Field Emission Scanning Electron Micrographs Research Articles

Optical Properties, Microstructure, and Phase Fraction of Multi-Layered Monolithic Zirconia with and without Yttria-Gradient.

The differences in the optical properties of multi-layered zirconia with and without yttria-gradient are not fully understood. This study aimed to evaluate and compare the optical properties, related microstructures, and phase fractions of multi-layered zirconia with and without yttria-gradient. For this, multi-layered zirconia of 5 mol% yttria (5Y) stabilized (Katana STML) and 4Y/5Y stabilized (e.max MT Multi) were cut layerwise, sintered, and analyzed using the opalescence parameter (OP), average transmittance (AT%), translucency parameter (TP), and contrast ratio (CR). The average grain size and phase fractions were obtained from field-emission scanning electron micrographs and X-ray diffraction patterns, respectively. Although the TP values of Katana STML and e.max MT Multi did not show a significant difference (except for transition layer 1), the results of AT and CR showed that the translucency of e.max MT Multi was slightly higher than that of Katana STML (p < 0.05). The opalescence gradient was higher in Katana STML than in the e.max MT Multi. In both zirconia types, translucency increased from the dentin to enamel layer based on the AT, TP, and CR results, while OP decreased (p < 0.05). The higher translucency from the dentin to enamel layer in Katana STML was caused by the pigmentation gradient, while in e.max MT Multi, it was caused by the difference in phase fraction and the pigmentation gradient.

Oxovanadium(IV)‐salophen covalently immobilized on silica‐coated Fe3O4 nanoparticles: A magnetically recoverable nanocatalyst for the selective oxidation of sulfides

The current study introduces an approach toward the development of heterogeneous, magnetically recoverable oxovanadium(IV)‐salophen complex to employ in the selective oxidation of sulfides using H2O2 as oxidant. A salophen ligand containing hydroxyl functional group was synthesized, which is conducive to successful, covalent immobilization of metal complex onto the silica‐modified Fe3O4 magnetic nanoparticles (SMNPs). This type of metal anchoring is achieved through an intermolecular condensation reaction. The in‐depth investigation on the catalyst (Fe3O4@SiO2@VO(salophen)) productivity and lifetime in the oxidation of a wide range of linear and aromatic sulfides is well represented and discussed. The use of the current catalyst in the selective oxidation of prototype substrate (methyl phenyl sulfide) resulted in an appreciable increase in the selectivity toward the desired sulfoxide (92%) and conversion rate (95%) compared with similar studies, reported to this day. Analytical techniques such as field emission scanning electron micrograph (FE‐SEM), energy‐dispersive X‐ray spectroscopy (EDX), Fourier transform infrared (FT‐IR), X‐ray diffraction (XRD) analysis, and inductively coupled plasma optical emission spectrometer (ICP‐OES) provided data on structural/compositional characterization of materials in catalyst preparation steps.

Influence of halloysite nanotubes/microfibrillated cellulose on pine leaves waste based ethylene scavenging composite paper for food packaging applications

Pine leaves and pine cone waste contain substantial lignocellulosic mass, which is the major constituent for making paper-based packaging material. The utilization of plant waste as packaging materials eliminates plastics in packaging and promotes a circular economy. In this study, we have developed ethylene scavenging paper from the waste pine leaves (PL) incorporated with microfibrillated cellulose (MFC) and halloysite nanotubes (Hal). MFC attributes include high mechanical properties and gas barrier ability and biodegradability. Hal is a nano clay that possess ethylene gas scavenging properties of the base matrix thus helping in extending the shelf life of fresh produce. The Hal loading affected the fabricated paper's physical and mechanical properties. Field emission scanning electron micrographs revealed that the paper had a rough surface, which was confirmed by atomic force microscopy. The transmission electron micrographs showed that MFC formed a network-like structure. The contact angle and water vapor transmission rate of neat and 30% Hal were decreased from 64° to 52° and 5.7 × 10−3 to 5.5 × 10−3 g/cm2/day, respectively. The X-ray crystallography showed an increase in crystallinity with the addition of Hal and MFC. 30% Hal loading had shown the highest ethylene scavenging efficiency, 79.4% at 25 °C. The results conclude that PL/MFC/Hal functional paper can be effectively utilized as ethylene scavenging material for active packaging applications.

Highly c-axis oriented (Mg, Sn) co-doped ZnO thin films for optoelectronic applications

In this paper, results on the microstructural, optical and electrical characteristics of the (Mg, Sn) co-doped ZnO films as a function of Mg, Sn dopant concentrations have been presented. All the films are highly oriented along the c-axis in the (0 0 2) plane, possessing a hexagonal wurtzite crystal structure of ZnO. Upon doping and codoping, the crystallite size is found to decrease. The root mean square (RMS) roughness is maximum for the undoped ZnO film and decreases upon doping and codoping. The field emission scanning electron micrographs reveal granular surface morphologies of the films. The undoped ZnO films' transmittance is minimal and improves upon doping and codoping with a maximum of ∼95% of transmittance for the Mg:Sn (1:1 at%) co-doped ZnO film in the wavelength range 420–550 nm and beyond 700 nm. The electrical conductivity of the film increases upon doping and codoping with a maximum of 1.38x102 (Ω-cm)−1 for the Mg:Sn (1:1 at%) co-doped ZnO film. It has been established that the Mg:Sn (1:1 at%) co-doped ZnO film is a potential candidate to be used as transparent conductive oxide for optoelectronic applications.

Preparation and electrical properties of Ni-doped InZnO thin film transistors

In this work, Ni-doped InZnO (IZO: Ni) thin film transistors (TFTs) with staggered bottom-gate structure were fabricated on SiO2/Si substrates by radio frequency (RF) magnetron sputtering, and IZO: Ni thin films severed as active layer, Al electrodes were used as the source and drain electrodes. X-ray Diffraction (XRD) results showed that IZO: Ni film was amorphous structure. Transmittance of the deposited sample was higher than 80% in the visible range. Secondary ion mass spectroscopy (SIMS) exhibited a uniform distribution of all the elements in the film. Field emission scanning electron micrograph (FESEM) and Atom force microscopy (AFM) results revealed that the film had a smooth surface and a root-mean-square (RMS) roughness of 0.225 nm. The TFTs annealed at 265 °C in nitrogen atmosphere showed the excellent electrical performance with a high saturation mobility (μSAT) of 37.2 cm2V−1s−1, a low threshold voltage (VTH) of 2.5 V, a low subthreshold swing (SS) of 0.39 V/dec, and a high on/off current ratio (Ion/Ioff) of 4.1 × 108.

Structural properties of ordered porous SnO2 nanostructure

Three-dimensional porous ordered SnO2 nanostructures have been fabricated by templating a sol–gel pre- cursor solution against the polystyrene nanospheres for the first time. Field emission scanning electron micrography (FESEM) indicates that the surface of the nanostructures is highly regular and the porous structures are perfectly ordered. Besides a broad emission band at 600 nm, the porous SnO2 nanostructures show an additional emission band at 430 nm, which is seldom seen in the bulk SnO2 materials. Spectral examinations and analyses reveal that the 430 nm band is induced by the interfacial effects between the porous frameworks.

Centrifugally spun alginate-poly(lactic acid) microbeads: A promising carrier for drug delivery and tissue engineering

A facile and high yield centrifugal spinning technique known as Forcespinning® (FS) was used to develop unique microstructures consisting of PLA microbeads along alginate fibers. Morphological variation and structural features appeared in the field-emission scanning electron micrographs for the PLA-alginate composites and dried PLA-alginate films from precursor emulsions at constant PLA and varied alginate contents. Shrunk and deflated microbeads were observed for composites whilst spherical beads were evident for the PLA control. Furthermore, PLA was found surrounding the alginate when the alginate was present at 0.24 wt% or lower, while alginate (mushroom-like structures), were seen protruding through the PLA layer at ≥0.34 wt% alginate. Rheological characterization of the composite emulsions revealed that the filler (alginate) provided shear thinning properties including pseudoplasticity, desirable for printing and other related applications in contrast to the Newtonian flow shown by the PLA control. Along with infra-red spectroscopy, the nanocomposites were further characterized using thermal gravimetry and differential scanning calorimetry featuring reversible events influenced by heat capacity and irreversible kinetic/thermodynamic counterparts. The work provides a comprehensive investigation of biocompatible networks of PLA-alginate microbeads embedded in nano-sized fibers and the prospective application of these microbeads as a drug delivery system.

Study of electronic and optical response of Zn-CeO2 using first principle and experimental investigations

Ceria (CeO2) is an important material mainly for microelectronic and fuel-cell applications due to having high dielectric constant and good catalytic properties. The first principle and experimental investigations were carried out to study the effect of Zn incorporation on the electronic and optical response of CeO2. Density of states spectra depict the prominent hybridization of Ce–f and O–p states while band structure reveals the decrease in bandgap with the incorporation of metallic Zn content in ceria structure. X-ray diffraction analysis detects the crystalline traces of CeO2 in pristine and doped thin films. Field emission scanning electron micrographs and energy dispersive x-ray spectra of synthesized thin films present the uniform distribution of grains with clear grain boundaries with expected elemental contents. The experimental observations comparatively follow the trend of simulation curves. Optical studies demonstrate a clear increment in absorption coefficient, optical conductivity, and real epsilon with Zn incorporation in ceria which makes these compositions favorable for applications in modern electronic devices.

Investigation of mechanical properties based on the particle size of alumina ceramics prepared by circulatory bead milling

The combined action of circulatory grinding and bead milling on the microstructure and mechanical characteristics of alumina was examined in this study. Reduction in particle size of as received alumina powder was obtained under different milling durations: 0, 6, 15 and 20 h (hereafter abbreviated as BM00, BM06, BM15 and BM20, respectively). X-ray diffraction studies revealed the conspicuous effect of milling duration on FWHM, crystalline size and crystallinity. The alumina powder's field emission scanning electron micrograph displayed the finest particles (D50-170 nm) in BM15 samples, which achieved a uniform grain size (∼1 μm) and relative density of ∼96% after sintering at 1600 °C. Ultrasonic interferometer study has also been utilized because wave velocity depends on the elastic properties of the propagation medium, and using this phenomenon, compressibility (β), Young's modulus (E) and ballistic energy dissipation ability (D-criterion) of the prepared ceramics have been calculated. The bead milled samples exhibited substantial improvement in mechanical properties as compared to as-received powder, and BM15 samples achieved the highest hardness (17 GPa), flexural strength (389 MPa), fracture toughness (4.13 MPa m1/2) and compressive strength (2290 MPa) values.

Effect of Ammonia Addition on the Growth of an AlO(OH) Film during Steam Coating Process

Al alloys possess excellent physical and mechanical properties, such as low density, high specific strength, and good ductility. However, their low corrosion resistance limits their use in corrosive environments. The steam coating process has attracted considerable attention as a new coating technology that can improve the corrosion resistance of Al alloys. This surface treatment technology uses steam to form a corrosion-resistant film on Al alloys. However, a decrease in the processing time, which can result in a lower cost, is needed for the practical application of the steam coating process. In this study, an Al-Mg-Si alloy is used as the base material, and ammonia is added to the steam source to increase the film formation rate. By adding ammonia (0.5 mol/L) to the steam source, the rate constant, K, for film formation increases 1.82 times compared to that of the pure-water-only treatment. Field emission scanning electron micrographs of the film surface confirms that the crystal morphologies of the crystals change from rectangular to parallelepiped shape with increasing process time by ammonia addition. Furthermore, X-ray diffraction patterns show that AlO(OH) crystals are successfully synthesized without byproducts, even when ammonia is added.

Facile Preparation of Fluoroalkyl End-Capped Vinyltrimethoxysilane Oligomer/Sand Composites Possessing Superoleophilic/Superhydrophobic Characteristic: Application to Oil/Water Separation and Selective Removal of Fluorinated Aromatic Compounds from Aqueous Methanol Solution

Fluoroalkyl end-capped vinyltrimethoxysilane oligomer [RF-(CH2-CHSi(OMe)3)n-RF: n = 2, 3, RF = CF(CF3)OC3F7: RF-(VM)n-RF], was applied to the facile preparation of the corresponding oligomer/sand (Ottawa sand: OS) composites [RF-(VM-SiO3/2)n-RF/OS] through the sol-gel reaction of the oligomer in the presence of micro-sized OS particles (590 - 840 μm) under alkaline conditions at room temperature. FE-SEM (Field Emission Scanning Electron Micrograph) images showed that the obtained composites consist of the RF-(VM-SiO3/2)n-RF oligomeric nanoparticles and the micro-sized OS particles. Interestingly, the RF-(VM-SiO3/2)n-RF/OS composites thus obtained can provide the superoleophilic/superhydrophobic characteristic on the composite surface, applying to the separation of not only the mixture of oil/water but also the W/O emulsion to isolate the transparent colorless oil. The fluorinated oligomeric OS composites were also found to be applicable to the selective removal of fluorinated aromatic compounds from an aqueous methanol solution. Especially, it was demonstrated that the fluorinated OS composites can supply a higher efficient and smooth separation ability for the separation of the mixture of oil and water than that of the corresponding fluorinated micro-sized controlled silica gel (μ-SiO2) composites (average particle size: 9.5 μm), which were prepared under similar conditions. In addition to the separation of oil/water, the fluorinated OS composites provided higher and more selective removal ability for the fluorinated aromatic compounds from aqueous solutions than that of the μ-SiO2 composites.

Comparative evaluation of the effect of cold ceramic and MTA-Angelus on cell viability, attachment and differentiation of dental pulp stem cells and periodontal ligament fibroblasts: an in vitro study

BackgroundBiocompatibility and induction of mineralized tissue formation are the properties expected from a material used in vital pulp therapy and repair of perforations. Cold ceramic (SJM, Iran; CC) is a newly introduced calcium silicate-based cement for above mentioned therapeutic applications. This in-vitro study aimed to compare the effect of CC and White MTA-Angelus (MTA) on cell viability, attachment, odontogenic differentiation, and calcification potential of human dental pulp stem cells (DPSCs) and periodontal ligament fibroblasts (PDLFs).MethodsCell viability of DPSCs and PDLFs was assessed using MTT on days 1, 3, 7, and 14 (n = 9) in contact with freshly mixed and set states of CC and MTA. Field emission scanning electron micrographs (FESEM) were taken to evaluate cell-bioceramic interaction (n = 6). Gene expression levels of osteo/odontogenic markers (Dentin sialophosphoprotein, Dentin matrix protein 1, Collagen type I alpha 1, and Alkaline phosphatase (DSPP, DMP1, COL 1A1, and ALP, respectively) (n = 8) were assessed using qrt-PCR. ALP enzymatic activity was evaluated to assess the mineralization potential. A two-way ANOVA test was applied, and p < 0.05 was considered to be statistically significant.ResultsThe effect of freshly mixed and set MTA and CC on the survival of DPSCs and PDLFs in all study groups was statistically similar and comparable to the positive control group (p > 0.05); the only exception was for the viability of PDLFs in contact with freshly mixed cements on day 1, showing a more significant cytotoxic effect compared to the control and the set state of materials (p < 0.05). PDLFs attached well on CC and MTA. The spread and pseudopodium formation of the cells increased on both samples from day 1 to day 14. Contact of MTA and CC with DPSCs similarly increased expression of all dentinogenesis markers studied on days 7 and 14 compared to the control group (p < 0.001), except for DSPP expression on day 7 (p = 0.46 and p = 0.99 for MTA and CC, respectively).ConclusionsWithin the limitation of this in-vitro study, cold ceramic and MTA-Angelus showed high biocompatibility and induced increased expression of osteo/dentinogenic markers. Therefore, cold ceramic can be a suitable material for vital pulp therapy and the repair of root perforations.

Investigation of structural, optical and electrical properties of Barium (Ba2+)- and Strontium (Sr2+)-doped Bi0.9La0.1FeO3 ceramics

In this work, we discuss the synthesis, characterization and dielectric properties of Bi[Formula: see text]La[Formula: see text](Ba/Sr)[Formula: see text]FeO3 [[Formula: see text]] ceramic compounds. These samples were synthesized via a solid-state reaction method and then characterized for structural analysis exploiting the X-ray diffraction (XRD) technique. The Rietveld refinement data inferred that all the prepared samples were acquired a monoclinic phase with space group C1c1. Field emission scanning electron micrographs (FE-SEM) images of the samples indicated highly grown grains with a moderate level of grain boundary development across the sample. The energy dispersive analysis of the X-ray (EDAX) diffraction spectra analysis confirmed that the composition was free from foreign impurities. Further, UV–Vis experiment was conducted and estimated average value of optical bandgap was about 2.2 eV, which is highly recommended for photocatalytic and opto-electronic device applications. Room-temperature dielectric studies revealed that samples were extremely good dielectric materials with low dielectric loss, which is important for storage device applications. In addition, the depressed semicircles obtained from impedance analysis indicated that the samples exhibited distributed relaxation times and non-Debye behavior.

The effect of dopped Al3+-Gd3+- Cr3+ on the chemical structure of M−type strontium hexaferrite and investigation on their photocatalysis properties

M−type strontium hexaferrite and substituted derivatives were synthesized via sol–gel auto combustion method with the formula of SrGdx Alx Crx Fe(12-3x) O19 ((x = 0, 0.2, 0.4, 0.6, 0.8)(B0, B1, B2, B3, B4)). The findings of the Fourier-transform infrared spectroscopy (FTIR) spectrum revealed that characteristic peaks between 400 and 560 cm−1 were related to Fe-O bonds at octahedral and tetrahedral sites confirmed the hexaferrite bonding. Moreover, the X-ray diffractometer (XRD) represented that magnetoplumbite hexagonal structure had formed with little impurities. The crystallite sizes of the synthesized nanoparticles (NPs) were also around 42.6–75.4 nm and there is an increase in a lattice parameter from 5.79 to 5.87. The surfaces of the prepared samples were subsequently analyzed through field emission scanning electron microscopy (FESEM) surface images and micrographs illuminated the prepared ferrites have hexagonal structures and EDX spectra represent that all elements are belonging to the prepared composition. Hysteresis loops of SrGdx Alx Crx Fe(12-3x)O19 ((x = 0, 0.2, 0.4, 0.6, 0.8)(B0, B1, B2, B3, B4)) depicted that Ms had decreased in a dramatic manner (from 68.36 to 27.66) as the number of dopants had increased (from 0.0 to 0.8).The c/a confirmed the formation of the hexaferrite. Also, the photocatalysis capability of prepared samples was studied under Visible light and the results declare that Sr Fe12O19 without any dopant shown 60% degradation while SrGd0.8 Al0.8 Cr0.8Fe11.2 O19 has shown the best ability under visible light with a 90% degradation rate. By contrast, SrGd0.8 Al0.8 Cr0.8 Fe11.2 O19 represented the highest photodegradation even after 3 times of recycling.

Multifunctional characterization of Ca-modified new double perovskite for energy harvesting devices

The conventional solid-state route method was adopted for the synthesis of the double perovskite Ba1.5Ca0.5FeVO6. The well define spikes that appear in the XRD profile of the investigated sample suggested the formation of a single-phase new compound. The structural refinement carried out through POWD and MAUD software suggested the material crystallize in the monoclinic phase having a space group of P21/m. The morphological investigation of the sample was carried out by field emission scanning electron micrograph (FESEM). The involvement of different vibrational modes such as stretching, bending, etc. as well as functional groups associated with the compounds was studied through Raman and Fourier transform infrared (FTIR) spectroscopic techniques. The electronic configuration and chemical valence state of the involved elements were investigated by incorporating X-ray photoelectron spectroscopy. The optical sensitivity and bandgap of the material were studied through UV–Visible spectroscopy. The dielectric properties of the material were investigated by monitoring the variation of dielectric parameters (dielectric constant and loss tangent) with frequency while non-destructive impedance and modulus techniques were adopted for electrical characterization. Besides, the AC and DC conductivity spectra were studied for a detailed investigation of electrical properties and the type of charge carriers in the material. The identification of ferromagnetism in the material at room temperature was done by M-H loop.

Ecofriendly green synthesis, characterization and biomedical applications of CuO nanoparticles synthesized using leaf extract of Capsicum frutescens

The green technology is creating an interest among researchers as they are simple, ecofriendly, and also cost-effective especially in synthesizing nanoparticles. In the present study, CuO nanoparticles were synthesized by taking copper nitrate as precursor and using the leaf extract of Capsicum frutescens as capping and stabilizing agent. The visual observation of dark green color indicated the formation of CuO nanoparticles. The gas chromatograph illustrated the phytochemicals in leaf extract. The synthesized CuO nanoparticles were characterized by various analytical techniques such as UV–visible, X-ray diffraction, Fourier transform infra-red, dynamic light scattering, zeta potential and energy dispersive X-ray analyses. Field emission scanning electron micrographs and transmission electron micrographs illustrated the spherical and rectangular-rod shaped nanoparticles with its diameter (width) ranging from 20 to 40 nm. The antibacterial and biofilm activities against Gram-positive (Bacillus anthracis, and Listeria monocytogenes) and Gram-negative (Klebsiella pneumoniae) bacterial human pathogens showed strong inhibition at 95%, 94% and 92% in 150 μg/mL concentration, respectively. The antioxidant activity revealed high (97%) free radical scavenging property at 80 μg/mL concentration. The anti-inflammatory and anti-diabetic activities showed 90% and 85% efficacy at 500 μg/mL concentration, respectively. These results assured the synthesized CuO nanoparticles by using Capsicum frutescens leaf extract may have applications in the biomedical field.

Capacitance and Resistivity Measurements of Polythiophene /Metallic Nanoparticles-based Humidity Sensors

Capacitive–resistive humidity sensors based on polythiophene (P3HT) organic semiconductor as an active material hybrid with three types of metallic nanoparticles (NP) (Ag, Al, and Cu) were synthesized by pulsed laser ablation (PLA). The hybrid P3HT/metallic nanoparticles were deposited on indium-tin-oxide (ITO) substrate at room temperature. The surface morphology of theses samples was studied by using field emission scanning electron micrographs (FE-SEM), which indicated the formation of nanoparticles with grain size of about 50nm. The electrical characteristics of the sensors were examined as a function of the relative humidity levels. The sensors showed an increase in the capacitance with variation in the humidity level. While the resistivity While the resistivity decrease nonlinearity in the variation of humidity level from 10% to 100%.. The results show that the recovery and response times were higher for the Al/P3HT/Cu/Al sensor compared with those of the other nanoparticles.

Structural, optical and magnetic properties of α- and β-MnO2 nanorods

Herein, we synthesise various polymorphs of MnO2 through hydrothermal technique. Formation of pure tetragonal structured α-, β- and mixture of α and β phase of MnO2are identified through Fourier transform infrared spectroscopy (FTIR) and X-Ray diffraction (XRD).Rietveld refinement reviles 73% of α-MnO2 and 27% of β-MnO2 present in αβ-MnO2. From Field emission scanning electron micrographs (FESEM), average diameter of α- and β-MnO2nanorods is found to be 36 nm and 23 nm, respectively, while in αβ-MnO2, nanorods of two different sizes, 28 and 116 nm are observed. Among all polymorphs, small size of nanorods in β-MnO2 results high specific capacitance. Through UV–visible absorption spectra, the optical band gap of α-, β- and αβ-MnO2nanorods are estimated to be 1.53, 1.30 and 1.45 eV, respectively. XPS confirms the presence of large concentration of Mn3+ in α- and αβ-MnO2 nanorods results high effective magnetic moment in comparison to the theoretical one which is almost same in β-MnO2. Henceforth, we evaluate the accurate composition of MnO2 as α-MnO1.48, β-MnO1.86 and αβ-MnO1.15. Spin-glass/cluster-glass behavior is confirmed from ac susceptibility and remanent magnetization measurements in β-MnO2and αβ-MnO2which is absent in α-MnO2 depending on a critical concentration of Mn3+ions.

Thermal, mechanical, rheological, electrical and electromagnetic interference shielding performance of polypropylene/magnetic carbon nanocomposites

Novel magnetic bio-nanocomposites were fabricated using polypropylene (PP) as polymer matrix and graphene supported magnetic carbon nanocomposite (MCNC, produced by solvothermal carbonization co-precipitation route integrating low-cost graphene, renewable biomass and iron oxide nanoparticles) serving as filler by incorporating nano-fillers of loading 5%, 10% and 15% with PP using a convenient and time efficient route melt processing. Utilizing waste biomass as integral part of MCNC offers cost effective solution for hybrid nanocomposite synthesis and its application in advance field as electromagnetic interference (EMI) shielding material. The study provides comprehensive analysis for its upgradation in rheological properties that have exclusive impact on its final application. Furthermore, the behaviour for thermal, structural, mechanical, chemical, magnetic, and electrical features using various characterization techniques. Field emission scanning electron micrographs revealed good dispersion of MCNC in PP matrix and formation of network for 15% loading of the filler facilitated 800% higher shielding effectiveness as compared to that of neat PP. It was revealed that functionalization with graphene supported magnetic nanocomposite and polymer matrix have improved the overall conductivity for the composites. Rheological studies indicated the upgradation in viscoelastic properties as solid like behaviour was seen with the increment of filler concentration. X-ray diffractometer demonstrated that MCNC had a substantial impact on the crystallinity of nanocomposite that is validated with modulated differential scanning calorimetry analysis.

Influence of 3D-printing method, resin material, and sterilization on the accuracy of virtually designed surgical implant guides

Statement of problemThree-dimensional printing has introduced new manufacturing methods. However, information on the influence of the specific printing technology, material, sterilization, and the comparison between printing and milling on the accuracy of surgical guides is lacking. PurposeThe purpose of this in vitro study was to evaluate the influence of the manufacturing method (printing and milling), printing technology stereolithography (SLA) and digital light processing (DLP), material, and sterilization on the accuracy of digitally designed surgical implant guides. Material and methodsResin patient replicas with a single edentulous space were used to place 132 implants with digitally designed surgical guides. The accuracy of postoperative implant position was analyzed for the manufacturing method (printing and milling), resin materials, and preoperative autoclaving. To determine 3D accuracy, angular displacement, mean horizontal crestal, apical displacement, and the linear vertical displacement at the apex were calculated separately for each group (n=12). In addition, the surgical guides were qualitatively analyzed by using field emission scanning electron micrograph. ResultsThe postoperative angular deviation ranged from 0.76 ±0.52 degrees (Rapidshape D20II with NextDent SG) to 2.43 ±0.64 degrees (Form2 with NextDent SG) (P<.001). Linear horizontal displacement at the crest was smallest for Rapidshape D20II with 3Delta Guide (0.27 ±0.08 mm) and highest for Form2 with NextDent SG (0.54 ±0.10 mm) (P<.001). Linear horizontal displacement at the apex ranged from 0.36 ±0.10 mm (SolFlex 350 with V-Print SG) to 0.89 ±0.32 mm (Form2 with NextDent SG) (P<.001). Considering the vertical position displacement was no more than 0.43 ±0.07 mm (Form2 with NextDent SG) short of the apex, none of the implant tips were displaced apically. Preoperative autoclaving differentially impaired the accuracy of surgical guides. ConclusionsThe specific manufacturing technique, the 3D printing device, the resin material, and the application of preoperative sterilization all affected the accuracy of the postoperative implant position. Irrespective of the manufacturing method, all implants were placed within the commonly accepted safety distance.