Dispersive Raman Spectroscopy Research Articles

Synthesis and Biocompatibility Evaluation of PCL Electrospun Membranes Coated with MTA/HA for Potential Application in Dental Pulp Capping.

This study aimed to develop polycaprolactone (PCL) electrospun membranes coated with mineral trioxide aggregate/hydroxyapatite (MTA/HA) as a potential material for dental pulp capping. Initially, the PCL membrane was prepared by an electrospinning process, which was further surface coated with MTA (labeled as PCLMTA) and HA (labeled as PCLHA). The physico-chemical characterization of the fabricated membranes was carried out using field emission scanning electron microscopy (FE-SEM)/Energy dispersive X-ray (EDX), X-ray diffraction (XRD), Raman spectroscopy, and contact angle analysis. The biocompatibility of the human dental pulp stem cells (hDPSCs) on the fabricated membranes was checked by XTT assay, and the hDPSCs adhesion and spreading were assessed by FE-SEM and confocal microscopy. The wound healing ability of hDPSCs in response to different electrospun membrane extracts was examined by scratch assay. The surface morphology analysis of the membranes by FE-SEM demonstrated a uniform nanofibrous texture with an average fiber diameter of 594 ± 124 nm for PCL, 517 ± 159 nm for PCLHA, and 490 ± 162 nm for PCLMTA. The elemental analysis of the PCLHA membrane indicated the presence of calcium and phosphorous elements related to HA, whereas the PCLMTA membrane showed the presence of calcium and silicate, related to MTA. The presence of MTA and HA in the PCL membranes was also confirmed by Raman spectroscopy. The water contact analysis demonstrated the hydrophobic nature of the membranes. The results indicated that PCL, PCLHA, and PCLMTA membranes were biocompatible, while PCLMTA exhibited better cell adhesion, spreading, and migration.

Fabrication of ZnO Nanorods Structure for Drastically Enhancing Gas Sensing Response to NO2 Gas

In this report, zinc oxide thin film was successfully deposited on a glass substrate by using a simple and low-cost technique i.e. modified Successive Ion Layer Adsorption and Reaction (SILAR). Prepared zinc oxide thin film was characterized for its physical and chemical properties by using XRD diffraction, Field Emission Scanning Electron Microscopy (FESEM), energy dispersive spectroscopy (EDS), UV-VIS spectroscopy, Raman spectroscopy and Fourier transform infrared spectroscopy (FTIR). The results of structural and morphological properties show that the prepared film has wurtzite hexagonal structure with nanorods-like morphology. Gas sensing characteristics revealed that the prepared film was sensitive to NO2 gas. The response calculated at operating temperature 200 °C, was 1.37 when NO2 concentration was 10 ppm, the response increased when the NO2 concentration increased which reached to 2.16 when NO2 concentration was 80 ppm with short response and recovery time. HIGHLIGHTS Nanorods- like morphology of ZnO were fabricated via modified SILAR technique The ZnO nanorods exhibit high sensitive and short response/ recovery time for NO2 gas at operating temperature i.e. 200 °C The synthesis method and sensing behavior of synthesized ZnO nanorods- like morphology, revealed a promising candidate for fabricating low-consumption gas sensors GRAPHICAL ABSTRACT

Spectroscopic, structural and thermal study of Y(OH)3microstructures synthesized by hydrothermal method: effect of the reaction time

Rare earth hydroxides have a wide variety of applications due to their interesting optical and magnetic properties. Specifically, yttrium hydroxide Y(OH)3 is an essential compound of rare earth hydroxides that can be used in areas such as electronics and chemistry due to its optical and structural properties. In this work Y(OH)3 was synthesized under nine reaction times (2–24 h) using the hydrothermal method in order to analyze the morphology evolution process that the Y(OH)3 follow to obtain the expected bar morphology. Also, a characterization study of Y(OH)3 through several techniques such as x-ray diffraction, scanning electron microscopy, energy dispersive x-ray spectroscopy, infrared, Raman and UV-Vis spectroscopy, thermogravimetric analysis, and differential scanning calorimetry is presented. The obtained samples in every reaction time were compared on phase purity, particle size and shape, and spectroscopic and thermal properties. It was concluded that the reaction time has an important effect in obtaining yttrium hydroxide using the hydrothermal method. During the study, the optimal time to obtain only Y(OH)3 was evaluated, as well as the evolution of the morphology over time. At 12 hours, only Y(OH)3is obtained, therefore this time is proposed as the optimal time.

Materials Exposure Testing in Chloride Molten Salts for Nuclear Applications

Advanced nuclear reactors using alkali chloride molten salts are actively being developed for deployment as safer next generation reactors. These reactors operate more efficiently and can enable a more flexible nuclear fuel cycle. These designs require the development of the understanding of corrosion at operational conditions. Static corrosion studies fail to capture the effects of flowing electrolyte on the corrosion in these systems. To simulate the effects of flow, we have designed and commissioned an apparatus for such corrosion studies. This study explored the corrosion of alloys in LiCl-KCl eutectic molten salt. After long-term exposure under simulated flow conditions, corrosions samples were evaluated using gravimetric analysis, scanning electron microscopy and energy dispersive spectroscopy, Raman spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy and the results are compared to corrosion under static conditions. Results and analysis of the effects of fluid flow on the corrosion on structural materials will be presented.Acknowledgement:This research is being performed using funding received from the DOE Office of Nuclear Energy's Nuclear Energy University Programs under awards DE-NE0008889 and DE-NE0008236, and the US Nuclear Regulatory Commission (USNRC) under contract 31310018M0032. Dr. Kenny Osborne and Ms. Nancy Hebron-Isreal serve as the program managers for the DOE and NRC awards, respectively.

Tribological behavior of WC-Al2O3-graphene composite at different temperatures

ABSTRACT WC-Al2O3-graphene composite powder was synthesized by ultrasonic treatment and ball milling, then consolidated by hot pressing sintering (HPS). For potential applications, the friction coefficient and wear resistance of the sintered bulks at different temperatures (room temperature, 200, 400, and 600°C) were investigated. The wear tracks were characterized by scanning electron microscope, energy dispersive spectroscopy and Raman spectroscopy, X-ray photoelectron spectroscopy, respectively. The results show that the friction coefficient decreases and the wear rate increases with the increase of temperature, mainly because oxidization wear occurs on the wear surface of WC-Al2O3-graphene composite under high temperature. The main wear mechanism is the destruction and formation of tribochemical compacted layer. Graphene reduces the wear rate of WC-Al2O3-graphene composite under high tampere. The reason is that graphene reduces oxidation wear by blocking or absorbing oxygen; moreover, graphene reduces the cycle frequency of damage and reconstruction of tribochemical compacted layer by reducing the peeling of it.

Synthesis of carbon nanofibers from electrospun polyvinylidene fluoride nanofibers for cathode electrodes in Li-O2 batteries

PVDF nanofibers were fabricated by the electrospinning method from polyvinylidene fluoride (PVDF) solutions in mixture of DMF and acetone solvents. PVDF fibers were then converted to CNF fibers through the low-temperature chemical stabilization ("dehydrofluorination") before carbonization at 800°C. The free-standing, perforated features of the CNF-based PVDF enabled the CNF to be directly applied as an air cathode in a LOB just after drying, without requiring additional conducting additives or polymeric binders. The interconnected pores between the individual CNFs were estimated to be 2‒4 µm. This could prevent the electrode from clogging when the discharge product was formed. With the interstitial voids and a large surface area, the CNF electrode synthesized from polymer PVDF had a capacity of 2,600 mAh/g with a current density of 200 mA/g. Moreover, CNF fibers, synthesized from electrospun PVDF nanofibers containing C‒F bonds, could improve the electrode conductivity, forming Li2O2 discharge products with less crystalline properties, leading to overpotential reduction during a discharge. This contributed to the longer cycle life of Li-O2 batteries using the CNF synthesized from electrospun PVDF nanofibers electrode (97 cycles) compared to the one synthesized from electrospun PAN nanofibers electrode (73 cycles) at a limited capacity of 1,000 mA/h and a current density of 200 mA/g. Their structure and morphology were evaluated by Scanning Electron Microscopy, Fourier-transform infrared Spectroscopy, Energy Dispersive X-ray Spectroscopy, X-ray diffraction, and Raman Spectroscopy.

Рост кристаллов Cu2ZnSnSe4 из раствор-расплава KI-KCl в градиенте температуры

In this work, a two-step method for preparation of CZTSe (Cu2ZnSnSe4) single crystals was demonstrated for the first time by recrystallization of a polycrystalline material in a KI-KCl melt-solution in a temperature gradient. At the first step, a polycrystalline material consisting of a mixture of metal selenides was synthesized by direct fusion of elemental Cu, Zn, Sn, and Se at 1000°C. Next, recrystallization process was carried out at a temperature gradient of 100°C, while the temperature of the cold zone was 750°C. The phase and chemical composition of the crystals were studied by energy dispersive X-ray and Raman spectroscopy. It was shown that the charge composition does not affect the composition of the obtained crystals. According to the amount of the remaining charge in the hot zone, one can speak of a very low recrystallization rate and a low product yield. Analysis of the elemental composition of crystals from the cold zone revealed a high inhomogeneity even in one experiment, which indicates the need to optimize the experimental parameters. On the other hand, according to the full line width at half height of the main peak, it can be argued that the obtained samples have a high degree of order in the structure and are suitable for measuring of physical characteristics.

Fabrication and analysis of barium-based metal organic framework characteristic properties

Metal Organic framework (MOFs) a diverse class of complex organic metal assemblages has been attracting a great interest due to its easy tunability and modified characteristics during the past few years. These nanoscale-to-microscale-sized structures have been employed in different applicative fields due to their striking functional chemistry. Barium MOF synthesis is based on barium metal ions tri-linked organically to form a cubic structure and features photolumincity. Ba-MOF was synthesized by hydrothermal method and structural and optical analysis was performed using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), Raman Spectroscopy and Zeta Potential. The presence of cubic structure and organic carbon and oxygen linkages was indicated by XRD peaks. EDS directs the presence of barium as well as carbon and oxygen (organic linkers). Raman analysis paid for witnessing the evidence of the synthesis of MOF structure by validating the peak location. The photoluminescence spectrum was applied to measure the bandwidth to study the photoluminescence characteristics. The PL spectrum presented a wide bandwidth of 107.4 nm indicating Ba-MOF to be an efficient photoluminescent nanocomposite for photoluminescence-based applications. Zeta potential value of [Formula: see text] mV characterized anionic behavior and high stability of fabricated Ba-MOF.

Surface integrity studies on ZrB2 and graphene reinforced ZrB2 ceramic matrix composite in EDM process

Zirconium diboride is a potential ceramic for high temperature applications because of its combination of properties, such as very high melting point, high hardness, elevated temperature strength, good thermal and electrical conductivity. Although the near net shape components are made from this material, machining is required to create additional features for the application requirements. This ceramic's high hardness and low fracture toughness make it very difficult to use the conventional processes for machining. The good electrical conductivity of this ceramic makes electrical discharge machining (EDM) the preferred machining process. This paper presents the surface and sub-surface modifications during Wire cut EDM (WEDM) and EDM of ZrB2 an ultra high temperature ceramic (UHTC) and ZrB2-GNP (ceramic matrix composite with 7 vol% Graphene Nano Platelets) along with the surface characterization of the copper electrode (EDM tool). Scanning Electron Microscope (SEM) with Energy Dispersive Spectroscopy (EDS) and Raman spectroscopy (for GNPs) were used to characterize the melt-solidified layer and the recrystallized region. The presence of micro cracks and pores was observed in the melt-solidified layer. Growing dendrites of ZrB2 were observed in the high magnification SEM images of the melt-solidified layer surface. Under the melt-solidified layer, a recrystallized fine grain structure was observed with reduced porosity compared to the rest of the bulk. After the WEDM of ZrB2-GNP (7 vol%), the stacks of cut GNP were retained, whereas GNPs were damaged after EDM The end surface of the copper electrode showed the partial deposition of ZrB2 and the formation of a micro scale pattern on it. The effect of peak current and pulse ON time on surface roughness (Sa), material removal rate (MRR) and relative tool wear (%) were studied for ZrB2-GNP (7 vol%) The results indicated that the surface roughness (Sa), MRR and the relative tool wear (%) increase with increasing peak current. The rise in pulse ON time also increases surface roughness (Sa) and MRR but reduces the relative tool wear rate (%)

Preparation and Characterization of the Cr-Nanodiamonds/MoN Coatings with Performant Mechanical Properties

This paper presents the results of a study on the preparation and characterization of a Cr-DND/MoN detonation chromium-nanodiamond coating deposited on cemented tungsten carbide (WC–3 wt.% Co) mill blades using Arc-PVD and electrodeposition methods. The physical and mechanical characteristics of the coatings were investigated by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), XRD analysis, Raman spectroscopy, micro-identification, and scratch test (evaluation of the coating adhesion). It was shown that the Cr-DND/MoN coating consists of successive layers of Cr-DND (top), Cu (middle) and MoN (bottom) with separate phases of γ-Mo2N, α-Mo, α-Cu, Cr-DND and nanodiamonds. The Cr-DND composite electrochemical coating (CEC) was deposited from the conventional chromium plating electrolyte with the addition of nanodiamonds. The copper interlayer was deposited by the Arc-PVD method on the surface of the MoN coating to improve the adhesion strength of the Cr-DND CEC. The coating showed an optimum microhardness of about 14 ± 1 GPa and good adhesion with a critical load Lc of about 93 N. In addition to the expected experimental results, the coating has high wear resistance, confirmed by scratch tests.

Identification of self-lubricative mode for the ultrasonic treated AA6061-B4C-CNT hybrid composites

This research investigates the self-lubricative behavior of boron carbide (B4C) and carbon nanotube (CNT) reinforced 6061 aluminium alloy hybrid composites. Hybrid composites were prepared by varying the volume percentages (5–15%) of B4C and CNT. Novel ultrasonic vibration (frequency of 20 kHz and power of 2.5 kW) assisted stir casting process was used for fabricating hybrid composites. A pin-on-disc type tribometer mounted with EN-8 as the counterface material was used to evaluate the friction and wear behavior of hybrid composites under dry sliding conditions. Normal loads ranging from 15–45 N and sliding speeds ranging from 1–2 m/s were applied during the experiments. The self-lubricative properties of different hybrid composites were assessed through the examination of the worn surface of pins using surface characterization techniques such as Scanning electron microscopy, Electron dispersive spectroscopy and Raman spectroscopy. The experimental results indicated that the addition of CNT particles increased the hardness of hybrid composites. The matrix strengthening efficiency of CNT was found to be greater at 10 vol.% of B4C, indicating a maximum hardness ranging from 102 to 109 VHN. In comparison, 10 vol.% of CNT hybrid composites showed superior tribological performance at all wear testing conditions. The mode of wear of hybrid composites suggested by the analysis on the worn pin surface was as follows: Scarce (5 vol.% CNT), Tribolayer (10 vol.% CNT) and Fracture (15 vol.% CNT).

INTERFACE MODIFICATION OF SUBSTRATE FOR ENHANCING ADHESIVE STRENGTH OF CVD DIAMOND COATING BY SOLID PARTICLES

The strong adhesive strength is essential for the widespread applications of diamond coating in the mechanical field. In this paper, a novel method combining conventional chemical vapor deposition (CVD) diamond technique with solid particles was proposed to modify the interface material properties of substrate to improve the adhesive strength of the diamond coating. Prior to deposition, wet dispersion was adopted to uniformly distribute solid particles on the substrate, with which the diamond coatings with the WC, TiC and BN particles embedded at the interface were fabricated on Co-cemented tungsten carbide (WC-Co) substrate. In addition, the pure diamond coating was also fabricated for comparison. The as-deposited diamond coatings were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), energy dispersive X-ray spectroscopy (EDS) and Raman spectroscopy. The results indicated that the diamond coating with TiC exhibited the highest residual stress, which may be due to the larger lattice mismatch between TiC and diamond as compared to WC and BN. The indentation test suggested that WC and BN particles were favorable for the improvement of the adhesive strength and the crack resistance of diamond coating, while this phenomenon was not observed in the diamond coating with TiC particle. This might be caused by the large lattice parameter, high lattice mismatch, and high thermal expansion coefficient mismatch of TiC as compared with diamond. Furthermore, the lattice parameter of additional particles might be an important factor to determine whether or not the adhesive strength of diamond coating can be enhanced, because it determined the compressive stress or tensile stress generated inside diamond coating. Hence, interface modification of substrate by dispersing the solid particles with low lattice parameter or similar material properties of diamond may be an effective and convivence approach to improve the adhesive strength of the diamond coating.

Detection of porphyrins in vertebrate fossils from the Messel and implications for organic preservation in the fossil record

Organic molecules preserved in fossils provide a wealth of new information about ancient life. The discovery of almost unaltered complex organic molecules in well-preserved fossils raise the question of how common such occurrences are in the fossil record, how to differentiate between endogenous and exogenous sources for the organic matter and what promotes such preservation. The aim of this study was the in-situ analysis of a well-preserved vertebrate fossil from 48 Ma Eocene sediments in the Messel pit, Germany for preservation of complex biomolecules. The fossil was characterized using a variety of techniques including time-of-flight secondary ion mass spectrometry (ToF-SIMS), scanning electron microscopy/energy dispersive x-ray spectroscopy (SEM/EDX), x-ray diffraction (XRD) and Raman spectroscopy. A suite of organic molecules was detected, including porphyrins, which given the context of the detected signal are most probably diagenetically altered heme originating from the fossil though a microbial contribution cannot be completely ruled out. Diagenetic changes to the porphyrin structure were observed that included the exchange of the central iron by nickel. Further analyses on the geochemistry of the fossil and surrounding sediments showed presence of pyrite and aluminosilicates, most likely clay. In addition, a carbonate and calcium phosphate dominated crust has formed around the fossil. This suggests that several different processes are involved in the preservation of the fossil and the organic molecules associated with it. Similar processes seem to have also been involved in preservation of heme in fossils from other localities.

Preparation of CuO Nanorods by Thermal Oxidation in Ozone Ambient

CuO nanorods were prepared by thermal oxidation method in ozone ambient. The effect of annealing temprature in the range from 400 to 600 oC on morphology and structure of nanorods was studied thouroughly by scanning electron microscopy (SEM) and X-ray diffraction, combining with energy dispersive spectroscopy (EDS) and Raman spectroscopy. The results showed that annealing temprature strongly affected the structure and morphology of the produced CuO nanorods. The most uniform nanorods with highest crystal quality were obtained when annealing temperature is from 450 to 500 °C and annealing time was 2 h as suggested by SEM images together with Raman results.

Acid neutralizing and remineralizing orthodontic adhesive containing hydrated calcium silicate

ObjectivesThe objective of this study was to evaluate an orthodontic adhesive containing hydrated calcium silicate (hCS) in terms of its bond strength with the enamel surface and its acid-neutralization and apatite-forming abilities. MethodsThe experimental orthodontic adhesives were composed of 30 wt.% resin matrix and 70 wt.% filler, which itself was a mixture of silanized glass filler and hCS in weight ratios of 100% glass filler (hCS 0), 17.5% hCS (hCS 17.5), 35% hCS (hCS 35.0), and 52.5% hCS (hCS 52.5). The degree of conversion (DC) and shear bond strength (SBS) of bovine enamel surfaces were tested. pH measurements were performed immediately upon submersion of the specimens in a lactic acid solution. The surface precipitates that formed on specimens immersed in phosphate-buffered saline (PBS) were analyzed by scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS) and Raman spectroscopy after 15, 30, and 90 days. ResultsThe experimental groups exhibited no significant differences in DC and had clinically acceptable SBS values. The hCS-containing groups showed increasing pH values as more hCS was added. hCS 52.5 produced Ca- and P-containing surface precipitates after PBS immersion, and hydroxyapatite deposition was detected after 15, 30, and 90 days. ConclusionsThese results suggest that orthodontic adhesives containing hCS are effective for acid neutralization. Furthermore, hCS has an apatite-forming ability for enamel remineralization. Clinical significanceThe novel orthodontic adhesive containing hCS exhibits a potential clinical benefit against demineralization and enhanced remineralization of the enamel surface around or beneath the orthodontic brackets.

Apatite in Hamipterus tianshanensis eggshell: advances in understanding the structure of pterosaur eggs by Raman spectroscopy

Pterosaur eggs can offer information about pterosaur reproductive strategies and are extremely precious because only a small number of specimens have been discovered. Previous studies have mainly focused on morphological descriptions of pterosaur eggs and their embryos while the chemical composition of pterosaur eggs has received little attention. The conventional view believed that the eggshell was composed of calcite. However, previous SEM–EDS results for Hamipterus tianshanensis showed that the eggshell contains phosphorus. Therefore, the object of this research is to determine the mineral composition of the eggshell of H. tianshanensis. Two eggs were analyzed by scanning electron microscopy coupled with energy dispersive X-ray spectrometry (SEM–EDS) and Raman spectroscopy. The SEM–EDS results show that both surface and cross section are porous and characterized by small irregularly shaped particulates. Moreover, the distribution of Ca and P has a strict coincidence in the cross-section of eggshells. Furthermore, neither the intense peaks of calcite nor organic peaks can be observed by Raman spectroscopy in eggshells. Meanwhile, the Raman spectroscopy mapping analysis result shows a sharp and intense peak at approximately 966 cm−1 among the white eggshell, which can be hard evidence that H. tianshanensis eggs are mainly composed of calcium phosphate. Combined with the present of F in the eggshell, it can be inferred that fluorapatite Ca5(PO4)3F is the main mineral. The fluorapatite eggshell can be interpreted in two ways. One explanation is that H. tianshanensis laid apatite-shelled eggs, similar to living Salvator merianae, and the bioapatite transformed to fluorapatite over geological time. Another possible explanation is that the fluorapatite comes from the result of phosphatization of soft egg membrane tissues through taphonomic processes, indicating that H. tianshanensis might have laid soft eggs. Regardless, the results show that fluorapatite, rather than calcite is the main preserved mineral composition of H. tianshanensis eggshell, correcting the previous view. This study contributes to the present understanding of the mineral composition of pterosaur eggshells and may offer some insight into the pterosaur reproduction pattern.

Rapid Single-Step Deposition of Nanostructured Hematite Thin Films Produced by PECVD Using Ferrocene as Precursor

Dense cauliflower type nanostructured hematite (<inline-formula> <tex-math notation="LaTeX">$\alpha $ </tex-math></inline-formula>-Fe₂O₃) thin films were grown by plasma-enhanced chemical vapor deposition (PECVD) using ferrocene (Fe(C₅H₅)₂) as precursor. The influence of the plasma parameters on the layer composition and growth rate was investigated and correlated with the plasma used during the deposition process. Optical emission spectroscopy (OES) data from the plasma in conjunction with scanning electron microscopy (SEM), energy dispersive spectrometry (EDX) and Raman spectroscopy showed that plasma power of about 50&#x2013;120 W with an O₂ content of 10&#x0025;&#x2013;15&#x0025; in the carrier gas Ar favors the growth of hematite rather than maghemite. The thickness of the thin films is position dependent due to the plasma reactor geometry. The growth rate can reach a very high value, up to 440 nm/min.

Raman Spectroscopy in Analyzing Fats and Oils in Foods

Fats and oils are ubiquitous in natural and processed foods, providing necessary energy storage. Fat and oil content in foods also have important contributions to the shelf life, texture, compatibility with processing operations, and sensory profiles of food products. Understanding the molecular properties of fats and oils separately within a heterogeneous food matrix requires a multidisciplinary approach. Vibrational spectroscopy techniques are used throughout the food industry to gain product understanding, identify adulterated products, ensure quality, and control processes. In analyzing fats and oils in food, near-infrared (NIR) spectroscopy is an established analytical technique, and there are other growing applications of infrared (IR) and Raman spectroscopies. In particular, Raman spectroscopy is well suited to measure fats and oils because their C-H and C-C bonds are polarizable. In this article, we review the historical use of Raman spectroscopy in studying fats and oils in foods from Fourier transform (FT)–Raman spectroscopy to dispersive Raman spectroscopy. We also provide an overview of various Raman approaches to understand fat compositional heterogeneity in solid foods, identify polymorph or crystallinity, and measure fatty acid saturation. Examples in a variety of fat-containing foods demonstrate feasibility for Raman applications in the laboratory and process environments.

Nanocomposite E(PbSnF4;SnF2)@SWCNT – Promising material for fluoride-ion batteries

The channels of single walled carbon nanotubes (SWCNT) were filled with eutectic composition consisting of PbSnF4 and SnF2. The nanocomposite was investigated by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM), X-ray energy dispersive (EDX) spectroscopy and Raman spectroscopy. The SnF2 and PbSnF4 nanocrystals form independent regions with disordered atomic region between them inside the SWCNT with a diameter of 20.0(3) Å. In the PbSnF4 region there are two separate fragments connected by a twinning plane. Structural models of the PbSnF4 twin nanocrystal and SnF2 nanocrystal inside the nanotube with chilarity (26,0) were constructed and computer modelling of TEM-image of E(PbSnF4;SnF2)@SWCNT nanocomposite was performed. Solid-state FIB with Ce as anode, dispersed E(PbSnF4;SnF2)@SWCNT + SnF2 as a composite-cathode and 95.03%LaF3+4.97%BaF2 electrolyte was investigated by the impedance spectroscopy and cyclic voltammetry. The current density reached ∼0.6 A/m2 at 180 °C, the open circuit voltage of the pellet at room temperature was 1.9 V.

Fabrication of a solid-state symmetrical supercapacitor based on polyaniline grafted multiwalled carbon nanotube deposit onto Created Vertically Oriented Graphene Nanosheets on graphite sheet

Binder-free PANI-g-MWCNT/VOGN/Graphite sheet electrode with very high surface area and excellent capacitive behavior was fabricated through the anodizing of the graphite Followed by electrodeposition and polymerization. The prepared samples were investigated by Fourier transform infrared (FT-IR) spectroscopy, Dispersive Raman Spectroscopy, scanning electron microscopy (SEM), Atomic Force Microscopy (AFM), and BET (Brunauer–Emmett–Teller). SEM and AFM images showed that the polyaniline was successfully grafted onto the MWCNTs. The BET test represented that created VOGN increased the surface area of the graphite sheet. The energy storage performance of the fabricated electrode was evaluated by cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy. The PANI-g-MWCNT/VOGN/Graphite sheet electrodes showed a very high capacitance of about 880 F g−1 at a current density of 1.5 A g−1, an excellent energy density of 68.4 mWh g−1, the power density of 895.4 mW g−1, and stable capacity of about 80.6% after 10,000 cycles in the charge/discharge process. To show the fabricated supercapacitor device's practical application, we made a solid-state supercapacitor separated by PVA/H2SO4 that exhibited high electrochemical performance. The observed superior capacity of the fabricated PANI-g-MWCNT/VOGN/Graphite sheet electrode can be attributed to the increased surface area by the VOGN layer and the synergistic effect of PANI-grafted-MWCNT.