Electronegative Properties Research Articles

Porphyrin for possessing low valence state of metal center

We discovered that metal center confined in the porphyrin structure can process lower valence state (LV) via reversible photoinduced electron transfer in both singlet and triplet states, which are confirmed by X-ray photoelectron spectroscopy (XPS), X-ray absorption fine structure (XAFS), electron spin resonance (ESR) and density functional theory (DFT) calculations. More importantly, this controlling strategy was hardly influenced by the electronegative properties of surrounding porphyrin structures, at the same time, it can be widely applied to various metal elements such as Zn, Cu, Ni, Co, Fe. This work provides a new vision to fabricate and deeply understand the metal center with lower valence state from single atom level.

Leaching Process of Weathered Crust Elution-Deposited Rare Earth Ore With Formate Salts.

To strengthen the rare earth leaching process and weaken the hydration of clay minerals for preventing landslides, it is of great importance to adopt a green and sustainable leaching agent in the industry. In this work, the leaching process of weathered crust elution-deposited rare earth ores with formate salts (ammonium formate, potassium formate, and sodium formate) was investigated. The effects of formate salts on the linear swelling ratio and zeta potential of the clay minerals were studied. The experimental results showed that ammonium formate could effectively recover the rare earth elements from weathered crust elution-deposited rare earth as well as inhibit the leaching of impurity aluminum. At room temperature, when the ammonium formate concentration was 1% wt, the leaching efficiencies of rare earth and aluminum were 87 and 37%, respectively. Compared with traditional inorganic ammonium salts, the inhibition effect of impurity aluminum was obvious. In addition, the results of the linear swelling ratio in the clay minerals showed that the inhibit ability of formate salts on the hydration of clay minerals enhanced with the increase of the formate concentration, and the order of the inhabitation on the clay minerals followed: 1% ammonium formate > 1.5% potassium formate > 2.5% sodium formate > distilled water. Based on the double layer theory, ammonium formate and potassium formate could effectively compress clay mineral particles to avoid water intake, which could increase the interaction between clay mineral particles and greatly reduce the electronegative property of the clay minerals, so as to effectively reduce the surface hydration of clay minerals to decrease the swelling of rare earth ore. The results of this experiment have important and practical significance in guiding the prevention of landslides, promoting the in-situ leaching technology, and effectively protecting the ecological environment in mining areas.

Effect of Active Site Modification towards Performance Enhancement in Biopolymer κ-Carrageenan Derivatives.

This research demonstrates a one-step modification process of biopolymer carrageenan active sites through functional group substitution in κ-carrageenan structures. The modification process improves the electronegative properties of κ-carrageenan derivatives, leading to enhancement of the material’s performance. Synthesized succinyl κ-carrageenan with a high degree of substitution provides more active sites for interaction with analytes. The FTIR analysis of succinyl κ-carrageenan showed the presence of new peaks at 1068 cm−1, 1218 cm−1, and 1626 cm−1 that corresponded to the vibrations of C–O and C=O from the carbonyl group. A new peak at 2.86 ppm in 1H NMR represented the methyl proton neighboring with C=O. The appearance of new peaks at 177.05 and 177.15 ppm in 13C NMR proves the substitution of the succinyl group in the κ-carrageenan structure. The elemental analysis was carried out to calculate the degree of substitution with the highest value of 1.78 at 24 h of reaction. The XRD diffractogram of derivatives exhibited a higher degree of crystallinity compared to pristine κ-carrageenan at 23.8% and 9.2%, respectively. Modification of κ-carrageenan with a succinyl group improved its interaction with ions and the conductivity of the salt solution compared to its pristine form. This work has a high potential to be applied in various applications such as sensors, drug delivery, and polymer electrolytes.

Charge Redistribution Caused by S,P Synergistically Active Ru Endows an Ultrahigh Hydrogen Evolution Activity of S-Doped RuP Embedded in N,P,S-Doped Carbon.

Water splitting for production of hydrogen as a clean energy alternative to fossil fuel has received much attention, but it is still a tough challenge to synthesize electrocatalysts with controllable bonding and charge distribution. In this work, ultrafine S‐doped RuP nanoparticles homogeneously embedded in a N, P, and S‐codoped carbon sheet (S‐RuP@NPSC) is synthesized by pyrolysis of poly(cyclotriphosphazene‐co‐4,4′‐sulfonyldiphenol) (PZS) as the source of C/N/S/P. The bondings between Ru and N, P, S in PZS are regulated to synthesize RuS2 (800 °C) and S‐RuP (900 °C) by different calcination temperatures. The S‐RuP@NPSC with low Ru loading of 0.8 wt% with abundant active catalytic sites possesses high utilization of Ru, the mass catalytic activity is 22.88 times than 20 wt% Pt/C with the overpotential of 250 mV. Density functional theory calculation confirms that the surface Ru (−0.18 eV) and P (0.05 eV) are catalytic active sites for the hydrogen evolution reaction (HER), and the according charge redistribution of Ru is regulated by S and P with reverse electronegativity and electron–donor property to induce a synergistically enhanced reactivity toward the HER. This work provides a rational method to regulate the bonding and charge distribution of Ru‐based electrocatalysts by reacting macromolecules with multielement of C/N/S/P with Ru.

Searching for Potential HDAC2 Inhibitors: Structure-activity Relationship Studies on Indole-based Hydroxamic Acids as an Anticancer Agent

Aim: To predict the most potent indole based HDAC2 inhibitors from several scientific reports through the process of lead identification and SAR development. Background: The current scenario is observing Histone Deacetylase (HDAC) as an alluring molecular target for the designing and development of drugs for cancer treatment. Background: The current scenario is observing Histone Deacetylase (HDAC) as an alluring molecular target for the designing and development of drugs for cancer treatment. Objective: To identify the lead and establish structure-activity correlation among indole based hydroxamic acid to find out promising HDAC2 based anticancer agent. Methods: A dataset containing 59 molecules was analyzed using structure and ligand-based integrated approach comprising atom-based 3D-QSAR (Quantitative Structure-Activity Relationship) and pharmacophore study, e-pharmacophore mapping and molecular modeling methodologies. The finest model was prepared by amalgamating the properties of electronegativity, polarizability, Vander Waals forces and other conformational aspects. Results: The result of 3D QSAR analysis, performed for 4 PLS factor, provided the following statistical information: R2 = 0.9461, Q2 = 0.7342 and low standard of deviation SD = 0.1744 for hypothesis ADDDH.10 and R2 = 0.9444, Q2= 0.7858 and again low standard of deviation SD = 0.1795 for hypothesis DDHRR.12. The XP molecular docking showed intermolecular interactions of small molecules with amino acids such as GLY154, HIP145, PHE210, HIE183, internal H2O and Zn2+. Conclusion: The interpretation of data generated as a result of this investigation clearly hints about the better biological activity of test compounds as compared to SAHA. Hence, the outcome of these structure and ligand-based integrated studies could be employed for the design of novel arylindole derivatives as a potent HDAC inhibitor.

Optimization of the nitrogen content for room temperature rapid synthesis of CuI thin films via liquid iodination method using Cu3N film as precursor

In this work, we demonstrate that CuI films can be obtained by the liquid–phase iodination method with the chemical reaction time only being 1 min between Cu3N and aqueous iodine solution at room temperature. This is a simple and eco-friendly method with high transparency and low resistivity. The Cu3N precursors were prepared by reactive DC magnetron sputtering using different N2 partial pressures. The effect of nitrogen content of precursor (Cu3N) on the structural, electrical, and optical properties of CuI thin films was discussed. Electronegativity property was used to explain the growth mechanism of CuI films prepared by different nitrogen content in the precursor. By growing the CuI films with a N2:Ar gas ratio of 5:2, the average transmittance achieved was 75% in the visible spectral range, and the lowest resistivity achieved was 3.67 × 10–2 Ω cm. These results suggest that the liquid iodination method using Cu3N film as precursor (N2:Ar gas ratio of 5:2) was suitable for preparing high-quality CuI films for application in transparent electronics.

Numerical Calculation of Electrophysical and Thermodynamic Characteristics of Glow Discharge Plasma in Atmospheric Pressure Oxygen Formed After Spark Breakdown

The paper presents the results of numerical calculations by finite elements method of the spatiotemporal dynamic of electrophysical and thermodynamic characteristics of atmospheric pressure oxygen plasma after the spark breakdown in the gas-discharge gap of 1 mm. Calculations relied on the use of two-dimensional axially symmetric model of plasma in drift-diffusion approximation, as well as Navier-Stokes and thermal conductivity equations. Discharge characteristics were calculated considering and without considering the plasma heating for various electrical circuit parameters. It was shown that at breakdown voltage of 3500 V and plasma heating, the discharge development leads to formation of the independent stationary discharge of constant current localized in a finite volume. Comparative analysis was done of the impact of electronegative properties of gas and plasma heating on the spatiotemporal dynamic of electrophysical and thermodynamic discharge characteristics.

Inhibitor design for 3‐hydroxy‐3‐methyl‐glutaryl‐CoA reductase enzyme; molecular docking and determination of molecular and electronic properties of ligands by density functional theory method

AbstractDesigning new inhibitors having less side effects is a need which also could reduce cholesterol levels. To fulfill this aim, we have carried out a molecular docking study toward 3‐hydroxy‐3‐methyl‐glutaryl‐CoA (HMG‐CoA) reductase. A set of designed structural derivatives of statin drugs, eight ligands which are used as HIV‐1 integrase inhibitor candidates, a set of terpenoids, and ligands downloaded from Zinc15 database were docked to HMG‐CoA reductase enzyme which contains atorvastatin in crystal structure. The analysis of docking studies revealed that statin derivative ligands are more appropriate for inhibition of HMG‐CoA reductase. To define the contribution of the molecular properties to the binding of ligands to enzyme structure; the highest occupied molecular orbitals‐lowest unoccupied molecular orbitals, hardness, electronegativity, and chemical potential properties of ligands have best score in their sets calculated by quantum mechanical tools.

Multifluorinated Aryl Azides for the Development of Improved H2 S Probes, and Fast Strain-promoted Azide-Alkyne Cycloaddition and Staudinger Reactions.

The development of advanced bioorthogonal reactions for detection and labeling of biomolecules is significant in chemical biology. Recently, researchers have found that multifluorinated aryl azides hold great potential for the development of improved bioorthogonal reactions. The fluorine atom can be a perfect substituent group because of its properties of excellent electronegativity and small steric hindrance. In this Minireview, we discuss recent developments of improved hydrogen sulfide (H2 S) fluorescence probes, fast strain-promoted azide-alkyne cycloaddition (SPAAC) and nonhydrolysis Staudinger reactions based on the use of multifluorinated aryl azides. Additionally, kinetic studies and biological applications of these reactions are also presented.

CHARACTERISTIC OF COMPLEX COMPOUNDS OF CUPRUM (II) NITRATE WITH ALIPHATIC AMINES PYRIDINE AND ITS DERIVATIVES IN CRYSTAL STATE

Complex compounds of CuCl 2 і Cu(NO 3 ) 2 with aliphatic amines in a crystalline state from alcohol solutions were obtained. The composition of the obtained compounds was determined by the method of equilibrium shift, molar ratios and intersection of the curves. Their electronic and IR spectra were studied, and a wide asymmetric absorption band was detected in the near region with a maximum of 870 - 900 nm. This band is characteristic of compounds of a tetrigonally curved octahedral configuration. The formation of complex compounds Cuprum (II) with amines of 1:1, 1:2 composition was established. Measured vibrational spectra in the region of 500 to 200 см -1 . IR-spectra of samples of complex compounds Cuprum (II) with the aliphatic amines, pyridine and its derivatives was measured as a suspension in vaseline oil. The measurements were carried out on an IKS-228 spectrophotometer. The frequency of stretching vibrations Me-N characterizes the coordination bond. The stretching vibrations of Me-N should manifest themselves in the low-frequency region as a result of a significant mass of the metal atom and the relatively low strength of the coordination bond. The IR spectra indicate Me-N stretching vibrations, which characterize the coordination bond. For aliphatic amines, absorption bands were identified in the region of 440–420 см -1 , which are assigned to V(Cu–N) vibrations. The bands in this region indicate coordination through the base nitrogen atom. The absorption bands of the ligands in the region of 210-220 см -1 disappear in the complex compounds. Most of the frequencies in complex compounds are explained by the dual nature of the σ- and π- dative interactions. In coordination compounds of Cu(NO 3 ) 2 with pyridine and its derivatives, an increase in vibration frequencies is observed with an increase in the stability of complex compounds, which is explained by the double nature of the bond (σ,-and π-dative interaction). Complex compounds were studied by differential thermal analysis. As a result, it was concluded that the nature of the decay of the complexes is affected by the nature of the ligand, complexing agent, electronegativity and polarizing properties of the ligand, steric effects and the nature of cations. The process of breaking the coordination bond for primary and secondary aliphatic amines occurs stepwise, and for tertiary amines in one step. At the first stage, one ligand molecule is cleaved, and at the second, the second molecule. Secondary amines have small cleavage. With an increase in the spatial factors of amines, the thermal stability of the complexes decreases.

Collective effects and optical characteristics of CdSexTe1-x

Collective effects and some response characteristics such as piezoelectric stress and strain constants, Fröhlich coupling parameter, optical electronegativity and exciton properties of CdSexTe1-x common-cation ternary alloys have been investigated. The calculations are carried out using a pseudopotential approach under a modified virtual crystal approximation that takes into account the alloy disorder effect, combined with the Adachi model. Generally, a good accord is obtained between our results and those available in the literature. The composition dependence of the features of interest shows that the Fröhlich coupling parameter remains almost constant, the piezoelectric properties vary almost linearly and the optical properties exhibit a non-linear behavior.

The halogen atoms induced different oxygen vacancies in RbNa2B6O10X (X = Cl, Br) for the enhanced photo-dechlorination properties

The halogen (X = Cl, Br) atom-substituted oxyhalide borate crystal materials RbNa2B6O10Cl (RNBC) and RbNa2B6O10Br (RNBB) with different oxygen vacancies were successfully prepared by high-temperature solid-phase method. Due to the Cl atom has a larger electronegative property can bring a greater deformation compared with Br atom, resulting in a larger oxygen vacancies concentration in the crystal. ESR tests also confirmed that the oxygen vacancy concentration of RNBC was higher than that of RNBB. The different alignment of B6O13 groups in two materials cause a non-central symmetric for RNBC and central symmetric for RNBB, this brought a built –in electric field existing in the RNBC which facilitate the electrons and holes separation when the light irradiation on the surface of the material. The photocatalytic activity of 2-CP under UV light irradiation showed that the degradation efficiency of RNBC was superior to RNBB, and the reaction rate constants of RNBC and RNBB were 0.1577 and 0.1257 min−1 respectively. Active radical experiments confirmed that in the photo-degradation of 2-CP, the O2– was the main active species and followed by e−, h+, OH.

Effect of microplastic size on the adsorption behavior and mechanism of triclosan on polyvinyl chloride

Microplastics in water environment and its ability to load various environmental pollutants have attracted wide attention in recent years. However, effect of microplastic size on the adsorption behavior of environmental pollutants and interaction mechanism has not been thoroughly explored. In this study, triclosan (TCS) was selected as model pollutant, and polyvinyl chloride (PVC) with different particle sizes (small size (<1 μm) is recorded as PVC-S and PVC-L means large particle size of about 74 μm) were used as the typical microplastics, the adsorption behavior of TCS on PVC was investigated by studying kinetics, isotherms, and other influencing factors, such as pH and salinity. The results indicate PVC-S has greater distribution coefficient kd values of TCS (1.35 L/g > 1.05 L/g) and stronger adsorption capacity (12.7 mg/g > 8.98 mg/g) compared with PVC-L, which may be due to higher specific surface area, stronger hydrophobicity and relatively small electronegative property of PVC-S. Moreover, the initial pH value and salinity of the solution played crucial role in the adsorption process. The distribution diffusion mechanisms (including liquid-film diffusion and intra-particle diffusion), hydrophobic interaction, electrostatic interaction, halogen bonding, and hydrogen bonding may be the important reasons for adsorption. These findings show that MPs with different particle sizes have vary adsorption behaviors and load capacities for environmental pollutants, which deserve our further concerned.

Effect of the formation of silver nano‐binuclear complex on the refinement of cytotoxic and antibacterial potency of coumarin Schiff base: Spectroscopy, thermal, X‐ray diffraction analyses and density functional theory calculations

A new Schiff base (SCH) was prepared using 8‐acetyl‐7‐hydroxy‐4‐methylcoumarin and sulfaclozine. Its silver complex was also synthesized. These compounds were subjected to elemental and spectral analyses. The silver complex was also subjected to thermogravimetric analysis, molar conductance measurements, scanning electron microscopy, energy‐dispersive X‐ray analysis and X‐ray diffraction measurements. The formula of the complex was determined as [(Ag2SCH(NO3)2]. The molar conductance indicates its non‐electrolyte character. The electronic structure and nonlinear optical parameters of SCH and its complex were investigated theoretically at the B3LYP/GENECP level. The geometry of the studied complex is non‐planar as indicated from the dihedral angles between central Ag metal ion and coordinated centres of SCH. Density functional theory calculations were also carried out to calculate the global properties of hardness, global softness and electronegativity. The calculated energy gap between HOMO and LUMO energies shows that charge transfer occurs within the studied complex. The total static dipole moment, the mean polarizability, the anisotropy of the polarizability and the mean first‐order hyperpolarizability were calculated and compared with those of urea as a reference material. The results of the mean first‐order hyperpolarizability showed that SCH and its silver complex are excellent candidates as nonlinear optical materials. The compounds were screened for their antimicrobial effect against various species of bacteria and fungi. Their anticancer activities were evaluated in vitro against the human cancer cell line MCF‐7 (human breast adenocarcinoma).

Preparation of N,F,B-Doped Carbon Materials for High-Performance Electric Double Layer Capacitors

The incorporating heteroatom species into carbon materials give opportunities for improving electrochemical properties. Single N-doping strategies are widely studied because of easy preparations and relative abundance in nature. However, facile synthetic methods of multiple-heteroatom-doped carbons are urgent for high-performance supercapacitors. In this study, we propose N,F,B-doped carbons for electric double layer capacitors derived from polyamic acid mixed with boric acid using pyrolysis process. Fluorinated polyamic acid is applied for a N,F-doping source and boric acid acts as a B-doping source. The synthesized carbon materials exhibit excellent electrochemical performances because of the synergetic effects of each N, F, and B atoms. The N and F atoms improve electronegativity property and also low doped B atoms improve redox reactivity in the carbon. The electrode is fabricated by direct pyrolysis process with carbon fabrics, which is an advantage for binder-free type electrodes and flexibility. The morphology and surface properties of the fabricated electrodes are studied by SEM, XPS, Raman, sheet resistance, and contact angle measurement. Furthermore, the flexible symmetric device with PVA-1M H2SO4 gel electrolyte fabricated from the N,F,B-doped carbon indicates a high volumetric capacitance and an energy density as well as mechanical stabilities under various deformations. These results are expected that the synthesized N,F,B-heteroatom-doped carbons offer great potentials as electrode materials for supercapacitor applications.

High-Tc fullerides

The critical temperature of the fulleride superconductors A2BC60 (A, B = Na, K, Rb, Cs) with the alkali metals solvated with ammonia, methylamine, and water molecules is calculated using a multivariate analysis of the lattice parameter, ionic radius, electronegativity, and other electronic properties obtained from density functional theory calculations. Results are in good agreement with the experimental data both for the alkali-metal fullerides and for the solvated (NH3)4Na2CsC60, (CH3NH2)K3C60 and (NH3)K3C60 compounds. The expansion of the crystalline lattice and the increase of the ionic character of the chemical bonds with solvation of the metal can modify significantly the critical temperature of the material. In the ammoniation of Na2CsC60, there occurs an expansion of the lattice and an increase of the ionic character of the chemical bonds in the material, which increases its critical temperature by about 20 K. Methylamine also can raise the critical temperature but is not as efficient as ammonia. Our results suggest that hydration of Na3C60 leads to the superconducting state and that (H2O)4Cs3C60 is a high-Tc fulleride at 50.9 K.

Increased electronegativity of high-density lipoprotein in uremia patients impairs its functional properties and is associated with the risk of coronary artery disease

Background and aimsUremia patients have impaired high-density lipoprotein (HDL) function and a high risk of coronary artery disease (CAD). Increased lipoprotein electronegativity can compromise lipoprotein function, but the effect of increased HDL electronegativity on HDL function and its association with CAD in uremia patient are not clear.We aimed to assess HDL electronegativity and various properties of HDL in uremia patients and investigate whether electronegative HDL is a risk factor for CAD in these individuals. MethodsHDL from 60 uremia patients and 43 healthy controls was separated into 5 subfractions (H1H5) with increasing electronegativity by using anion-exchange chromatography. Lipoprotein content was analyzed by gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight-mass spectrometry. HDL anti-oxidant, anti-apoptosis and cholesterol efflux activities were examined by fluorescence-based assays. ResultsThe percentage of H5 HDL (H5%) was significantly higher in uremia patients than in controls (p < 0.001). The concentration of apolipoprotein (Apo) AI was lower and apolipoprotein modifications were more prevalent in uremia HDL subfractions than in control HDL subfractions. Carbamylation of ApoAI and ApoCIII was increased in more electronegative HDL subfractions from uremia patients. Anti-oxidant activity, anti-apoptotic activity, and cholesterol efflux capability were reduced in HDL subfractions from uremia patients when compared with control HDL subfractions. Multiple logistic regression analysis showed that H5% was associated with CAD risk in uremia patients. ConclusionsIn HDL of uremia patients, increased electronegativity is accompanied by compositional changes and impaired function. Our findings indicate that increased H5% is associated with increased CAD risk in uremia patients.

Preparation and spectroscopic properties, density functional theory calculations and nonlinear optical properties of poly (acrylic acid-co-acrylamide)-graft-polyaniline

Poly (acrylic acid-co-acrylamide)-graft-Polyaniline was synthesized via chemical oxidation polymerization using ammonium persulphate as initiator at 40 °C under N2 atmosphere. The prepared poly (acrylic acid-co-acrylamide)-graft-Polyaniline was characterized by different analytical tools. The apparent activation energy of grafting reaction was calculated and found to be 48.7753 kJ/mol. Also, ΔH*and ΔS* as thermodynamic parameters for activation were calculated which equal to 46.4300 k J/mol. and −14.0379 J/mol. K respectively. The optimized structures of the graft (one, two and three units or ( monomer, dimer and trimer) were theoretically investigated at the B3LYP/6-311G level. The geometry of the graft are non-planar as indicated from the values of dihedral angles. The global properties of hardness, global softness and electronegativity were calculated. The calculated small energy gap between highest occupied and lowest unoccupied molecular orbital energies shows that charge transfer occurs within the graft compound. The molecular electrostatic potential for the graft was investigated. The obtained total static dipole moment, mean polarizability, anisotropy of polarizability and mean first-order hyperpolarizability (<β>) were compared with those of urea as a reference material. The results for <β> showed that the graft is excellent candidates as nonlinear optical materials.

Highly sensitive electrochemiluminescence immunosensor based on ABEI/H2O2 system with PFO dots as enhancer for detection of kidney injury molecule-1

In this work, poly[9,9-dioctylfluorenyl-2,7-diyl] (PFO) dots is discovered to display an appealing dual enhancement effect for the electrochemiluminescence (ECL) system of N-(aminobutyl)-N-(ethylisoluminol)/hydrogen peroxide (ABEI/H2O2), which not only enhances the ECL intensity of ABEI but also catalyzes decomposition of H2O2 to further amplify the ECL signal of ABEI. Owing to the electronegative property of PFO dots, electropositive ABEI-PEI as ECL reagent could be adsorbed on their surface and thus form a novel luminescence emitter (ABEI-PEI-PFO dots) with high ECL efficiency based on electrostatic attraction. Meanwhile, the water solubility and stability of this emitter are improved in virtue of the amine-rich property of ECL reagent (ABEI-PEI), which could increase the luminous efficiency of ECL reaction in aqueous solution. To increase the electron transfer efficiency, Pt nanoparticles (PtNPs) supported on reduced graphene oxide nanosheets (RGOs) via a onepot synthetic strategy are chosen as immobilizing platform for the ECL emitter (ABEI-PEI-PFO dots). Herein, the obtained dual-amplifed ABEI-PEI-PFO dots-RGOs/PtNPs complex is served as an ideal nanocarrier to capture detection antibody (Ab2). According to sandwiched immunoreaction, a highly sensitive ECL immunosensor is constructed for the detection of kidney injury molecule-1 (KIM-1) with a linearity from 50 fg mL−1 to 1 ng mL−1 and a detection limit of 16.7 fg mL−1. The developed ECL emitter combining dual amplified property for signal enhancement purpose would provide new thought and potential for sensitive bioanalysis and clinical application.

On the development of a deployable cold plasma endoscope

A novel non‐thermal atmospheric‐pressure plasma jet source for endoscopic application is presented. Specific challenges in the endoscopic plasma source development, such as small dimensions, flexibility, operation in half‐closed cavities, and the avoidance of in‐tube plasma, are addressed. Besides plasma characterization of the jet freely operating in ambient air, special focus is laid on the investigation of in‐cavity operation. In order to avoid saturation of the cavity atmosphere with the feed gas and at the same time allow a distinct jet formation, a second gas with electronegative properties is introduced as shielding gas. Depending on the flow rate ratios between feed gas and the shielding gas, arcing and jet‐to‐glow transition can be suppressed.