Diffraction Peak Research Articles

Direct observation of the atomic density fluctuation originating from the first sharp diffraction peak in SiO2 glass

The intermediate-range order of covalently bonded glasses has been extensively studied in terms of their diffraction peaks observed at low scattering angles; these peaks are called the first sharp diffraction peaks (FSDPs). Although the atomic density fluctuations originating from the quasilattice planes are a critical scientific target, direct experimental observations of these fluctuations are still lacking. Here, we report the direct observation of the atomic density fluctuations in silica glass by energy-filtered angstrom-beam electron diffraction. The correspondence between the local electron diffraction patterns of FSDPs and the atomic configurations constructed based on the X-ray and neutron diffraction results revealed that the local atomic density fluctuations originated from the quasi-periodic alternating arrangements of the columnar chain-like atomic configurations and interstitial tubular voids, as in crystals. We also discovered longer-range fluctuations associated with the shoulder of the FSDP on the low-Q side. The hierarchical fluctuations inherent in materials could aid in the elucidation of their properties and performance.

Picometer-Scale Atomic Shifts Governing Subdisordered Structures in Diamond

Picometer-Scale Atomic Shifts Governing Subdisordered Structures in Diamond

In Situ Generation of TiCN Ni‐Based Coatings by Laser Cladding and Study of Their Structure and Properties

The influence of the ratio of TiN powder, graphite powder, and Ni60 powder on the phase composition, microstructure, microhardness, and wear properties of the TiCN Ni‐based coating on H13 steel is investigated. The findings indicate that varying proportions of TiN powder, C powder, and Ni60 powder have a minimal impact on the coating's phase composition. The diffraction peak intensity of TiC0.3N0.7 increases with the addition of (C + TiN) in the blended powder, while the crystallinity of TiC0.3N0.7 in the Ni‐based coating with a 30% (C + TiN) mass fraction decreases. The grain structure of the 20% Ni‐based coating is fine and uniform, while the microstructure of the 30% Ni‐based coating is characterized by a large polymerization phase‐containing Ti elements, with the TiCN‐reinforced phase exhibiting irregular grain morphology. The microhardness HV0.5 of the coating with a 20% (C + TiN) mass fraction ranges from 725 to 772, with an average hardness of 747.8 HV0.5, which is 3.4 times the hardness of the substrate material and 1.3 times the hardness of the Ni‐based coating. As the mass fraction of (C + TiN) in the hybrid powder increases, the friction loss mass of the coating tends to decrease and then increase. The average wear of the Ni‐based coating with a 20% (C + TiN) mass fraction is ≈22.4% of that of the substrate and 50% of that of the Ni‐based coating, demonstrating excellent wear resistance. The wear mechanism is primarily characterized by brittle spalling and abrasive wear.

Compressive strength prediction of Portland cement clinker using machine learning by XRD data

Accurately predicting the 28-day compressive strength of Portland cement clinkers is challenging due to their complex multiphase nature, especially when production processes and environmental conditions vary. To address this issue, the TransXRD model was introduced, which is a novel deep learning approach that combines the Transformer architecture with CNN design. 214 clinker samples were collected from 6 cement plants. The diffraction peak sequence of samples ranging from 10° to 55° was used as required input for the model. A combination of one-dimensional convolution is incorporated to extract local features, and self-attention mechanisms are leveraged to perform global feature integration. XRD data were directly utilized, bypassing additional processing to minimize signal loss. Compared to other DNN (deep neural network) models, the TransXRD model demonstrates promising performance, achieving a root mean square error (RMSE) of 1.15, a mean squared error (MSE) of 1.33, a mean absolute error (MAE) of 0.93, and a mean absolute percentage error (MAPE) of 1.76 on the test set. Notably, in the training set, 100% of the data exhibit prediction errors within 2 MPa, while within the test set, 90% of the prediction errors are within 2 MPa. The application potential of XRD data in predicting the compressive strength of cement clinker also offers novel insights into predicting the performance of other materials.

Synthesis and characterization of CuxCd1‐xS nanocrystals into functionalized nitrile butadiene rubber matrix

AbstractIntroductionPolymetallic sulfides and heterostructures like CdIn2S4, CdZnS2, CuxS‐NiySz, Cu2CoSnS4, CoNi2S4, Zn0.76Co0.24S have been fabricated with various shapes and forms for new applications. Ternary copper cadmium sulfides (CuCdS2) are a p‐type semiconductor with a direct band gap of about 2.4 eV forms very good nanocrystals like copper sulfide could be potentially applied to optical and electronic applications. Knowing that the SILAR synthesis, optical, paramagnetic, dielectric properties, and annealing of copper cadmium sulfides have not been sufficiently investigated, they are extensively analyzed and studied in the present work.ObjectivesCuxCd1−xS (x = 0, 0.5, and 1) nanoparticles have been synthesized on the base of functionalized nitrile butadiene rubber by SILAR method and characterized using scanning electron microscopy, x‐ray diffractometer, UV–visible spectroscopy, Fourier‐transform infrared spectroscopy, electron paramagnetic resonance spectroscopy, and Raman spectroscopy. Effects of cycles, reaction time, and precursor concentration on the particle size, crystal growth and structure, bandgap energy, dielectric and paramagnetic properties, elemental composition, and morphology were investigated.MethodsThe synthesis of CuxCd1−xS nanocrystals was carried out into the obtained functional polymer matrix by SİLAR method. The functional polymer (FNBR) is a dark brown powder which contains ‐PO(OH)2 and ‐OPO(OH)2 functional groups and does not dissolve in organic and inorganic solvents, can be used as a very good stabilizer of nanostructures. The synthesis of CuxCd1−xS/FNBR nanocompsite was carried out in 3, 5, and 15 cycles.Results and discussionIn the process of ternary sulfide formation, the nucleation rate of CdS was high at the beginning of the reaction, while the growth rate and stability of CuS were high in the later course of the reaction. The average crystallite size of the nancrystallites has been increased from 1.13 nm to 7.39 nm by the increasing of the number of cycles from 5 to 15, respectively. It is explained by the inclusion of copper in the composition and getting more stable material. Copper cadmium sulfide nanostructures demonstrate wide band gap energy (~3.7 eV) in this work which is explained by the formation of nanosized particles in a limited volume of FNBR matrix.ConclusionsThe synthesis of CuxCd1‐xS nanocrystals was carried out into the obtained functional polymer matrix by SİLAR method. Strong diffraction peaks corresponding to cubic CdS are found with low SILAR cycles. SEM images of CuxCd1−xS/FNBR nanocomposite show that the atomic percentage of Cu and Cd into the ternary sulfide is 20.19% and 0.61%, respectively. It is explained by the inclusion of copper in the composition and getting more stable material with low solubility products (Ksp) which is in good agreement with XRD results. The calculated band gaps are higher than that of bulk CdS, CuS, and CuCdS2. Larger band gap is usually reported for defects or structural disorders, which is in good agreement with XRD and Raman results.

Copper Oxide Nanoparticles Anchored on Porous Carbon Nitride Nanosheets for Supercapacitor Applications

Electrochemical energy storage devices are vital for renewable energy integration and the deployment of electric vehicles. Ongoing research seeks to create new materials with innovative morphologies capable of delivering high specific capacitance for the next generation of customizable energy devices. Carbon nitride is an excellent candidate for electrochemical energy storage devices; however, it has limitations such as layer stacking, poor electric conductivity, a restricted number of electroactive sites, and static electrochemical reaction rates. This research objective is to make porous structures in carbon nitride nanosheets and integrate them with CuO particles to increase surface area and improve electrochemical performance. The use of thermal heating, acidic treatment, and hydrothermal processes accomplishes this. Along with X-ray diffraction peaks of the CuO phase, a prominent peak (002) at 27.67° indicates the presence of graphitic-structured carbon nitride. TEM images show that CuO particles are evenly attached to the surface of g-C3N4 nanosheets with lattice intervals of 0.336 and 0.232 nm, which are the (002) and (111) orientations of the g-C3N4 and CuO phases, respectively. Adding CuO nanoparticles to porous g-C3N4 nanosheets avoids layer stacking and provides micro- and mesopore channels, increasing the specific surface area (42.60 m2 g-1). The CuO@ porous g-C3N4 electrode delivered 817 F g-1 of specific capacitance at 1 A g-1 and admirable capacitance retention (92.3% after 6000 cycles) due to the synergistic impact of its unique composition and structural characteristics. Because of its outstanding electrochemical performance and fascinating discoveries, CuO@ porous g-C3N4 may be employed as a cathode material for high-performance supercapacitors.

Tailoring the dielectric properties of bentonite for advanced capacitor Applications: The role of ruthenium and strontium incorporation

This study utilized incipient wetness impregnation to synthesize bentonite materials and to enhance their physical characteristics with ruthenium (Ru) and strontium (Sr) ions. The atomic composition of the materials was confirm confirmed via the analysis of the EDX measurements. X-ray crystallography indicates that the materials have almost similar diffraction peak profiles, and that the addition of Sr increases the crystallinity of the bentonite grains. Dielectric and electrical properties, measured between 25 °C and 55 °C at frequencies of 1 kHz −1 MHz, revealed that the real and imaginary impedances increased upon the introduction of 5 % Ru and 5 % Sr, possibly due to Ru and Sr segregation into the grain boundaries, increasing the resistance of the bentonite granular structure. For all materials, the observed saturation of the real electric modulus at high frequencies, and the reduction of the permittivity with increasing frequency, may be explained by the Maxwell-Wagner interfacial polarization and Koop's empirical theory. This trend is more pronounced for the bentonite with Sr, highlighting the essence of the present work for engineering interfacial polarisation applications associated with supercapacitors and batteries.

Novel starch–tungsten (VI) oxide biocomposites: Preparation, characterization, and comparisons between experimental and theoretical photon attenuation coefficients

This study synthesized biocomposites containing starch and WO3 at varying ratios of 10 %, 20 %, 30 %, 40 %, and 50 % and assessed their thermal and radiation-shielding properties. These biocomposites were characterized using Fourier-transform infrared spectroscopy, X-ray diffraction (XRD) analysis, particle-size distribution assessments, scanning electron microscopy–energy dispersive X-ray spectroscopy, and thermogravimetric analysis–differential thermogravimetry measurements. Furthermore, the linear attenuation coefficients of the biocomposites were experimentally measured using an NaI(Tl) gamma spectrometry system and theoretically computed using XCOM and GAMOS simulations for comparisons. The XRD and particle-size distribution profiles of the WO3.2H2O powder, respectively, demonstrated evident diffraction peaks and favorable pore-size distributions. Morphological characterizations revealed that the WO3 particles were homogeneously dispersed throughout the starch matrix without any agglomeration. Comparisons of the thermal degradation rates revealed that the pure starch and starch +50%WO3 biocomposite began decomposing at approximately 200°Cand 300 °C, respectively, indicating that increasing WO3 proportions enhanced thermal stability. Furthermore, the starch +50%WO3 biocomposite demonstrated the highest experimental linear attenuation coefficient, with a value of 0.2510 ± 0.0848 cm−1 at a gamma energy of 662 keV. Meanwhile, XCOM and GAMOS simulations revealed theoretical attenuation coefficients of 0.1229 and 0.1213 cm−1 for pure starch and 0.2202 cm−1 and 0.2178 cm−1 for the starch +50%WO3 biocomposite at 662 keV, respectively.

Determine elastic parameters and nanocrystalline size of spinel ferrites MFe2O4 (M = Co, Fe, Mn, Zn) through X-ray diffraction and infrared spectrum: Comparative approach

MFe2O4 (M = Co, Fe, Mn, Zn) nanoparticles were successfully synthesized by coprecipitation. Analyzing the X-ray diffraction by the Rietveld method confirmed the spinel ferrite structure of the samples. Rietveld refinement results show that Co, Mn and Zn occupy both the tetrahedral and octahedral sites. Variation in elastic parameters was determined by Fourier transform infrared spectroscopy, and cation distribution was deduced from X-ray diffraction. X-ray diffraction peak expansion was analyzed by employing a variety of calculating methods such as modified Scherrer, Williamson–Hall, size–strain, and Halder–Wagner to determine the crystallite size and elastic parameters of the cubic-structured MFe2O4 nanoparticles, including intrinsic strain, stress, and energy density. Comparison of the results obtained from these different methods revealed that they are ideally suited to each other. Moreover, the transmission electron microscopy image confirmed that the average size of MFe2O4 (M = Co, Fe, Mn, Zn) nanoparticles ranges from 10 to 14nm, consistent with the dimensions obtained from the preceding methods.

Synergistic effects of chemical composition on precipitates, dislocations, and mechanical properties of precipitation-strengthened alloys

The properties of materials are intricately dependent on their chemical composition, and microstructures. Achieving a precise modulation in the composition and microstructure of materials to enhance properties significantly is a huge challenge. In this work, we uncovered the effects of nickel and silicon composition on the precipitates, dislocations, and properties of Cu-Ni-Si alloys. The results show that the volume fraction of precipitates increased from 0.84% to 4.80% with the increase of Ni and Si contents. The average diameter of the precipitates increased from 6.20 nm to 20.21 nm, and the dislocation density increased from 2.16×1013 m-2 to 4.08×1015 m-2 concerning the Ni and Si contents. In addition, the dislocation type changes from half-edge dislocation and half-screw dislocation to screw dislocation. The modified WHWA (Williamson Hall-Warren Averbach) method was proved to be the most accurate way of calculating dislocation density. As anisotropy was present in the alloy, adding a dislocation contrast factor and removing some lower-intensity diffraction peaks could further correct the obtained results and reduce the calculation error. Furthermore, the above analysis and findings were employed to design a Cu-3.21Ni-0.66Si alloy with a high yield strength (814 MPa), high ultimate tensile strength (970 MPa), and comparable electrical conductivity of 42.4% IACS. This work offers a meaningful way to develop precipitation-strengthening alloys.

Preparation and optical properties of rare earth fluoride and its related composite materials

Rare earth fluoride and its composite materials have shown broad application prospects in fields such as optoelectronics and photocatalysis. In this study, we prepared rare earth fluoride (β-NaYF4 nanocrystals) and its related composite materials (β-NaYF4/ZnO composite and GQDs@NaYF4 nanomaterials) using a solvothermal method and investigated their optical performance. The characterization and performance of the prepared materials were analyzed using a transmission electron microscope, X-ray diffraction, upconversion emission spectra, and fluorescence lifetime imaging microscopy. The results show that the crystal thickness of β-NaYF4 nanocrystals is approximately 45.0 nm when the F−: Ln3+ value is 6. Furthermore, X-ray diffraction analysis reveals that diffraction peak positions in β-NaYF4 nanocrystals correspond to the peak positions of standard card at different doping concentrations of Zn2+ Moreover, it was observed that the highest fluorescence lifetime of Tm3+ ion in 1G4 is 778 μs when the doping concentration of Zn2+ is 1 mol%. When the concentration of exonuclease III increases to 22.5U, the upconversion fluorescence emission intensity of GQDs@NaYF4 nanomaterial is about 34 ∗ 106 a.u. When the activation reaction time is 90 minutes, the upconversion emission intensity of GQDs@NaYF4 nanomaterial is about 37 ∗ 106 a.u. In conclusion, we successfully prepared rare earth fluoride and its composite materials with excellent optical properties through the solvothermal method.

Deposition and structural investigation of uniform AlN(100) films at wafer scale through RF magnetron sputtering

a-axis-oriented AlN(100) films are identified as promising candidates for surface acoustic wave devices owing to their high transversal-acoustic velocity. Achieving uniform films across a wafer scale is crucial for enhancing device performance and minimizing manufacturing costs. In this study, we employ radio-frequency magnetron sputtering to deposit AlN(100) films on 2-in Si(100) wafers. We further examine the influence of various process parameters on the nonuniformity of film thickness and structural properties, including crystallite size, microstrain, and dislocation density. The optimization of parameters leads to the selection of a gas flow ratio of N2:Ar = 4:7, a sputtering power of 160 W, and a substrate temperature of 350 °C. Under these optimized conditions, the AlN films not only demonstrate a preferred (100) orientation and remarkable crystallinity, as indicated by a full width at half maximum of the X-ray diffraction peak of just 0.03°, but also achieve an optimal film thickness nonuniformity of 1.66%. Our results offer valuable insights for the wafer-scale fabrication of AlN(100) films, potentially enhancing industrial production yields and reducing costs.

High Potential Electrochemical Synthesis of Thermally Reduced Graphene Nanomaterial

In this study, we provide electrochemical techniques for synthesizing thermally reduced graphene nanomaterial that have high potential, low defects, cost-effectiveness, and ecological sustainability. The electrochemical exfoliation is carried out by employing a 195 W DC (voltage = 60[Formula: see text]V and current = 3.25 A) power source at a maximum electrolyte temperature of about 92.5∘C within the aqueous suspension of 2[Formula: see text]M of sulfuric acid (H2SO[Formula: see text]. Thereafter, the synthesized nanomaterial was treated in the weak piranha [combination of sulfuric acid and hydrogen peroxide (H2O[Formula: see text]] solution using an electrochemical technique inside the water bath sonicator at 80∘C. X-ray diffraction (XRD) analysis shows the peak of diffraction to the (002) plane of the reduced graphene oxide (RGO) samples emerges at around 2[Formula: see text] and 26.56∘ with an interplanar distance of 3.40 Å and 3.54 Å. According to the XRD data, after the high-temperature thermal reduction phase, the structure of the crystals and interplanar separation were recovered. The size of the crystallite of RGO produced under H2SO4 conditions was discovered to be greater than the crystallite size of graphene oxide produced under piranha solution conditions. The Raman analysis results show that the degree of disorder of the graphene synthesized within the H2O2 was higher than in comparison to the graphene synthesized in H2SO4. Field emission scanning electron microscopy (FE-SEM) results show that graphene synthesized in the presence of H2O2 has a thin and porous microstructure in comparison to H2SO4 with no significant effect on the presence of the availability of the C/O ratio. The atomic force microscopy (AFM) analysis indicates that the surface roughness of the graphene synthesized in the H2O2 was higher than that of the H2SO4. The Fourier transform infrared spectroscopy (FT-IR spectroscopy) analytical results show that the majority of the functional groups have been eliminated within the samples.

Giant Seebeck coefficient in SnTe thin films grown by thermal evaporation using layered structure engineering

In this work, we have reported a giant Seebeck coefficient (8033 µV/K) in SnTe thin films by controlling the layered structure using post growth annealing technique. The samples used in the current study were synthesized using a vacuum tube furnace having an evaporation temperature 700 °C, base pressure 180 m Torr and source to substrate distance 7 cm. Sn and Te metal powders with an equal weight ratio were evaporated on the glass substrate to form SnTe composite. Post-growth annealing in vacuum environment was performed for different time’s duration of 1–4 h with a step of one hour. XRD analysis reveals six diffraction peaks for all samples, which correspond to different crystal planes of SnTe structure. Raman spectra exhibit the presence of specific vibrational modes associated with SnTe. Using the giant value of Seebeck coefficient and moderate electrical conductivity, a strong power factor value of 8.1 × 10−3 W m−1 K−2 was observed for optimized sample (annealed for 3 h). The strongest values of Seebeck coefficient and power factor are supposed to be the layered structure of SnTe thin films which was verified by the SEM images.

Sub-high amylose maize starch: an ideal substrate to generate starch with lower digestibility by fermentation of Qu.

The fermentation of Qu (FQ) is a novel method to modify the properties of starch to expand its application and especially to increase the resistant starch (RS) content. Using waxy maize starch (WMS) as a fermentation substrate can increase the RS content significantly but it may be time consuming and not cost effective due to the almost negligible RS content of WMS. To solve this problem, we hypothesized that sub-high amylose starch (s-HAMS), with an amylose content close to 50% could be an ideal substrate for FQ. The results showed that FQ did not change the shape and the particle size of starch granules, the gelatinization peak (Tp), or the conclusion temperature (Tc), but the slowly digested starch content declined. Rapidly digested starch content fluctuated during FQ and the amylose content decreased within 36 h and then increased. Within 24h, FQ significanlty increased these values: the RS content, relative crystallinity (RC), the ratio of FTIR absorbances at 1047/1022cm-1, the diffraction peak at 19.8° in X-ray diffraction (XRD), and the gelatinization onset temperature (To) increased significantly, within 24 h of FQ. However, after 24 h of fermentation, the RS content, RC, the ratio of FTIR absorbances at 1047/1022 cm-1, and gelatinization enthalpy (ΔH) decreased significantly. Sub-high amylose starch is more suitable for FQ to produce low digestibility starch, and the increase in RS may be due to the formation of 'amylose-lipid' complexes (RS5). © 2024 Society of Chemical Industry.

Promoting the optoelectronic and nonlinear optics properties of MoS2 nanosheets via metal Al anchoring

Molybdenum disulfide (MoS2) has attracted much attention in the field of optoelectronic materials due to its stability and adjustable bandgap structure. However, improving the optoelectronic properties of MoS2 is still a challenging research. Herein, Al doped MoS2 (AMS) films were prepared by a simple single-step magnetron sputtering method. The bonding modes of Al implantation and auxiliary MoS2 were investigated by adjusting metal Al anchoring. The successful synthesis of AMS films was confirmed by the analysis of X-ray diffraction and X-ray photoelectron spectroscopy measurements to investigate the diffraction peaks of Al and Al2S3 and the valence electron structures of Al3+. Compared to MoS2, the A1g Raman peaks of AMS films are slightly blue-shifted, and the peak positions of both Mo3d and S2p are slightly shifted towards higher binding energies. This is attributed to the surface plasmon resonance effect produced by Al doping resulting in a large amount of electron transfer to the conduction band (CB) of MoS2. In addition, the density functional theory calculations reveal that Al doping of MoS2 results in a higher concentration of electrons in CB of MoS2, the band gap of MoS2 can be adjusted by changing the doping concentration of Al. The Z-scan results illustrated that MoS2 was converted from saturable absorption to reverse saturable absorption (RSA) by adjusting the sputtering power of Al. This is attributed to the fact that Al doping increases the electron concentration in the CB of MoS2, which promotes the RSA of the excited states and doping energy levels of AMS films. The values of the nonlinear absorption coefficients of AMS films are 2–5 times higher than those of MoS2, which significantly improves the nonlinear absorption performance of MoS2. The carrier relaxation process and kinetic mechanism of AMS films were investigated by transient absorption spectroscopy, moderate doping of Al can effectively improve the carrier lifetime. This implies that AMS films have good optoelectronic properties and have a wide application potential in optoelectronic devices.

Effect of Nano Spinel Ferrites Co0.9Cu0.1Fe2O4 on Non-Isothermal Cold Crystallization Behaviours and Kinetics of Its Composites with Polylactic Acid.

Nanoparticles of spinel ferrites with a composition of Co0.9Cu0.1Fe2O4 (AM NPs) were effectively synthesized via a hydrothermal route. The structure of ferrite nanoparticles was characterized with X-ray diffraction, which showed a single cubic spinel phase. Energy-dispersive X-ray (EDX) spectroscopy and field emission-scanning electron microscopy (FE-SEM) were employed to analyse elemental composition and surface morphology, respectively. Moreover, the effects of the Co0.9Cu0.1Fe2O4 on the morphology of [PLA = polylactic acid] nanocomposites were examined through polarized light optical microscopy (POM) and X-ray diffraction (XRD). The thermal behaviours for tested samples were studied through [DSC = differential scanning calorimetry] and [TGA = thermal gravimetric analysis]. A great number of minor PLA spherulites were detected using POM in the presence of the Co0.9Cu0.1Fe2O4 ceramic magnetic nanoparticles (AM), increasing with AM nanoparticle contents. X-ray diffraction (XRD) analysis showed that the presence of nanoparticles led to an increase in the intensity of diffraction peaks. The DSC findings implied that the crystallization behaviours for the efficient PLA as well as its nanocomposites were affected by the addition of AM nanoparticles. They act as efficient nucleating agents because they shift the temperature of crystallization to a lower value. The Avrami models were used to analyse kinetics data. The experimental data were well described using the Avrami method for all samples tested. The addition of AM to the PLA matrix resulted in a decrease in the crystallization half-time t1/2 values, indicating a faster crystallization rate. TGA data showed that the occurrence of AM nanoparticles decreased the thermal stability of PLA.

Improving the glass ionomer restoration by Incorporating strontium NPs coated with AuNPs manufactured by laser ablation in liquid

The study entailed the preparation of SrNPs using laser ablation in liquid, which were then decorated with AuNPs. These decorated SrNPs were subsequently incorporated into glass ionomer cement. The addition of AuNPs/Sr NPs mixture to the glass ionomer resulted in enhanced antibacterial activity against caries decay, leading to increased susceptibility to fracture. The x-ray diffraction peaks (220) and (200) occur at angles of 60 and 41 degrees, respectively. The strontium peaks (111) and (130) occur at angles of 28 and 32 degrees, respectively. Furthermore, infrared spectroscopy revealed the chemical bonds present in gold nanoparticles and strontium particles within DDW. The nanoparticles have a near-spherical morphology, as shown under transmission electron microscopy (TEM), with a size range of 10–50 nm. This morphology is advantageous for achieving compatibility with the spherical shape of glass ionomer restorations. Aside from examining the characteristics of the nano-material (Au-Sr NPs), the introduction of nanoparticles onto the glass ion resulted in an enhancement that was observed by atomic force microscopy (AFM). This enhancement was manifested by a reduction in surface roughness when comparing the glass ions before and after the addition of nanoparticles. The antibacterial efficacy against Streptococcus mutans, a decay-causing bacteria, was dramatically enhanced upon the use of nanoparticles at varying concentrations. Furthermore, the incorporation of nanoparticles resulted in a significant enhancement of the compressive strength of the enhanced glass ion, elevating it from 370 to 600 N.

Layered assembling of energetic molecules with improved thermostability templated by in-situ generated 2D crosslinked macromolecules

Low-sensitivity but high-energy layered HMX crystals have been prepared by using an in-situ crosslinked network as the templated confinement, following a solvent-antisolvent procedure. The as received layered-HMX (L-HMX) crystals have only three diffraction peaks at 13.8°, 28.0° and 42.6°. It reveals that the conformation of the HMX molecule was largely changed after the squeezing and templating effect of the high nitrogen layers. The endothermic peak was not observed prior to decomposition, as the polymorphic transition and melting processes were excluded. This suggests that a new phase of HMX has been achieved. Unexpectedly, the L-HMX also shows significant fluorescent properties with incident laser wavelength of less than 932 nm. L-HMX has a calculated VoD value of 9425 km·s−1 and a calculated PC-J value of 41.5 GPa even 5 % higher than that of pure HMX. It is worth mentioning that the mechanical sensitivity of L-HMX crystals has been significantly reduced, and the excitation energy required for impact initiation is greater than 50 J, whereas that of pure HMX is about 6 J. The friction sensitivity is greater than 200 N. This approach may offer an efficient means to significantly enhance mechanical and thermal safety performance, while still maintaining a high energy level.

Effect of Polyethylene Pyrolysis Oil Hydrotreatment on the Pt/Al2O3 Catalyst: Experimental Characterization.

The dramatic increase in plastics production, coupled with a low recycling and recovery rate, has been a major challenge for sustainable practices and combating climate change. Hydrotreatment processing to upgrade fuel oils is a well-known process in the petroleum industry. In this work, we aim to investigate the catalyst properties before and after the hydrotreatment of pyrolysis oil derived from plastics, namely, linear low-density polyethylene, as no such report is available in the literature. Granular and powder forms of the Pt/Al2O3 catalyst were used in this study with characterization methods executed as such: transmission electron microscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and IR-RIS. XRD data show that the crystallinity of the catalyst support was unaffected by the hydrotreatment without any residues left, as the characteristic diffraction peaks were indicated for the crystalline phase of the support as 37.4, 39.8, 46.3, and 67.3°. In addition, the TGA experiments revealed that the carbon deposition on the spent catalyst was higher, as indicated by the higher weight loss (15.359%) compared to the fresh catalyst sample (11.43%). XPS analysis showed that the carbon deposition is more intense on the granular spent catalyst, as the intensity of the peaks is some 15 times greater than the peaks from the fresh catalyst. Also, compared to the observed peaks of the powder catalyst, less coke is formed. The band at 1624.05 cm-1 from the IR-RIS spectra was attributed to a shifted C=O band from the coke formation. The extension of these investigations using different catalysts to improve their characteristics and performance and to inhibit coke deposition will contribute to the incorporation of such processes in industry as well as the cost of fuels.