nm, confirming a uniform and homogeneous surface. We explain the conduction mechanism in our Au/BYO/Pt devices using space charge limited current (SCLC) and Ohmic conduction models. The bipolar RS characteristics of the BYO devices are empirically modeled on the basis of the oxygen ion driven filamentary switching process.

2025

In this work we propose a method to detect turmeric adulteration using the Cavity Perturbation Technique (CPT) at 2.4GHz. Two different adulterants are examined (egg-yellow color and starch). We show that when a single adulterant is added, the resonant frequency and unloaded quality factor values follow clear trends as a function of added contaminant. Unfortunately, when the turmeric is adulterated with different concentrations of two adulterants (e.g., a 50% color/50% starch) CPT does not lead to good results. To address this, we also present an automated machine learning flow that dramatically enhances the adulteration detection. The proposed flow has the additional uniqueness that it optimizes the predictive model based on the selected target hardware platform doing technology independent as well as technology dependent model optimizations. Experimental results show that our predictive model can be optimized based on the accuracy required for different hardware platforms. In particular we target a microcontroller and a dedicated hardware implementation.

2025, Sains Malaysiana

Electrolyte activated battery finds its important use during natural disaster emergencies, such as floods and typhoons. Nevertheless, high corrosion rate will deteriorate the discharge performance of the battery and it is influenced by the type of electrolyte and discharge current. In this study, the corrosion and discharge performance of a commercial Al 6061 aluminum alloy as an anode are investigated at different discharge currents (0.001, 0.01, and 1 mA) and in different electrolytes, namely salt water, urea, and distilled water. Scanning electron microscopy results show that electrode in salt water has the most serious corrosion, followed by that of in urea and in distilled water. These electrodeelectrolyte combinations are further investigated with potentiodynamic polarization, galvanostatic discharge, and electrochemical impedance spectroscopy (EIS) to understand their discharge potential, discharge behavior, and corrosion mechanism. Among all combinations, aluminum in water is found to have the highest discharge performance with discharge potentials ranging from 716 to 744 mV, regardless of discharge current.

2025, Sains Malaysiana

Electrolyte activated battery finds its important use during natural disaster emergencies, such as floods and typhoons. Nevertheless, high corrosion rate will deteriorate the discharge performance of the battery and it is influenced by the type of electrolyte and discharge current. In this study, the corrosion and discharge performance of a commercial Al 6061 aluminum alloy as an anode are investigated at different discharge currents (0.001, 0.01, and 1 mA) and in different electrolytes, namely salt water, urea, and distilled water. Scanning electron microscopy results show that electrode in salt water has the most serious corrosion, followed by that of in urea and in distilled water. These electrode-electrolyte combinations are further investigated with potentiodynamic polarization, galvanostatic discharge, and electrochemical impedance spectroscopy (EIS) to understand their discharge potential, discharge behavior, and corrosion mechanism. Among all combinations, aluminum in water ...

2025, Processing and Application of Ceramics

Cu 2+ and Er 3+ doped BaZr 0.05 Ti 0.95 O 3 (BZT) ceramics were prepared using the solid-state reaction method, where amount of CuO + Er 2 O 3 was fixed at 2 wt.% and different CuO : Er 2 O 3 molar ratios (i.e. 1:1, 1:2, 1:3, 2:1 and 3:1) were used. The influence of Cu 2+ and Er 3+ doping on crystal structure and dielectric properties of the samples sintered at 1300 °C was investigated. X-ray diffraction analysis confirmed the formation of a single-phase material and tetragonal crystal structure with P4mm symmetry. Microstructural analysis conducted with a scanning electron microscope revealed well-defined and uniformly distributed grains across the surface of the sintered samples and reduction of grain size and density with doping. The highest energy storage density of 40.51 mJ/cm 3 with an energy efficiency of 78.8% was obtained in the sample with CuO : Er 2 O 3 molar ratio of 2:1. The doped BZT ceramics have high dielectric constant and significantly lower tangent loss in comparison to the undoped BZT. The dielectric data confirm the non-Debye behaviour for all the samples. Impedance spectroscopy and electrical modulus analysis indicated that conduction in the materials was influenced by both the grains and grain boundaries. The AC conductivity is described by the Jonscher's universal power law, whereas DC conductivity follows a dependency based on the Arrhenius's theory. The results revealed a conduction mechanism characterized by non-overlapping small Polaron tunnelling up to 340 °C and a transition to correlated barrier hopping conduction above 340 °C within the selected temperature range for all the samples. According to the Arrhenius fitting of DC conductivity the activation energy of the undoped BaZr 0.05 Ti 0.95 O 3 sample is 0.168 eV and decrease with doping to 0.138 and 0.131 eV for the sample with lower Cu 2+ contents (CuO : Er 2 O 3 molar ratios of 1:2 and 1:3, respectively).

2025, International Journal of Energy Research

A literature review of electrochemical impedance spectroscopy (EIS) analysis of proton exchange membrane fuel cells (PEMFCs) is presented. Emphasis is placed on the papers that analyse the impedance response of the cathode and anode half-cells of the PEMFCs based on a continuum-mechanics approach. The other type of analysis, which is based on the equivalent-circuits approach, is addressed for comparison. The relative advantages and disadvantages of the two approaches are discussed. Papers dealing with continuum-mechanics-based EIS modelling of general electrochemical systems are briefly reviewed.

2025, Journal of Failure Analysis and Prevention

Molybdate and tungstate inhibitors were introduced in stagnant and flowing conditions for determining pitting corrosion resistance of Cr-Mn SS in chloride-containing media. Corrosion behavior was investigated using potentiodynamic and electrochemical impedance spectroscopy measurements in different NaCl concentrations (1, 2% and 3 wt.%). It was found that increase in NaCl concentration increases the corrosion rate. The addition of 0.01 M inhibitors decreased the corrosion rate in Cr-Mn SS. Better corrosion resistance was found with the addition of molybdate in stagnant conditions. However, the opposite behavior was observed in flowing conditions, but there was an increase in E pit with addition of molybdate. Additionally, the mechanism of the corrosion attack developed on the material surface after polarization was analyzed by scanning electron microscopy and energy-dispersive spectroscopy (EDS mapping and point scan). The inhibition effect of the additions was due to a more stable passive film against Cl ions. Mn in the steel may cause opposite effect (initiation of the pits on steel), mainly due to the presence of MnS inclusions which acted as pitting initiators.

2025, Talanta

This article describes the development of a new electrochemical platform composed by a polymer mixture and graphene oxide (GO). The working electrode of a screen-printed carbon electrode (SPCE) was modified with nanocomposite constituted by poly-vinyl alcohol (PVA), poly-vinylpyrrolidone (PVP) and GO, which was electrochemically reduced to obtain PVA/PVP/RGO/SPCE. The interactions and morphology of the PVA/PVP/GO nanocomposite were investigated by SEM, FTIR and UV-Vis. SEM images indicated an excellent dispersion of the GO sheets in the polymer matrix. Besides, FTIR and visible UV studies revealed strong interactions between polymer mixture and GO sheets. According to electrochemical studies, the new platform increased the electroactive surface area by a factor of 20.46 compared to the unmodified SPCE. Also, the PVA/PVP/RGO/SPCE had a fast electron kinetics transfer process with a value of k s = 9.6 s -1 . The modified electrode was applied to the determination of IgG anti-T. gondii antibodies for the serological diagnosis of toxoplasmosis. The IgG anti-T. gondii antibodies quantification showed a detection limit of 0.012 U mL -1 , and the coefficients of variation intra-day and inter-day assays were lower than 4.5 % and 6.2 %, respectively. The electrochemical platform proved to be a sensitive and easily applicable tool applied to the serological diagnosis of toxoplasmosis. Therefore, the developed nanocomposite represents an excellent alternative for the electrochemical biosensor fabrication.

2025, Materials research express

The effect of hexadecyltrimethylammonium bromide (CTAB) concentration on the galvanostatic electrodeposition of Ni-B matrix nano hexagonal boron nitride (hBN) reinforced composite coatings was investigated. XRD and FE-SEM analyzes were used for crystallographical and morphological investigations, respectively. Vickers indentation, nanoindentation, and nanoscratch experiments were carried out to investigate the micromechanical, nanomechanical and tribological properties, respectively. Potentiodynamic polarization and electrochemical impedance spectroscopy techniques were applied for corrosion characterization. The investigated properties have been improved with the increasing CTAB concentrations up to 900 μM. In a general manner, CTAB has a beneficial effect at lower concentrations and can be useful for metal matrix nano ceramic reinforced composite coating electrodeposition in the lower concentration range.

2025, Electrochimica Acta

A bioactive hydroxyapatite layer deposited on the CoCrMo bio-metallic alloys by electrodeposition under different concentrations of calcium, phosphate and H 2 O 2 . Response Surface Methodology (RSM) and Central Composite Design (CCD) were used to optimize electrolyte concentrations. RSM and CCD were used to understand the concentration effects on the in vitro corrosion performance of biomaterials. 5level-3-factor CCD was employed to evaluate effects of deposition parameters such as calcium concentration (0.016-0.184 M), phosphate concentration (0.005-0.055 M) and H 2 O 2 concentration (2.4-27.6 ml/L) on the hydroxyapatite coatings and their corrosion resistance. Data obtained from RSM were subjected to analysis of variance (ANOVA) and analysed using a second order polynomial equation. Optimum conditions for the deposition parameters of the hydroxyapatite layer coating were found to be a calcium concentration of 0.05 M, phosphate concentration of 0.04 M and H 2 O 2 concentration of 22.11 ml/ L. Maximum phase angle under the optimum conditions was determined to be 85.4 . Ringer's simulated body fluid was used for in vivo electrochemical impedance spectroscopy analyses of biomaterials.

2025, Progress in Organic Coatings

Zinc-cobalt alloy plating (ZnCo) was successfully deposited on carbon steel (CS) applying current of 2 mA with galvanostatic technique. Polyaniline film (PANI) was synthesized with cyclic voltammetry technique from 0.20 M aniline containing 0.20 M sodium tartrate solution on zinc-cobalt plated carbon steel (CS/ZnCo) electrode. PANI film characterized by scanning electron microscopy (SEM), was covered with a dark green-brown homopolymer film of strongly adherent homogeneous characteristic while the other one was plated with a porous light ZnCo one. The corrosion behaviour of zinc-cobalt deposited carbon steel electrodes with and without polyaniline (PANI) film in 3.5% NaCl solution was investigated with AC impedance spectroscopy (EIS) technique and anodic polarization curves. The results showed that PANI coating led to decrease of the permeability of metallic plating. The PANI homopolymer film provided an effective barrier property on zinc-cobalt coating and a remarkable anodic protection to substrate for longer exposure time.

2025, Journal of Energy Storage 111(115442):1-13 DOI:

This study aims to create a prototype supercapacitor (SC) using free-standing-solid polymer electrolytes and tea waste (TW) doped boron carbide (B 4 C) electrodes. Quasi-solid polymer electrolyte (QSPE) films are made using a solution-casting approach, with poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and polymethyl methacrylate (PMMA) as host polymers and potassium oxide (KOH) salt as an ion source. PVDF-HFP: PMMA (80:20 wt%) + 30 wt% KOH showed a maximal ion conductivity of 3.63 ± 0.18 × 10-4 S cm-1 and a relative permittivity of 31.48 × 10 3 at 10 5 Hz at ambient temperature. The linear speed voltammetry (LSV) test measurements demonstrate that the enhanced solid polymer electrolyte (SPE) sample can endure breakdown up to 1.85 V. The study utilized TW: B 4 C (95:05 wt%) activated electrode material for an SC device embedded with the highly conductive blend electrolyte film. The galvanostatic charge/discharge (GCD) method revealed the charge/ discharge behavior of an ideal SC indicating a low Faradic process and equivalent series resistance (ESR) value for the capacitor with a coulombic efficiency (η) of 100 %. The GCD data reveals that the SC's specific capacitance (C sp) was 42.30 F g-1 , and the calculated value of energy density (E s) and power density (P d) was 21.15 Wh. g-1 and 69.21 × 10 3 Wg-1 at 5 mA g-1 respectively. Cyclic voltammetry (CV) aids in studying the capacity behavior of the electrical double-layer capacitor (EDLC), revealing no redox peaks over a potential range of-1 to +1V and C sp was 50.72 F g-1. The C sp of 56.67 F g-1 was obtained using the Impedance data recorded over a range of frequency 0.01-1 MHz.

2025, Materials Chemistry and Physics

In the present work bronze alloys with a new chemical composition and suitable for the outdoor sculptures production have been developed. The effect of different elements as Ni, Bi and Si on the corrosion resistance of bronze alloys has been investigated. A particular effort has been made to obtain materials with an advanced resistance toward corrosion and also having a reduced content of lead. The behaviour toward corrosion has been investigated by linear polarization resistance measurements (LPR) and electrochemical impedance spectroscopy (EIS). The material characterization has been carried out by SEM-EDS measurements. An artificial K 2 S patina has been produced on materials in order to obtain a surface similar to that of artworks for outdoor exposures. The results arising from the LPR and EIS techniques have been comparatively evaluated in order to select the bronze alloys showing the best corrosion resistance. The results indicate that the presence of Ni and Si along with a reduced Pb content improves the anticorrosive characteristics of the alloys while the absence of Pb makes the material performances worse.

2025, Journal of Applied Physics

We present results from the anodization of an aluminum single crystal [Al(111)] and an aluminum alloy [Al 6060] studied by in situ x-ray reflectivity, in situ electrochemical impedance spectroscopy and ex situ scanning electron microscopy. For both samples, a linear increase of oxide film thickness with increasing anodization voltage was found. However, the slope is much higher in the single crystal case, and the break-up of the oxide film grown on the alloy occurs at a lower anodization potential than on the single crystal. The reasons for these observations are discussed as are the measured differences observed for x-ray reflectivity and electrochemical impedance spectroscopy.