Powder Diffraction Research Articles

Investigations on the synthesis, growth and physicochemical properties of nonlinear optical material: l-lysine monohydrochloride nickel bromide (LLMNB)

A good-quality single crystal of l-lysine monohydrochloride nickel bromide (LLMNB) with an optimum size of 7 mm × 3 mm x 2 mm was obtained within 40–45 days. SXRD examinations revealed the unit cell measurements and cell characteristics of l-lysine monohydrochloride nickel bromide (LLMNB) crystals. By using powder X-Ray diffraction (PXRD) studies, the grown crystal's crystalline nature was determined. The functional groups of the crystal were determined using Fourier transform infrared (FT-IR). The optical transmission of a LLMNB crystal was investigated to characterize the crystal. This illustrates the LLMNB crystal's broad transmission window spanning the whole visible range and its extremely low UV cut-off wavelength of 230 nm. According to the findings, the LLMNB crystal's SHG efficiency was 1.62 times higher than that of the reference crystal KDP. The dielectric property of the grown crystal was studied at various temperatures. The grown LLMNB crystal Vickers hardness number increases when a load is applied. Photoconductivity research looked into the nature of photoconductivity. Hence, all these investigations suggest that the grown LLMNB crystal can be used for nonlinear optical devices and it is a potential candidate for optoelectronic utilization.

Chromoionophoric molecular probe infused bimodal porous polymer rostrum as solid-state ocular sensor for the selective and expeditious optical sensing of ultra-trace toxic mercury ions

This study presents a distinctive solid-state naked-eye colorimetric sensing approach by encapsulating a chromoionophoric probe onto a hybrid macro-/meso-pore polymer scaffold for fast and selective sensing of ultra-trace Hg(II). The customized structural/surface properties of the poly(VPy-co-TM) monolith are attained by specific proportions of 2-vinylpyridine (VPy), trimethylolpropane trimethacrylate (TM), and pore-tuning solvents. The interconnected porous network of poly(VPy-co-TM), inherent superior surface area and porosity, is captivating for the homogeneous/voluminous incorporation of probe molecules, i.e., 7-((4-methoxyphenyl)diazenyl)quinoline-8-ol (MPDQ), for the target-specific colorimetric detection. The structural morphology, surface topography, and phase characteristics of the bare poly(VPy-co-TM) monolith and MPDQ@poly(VPy-co-TM) sensor are examined using HR-TEM-SAED (High-Resolution Transmission Electron Microscopy - Selected Area Electron Diffraction), FE-SEM-EDAX (Field Emission Scanning Electron Microscopy - Energy Dispersive X-ray Spectroscopy), XPS (X-ray Photoelectron Spectroscopy), p-XRD (Powder X-Ray Diffraction), FT-IR (Fourier Transform Infrared Spectroscopy), UV-Vis-DRS (Ultraviolet-Visible Diffuse Reflectance Spectroscopy), and BET/BJH (Brunauer-Emmett-Teller / Barrett-Joyner-Halenda) analysis. The distinctive properties of the sensor reveal a constrained geometrical orientation of the MPDQ probe onto the long-range continuous monolithic network of meso-/-macropore template, enabling selective interaction with Hg(II) with peculiar color transfiguration from pale yellow to deep brown. The sensor demonstrates a linear spectral-color alliance in the 0–200 ppb concentration range for Hg(II), with quantification and detection limits of 0.63 and 0.19 ppb. The sensor efficacy is verified using certified contaminated water and tobacco samples, with excellent reusability, reliability, and reproducibility of ≥ 99.23 % (RSD ≤1.89 %) and ≥ 99.19 % (RSD ≤1.94 %) of Hg(II), respectively.

Extraction and characterization of biocompatible hydroxyapatite (Hap) from red big eye fish bone: Potential for biomedical applications and reducing biowastes

In this study, nanostructured hydroxyapatite (HAp) was successfully extracted from the bones of Priacanthus macracanthus (Red Big Eye), a species commonly processed in the fish industry, generating significant waste. The extraction process utilized an alkaline hydrolysis method optimized with 2 M sodium hydroxide at 250 °C for 5 h, producing high-purity HAp. Fourier transform infrared spectroscopy (FT-IR) confirmed the presence of characteristic phosphate peaks at 1044 cm⁻¹ and 963 cm⁻¹, and hydroxyl peaks at 632 cm⁻¹. Powder X-ray diffraction (XRD) analysis showed prominent peaks at 2θ values of 25.9°, 32.2°, 39.8°, and 46.7°, corresponding to the crystalline planes of HAp. Field-emission scanning electron microscopy (FESEM) revealed spherical HAp particles with sizes ranging from 50 to 80 nm. Biocompatibility was assessed using human osteoblast-like MG-63 cells, showing a proliferation rate of 92 % compared to the control. Cytotoxicity tests indicated no significant adverse effects, supporting the potential use of this HAp in biomedical applications. Importantly, this method offers a sustainable solution for managing fish bone waste, contributing to pollution control by reducing environmental burdens associated with discarded bone wastes. Future research will focus on in vivo biocompatibility studies and exploring applications in pollution mitigation and tissue engineering. This study highlights the dual benefits of utilizing biowaste for valuable HAp production and addressing environmental pollution challenges, making it a promising approach for sustainable material synthesis and environmental management. The cost-effective and environmentally friendly process further underscores the feasibility of scaling up this method for industrial applications, providing a greener alternative to conventional HAp synthesis.

Synthesis, structure, and photochromic properties of Zn-coordination polymers derived from hexyl viologen cations

This study presents the synthesis, structural characterization, and investigation of the photochromic properties of two Zn-coordination polymers, formulated as {(HV)0.5[Zn(MIC)(HMIC)]·H2O}n (1) and {(HV)2[Zn4(BTEC)3]}n (2) (H2MIC = 5-methylisophthalic acid, H4BTEC = 1,2,4,5-benzenetetracarboxylic acid, HVBr2 = 1,1’-bis(n-hexyl)-4,4’-bipyridinium dibromide), derived from hexyl viologen cations. Compound 1 is characterized by a one-dimensional (1D) structure, while compound 2 exhibits a three-dimensional (3D) architecture, both crystallizing in distinct space groups and showcasing unique assembly and composition. Detailed structural analysis reveals the coordination modes of Zn(II) ions within these polymers. The photochromic behavior of two compounds under UV light exposure was thoroughly examined through ultraviolet-visible (UV-vis) and electron paramagnetic resonance (EPR) spectroscopy, demonstrating reversible color changes from light yellow to blue upon irradiation, with distinct rates of decolorization indicative of the stability of photo-induced viologen radicals. This reversibility was successfully replicated over multiple cycles, underscoring the durability of the photochromic transition. Furthermore, powder X-ray diffraction (PXRD) data confirmed the maintenance of crystal structures throughout the photochromic process, dismissing photolysis or photo-induced isomerization as underlying mechanisms. Instead, the observed photochromism is attributed to efficient electron transfer facilitated by the proximity between electron-donating and electron-withdrawing groups within the coordination polymers. This study highlights the influence of structural parameters on the photochromic properties of viologen-based coordination polymers, offering insights into the design of photo-responsive materials.

Elucidating Uniaxial Negative Thermal Expansion and Reversible Phase Transition in β-AgVO3 Microrods: In Situ PXRD and Raman Scattering Studies

This study investigates the thermal behavior and structural transitions of silver vanadate microrods (AgVO3) synthesized via coprecipitation. The samples were characterized at room temperature using scanning electron microscopy, Powder X-ray Diffraction, and Raman scattering. The AgVO3 was obtained in the monoclinic phase (β-phase) with a Cm space group and rod-like morphology of micrometer-sized diameter. In situ temperature-dependent studies utilizing XRD and Raman spectroscopy revealed notable findings: at low temperatures (298 – 12 K), the β-AgVO3 phase exhibited thermal stability alongside uniaxial negative thermal expansion (NTE) along the b lattice parameter of microcrystals. Conversely, experiments at high temperatures (298 – 673 K) demonstrated a reversible structural transition from the monoclinic phase to a triclinic phase at 473 K (β → β’), with NTE observed along the b direction in both high-temperature phases. These temperature-induced structural modifications and the observed uniaxial negative thermal expansion in β-AgVO3 microrods constitute significant contributions to the field, providing valuable insights into their thermal behavior and potential applications.

Two new 3D cobalt(II) coordination polymers constructed by semi-rigid carboxylic acid ligand: Syntheses, structures and properties

Two novel coordination polymers, {[Co2(L)(H2O)5]·H2O}n (1), and {[Co5(L)2(H2O)6(μ3-OH)2]·2C3H7NO·2H2O}n (2) (H4L = 3, 3′, 5, 5′-diphenyl ether tetracarboxylic acid, C16H10O9) have been synthesized by assembling semi-rigid aromatic polycarboxylic acids with transition-metal cobalt salts, and structurally characterized by elemental analysis, thermogravimetric analysis, IR spectrum, powder X-ray diffraction, and single crystal X-ray diffraction analysis. Structural analysis showed both the L ligands in CP 1 and CP 2 were regarded as 4 connection points, while the binuclear clusters in CP 1 and the pentanuclear clusters in CP 2 were regarded as 4 connection points and 8 connection points, respectively. Finally, both CP 1 and CP 2 were 3D network structures connected by two nodes (4, 4-connected for CP 1 and 4, 8-connected for CP 2). In addition, temperature-dependent susceptibilities have been measured in the range of 2 to 300 K, indicating that both CP 1 and CP 2 have antiferromagnetic coupling between adjacent Co(II) ions. Finally, Electrochemical experiments show that the CP 1 and CP 2 have good electrochemical behaviors.

Amorphous stabilization of BCS II drugs using mesoporous silica

This study aimed to investigate the amorphous stabilization of BCS Class II drugs using mesoporous silica as a carrier to produce amorphous solid dispersions. Ibuprofen, fenofibrate, and budesonide were selected as model drugs to evaluate the impact of molecular weight and partition coefficient on the solid state of drug-loaded mesoporous silica (MS) particles. The model drugs were loaded into three grades of MS, SYLYSIA SY730, SYLYSIA SY430, and SYLYSIA SY350, with pore diameters of 2.5 nm, 17 nm, and 21 nm, respectively, at 1:3, 1:2, and 3:1, carrier to drug ratios, and three different loading concentrations using solvent immersion and spray drying techniques. Differential scanning calorimetry (DSC) thermograms of SY430 and SY350 samples exhibited melting point depressions indicating constricted crystallization inside the pores, whereas SY730 samples with melting points matching the pure API may be a result of surface crystallization. Powder x-ray diffraction (PXRD) diffractograms showed all crystalline samples matched the diffraction patterns of the pure API indicating no polymorphic transitions and all 3:1 ratio samples exhibited amorphous halo profiles. Response surface regression analysis and Classification and Regression Tree (CART) analysis suggest carrier to drug ratios, followed by molecular weight, have the most significant impact on the crystallinity of a drug loaded into MS particles.

ZnO NPs-modified biochar derived from banana peels for adsorptive removal of methylene blue from water

In this work, biochar (BC) was synthesized from the thermal decomposition of banana peels and modified by different percentages of ZnO NPs using the wet impregnation method. The ZnOx/BC1-x nanocomposites’ (x = 0.00, 0.10, 0.20, 0.30, 0.50, 1.00 as a weight) physical and chemical properties were estimated utilizing X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), N2 sorption, Transmission electron microscopy (TEM), and zeta potential. The synthesized nanocomposites were utilized as adsorbents for eliminating methylene blue toxic dye from water. Through the adsorption batches, several parameters have been tested, such as the impact of x value, duration time, adsorbent dose, initial pH, dye concentration, and medium temperature. Compared to the tested nanocomposites, the ZnO0.10/BC0.90 nanocomposite revealed the best adsorption efficiency (96.5 %) with a high adsorption capacity reaching 118.8 mg/g. To ensure accurate identification of adsorption process behavior, the adsorption isotherms, kinetic models, and thermodynamic studies were investigated. Langmuir and pseudo-2nd order were discovered to be the most appropriate models that ascribe the adsorption behavior. Furthermore, the thermodynamic study reveals that the MB uptake on the nanocomposites is both spontaneous and exothermic.

Graphene/MWCNT/copper-nanoparticle fabricated printed electrode for diclofenac detection in milk and drinking water: Electrochemical and in-silico analysis

This study investigates the electrochemical sensing of Diclofenac sodium. A single carbon printed electrode was modified with the combination of graphene (GRP), multi-walled carbon nanotube (MWCNT), and copper-nanoparticle (CuNP) blended with oleic acid (OA) (i.e. CuNP@OA) as working electrode material of the three-electrode system (i.e. GRP-MWCNT-CuNP@OA). Here, copper nanoparticles, being responsible for catalysis, are embedded on the matrix comprising of GRP and MWCNT which serves as the conductive matrix material for electrode. The OA acts as a stabilising agent for the active CuNPs. The chemical sensitivity feature (in terms of binding interaction) of the GRP-MWCNT-CuNP@OA composite model interacting with the Diclofenac has been examined by implementing quantum chemical calculation approaches like molecular modelling, semi-empirical, QTAIM, and NCI-plot based tools. Some useful and important properties have also been examined using electronic parameters such as HOMO, LUMO, HOMO-LUMO gap, charge transfer (CT), QTAIM-based topological parameters, etc. which could indeed be helpful for the experimentalists in understanding the structural, stability/energetics, and electronic features of the probed composite models at nano-level. Further, the characterization of the composite was carried out through some sophisticated characterization techniques like scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDX), and powder XRD. Cyclic voltammetry (CV) is used for studying stability of the composite and chemical kinetics of the oxidation of Diclofenac sodium. Differential pulse voltammetry (DPV) was used to evaluate the sensing performance of the above-mentioned material by determining the lower range detection limit of Diclofenac (57.7 nM) and linear range (17.41 μM – 206.45 μM) of the electrochemical sensor. Further to validate the results obtained, real sample analysis was performed using the developed electrode in drinking water and milk spiked with Diclofenac.

Three new complexes of Zn(II) with a quinoline based Schiff base ligand: Syntheses, crystal architectures, Hirshfeld surface analyses, DFT study, photoluminescence and thermal properties

This report deals with one dinuclear and two mononuclear zinc(II) complexes of compositions [Zn2L2(μ1,1-N3)(N3)] (1), [ZnL(NCO)(H2O)] (2) and [ZnL(NCS)(H2O)] (3), where HL ((E)-2-ethoxy-6-((quinolin-8-ylimino)methyl)phenol)) is the 1:1 condensation product of 3-ethoxysalicylaldehyde and 8-aminoquinoline. All the three metal complexes have been characterized by C, H, N elemental analyses, FT-IR spectra, single crystal X-ray structures and powder XRD. The structures of 2 and 3 are isomorphous. The metal centres in 1–3 are five coordinated and adopt vacant octahedral or distorted square pyramidal geometry for 1 and distorted trigonal bipyramidal geometry for 2 and 3. Supramolecular interactions and topologies in all the three crystal structures have been analyzed, revealing 3–D assemblies in 1–3 due to a number of non-covalent interactions (C–H∙∙∙O, C–H∙∙∙N and π∙∙∙π in 1; C–H∙∙∙O, O–H∙∙∙O, O–H∙∙∙N, π∙∙∙π and C–H∙∙∙π in 2; C–H∙∙∙S, O–H∙∙∙O, O–H∙∙∙N, π∙∙∙π and C–H∙∙∙π in 3). To gain additional insight into the intermolecular contacts and their relative contributions towards the packing, Hirshfeld surface analyses have been undertaken for 1–3 and demonstrated in detail with respect to structural parameters, depressions in surfaces, fingerprint plots and enrichment ratios. The thermo-gravimetric and differential thermal analyses (TG/DTA) have been performed and the decomposition patterns are well explained. Steady state and time resolved fluorescence properties have been investigated. Optical band gaps have been determined from the data of the UV-Vis spectra. DFT calculations have been undertaken. The DFT computed HOMO-LUMO gaps corroborate the optical gaps and the DFT computed electrostatic potential (ESP) surfaces rationalize the supramolecular interactions nicely.

Influence of Rare-Earth Doping Content and Type on Phase Transformation and Transport Properties in Highly Doped CeO2.

Rare-earth doped CeO2 materials find extensive application in high-temperature energy conversion devices such as solid oxide fuel cells and electrolyzers. However, understanding the complex relationship between structural and electrical properties, particularly concerning rare-earth ionic size and content, remains a subject of ongoing debate, with conflicting published results. In this study, we have conducted comprehensive long-range and local order structural characterization of Ce1-xLnxO2-x/2 samples (x ≤ 0.6; Ln = La, Nd, Sm, Gd, and Yb) using X-ray and neutron powder diffraction, Raman spectroscopy, and electron diffraction. The increase in the rare-earth dopant content leads to a progressive phase transformation from a disordered fluorite structure to a C-type ordered superstructure, accompanied by reduced ionic conductivity. Samples with low dopant content (x = 0.2) exhibit higher ionic conductivity in Gd3+ and Sm3+ series due to lower lattice cell distortion. Conversely, highly doped samples (x = 0.6) exhibit superior conductivity for larger rare-earth dopant cations. Thermogravimetric analysis confirms increased water uptake and proton conductivity with increasing dopant concentration, while the electronic conductivity remains relatively unaffected, resulting in reduced ionic transport numbers. These findings offer insights into the relationship between transport properties and defect-induced local distortions in rare-earth doped CeO2, suggesting the potential for developing new functional materials with mixed ionic oxide, proton, and electronic conductivity for high-temperature energy systems.

Two types of cubic components coexisting in the paraelectric phase of relaxor ferroelectric Pb(Mg1/3Nb2/3)O3 revealed by synchrotron radiation X-ray diffraction

The crystal structures of relaxor ferroelectric Pb(Mg1/3Nb2/3)O3 (PMN) have been investigated using synchrotron radiation X-ray powder diffraction. Two different types of cubic components coexist in the paraelectric phase at 600 K. The first is Cubic-I, in which the Pb ion is isotropically off-centered from the corner of the perovskite-type unit cell. The other, Cubic-II, has the Pb ion preferentially off-centered in the <111> directions from the corner. The volume fractions of Cubic-I and Cubic-II are approximately 83% and 17%, respectively. Previous studies have shown that only approximately 20% of PMN transitions to a rhombohedral structure at 100 K. This observation suggests a close relationship between Cubic-II and the rhombohedral structure at low temperatures. The intrinsic structural inhomogeneity observed in the paraelectric phase, such as variations in the disordering behavior of Pb ions, is potentially linked to the relaxor characteristics of PMN.

Structural Stability and Adsorption Behaviour of CO2-Loaded Pure Silica CHA and ITW Zeolites upon compression

The present study investigates the structural stability and adsorption behavior of ultrahigh CO2-loaded pure-silica zeolites chabazite (CHA) and ITQ-12 (ITW) under high pressure conditions. To analyze these properties, we have utilized in situ synchrotron-based X-ray powder diffraction techniques. Lattice indexation provides information of the filling process and, through Rietveld refinements and Fourier recycling methods, we have been able to (i) determine the location and amount of guest carbon dioxide molecules within the cavities of pure-SiO2 CHA zeolite and (ii) tentatively determine that within the channels of the porous pure-SiO2 ITW framework. The filling of the zeolite pores with CO2 molecules was found to have a positive impact on the structural stability of both CHA and ITW under compression, which do not undergo pressure-induced amorphization up to 12.2 GPa and 15.9 GPa, respectively. Interestingly, low compressibility takes place in CHA zeolite below 4 GPa during CO2 loading and a second-order phase transition occurs in CO2-filled ITW zeolite at 2.1 GPa. These results highlight the influence of CO2 adsorption on the compressibility behavior of these zeolites. Overall, our study provides detailed insights into the structural behavior of CO2-loaded CHA and ITW under high pressure and allows comparison with other pure silica zeolites described in the literature.

Utilizing Taguchi method and in situ X-ray powder diffraction monitoring to determine the influence of mechanical activation conditions on the physico-chemical properties and Al leachability of K-feldspar

K-feldspar represents an important natural resource of potassium and aluminum. Within the framework of this study, the K-feldspar was mechanically activated in a planetary ball mill under different conditions planned according to 43 Taguchi orthogonal array experimental design. As outputs, specific surface area (SBET), median particle size (d50), amorphization degree of mineral phases detected, and Al recovery were used. It was found that the initial d50 value of 293 μm could be reduced to 6.7 μm and the SBET value of 4.7 m2/g could be increased up to 32.5 m2/g upon milling. Both microcline KAl3SiO8, and albite NaAl3SiO8 could be almost completely amorphized, whereas quartz SiO2 still maintained some crystallinity even under the most intensive conditions. Increasing SBET and decreasing the d50 values did not lead to a significant improvement in Al leach recovery, whereas a clear relationship between the amorphization of microcline and the recovered aluminum was found. Analysis of Variance (ANOVA) showed that increasing ball-to-powder ratio is the most beneficial for the improvement in Al recovery. In situ powder X-ray diffraction monitoring performed in an oscillation ball mill has shown very rapid amorphization of microcline phase and only limited amorphization, apart from almost complete process in the planetary ball mill. In the end, regressions for the calculation of Al recovery by knowing the values of input parameters were calculated. In general, by just using mechanical activation without the subsequent roasting process that is commonly used to boost metal recoveries, it was possible to quantitatively recover aluminum from K-feldspar.

Conversion of CO2(g) to CO(g) via reverse water–gas shift cycle on mixed cerium/praseodymium oxides at 500 °C

Reactions of cerium/praseodymium oxides under hydrogen atmospheres, and subsequently, carbon dioxide, involved in chemical looping reverse water–gas shift cycles (RWGS) at 500 °C were investigated by in-situ high-temperature X-ray powder diffraction, FTIR and thermogravimetry. The RWGS cycle is a critical chemical process for converting carbon dioxide into useful products, such as carbon monoxide, which can be used to synthesize fuels and chemicals. The mixed oxides exploit the redox properties of Ce and Pr, which can switch between oxidation states, making them suitable for oxygen incorporation and release during the RWGS process allowing them to react with H2(g), and subsequently with CO2(g), promoting their interaction and conversion into H2O(g) and CO(g). Pure cerium and praseodymium oxides showed poor CO2(g) conversion efficiency. However, we found that nanometric Ce/Pr mixed oxides exhibit enhanced oxyreduction performance suitable for this application, particularly with a composition of 75 mol% Ce and 25 mol% Pr, significantly improved performance, achieving an average CO(g) yield of 0.6 mmol/(goxide.cycle) and a maximum rate of 0.26 mmol/(goxide.min). Pr enhances oxygen mobility in CeO2, which improves the dissociation of C═O bonds in CO2(g). This is because the remaining oxygen atoms are delivered more quickly to the support sink, thereby cleaning up the vacant sites generated during the reduction step. These findings suggest that Ce/Pr mixed oxides are highly effective for CO2(g) conversion to CO(g) via RWGS cycle, offering a potentially viable option for industrial application.

The role of thickness on the structural and luminescence properties of Y2O3:Ho3+, Yb3+ upconversion films

The structural, surface, and upconversion (UC) luminescence properties of Y2O3:Ho3+,Yb3+ films grown by pulsed laser deposition, for different numbers of laser pulses, were studied. The crystallinity, surface, and UC luminescence properties of the thin films were found to be highly dependent on the number of laser pulses. The X-ray powder diffraction analysis revealed that Y2O3:Ho3+,Yb3+ films were formed in a cubic structure phase with an Ia 3¯\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\overline{3 }$$\\end{document} space group. The thicknesses of the films were estimated by using cross-sectional scanning electron microscopy, depth profiles using X-ray photoelectron spectroscopy (XPS), and the Swanepoel method. The high-resolution XPS was used to determine the chemical composition and oxidation states of the prepared films. The UC emissions were observed at 538, 550, 666, and 756 nm, assigned to the 5F4 → 5I8, 5S2 → 5I8, 5F5 → 5I8, and 5S2 → 5I7 transitions of the Ho3+ ions. The power dependence measurements confirmed the involvement of a two-photon process in the UC process. The color purity estimated from the Commission International de I’Eclairage coordinates confirmed strong green UC emission. The results suggested that the Y2O3:Ho3+,Yb3+ UC transparent films are good candidates for various applications, including solar cell applications.

Candesartan Cilexetil Formulations in Mesoporous Silica: Preparation, Enhanced Dissolution In Vitro, and Oral Bioavailability In Vivo

Candesartan cilexetil (CC) is one of well-tolerated antihypertensive drugs, while its poor solubility and low bioavailability limit its use. Herein, two mesoporous silica (Syloid XDP 3150 and Syloid AL-1 FP) and the corresponding amino-modified products (N-XDP 3150 and N-AL-1 FP) have been selected as the carriers of Candesartan cilexetil to prepare solid dispersion through solvent immersion, and characterized through using powder X-ray diffraction analysis, infrared spectroscopy, differential scanning calorimetry, scanning electron microscopy, and solid-state nuclear magnetic resonance spectroscopy, etc. The state of CC changed from crystalline to amorphous after loading onto the silica carriers, in which no interactions between CC and silica existed. Then, the dissolution behaviors in vitro were studied through using flow-through cell dissolution method. CC-XDP 3150 sample exhibited the most extensive dissolution, and the cumulative release of CC from it was 1.88-fold larger than that of CC. Moreover, the pharmacokinetic results in rats revealed that the relative bioavailability of CC-XDP 3150 and CC-N-XDP 3150 solid dispersions were estimated to be 326 % % and 238 % % in comparison with CC, respectively. Clearly, pore size, pore volume, and surface properties of silica carrier have remarkable effect on loading, dissolution and bioavailability of CC. In brief, this work will provide valuable information in construction of mesoporous silica-based delivery system toward poorly water-soluble drugs.

Sodium yttrium fluoride doped with Er3+ ions for thermally and non-thermally coupled nano-thermometry and IR detection applications

Microwave-assisted combustion synthesis approach was adopted to prepare sodium yttrium fluoride doped with erbium (NaYF4: Er3+) nanoparticles. Powder x-ray diffraction study confirmed the formation of mixed phase of NaY1-xF4: xEr3+ (x = 1, 3, 5, 7 and 9 mol%) sample with cubic and hexagonal phases (predominant). Three characteristic emission peaks appearing at 526, 546 and 670 nm were attributed to the transitions 2H11/2, 4S3/2 and 4F9/2 to 4I15/2 respectively which are characteristic emissions of Er3+ ions when excited with 980 nm radiation. The optimal dopant concentration was determined as 7 mol% of Er3+ ions in yellowish-green region, and the asymmetric ratio was also calculated. The synthesized up-converting sample follows two-photon process for excitation which was confirmed by power law by varying pump-power in the range of 49–143 mW. The thermally and non-thermally coupled levels attributed to the transitions (2H11/2 and 4S3/2), (2H11/2 and 4F9/2) of Er3+ ions were employed to study the temperature sensing which was recorded in 300–550 K and the relative sensitivities were evaluated to be 0.92 and 0.58 %K−1 correspondingly. The significant thermal sensitivity of the synthesized phosphor materials promises its possibility in optical thermometry applications. The synthesized sample when excited with 980 nm laser radiation produced emission in the visible region which facilitates the utilization of sample as infrared (IR) detector. In the purview of solid-state lighting, the luminous efficiency and luminous efficacy of radiation were evaluated as 23.57 % and 161 lm/Wop respectively. The optical thermometry, IR detection and light generation capabilities of the hexagonal-phased sodium yttrium fluoride doped with erbium (NYF:Er) ions are demonstrated with the obtained results.

Crafting copper complexes of variable nuclearity and coordination geometry through solvent tailoring: Unveiling novel structure, magnetic insight and computational marvels

The solvent tuning technique has been employed to synthesize two new copper complexes [Cu3(L)(NO3)2(DMSO)4] (1) and [Cu6(L)2(NO3)2(DMF)4(H2O)2(µ-HCOO)2] (2) which display variable nuclearity and coordination geometries. The synthesized complexes further characterized by using spectroscopic, single crystal and powder X-ray diffraction techniques. Supramolecular assembly of the complexes in the solid state is stabilized by a range of intermolecular interactions including O-H⋅⋅⋅O, C-H⋅⋅⋅O, π⋅⋅⋅π and C-H⋅⋅⋅π. Magnetic susceptibility measurements (χT vs T curves) over a wide range of temperature indicate dominant antiferromagnetic interactions between the Cu(II) centres in both complexes, while DFT calculations reveal the nature and amplitude of the main magnetic interactions. Theoretical study further shows strong antiferromagnetic interactions inside the trimeric units of both complexes as well as both weak ferro- and antiferromagnetic interactions among the trimers. The so-obtained J values have been employed to fit the χT vs T curves, using simplified spin models which correctly reproduce the main features of the experimental curves. Thus, this combined experimental and theoretical study provides insight into the magnetic structure of the copper complexes.

A comparative analysis of crustacean exoskeletons: structural, microstructural, morphological, and UV absorption studies

This study aims to investigate the structural, thermal, and spectral characteristics, along with the ultra-violet (UV) absorption of various marine benthos exoskeletons, such as various species of crabs (Portunus sanguinolentus, Portunus pelagicus, Charybdis feriata) and mantis shrimp (Oratosquilla oratoria). Their unique properties and ability to survive in harsh oceanic environments make them interesting research subjects. This research utilized powder x-ray diffraction (XRD) analysis to determine the crystal structure of the benthic varieties. The sample surface was analyzed using high-resolution micrographs obtained from field-emission scanning electron microscopy (FESEM), which identified the presence of chitin and calcite in the marine benthos. This was further confirmed by differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FTIR). The optical characteristics were investigated using UV-visible spectroscopy. The proximate analysis revealed high protein content in the mantis shrimp exoskeleton compared to other crab species, highlighting its excellent UV absorption characteristics. Overall, this research has the potential to broaden our understanding of marine organisms, which can have potential applications in biotechnology and materials science to develop nature-inspired innovative materials sustainably.