X-ray Diffraction Results Research Articles

Formulation and Characterization of Triamcinolone Acetonide Acetate-Loaded Microspheres Prepared by a Static Mixing Technique

Purpose: Reproducibility and scale-up production of microspheres through spray drying present significant challenges. In this study, biodegradable microspheres of Triamcinolone Acetonide Acetate (TAA) were prepared using a novel static mixing method by employing poly( lactic-co-glycolic acid) (PLGA) as the sustained-release carrier. Methods: TAA-loaded microspheres (TAA-MSs) were prepared using a static mixing technique. The PLGA concentration, polyvinyl alcohol concentration (PVA), phase ratio of oil/water, and phase ratio of water/solidification were optimized in terms of the particle size, drug loading (DL), and encapsulation efficiency (EE) of TAA-MSs. The morphology of TAA-MSs was examined using Scanning Electron Microscopy (SEM), while the physicochemical properties were evaluated through X-ray diffraction (XRD), Differential Scanning Calorimetry (DSC), and Fourier Transform Infrared Spectroscopy (FT-IR). The in vitro release of TAA-MSs was compared to that of the pure drug (TAA) using a water-bath vibration method in the medium of pH 7.4 at 37°C. Results: The formulation composition and preparation condition for the preparation of TAA-MSs were optimized as follows: the PLGA concentration was 1%, the phase ratio of oil(dichloromethane) /water (PVA solution) was 1:3, the phase ratio of water (PVA solution)/solidification was 1:2. The optimized TAA-MSs displayed spherical particles with a size range of 30-70 μm, and DL and EE values of 27.09% and 98.67%, respectively. Moreover, the drug-loaded microspheres exhibited a significant, sustained release, with 20% of the drug released over a period of 28 days. The XRD result indicated that the crystalline form of TAA in microspheres had been partly converted into the amorphous form. DSC and FT-IR results revealed that some interactions between TAA and PLGA occurred, indicating that the drug was effectively encapsulated into PLGA microspheres. Conclusion: TAA-loaded PLGA microspheres have been successfully prepared via the static mixing technique with enhanced EE and sustained-release manner.

Nb2O5 film optical properties and laser-induced damage by phase-change-driven tuning

Niobium oxide (Nb2O5) is widely used in optical and electrical fields because of its high refractive index, wide band gap, high laser-induced damage threshold (LIDT) and high transparency in the ultraviolet to middle-infrared-wavelength range (0.35–7 μm). In this study, Nb2O5 films with different crystalline phases were successfully prepared on BK7 and Si substrates through electron beam evaporation (EB) and post-annealing. Based on the results of X-ray diffraction (XRD) and Raman spectroscopy analysis, the impact of the post-annealing technique on the structure, and optical and physical properties of Nb2O5 films was thoroughly discussed at the molecular level. The crystal phase of an Nb2O5 film and its molecular bonds considerably affect its properties. The Nb2O5(-12 1 2) film prepared in this study exhibited a higher LIDT (17.72 J/cm2) and a higher RMS (0.447 nm) than the corresponding films prepared in previous studies. Following the post-annealing process, the band gap and refractive index of the prepared films were significantly higher than those of the as-deposited film. Thus, this study has significant guiding implications for Nb2O5 film applications and the development costs of the films.

Fe-Doped g-C3N4/Bi2MoO6 Heterostructured Composition with Improved Visible Photocatalytic Activity for Rhodamine B Degradation.

The binary heterostructured semiconducting visible light photocatalyst of the iron-doped graphitic carbon nitride/bismuth molybdate (Fe-g-C3N4/Bi2MoO6) composite was prepared by coupling with Fe-doped g-C3N4 and Bi2MoO6 particles. In the present study, a comparison of structural characteristics, optical properties, and photocatalytic degradation efficiency and activity between Fe-doped g-C3N4 particles, Bi2MoO6 particles, and Fe-g-C3N4/Bi2MoO6 composite was investigated. The results of X-ray diffraction (XRD) examination indicate that the hydrothermal Bi2MoO6 particles have a single orthorhombic phase and Fourier transform infrared (FTIR) spectroscopy analysis confirms the formation of Fe-doped g-C3N4. The optical bandgaps of the Fe-doped g-C3N4 and Bi2MoO6 particles are 2.74 and 2.73 eV, respectively, as estimated from the Taut plots obtained from UV-Vis diffuse reflectance spectroscopy (DRS) spectra. This characteristic indicates that the two semiconductor materials are suitable for absorbing visible light. The transmission electron microscopy (TEM) micrograph reveals the formation of the heterojunction Fe-g-C3N4/Bi2MoO6 composite. The results of photocatalytic degradation revealed that the developed Fe-g-C3N4/Bi2MoO6 composite photocatalyst exhibited significantly better photodegradation performance than the other two single semiconductor photocatalysts. This property can be attributed to the heterostructured nanostructure, which could effectively prevent the recombination of photogenerated carriers (electron-hole pairs) and enhance photocatalytic activity. Furthermore, cycling test showed that the Fe-g-C3N4/Bi2MoO6 heterostructured photocatalyst exhibited good reproducibility and stability for organic dye photodegradation.

Synthesis and characterization of composite membranes based on bacterial cellulose and coral powder

Preparation of bacterial cellulose and coral powder composite membranes has been carried out. Composite membranes were made by mixing bacterial cellulose with coral powder at different mass ratios at temperatures of 25 ºC, 40 ºC, 60 ºC and At 80 ºC, the composite membrane was evaluated for Fourier Transformation of Infrared, X-Ray Diffraction, degree of swelling, proton conductivity and methanol permeability. From the FT-IR analysis it was found that in the absorption area around 1461.385 – 911cm-1 showing the Si-O-Si stretching functional group, and in the absorption area around 3000 - 3500 cm-1 showing the (O-H) group which shows the semicrystalline composite membrane for each mass variation, according to the results of X-Ray Diffraction. The maximum proton conductivity has been measured as 3.32 x 10-3 S.cm-1 at 60°C, produces a degree of swelling of 31.14% and methanol permeability of 3.72 × 10-9 mol/cm.s for a mass ratio of bacterial cellulose:coral powder composite membrane 4:1.

Low-temperature sintering of ceramic bricks from clay, waste glass and sand

In the present work, bricks were made on a real 1:1 scale for the construction of housing. For the preparation of the mixtures, raw materials such as clay, sand and glass obtained from the recycling of brown beer containers were used, applying the method plastic molding for the preparation of the semi-products. It has been established that the addition of sand containing a small amount of montmorillonite to such clay enabled to realization of plastic molding. The incorporation of glass into the clay provided to substantially reduce the sintering time of the bricks up to 8h and to vary their strength properties. Sintering was carried out at 800°C in an air atmosphere. The results of X-ray diffraction (XRD), X-ray fluorescence (XRF) and field emission scanning electron microscopy (FESEM) and EDS microanalysis have shown that the raw materials and ceramic bricks contains quartz and feldspars. Low-temperature sintering has made it possible to obtain high-quality, high-strength building bricks in accordance with standards.

Microwave assisted synthesis of α-Fe2O3 half-hexagon nanoplates as an anode material for Li ion batteries

In this study, hematite α-Fe2O3 half-hexagon nanoplates have been successfully prepared by ethanol–water mediated microwave assisted solvothermal method. The high crystalline nature and rhombohedral crystal structure of the synthesized α-Fe2O3 were confirmed from X-ray diffraction (XRD) results. No impurity phase other than hematite α-Fe2O3 was detected. Raman spectroscopy results further revealed the hematite structure of α-Fe2O3. X-ray photoelectron spectroscopy (XPS) study disclosed the chemical composition and valence states in the synthesized α-Fe2O3 material. Field emission scanning electron microscope (FE-SEM) and transmission electron microscope (TEM) studies confirmed the half-hexagon plate like architecture for α-Fe2O3 along with some irregular shape nanoplates. When treated as an anode material for Li ion battery (LIB), α-Fe2O3 half-hexagon nanoplates delivered a reversible discharge capacity of 520 mAh.g−1 after 100 cycles at a high current density of 500 mA.g−1. The α-Fe2O3 half-hexagon nanoplates also exhibited excellent cycling performance and coulombic efficiency. The excellent performance of the α-Fe2O3 electrode is mainly ascribed to the plate like morphology of the particles, which offers large effective contact area with the electrolyte and significantly enhances the electrochemical performance.

Fatigue and tensile behaviour of Ti+TiN+Ti+TiVN multilayer nitride films coated on AZ91 magnesium alloy by closed field unbalanced magnetron sputtering

Despite their extensive use in the automotive and aerospace industries, Mg and Mg alloys, which are light metals, exhibit low fatigue and tensile strength. In this study, transition metal-nitride (TMN) multilayer coatings (Ti+TiN+Ti+TiVN) were coated twice on AZ91 Mg alloy using a Confined Field Unbalanced Magnetron Sputtering (CFUBMS) system to increase fatigue and tensile strength. The structural properties of the films were analyzed by using X-ray diffraction (XRD), scanning electron microscope (SEM), and energy dispersive spectrometry (EDS) methods, and the mechanical properties were analyzed by rotating bending fatigue and tensile testing machines. Ti+TiN+Ti+TiVN multilayer nitride surface coatings on AZ91 Mg alloys showed a dense and columnar microstructure and according to XRD results (111) was the preferred orientation with the dominant peak. The fatigue limit value of the AZ91 base material was fixed at 60.46 MPa, while it increased to 68.48 MPa after being coated with multilayer nitride. Along with the multilayer nitride coating, the tensile strength increased from 169.98 MPa to 175.43 MPa. As a result, the multilayer hard nitride coating with low surface roughness, which fills the defects, notches, and voids on the surface of the AZ91 base material, increased the fatigue and tensile strength in parallel. Based on the outcomes of the research, the literature has been enriched with an innovative approach through the enhancement of fatigue and tensile strengths by applying a CFUBMS coating to lightweight metals and alloys, such as AZ91, especially in the transportation industry where lightness and dynamic load resistance are essential.

Hot injection synthesis of CuS decorated CdS and ZnS nanomaterials from metal thiosemicarbazone complexes as single source precursors: Application in the photocatalytic degradation of methylene blue

CdS and ZnS are considered excellent semiconductors for photocatalysis, but photocorrosion and low photocatalytic activity limit their practical application. In order to improve on their photocatalytic activities, Copper sulfide-decorated CdS and ZnS (CuS@CdS and CuS@ZnS) nanocomposites were synthesized from Cu(II), Zn(II) and Cd(II) complexes of 2–(phenyl(pyridin–2–yl)methylene)hydrazine–1–carbothioamide, as single source precursors using a facile hot injection method at 250 °C, employing olive oil as capping agent. The structure, morphology, and optical properties of the as-prepared nanocomposites were determined using various analytical techniques. The results of powder X-ray diffraction (p-XRD), energy dispersive X-ray spectroscopy (EDX) and elemental mapping showed the presence of CuS, CdS and ZnS in CuS@CdS and CuS@ZnS, confirming the formation of nanocomposites. Transmission Electron Microscopy (TEM) images show agglomeration of CuS nanoparticles on the surface of CdS and ZnS nanoparticles. Scanning electron microscopy (SEM) images of CuS@CdS and CuS@ZnS nanocomposites revealed an agglomerated flower-like structure with porous surface. The band gap energies of 2.84 eV and 3.12 eV for CuS@CdS and CuS@ZnS, respectively, obtained from Tauc plots, demonstrate that combining CuS with single CdS and ZnS has an effect on their optical properties which probably account for the improved photocatalytic responses. The photocatalytic performance of the as-prepared materials was evaluated using the photodegradation of methylene blue (MB) dye under UV light irradiation. Results show that the degradation efficiencies for CuS@CdS (57 %) and CuS@ZnS (65 %) nanocomposites exhibited higher photocatalytic activity compared to those of pure CuS (42.0 %), CdS (35.1 %) and ZnS (57 %), suggesting that thiosemicarbazone complexes can be used as precursors for the development of metal sulphide nanocomposites as useful photocatalysts for the degradation of organic pollutants.

Effects of Premna microphylla turcz polysaccharide on rheological, gelling, and structural properties of mung bean starch and their interactions

The aim of this study was to investigate the effects of Premna microphylla turcz polysaccharide (PMP) on the rheological, gelling, and structural properties of mung bean starch (MBS) and their potential interaction mechanism. Results showed that the addition of PMP significantly improved the pasting properties, rheological properties, water holding capacity, and thermostability of MBS. The texture tests showed a decrease in hardness, gumminess and chewiness, indicating the retrogradation of MBS was inhibited. Scanning electron microscopy (SEM) suggested the MBS-PMP composite gels expressed a denser microstructure with obvious folds and tears. Moreover, the results of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and interaction force tests revealed the main forces between MBS and PMP were hydrogen bonds and hydrophobic interactions to form composite gels with great gelling properties. These results facilitate the practical application of MBS and PMP, and provide some references for understanding the interaction mechanism between starch and polysaccharide.

Extraction and Characterization of Cellulose from Coffee Husk and Brewery’s Spent Grain Fibers Using Alkali-Hydrogen Peroxide Treatment Method

Coffee husk (CH) and brewery spent grain (BSG) fibers are sustainable industrial residues that consist of cellulose. The present study aimed at the extraction of cellulose from CH and BSG fibers and to study the effect of alkali-hydrogen peroxide (5% NaOH–7% H2O2) treatment during the extraction by characterizing the extracted cellulose. Characterization of cellulose particles, such as crystallinity, functional groups, thermal properties, and morphology, was conducted by performing X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analyzer (TGA), and scanning electron microscopy (SEM), respectively. The finding shows that the maximum cellulose yields obtained from CH and BSG fibers are 37.3% and 26.5%, respectively. From the XRD results, the cellulose obtained from CH fiber (C-CH) and from BSG fiber (C-BSG) showed diffractive peaks with the highest intensity of approximately 1,003 and 1,236 counted at 2θ = 22°, respectively. A reduction in the absorption of peaks was observed on the FTIR spectrum for both C-BSG and C-CH samples at different wavelengths. SEM demonstrated that the surface roughness of the celluloses was enhanced. TGA showed that the maximum temperature decomposition observed for both C-CH and C-BSG is 360°C and 380°C, respectively. Generally, in this study, alkali-hydrogen peroxide (5% NaOH–7% H2O2) treatment was effectively used for the treatment of BSG and CH fibers for the extraction and surface modification of cellulose particles. The extracted cellulose in the present study can be used as an alternative to conventional cellulose for the manufacturing of biocomposite materials, preparation of particle boards and furniture, and production of food packaging materials.

Investigation of photoluminescence properties of Eu3+ doped La(OH)3 nanopowder synthesized by combustion method

Pure and different doping percentages of Eu 3+ ion (2, 5, and 10 wt%) doped La(OH)3 nanoparticles were produced using the urea-assisted combustion method followed by a three-hour calcination at 800 °C. A pure hexagonal phase of La(OH)3 structure is confirmed using X-ray diffraction (XRD) results. The photoluminescence (PL) investigations of Eu-doped La(OH)3 nanoparticles revealed orange and red emissions from 5D0→7F1 and 5D0→7F2 transitions of Eu3+ ions with excitation wavelength 395 nm. The CIE coordinate represents the orange and red zone of the La(OH)3 sample doped with Eu3+ions. The CCT values obtained are 2145 K, 2469 K, and 2583 K also the decay lifetime is 0.273 ns, 0.266 ns, and 0.493 ns for 2, 5, and 10 wt% of Eu3+ ions. The results confirmed among the three dopant concentrations of Eu3+ doped La(OH)3 nanoparticles, the optimal concentration of 10 wt% Eu3+ ion can be used for red and orange emitting phosphors.

Tailoring perovskite ceramics for improved structure, vibrational behaviors and radiation protection: The role of lanthanum in PbTiO3

This study investigates the characteristics of lanthanum (La)-doped lead titanate (PbLaxTi(1-3x/4)O3 where, x = 0.0, 0.02, 0.04, 0.06, 0.08, and 0.1), a type of perovskite ceramic. It specifically focuses on analyzing its structure, vibrational properties, and efficacy in shielding against radiation. The prepared samples are investigated by X-ray diffraction (XRD), which clarified that the small doping of La (x ≤ 0.06) produced the required phase, and increasing the La doping (x > 0.06) produced nonrequired phases (secondary phase). Also, increasing the La doping converted the crystal symmetry from tetragonal to cubic, which was confirmed by the tetragonality raio (c/a) calculations. Also, the samples are investigated by Fourier transform infrared (FTIR) spectroscopy to confirm the XRD results. Transmission electron microscopy (TEM) examination clarified that the prepared samples were in the nanoscale range with a maximum crystallite size value of around 70 nm. In addition, the shielding effectiveness of all the prepared samples was theoretically evaluated using the Phy-X/PDS program by considering characteristics such as the linear attenuation coefficient (GLAC), mean free path (GMFP), transmission factor (TF), and radiation protection efficiency (RPE). Increasing the La concentration increases the theoretical density to 4.98 gm/cm3 at x = 0.1, leading to low TF and GMFP values and high GLAC values. This produces samples with high attenuation to radiation and high shielding effectiveness.

High-temperature tensile behavior and constitutive model in Co-free Fe40Mn20Cr20Ni20 high-entropy alloy

High-entropy alloys (HEAs) have attracted widespread attention from scholars as a new type of material employed in extreme environments. However, as a main kind of HEAs, many face-centered cubic single-phase HEAs are restricted in industrial applications due to their lower yield strength and high cost when containing expensive elements such as Co. In this study, dispersion strengthening by heat treatment was introduced in low-cost Co-free Fe40Mn20Cr20Ni20 HEA to improve its strength, and its high-temperature tensile behavior and constitutive model were studied to explore its potential application at high temperatures. It is found that when subjected to quasi-static room-temperature stretching, the heat-treated sample exhibits a yield strength of 534 MPa and a tensile plasticity of 26.8%. In addition, the tensile behavior of samples after heat treatment was investigated at high temperature (573–873 K) and low strain rate (10−3–10−1 s−1). The results suggest that the yield strength decreases with increasing temperature and decreasing strain rate. Moreover, at 873 K and 10−3 s−1, the electron backscatter diffraction system and x-ray diffraction results of the deformed sample indicate that the softening curve is driven from the recovery of materials. Finally, the flow stress was predicted using the Arrhenius equation and Artificial Neural Network model (ANN), and the two models were assessed using the average absolute relative error and coefficient of correlation (R). The results showed that the ANN had higher accuracy.

A dual-purpose photocatalytic reaction for hydrogen evolution and simultaneous organic pollutant degradation of V2O5/Ppy based composite photocatalyst

The present work reports for the facile synthesis of novel vanadium oxide/polypyrrole (V2O5/Ppy) nanohybrids using various loadings of the V2O5. This novel hybrid photocatalyst was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman, UV–Visible absorption spectra (UV–Vis), photoluminescence spectra (PLS) and N2 adsorption-desorption analysis. XRD and TEM results suggest that V2O5 with individual spherical shaped nanoparticles of around 20–25 nm, which is uniformly wrapped on the surface of the Ppy sheets. A significant reduction in the bad gap energy (3.06–2.13 eV) and prevent the electron-hole recombination process was examined by UV and PL studies. The photocatalytic degradation efficiency was carried out for Reactive Black 31 (RB 31) and 4-chlorophenol (4-CP) dyes under visible light. The results illustrate that the optimal hybrid catalyst could reach 99 % of removal efficiency towards RB31 with visible light irradiation for 60 min. Moreover, the catalyst show high TOC efficiency (88%) high apparent constant (0.9189 min−1), and good stability with multiple cycle experiments. The improved photocatalytic mechanism was also discussed in detail. In comparison to V2O5 (425 μmol−1h−1 of H2) and PPy (151 μmol−1h−1 of H2), the optimised composite, 15 wt% V2O5 incorporated PPy showed a remarkable production rate under visible light (2255 μmol−1h−1 of H2).

Batch Sintering of FeO·OH and Fe2O3 Blends: Chemical and Metallurgical Characterization

A sample of goethite iron ore sinter feed (G_SF) was employed as a raw material in a sintering bed. This sample partially replaced hematite sinter feed (H_SF), which is currently used as raw material in a sintering plant in the state of Minas Gerais, Brazil. This substitution did not adversely affect the chemical and metallurgical proprieties of the sinter mix product, provided that the utilization of G_SF was kept below 30% in weight. Despite the higher proportion of fines in G_SF, the presence of argillaceous minerals in the sample led to an improvement in the granulation index (GI) of the sinter mix product. The GI value increased from 68.4 to 82.7% for the experiments conducted without the presence of goethite ore and with 40% of goethite ore in the sintering mix, respectively. Consequently, the qualities of both the process and the produced sinter product were not compromised. The raw materials and the various sinters produced were characterized through X-ray fluorescence (XRF) and X-ray diffraction (XRD), as well as thermal gravimetric analysis (TGA). The XRD results were used to perform a quantitative assessment of the mineral phase using the Rietveld method (RM). This technique allowed for the determination of goethite content in the studied sample, which was 35.5%. Finally, the incorporation of G_SF in the sintering bed led to a 20% reduction in the cost of raw materials.

Exploring the potential of nitrophosphogypsum and calcined water-treatment plant sludges in mortar mixtures: A study on workability and strength

Mortar mixtures that consider alternative mineral admixtures are of constant research interest to reduce ordinary Portland cement (OPC) content thereby lowering final cost and carbon footprint. An additional concern is the proper management of industrial process residues that could be used in mortar mixes to avoid their disposal in landfills or water bodies. This work investigated the potential of using calcined water treatment plant sludge (CWTPS) and nitrophosphogypsum (NPG) - a byproduct of the fertilizer industry - as partial replacements of OPC in mortar mixtures. For this purpose, this research evaluates the crystallographic, chemical, and physical properties of NPG and CWTPS through X-ray diffraction (XRD), X-ray fluorescence (XRF), and Scanning Electron Microscope (SEM). XRF and XRD findings strongly suggests that CWTPS qualifies as supplementary cementitious materials, due to its high content of silicon and aluminum oxides in a non-crystalline state. On the other hand, NPG could be used as a mineral admixture. The design of mixtures was based on the workability of 85% flow. The evaluation of properties encompasses the measurement of density, compressive strength, durability (pH and sulfate environments), and water absorption. The results demonstrate that incorporating of NPG and CWTPS to mortar mixes, each at a 5% inclusion rate (with a total replacement of 10% of OPC), increase compressive strength by up to 6.65% at 90 days compared to the control group in mortar mixes. However, the inclusion of NPG and CWTPS significantly decreases the workability of mortar mixes by up to 51.49%. The utilization of NPG as a partial replacement for OPC increases the water-to-cement ratio proportionally compared to the control sample, which can be explained by the anhydrite content of this byproduct. For its part, replacing 10% of OPC with NPG and CWTPS results in a 1.99% decrease in resistance after 28 days in sulfated environments compared to specimens cured in lime water. This protection of NPG against sulfate attack on mortars is based on the fact that SO3 saturation hinders the phase change from AFt to AFm during curing, as demonstrated by the XRD results. Additionally, the inclusion of NPG in mortar mixes increases capillary water absorption by up to 19.8%, while CWTPS, due to its pozzolanic nature, reduces it by up to 5.75%. Finally, this study explores the potential combined use of NPG and CWTPS in mortar mixes as a partial replacement for cement, presenting a viable and sustainable alternative for these cementitious-based construction materials.

Synthesis and Characterization of WNiFeCo, WNiFeMo, and WNiFeCoMo Compositional Complex Alloys Manufactured by Powder Metallurgy Technique

AbstractThe WNiFeCo, WNiFeMo, and WNiFeCoMo compositional complex alloys (CCAs) were prepared by powder metallurgy technique. The thermodynamic investigations of the CCAs proved that WNiFeCo, and WNiFeMo, are medium entropy alloys (MEAs), whereas WNiFeCoMo is a high entropy alloy (HEA). The density of the prepared specimens was estimated. The sintered CCAs were characterized by investigating their microstructures and elemental distribution using SEM and EDX analysis. The crystal structure of the different phases was identified utilizing X-ray diffraction (XRD). From XRD results, W, Fe7W6, and FeNi were observed in all CCAs, whereas Co7W6, MoNi4, and Co7Mo6 phases were found in WNiFeCoMo HEA. WNiFeCo MEA contained a Co7W6 phase, while the MoNi4 phase was observed in WNiFeCo MEA. The A7B6 phases are formed in the CCAs which have good characteristics. The hardness, Young’s modulus, and corrosion behavior were evaluated. Among the investigated CCAs, WNiFeMo MEA showed the highest relative density percentage (95%), Young’s modulus (190 GPa), hardness (451 HV), and lowest corrosion rate in 3.5% NaCl (0.22 mm/y). The surface morphology of the WNiFeCo, WNiFeMo, and WNiFeCoMo alloys displayed uniform corrosion, galvanic corrosion, and localized corrosion.

Influence mechanism of original components on mechanical properties and transformation behaviors of natural bitumen

Natural bitumen is an important component with high-purity organic matter in fossil energy and energy engineering scenarios. However, the production and application of natural bitumen could be severely hindered by the lacking of understanding the effects and influencing mechanisms of original components on physical properties of natural bitumen. Therefore, the main purpose of this work is to illustrate the influence mechanisms of original components (saturated hydrocarbon, aromatic hydrocarbon, resin and asphaltene) on mechanical properties of natural bitumen by the combination of nanoindentation technology and molecular structure analysis. The effects of each original component on the mechanical properties were carried out for Wuerhe natural bitumen which collected from Junggar Basin of China, and the influencing mechanisms were further revealed based on nanoindentation and X-ray diffraction (XRD) results. The occurrence units of each component in the chemical structural stacking of bitumen were established for the first time. It was found that hydrocarbons and resins can disintegrate the chemical structural stacking, thereby reducing the mechanical strength of natural bitumen. According to our micro-scale analysis results, the plastic and elastic deformation of natural bitumen were controlled by the structural units of amorphous carbon and aromatic carbon microcrystalline, as determined by saturated and aromatic hydrocarbons, respectively. And the schematic diagram of occurrence of each component in solid bitumen for the first time. Hence, the mechanical strength of natural bitumen can be effectively reduced by retaining or increasing the content of alkanes during exploitation, transportation and processing of natural bitumen. This research provided a new understanding for the stacking structure and physical property change mechanism of natural bitumen.

Targeted delivery of 5-fluorouracil and shikonin by blended and coated chitosan/pectin nanoparticles for treatment of colon cancer

Herein, 5-fluorouracil and shikonin (extracted from Fusarium tricinctum) were loaded in chitosan/pectin nanoparticle (CS/PEC-NPs), prepared by blending (B-CS/PEC-NPs) and coating (C-CS/PEC-NPs) methods. The nanoparticles characterized by Fourier Transform Infrared (FTIR), X-ray diffraction (XRD), Energy-dispersive X-ray (EDX), Scanning Electron Microscope (SEM) and Differential Light Scattering (DLS). Then, some properties of the nanoparticles such as drug release rate and the nanoparticles cytotoxicity were studied. The FTIR, XRD, EDX, SEM and DLS results showed that the nanoparticles synthesized properly with an almost spherical morphology, an average size of 82–93 nm for B-CS/PEC-NPs, an average diameter of below 100 nm (mostly 66–89 nm) for C-CS/PEC-NPs, and hydrodynamic diameter of 310–817 nm. The drug release results indicated the lower release rate of drugs for B-CS/PEC-NPs relative to C-CS/PEC-NPs at different pHs, high release rate of drugs for the nanoparticles in the simulated large intestinal fluids containing pectinase, and Korsmeyer-Peppas model for release of the drugs. The results showed more cytotoxicity of B-CS/PEC-NPs containing drugs, especially B-CS/PEC-NPs containing both drugs (B-CS/PEC/5-FU/SHK-NPs) after treating with pectinase (IC50 of 18.6 μg/mL). In conclusion, despite the limitation of C-CS/PEC-NPs for simultaneous loading of hydrophilic and hydrophobic drugs, B-CS/PEC-NPs showed suitable potency for loading and targeted delivery of the drugs.

Properties of X-ray diffraction and Raman scattering in PbSe, PbS and PbS0,5Se0,5 thin films

Structural properties of PbSe, PbS and PbS0.5Se0.5 thin films and mechanisms of combinational scattering of light from phonons were studied by X-ray diffraction and Raman spectroscopy methods. The results of X-ray diffraction show that the crystallite sizes found in the thin layers of the studied substances are in the order of nanometers and vary in the interval d~10.7 ÷ 30.8 nm. It was determined that the scattering bands of the PbSe0.5S0.5 sample with large nanoparticle sizes shift to the region of large wave numbers compared to the scattering bands observed in the region of low wave numbers.