X-ray Powder Diffractometer Research Articles

Zinc Hydroxystannate/Carbon Nanotube Hybrids as Flame Retardant and Smoke Suppressant for Epoxy Resins.

Novel hybrid flame retardants containing zinc hydroxystannate and carbon nanotubes (ZHS-CNTs) were synthesized using the coprecipitation method, and the structure and morphology of ZHS-CNTs were investigate using an X-ray powder diffractometer (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM) and thermogravimetric analyzer (TGA). Then, the ZHS, CNTs and ZHS-CNTs were incorporated into EP, respectively, and the flame-retardant and smoke inhibition performance of the composites were compared and studied. Among the three composites, the EP/ZHS-CNT composites have the highest improvements on the fire resistance and smoke inhibition properties. With only 2.0 wt.% ZHS-CNT hybrids, the pHRR of EP/ZHS-CNT composite materials is reduced by 34.2% compared with EP. Moreover, the release of toxic gases including CO, CO2 and SPR from the composites was also effectively inhibited. The mechanisms of flame retardant and smoke inhibition were investigated and the improved properties were generally ascribed to the synergistic flame-retardant effects between ZHS and CNTs, the catalyzing effect of ZHS and the stable network structure of CNTs.

Thermal dehydration kinetics of SrB6O10·5H2O with different morphologies

The globular-like, sheet-like, coral-like SrB6O10·5H2O was prepared by hydrothermal method, and characterized by X-ray powder diffractometer(XRD), thermogravimetry(TG), differential thermal analysis(DTA), scanning electron microscopy(SEM). The activation energy of the thermal dehydration of SrB6O10·5H2O with different morphologies was calculated by Ozawa-Flynn-Wall (OFW) method. The most probable mechanism function of the dehydration reaction was determined by master-plots method, and the average pre-exponential factor of the thermal dehydration of the sample was calculated. The results show that the thermal dehydration of SrB6O10·5H2O is divided into two steps. The activation energy of thermal dehydration reaction is affected by the morphology and size. The activation energy of SrB6O10·5H2O in the first step of thermal dehydration is close, while there is a significant difference in the activation energy value of SrB6O10·5H2O in the second step of thermal dehydration. The order of activation energy, as well as the order of the average pre-exponential factor, is consistent with the size order of the constituent units of the sample microstructure. The first-step thermal dehydration mechanism functions of SrB6O10·5H2O (globular-like, sheet-like, coral-like) are all [-ln(1-α)]3, which belongs to random nucleation and growth, and the second-step thermal dehydration mechanism functions are α2(one-dimensional diffusion), α+(1-α)·ln(1-α) (two-dimensional diffusion), and [-ln(1-α)]3 (random nucleation and growth), the reasons for the difference of their two-step mechanistic functions are analyzed.

Green Synthesis, Characterization and Application of Proanthocyanidins-Functionalized Fe3O4 Magnetic Nanocomposites

In this study, proanthocyanidins-functionalized Fe3O4 magnetic nanocomposites were synthesized by the hydrothermal method. The prepared Fe3O4 nanocomposites were characterized by Fourier transform infrared spectrometer (FTIR), X-ray powder diffractometer (XRD), physical property measurement system (PPMS), particle size analyzer, scanning electron microscope (SEM), and transmission electron microscope (TEM). FTIR results indicated that the obtained products were coated with proanthocyanidins. The SEM and TEM results, as well as particle size distribution analysis, revealed that the obtained products were spherical particles with average diameter of [Formula: see text][Formula: see text]nm. XRD and PPMS characterization confirmed that the Fe3O4 nanoparticles have a cubic spinel structure with magnetic properties. The performance of the Fe3O4 nanocomposites for removing organic dyes in an aqueous solution was investigated. The synthesized products were found to be effective on removing various organic dyes, such as Methylene blue (MB), neutral red (NR) and Rhodamine B (RhB), indicating their considerable potential as efficient dyes adsorbents for wastewater treatment.

Electrocoagulation Combined with Synthetic Zeolite—Does the Size of Zeolite Particles Matter?

Although electrocoagulation combined with zeolite (ECZ) shows higher efficiency in wastewater treatment, the actual contribution of zeolite particle size has not been fully explored. In this work, the influence of particle size of synthetic zeolite SZ (<90, 90–160, and 160–600 μm) on ECZ treatment of compost leachate with very high organic load is investigated together with different electrode materials (Fe, Al, and Zn), current densities (0.003, 0.009 and 0.018 A/cm2), and contact times (10, 20 and 30 min). The results positively highlight that the largest particle size should be used in ECZ, as it leads to a lower increase in pH and temperature, a higher decrease of chemical oxygen demand (COD) and turbidity, and a lower electrode consumption, while causing more damage to the electrode surface. The estimated energy costs ranged from 3.960 kW/m3–1313.657 kW/m3. The Taguchi L9 orthogonal configuration showed the highest COD and turbidity decrease under the conditions of 160–600 µm zeolite particles. The powder X-ray diffractometer (PXRD) analysis shows that interplanar spacing decreases when smaller and medium SZ particle sizes are used, while this effect was not observed with larger zeolite particle size. SEM-EDS shows that oxygen, silicon, and aluminium are the predominant elements in electrogenerated sludge coupled with zeolite.

Mix-ligand strategy to construct a novel cadmium-based coordination polymer for effective antibiotic identification in water

A mixed-ligand cadmium-based coordination polymer was successfully synthesized by solvothermal method and named {[Cd3(L)(bipy)(H2O)3]·2H2O}n (1) (where L = 3,4-bis(3,5-dicarboxyphenyl)phthalic acid, bipy = 2,2′-bipyridine). Subsequently, complex 1 was characterized by single crystal X-ray diffractometer (SC-XRD), powder X-ray diffractometer (PXRD), Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA) and fluorescence spectroscopy. Due to the excellent photoluminescence properties of complex 1, it was used to identify antibiotics in water and it can turn-on detection of norfloxacin in water and also quenched detection of nitrofurazone in water with excellent limit of detection. The mechanism is finally discussed in a rational manner by UV–Visible absorption spectra and density functional theory calculations.

In situ growth of MIL-101(Cr)-SO3H sphere on polyethylenimine-reduced graphene oxide and its application as dopamine sensor

The present work synthesized MIL-101(Cr)-SO3H on the surface of rGO in situ with polyethyleneimine (PEI) as an intermediate linker to prepare MIL-101(Cr)-SO3H/PEI-rGO composite. Furthermore, a new dopamine electrochemical sensor was successfully constructed based on the composite. The morphological and structural characteristics of MIL-101(Cr)-SO3H/PEI-rGO were investigated by scanning electron microscope (SEM), X-ray powder diffractometer (XRD), X-ray photoelectron spectrometer (XPS), and Fourier transform infrared spectrometer (FTIR), which revealed that the MIL-101(Cr)-SO3H spheres were uniformly anchored on PEI-rGO surface. The findings indicate that MIL-101(Cr)-SO3H particles can be effectively stabilized and prevented from agglomeration by means of in-situ growth on rGO surface with PEI as an intermediate linker. Electrochemical studies proved that the proposed dopamine sensor possessed a linear range, limit of detection and sensitivity of 0.25–238.75 μM, 0.07 μM and 327.7 μA mM−1 cm−2 respectively. The results reveal that MIL-101(Cr)-SO3H/PEI-rGO is a promising electrode modification material.

Efficient purification of graphite industry wastewater by a combined neutralization-coagulation-flocculation process strategy: Performance of flocculant combinations and defluoridation mechanism

The wastewater generated by the graphite industry exhibits high acidity and contains elevated concentrations of toxic ions, posing challenges for its efficient and cost-effective treatment. This study presents a novel approach for treating graphite industry wastewater, involving a synergistic process that combines NaOH neutralization, Ca(OH)2 mid-stage coagulation, and compound agent flocculation. The results showed that when pH = 2 was adjusted with NaOH and continued to pH = 8 with Ca(OH)2, the amount of precipitation produced was 62% lower than that of the conventional Ca(OH)2 coagulation process. Based on the defluoridation mechanism, polyaluminum chloride sulfate (PACS) and poly(dimethyldiallylammonium chloride) (PDMDAAC) were identified as the best compound flocculants. The turbidity and fluoride removal efficiencies of raw water reached 99.37% and 99.80%, respectively, when the mass ratio was m(PACS:PDMDAAC) = 9:1, the stirring rate was 150 rpm, and the coagulant dosage was 170 mg/L. By using X-ray powder diffractometer (XRD), scanning electron microscope (SEM), and X-ray photoelectron spectroscopy (XPS) characterization, the flocculation-defluoridation mechanism of PACS in combination with PDMDAAC was examined for its synergistic effect. The flocculation-defluoridation mechanism confirmed that the adsorption complexation of Al3+ on F- is significant in the removal of low concentrations of fluoride ions. Practical applications have proved that this treatment strategy can effectively solve the problems of excessive sludge mass and low removal rate of fluoride and metal ions in graphite industrial wastewater treatment. This process provides a new idea to promote the application of combined flocculants in the large-scale treatment of industrial wastewater.

Effects of selected retarders on workability window and other properties of cement-based sprayed mortars

Setting reducing agents were studied with respect to rheological properties of sprayed mortars based on fast-setting cement binder. The aim was to slightly delay the fast-setting effect caused mainly by tricalcium aluminate presence in order to adjust the workability window resulting in improved pumpability. Main experiments were performed using rotational rheometer and powder X-ray diffractometer. Additionally, 7day, 14day and 28day strength tests were done. The results show that chosen chemicals work as retarders, but not in required extent. Moreover, apart from the usual slower development of the strength due to the presence of retarder, at applied amounts, some of them can even have undesirable side effects such as causing weaker overall structure of the cured specimens.

Improving the electrochemical performance of ternary material LiNi0.5Co0.2Mn0.3O2 by Mg2+ doping

A carbonate co-precipitation method is used to synthesize the precursor Ni0.5−xMgxCo0.2Mn0.3CO3, and then lithium source is added to synthesize LiNi0.5−xMgxCo0.2Mn0.3O2 cathode materials doped with different proportions of Mg2+ (x = 0, 0.02, 0.05, 0.1) after high temperature calcination. The material was characterized by scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and X-ray powder diffractometer (XRD), and the electrochemical properties of the material were analyzed by batteries test and electrochemical impedance spectroscopy (EIS). The results show that an appropriate amount of Mg2+ doping can stabilize the layered structure and reduce the mixing of Li+/Ni2+, which is conducive to the rapid deintercalation of lithium ions. Compared with the bare material, the samples with Mg2+ doping amount of 0.02 have significant improvements in the first coulombic efficiency (91.9 %), cycle performance (86.2 % after 100 cycles). Especially, the rate performance of Mg2+-0.02 doping sample shows an excellent capability of 130 mA h/g at 5 C, while the bare sample only has 90 mA h/g.

Decoupling combustion characteristics of biomass pellets and their mixture with bituminous briquettes

Co-firing coal and biomass has been thought to be a promising way to achieve the efficient and clean combustion of them, but few researches were concentrated on the application of the co-firing technology in the residential field. In this study, the decoupling co-combustion characteristics of bituminous briquettes (BB) and biomass pellets (BP) were first evaluated by thermalgravimetric mass spectrometer (TG/MS) measurements, followed by the experiments on the pollutant emissions of burning blending fuels in a typical household decoupling stove as well as the thermodynamic equilibrium calculation and X-ray powder diffractometer (XRD) analysis of their slagging/fouling characteristics. The synergistic effect of co-firing coal and biomass is clarified. The addition of BP improves the combustion performance of blending fuels, while bituminous briquettes enhance the combustion stability of blending fuels. In the decoupling combustion stove, the stable coal char layer together with biomass pyrolysis gases plays an important role in the suppression of NOx, which also promotes the burnout of combustibles and thus favors the reduction of CO emission. Possible ash-related issues of ultrafine/fine particle emissions and severe slagging/fouling tendency caused by burning BP alone can be effectively alleviated by the capturing and regulating effect of BB. Co-firing bituminous briquettes and biomass pellets directly in the decoupling furnace can be anticipated to find wide use in the residential field.

Effect of pH on the morphology of TiO2 nanostructures

Titanium oxide (TiO2) nanostructures with different morphologies ranging from spheres, rods to sheets were prepared using solvothermal route. The effects of pH on the structural, morphological and optical properties of TiO2 nanoparticles were investigated. Nanostructures are characterized using Attenuated Total Reflectance (ATR), Powder X-ray Diffractometer (XRD), Scanning electron Microscope (SEM) and UV- Visible Spectroscopy.

Effect of pH on the morphology of TiO2 nanostructures

Titanium oxide (TiO2) nanostructures with different morphologies ranging from spheres, rods to sheets were prepared using solvothermal route. The effects of pH on the structural, morphological and optical properties of TiO2 nanoparticles were investigated. Nanostructures are characterized using Attenuated Total Reflectance (ATR), Powder X-ray Diffractometer (XRD), Scanning electron Microscope (SEM) and UV- Visible Spectroscopy.

Effect of Diluents on Active Pharmaceutical Ingredient Loss Until Patients Ingest Powder Formulation.

In powder formulations, it is a problem that the required therapeutic dose is not obtained because of loss of the active pharmaceutical ingredient (API). In this study, we investigated three types of lactose diluents, which are widely used as pharmaceutical excipients, for dispensing prednisolone powder. Extra-fine crystalline lactose, commonly used as a diluent in compounding powder formulations, was used as a comparison. The effect of lactose on the API loss rate was examined by analyzing the amount of prednisolone in the powder formulation taken out of a single-dose package after dispensing. The results showed that Dilactose-F had the lowest API loss rate (22%), followed by powder lactose (37.8%), extra-fine crystalline lactose (45.9%), and crystal form lactose (48.6%), indicating that the use of Dilactose-F as a diluent significantly improved API loss when compounding the powder formulation. Because each mixture of commercial prednisolone powder and lactose was within acceptable uniformity and loss rate before packaging, we considered that API loss occurred when the powder was taken out of the single-dose package before patients ingested them. Then, the physical properties of these lactose types affecting the API loss rate were examined. Strong correlation was not found between flowability and the API loss rate, but particle size distribution and bulk density were strongly correlated with the API loss rate. Furthermore, Dilactose-F, which showed the lowest API loss rate, did not show an exothermic peak due to epimerization to anhydrous β -lactose in differential scanning calorimetry and showed a peak specific to β -lactose in powder X-ray diffractometer. These results suggested that in powder compounding where the API content is low, the physical properties of lactose, such as particle size distribution, bulk density, and crystalline form, are intricately related to API loss.

Prospective in vitro A431 cell line anticancer efficacy of zirconia nanoflakes derived from Enicostemma littorale aqueous extract.

Biomedical applications of zirconia nanomaterials were limited in biological systems. In this research, 8-15 nm size zirconia nanoflakes (ZrNFs) were fabricated and their nature, morphology, and biocompatibility were evaluated. The synthesis was carried out using Enicostemma littorale plant extract as an effective reducing and capping agent. Physiochemical properties of prepared ZrNFs were characterized using diverse instrumental studies such as UV-vis spectrophotometer, Fourier-transform infrared, powder X-ray diffractometer, scanning electron microscope, transmission electron microscope (TEM), energy dispersive X-ray, and cyclic voltammetry (CV). The XRD pattern confirmed the tetragonal phases of ZrNFs and the highest crystallite size of Zr0.02, Zr0.02, and Zr0.06 was 56, 50, and 44 nm, respectively. The morphology of samples was assessed using TEM. Electrophysiological effects of ZrNFs in the cellular interaction process were revealed by the slower rate of electron transfer results in CV demonstration. Biocompatibility of synthesized ZrNFs was studied on A431 human epidermoid carcinoma epithelial cells. The cell viability was increased with an increasing the concentration of nanoflakes up to 6.50-100 μg/mL. The cell viability and observed IC50 values (44.25, 36.49, and 39.62 μg/mL) reveals that the synthesized ZrNFs using E. littorale extract is found to be efficient toxic to A431 cancer cell lines.

A Comparative Study on Gemological Characteristics and Color Formation Mechanism of Moqi Agate, Inner Mongolia Province, China

Agate attracts the attention of gem mineralogists because of its variable colors. The color of agate is closely related to its naming and classification, so it is necessary to study the color and mineral origin of agate. In this paper, the mineralogical characteristics and color origin of red, yellow and green Moqi agates from Inner Mongolia were systematically studied by means of Fourier transform infrared spectrometer, Raman spectrometer, X-ray powder diffractometer, electron probe microanalyzer and ultraviolet–visible spectrophotometer. It is found that the color of Moqi agate is related to the minerals and trace elements contained in it, and is associated with the electron transition or charge transfer of Fe ions in the contained minerals. Green agate has the highest Fe content, and its color is caused by celadonite inclusions. The red and yellow color in Moqi agate is mainly caused by hematite and goethite, while red agate contains more Fe than yellow agate. Raman spectroscopy and X-ray diffraction analysis show that the content of moganite in Moqi agate is 0–30%. It is calculated that the crystallinity of Moqi agate is 1.5–3.5. This work provides a theoretical basis for future research on the identification of Moqi agate.

Rietveld refinement, 3D view and electrochemical properties of rare earth lanthanum doped nickel ferrite to fabricate high performance electrodes for supercapacitor applications

Rare earth lanthanum doped nickel ferrite with chemical formula NiLaxFe2-xO4 having composition (x = 0, 0.1, 0.2, 0.3, 0.4, 0.5) have been synthesized using powder metallurgical route for the first time. The structural, morphological and electrochemical analysis of spinel ferrites have been studied by X-ray Powder Diffractometer (XRD), Scanning Electron Microscope (SEM), Energy Dispersive X-ray Spectroscopy (EDX), Cyclic Voltammtery (CV) and Galvanostatic Charging- Discharging (GCD) techniques. The structural analysis confirms the single–phase spinel ferrite. In order to refine the XRD data, Rietveld refinment method has been used. The Rietveld refinement specify the cubic phase of ferrite with the space group Fd3m. The surface analysis reveals the uniformally distributed spherical particles. The chemical composition of pure and La+3 doped nickel ferrites are in accordance with stoichiometric calculation. The lanthanum plays a vital role to improve the performance of electrochemical behavior for supercapactor applications. As the concentration of lanthanum increases the value of specific capacitance also increases. The highest specific capacitance is achieved at x = 0.4 which is ∼1050 F/g−1 at the low scan rate of 10 mV/s. Hence the fabricated lanthanum doped nickel ferrite electrodes may be recommended as a favorable candidate for the energy storage application like supercapacitor.

Nitrogen-doped carbon dots for doxorubicin-targeted delivery and two-photon cell imaging

Nitrogen (N) doped CDs (N-CDs) were prepared using citric acid and hexamethylenetetramine by a one-step hydrothermal method, characterized by transmission electron microscopy (TEM), Powder X-ray Diffractometer (PXRD), Nuclear Magnetic Resonance (13C NMR), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR), and ultraviolet–visible (UV–vis) absorption spectra. The doping mechanism and drug-loading characteristics of N-CDs were also studied. The results showed that N-CDs had both down- and up-conversion fluorescence properties and the average particle size was about 4.28 nm. N-CDs could be used as a drug carrier for doxorubicin (DOX) (N-CDs-DOX) via the formation of the NC bond, and the drug-loading rate of N-CDs-DOX was 35.88%. The N-CDs-DOX had pH-targeted properties and low cytotoxicity. In vitro release of N-CDs-DOX belonged to the Weibull model and Fick diffusion. The results showed that N-CDs could deliver DOX successfully, and collocate with DOX in the SH-SY5Y cells through two-photon imaging. The N-CDs-DOX system had sustained-release and pH-targeted properties. N-CDs were expected to deliver a type of drugs containing CO group and be used in cancer treatment.

Mössbauer Investigation of Mn-Doped La–Sr Ferrite Synthesized by the Sol–Gel Method

[Formula: see text] ([Formula: see text], 0.1, 0.3 and 0.5) series samples were prepared by sol–gel method and characterized by powder X-ray diffractometer (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and Mössbauer spectroscopy. The effects of Mn doping on the microstructure, morphology and electronic structure of La–Sr ferrite were investigated. The XRD results show that all samples are single phase and have orthorhombic structures with Pbnm space group. The surface morphology and composition of chemical elements of the samples were analyzed by SEM and EDS, and the experimental values were consistent with the expected values. The sample was tested by [Formula: see text]Fe Mössbauer spectroscopy at room temperature, and the results showed that the percentage of doublet increased gradually with the increase of Mn ion doping ratio, and at [Formula: see text], all the sextet disappeared and only the doublet existed. According to the analysis, it can be seen that the prepared series of samples underwent a transition from antiferromagnetic to paramagnetic.

Solubility and Scale-Up Potency of Norfloxacin-Urea Co-Crystal Prepared by Ultrasound-Assisted Slurry Co-Crystallization Method

Norfloxacin is an antimicrobial in treating urinary tract infections with low water solubility. This study aims to know the effect of norfloxacin-urea co-crystal formation on the solubility of norfloxacin and the potential for scale-up when prepared by ultrasound-assisted slurry co-crystallization method. Identification of the screening result of the norfloxacin-urea (1 : 1) co-crystal formation by a wet grinding method using an ethanol-acetone (1 : 1) solvent mixture was performed by powder X-ray diffractometer (PXRD). The ultrasound-assisted slurry co-crystallization method was used for co-crystal formation with five-fold the weight of norfloxacin and urea than the wet grinding method. The co-crystal product prepared by the ultrasound-assisted slurry co-crystallization method was observed for its crystal morphology and characterized by PXRD and differential scanning calorimeter (DSC). Solubility and dissolution tests in water and acetate buffer solution pH 4.0 were used to evaluate the physicochemical properties. Identification of co-crystal screening by PXRD revealed the formation of norfloxacin-urea co-crystal. The PXRD pattern of the norfloxacin-urea co-crystal product prepared by the ultrasound-assisted slurry co-crystallization method was similar to the wet grinding method. Norfloxacin-urea co-crystal has a different melting point and crystal morphology from pure norfloxacin and urea. The solubility and dissolution rate of norfloxacin-urea co-crystal was higher in water and not significantly different in acetate buffer solution pH 4.0 compared to pure norfloxacin. This study showed that the norfloxacin-urea co-crystal formation could enhance the solubility of norfloxacin in water and had the potential for scale-up when prepared using the ultrasound-assisted slurry co-crystallization method.

Experimental study on the preparation and physical thermal performance of coral sand-based phase change material concrete composites

To promote the application of phase change materials (PCMs) in the field of green building, this research prepared coral sand-based PCM composites by vacuum adsorption method with coral sand as the porous carrier and polyethylene glycol 1000 as phase change material. The thermal and physical properties of the material, and its leakage characteristics after cement encapsulation were investigated through scanning electron microscope (SEM), differential scanning calorimetry (DSC), fourier transform infrared spectrometer (FT-IR), x-ray powder diffractometer (XRD), and thermal gravimetric analysis (TGA). The DSC results indicated that the coral sand-PCM composites had a melting point and latent heat capacity of 28.55℃ and 48.57 J/g, respectively. TGA and thermal cycling test demonstrated that coral sand-based PCM composites had good stability in terms of their chemical structure, thermal degradation, and cycling reliability in latent thermal energy capacity properties. The coral sand-based PCM composites were later prepared as coral sand-based PCM concrete composites by replacing coarse aggregates with different proportions. And the compressive strength of the PCM concrete composites was tested. In addition, the thermal insulation properties of coral sand-based PCM concrete composites were verified through model tests. The results of model test showed that the maximum indoor temperature differences between the Oridinary-0 and CS-50 concrete rooms were 7.45℃ during heating and 2.61℃ during cooling. The strength of coral sand-based concrete still could meet the requirements according to the structural design code at a mass substitution ratio of 50%. The CS-50 composite concrete exhibited acceptable mechanical properties and was able to regulate indoor temperatures and reduce energy consumption in buildings. Therefore, it is suitable for engineering applications.