Powder X-ray Diffractometry Patterns Research Articles

Polysaccharides as Quality Marker to Rapid Profile for Ophiocordyceps sinensis by PXRD.

Ophiocordyceps sinensis has long been recognized as a mysterious and valuable traditional Chinese medicine but there has been little research on quality markers for O. sinensis. This study looked into the potential of using powder X-ray diffractometry (PXRD) to analyze polysaccharides as a quality marker for O. sinensis. There were 16 different habitats of O. sinensis collected in Qinghai, Gansu, Sichuan, Yunnan, and Tibet. In addition, five different types of Cordyceps species were collected. The characteristic diffraction peaks of O. sinensis were determined and then matched with the characteristic diffraction peaks of intracellular polysaccharides obtained from O. sinensis to determine the attribution relationship of the characteristic diffraction peaks. O. sinensis powder's X-ray diffraction pattern is determined by its composition, microcrystalline crystal structure, intramolecular bonding mechanism, and molecular configuration. After fractionation and alcohol precipitation of crude intracellular polysaccharide, mycelium crude intracellular polysaccharide (MCP) and fruiting body crude intracellular polysaccharide (FCP) were obtained and the fingerprint of O. sinensis was identified by the specific characteristic peaks of the X-ray diffraction pattern from intracellular polysaccharide. The results indicated that the PXRD patterns of different populations of O. sinensis were overlaid well with 18 characteristic diffraction peaks obtained by microcrystalline diffraction. Moreover, the powder diffractograms as a fingerprint provided a practical identification of O. sinensis from other Cordyceps species. In addition, we detected that the powder diffractograms of intracellular polysaccharide MCP and MCP75 could be coupled with the PXRD of O. sinensis. Specifically, 18 characteristic diffraction peaks were identified as coming from MCP and MCP75 according to those interplanar crystal spacing, which matched well with those of PXRD of O. sinensis. PXRD spectra combined with an updated multivariable discriminant model were found to be an efficient and sensitive method for O. sinensis quality control. According to the findings of this study, PXRD should be further investigated for quality control assessments and plant extract selection trials.

RETRACTED: Synthesis, Characterization and Photodegradation Studies of Copper Oxide–Graphene Nanocomposites

In this work, a simple hydrothermal method was employed to prepare a pristine sample of copper oxide (CuO) and three samples of copper oxide–graphene nanocomposites (CuO-xG) with x = 2.5, 5, and 10 mg of graphene. The synthesized samples were characterized using X-ray powder diffractometry (XRD), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), Fourier-transform infrared spectroscopy (FTIR) and ultraviolet–visible (UV-Vis) spectroscopy. The XRD patterns of CuO-xG nanocomposites exhibited the diffraction peaks related to the crystal planes of monoclinic CuO and hexagonal graphite. The surface morphology of the prepared samples was investigated using FESEM images. EDX analysis was used to investigate the chemical composition of the synthesized samples. FTIR spectroscopy identified the vibrational modes of the covalent bonds present in the samples. The allowed direct optical bandgap energy was calculated for all prepared samples using UV-Vis absorption spectra. The small bandgap of CuO-xG nanocomposites indicates their potential use as an effective photocatalyst in the presence of visible light. Photocatalytic activity of the samples was explored for the degradation of methylene blue (MB) dye contaminant under visible light irradiation. The results showed that the CuO-5G sample has the highest photodegradation efficiency (~56%).

Failure-Experiment-Supported Optimization of Poorly Reproducible Synthetic Conditions for Novel Lanthanide Metal-Organic Frameworks with Two-Dimensional Secondary Building Units*.

Novel metal-organic frameworks containing lanthanide double-layer-based secondary building units (KGF-3) were synthesized by using machine learning (ML). Isolating pure KGF-3 was challenging, and the synthesis was not reproducible because impurity phases were frequently obtained under the same synthetic conditions. Thus, dominant factors for the synthesis of KGF-3 were identified, and its synthetic conditions were optimized by using two ML techniques. Cluster analysis was used to classify the obtained powder X-ray diffractometry patterns of the products and thus automatically determine whether the experiments were successful. Decision-tree analysis was used to visualize the experimental results, after extracting factors that mainly affected the synthetic reproducibility. Water-adsorption isotherms revealed that KGF-3 possesses unique hydrophilic pores. Impedance measurements demonstrated good proton conductivities (σ=5.2×10-4 S cm-1 for KGF-3(Y)) at a high temperature (363 K) and relative humidity of 95 % RH.

SnAs: A 4K weak type-II superconductor with non-trivial band topology

Superconductors with non-trivial band topology are emerging as one of the best avenues to study quantum anomalies and experimental realization of Majorana Fermions. This article reports the successful crystal growth of superconducting SnAs, which can have topologically non-trivial states, as evidenced in DFT (Density Functional Theory) calculations, Z2 invariants and topological surface states. Here, we followed a two-step method to grow SnAs crystal. The powder XRD (X-ray Diffractometry) pattern of synthesized crystal ensures that the crystal is grown in a single phase with a NaCl type cubic structure and the EDAX (Energy Dispersive X-ray Analysis) endorses the stoichiometry of the as-grown sample. The DFT calculations performed with and without inclusion of spin-orbit coupling (SOC) show band inversion at various k symmetry points near the Fermi level. The recorded Raman spectra show two different modes, which are assigned as A1 and ETO vibrations. The ZFC (Zero-Field Cooled) & FC (Field Cooled), as well as the isothermal M − H (Magnetization vs. field) measurements, are also performed for the topological non-trivial SnAs superconductor, which eventually confirm the weak type-II superconductivity at 4K. Various other superconductivity parameters viz. kappa parameter, coherence length, and penetration depth are also calculated to probe the as-grown sample's characteristics.

Photocatalytic activity of cobalt substituted zinc ferrite for the degradation of methylene blue dye under visible light irradiation

Cobalt-zinc ferrite with composition CoxZn1-xFe2O4 (x = 0.0, 0.1, 0.2, 0.3, 0.4 and 0.5) was synthesized using citrate precursor method and the prepared samples were characterized by using X-ray powder diffractometry (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FT-IR) techniques. Single phase spinel structure was confirmed by the XRD patterns having (311) characteristic peak. SEM images showed the agglomeration of the powdered samples of cobalt-zinc ferrite. TEM images record an average crystallite size of 52 nm. Visible range light was used for the photocatalytic degradation of methylene blue by creating a Fenton-type system. It was observed that the degradation of methylene blue was enhanced with an increase in cobalt concentration. The degradation efficiency reached a maximum (77%) for x = 0.5 while it was the smallest (∼65%) for x = 0.0 in 1 h under visible light irradiation. Hence, we conclude that cobalt-zinc ferrite can be used as a potential material for purification of water and its degradation efficiency increased with an increase in cobalt concentration.

Compatibility studies with pharmaceutical excipients for aripiprazole–heptakis (2,6-di-O-methyl)-β-cyclodextrin supramolecular adduct

Aripiprazole (ARP) is one of the newest antipsychotic drugs, exhibiting very low aqueous solubility and high lipophilicity. Considering the necessity of improvement of ARP physicochemical properties and its biopharmaceutical profile, cyclodextrin complexation of the drug substance was performed. As selected cyclodextrin, a functionalized β-cyclodextrin was used, namely heptakis(2,6-di-O-methyl)-β-cyclodextrin (DIMEB), and the supramolecular adduct ARP/DIMEB was prepared by kneading technique and characterized using thermoanalytical tools (TG—thermogravimetry/DTG—derivative thermogravimetry/HF—heat flow), powder X-ray diffractometry patterns (PXRD), universal-attenuated total reflectance Fourier transform infrared (UATR-FTIR) and UV (ultraviolet) spectroscopy and, as well, saturation solubility studies. Job’s method was used for the stoichiometry of APR/DIMEB inclusion complex determination, which was found to be 1:2. Molecular modeling studies were complementary realized as to get a view over the way that ARP is hosted inside the cyclodextrin. The compatibility between the inclusion complex and some common pharmaceutical excipients, namely starch, magnesium stearate, lactose monohydrate, microcrystalline cellulose and methylcellulose, has been evaluated by means of thermal methods of analysis (TG/DTG/HF), UATR-FTIR spectroscopy and PXRD pattern. The preformulation data regarding the compatibility of ARP/DIMEB complex with selected excipients suggested that under ambient conditions, chemical interactions are observed solely between ARP/DIMEB inclusion complex and magnesium stearate, as indicated by the UATR-FTIR spectroscopy. The incompatibility in the system ARP/DIMEB + MgS is also confirmed by the PXRD study, this second investigational technique revealing also the advanced amorphization of components during mixing of complex with starch, microcrystalline cellulose and methylcellulose, but without indicating interactions. Later on, under thermal stress, thermally induced interactions occur between the components in the systems containing magnesium stearate and methylcellulose, while starch, microcrystalline cellulose and lactose can be safely used as excipients in developing solid formulations containing ARP/DIMEB inclusion complex as active pharmaceutical ingredient.

Albendazole-cyclodextrins binary systems

The aim of this study was to characterize the interaction between the binary systems of albendazole (ABZ)—cyclodextrins (CDs) with pharmaceutical excipients. Hydroxyl-propyl-beta-cyclodextrin (HPBCD) and random methyl-beta-cyclodextrin (RAMEB) were used as cyclodextrins and magnesium stearate, mannitol, polyvinylpyrrolidone K30 (PVP K30), colloidal silica, starch, and talc were used as excipients. The utilized investigation techniques were attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), powder X-ray diffractometry (PXRD) and thermoanalytical techniques: thermogravimetry (TG)/derivative thermogravimetry (DTG)/heat flow (HF) and differential scanning calorimetry (DSC). The ATR-FTIR analysis clearly suggested interactions under ambient conditions between ABZ-HPBCD with PVP K30 and SiO2 and between ABZ-RAMEB with SiO2 and talc. The PXRD patterns indicated the formation of less crystalline mixtures but with no clear indication of interactions, since no peaks appeared nor disappeared. The modifications on the DSC curves suggested an interaction between ABZ-HPBCD and PVP K30 and SiO2 respectively, and in case of ABZ-RAMEB was observed an interaction with talc. Thermal analysis (TG/DTG/HF) carried out in open crucibles in dynamic air atmosphere suggested that at temperatures over 40 °C dehydration of samples occurred, later followed by thermolysis and appearance of interactions in all studied cases. Our study concludes by recommending precautionary measures in elaborating new solid formulations containing ABZ, HPBCD and PVP K30/SiO2 and for the ones containing ABZ, RAMEB and Talc/SiO2, due to the present interactions under ambient conditions.

A glucose biosensor based on a glassy carbon electrode modified with poly orthotolidine-methyl anthranilate@MWCNT composites

We synthesized poly orthotolidine-methyl anthranilate@MWCNT nanocomposites by an in situ polymerization method. The nanocomposites were characterized by scanning electron microscopy (SEM), x-ray powder diffractometry (XRD), and UV- vis spectroscopic techniques. The results XRD patterns showed that the amorphous behavior in the copolymer and crystalline nature of the poly(OT-Co-MA)@MWCNT nanocomposites. Scanning electron microscopy was used to characterize the surface morphology of the copolymer and composites. The thermal properties of the composites were also studied by carrying out TGA. In addition, poly(OT-Co-MA)@MWCNT nanocomposites were fabricated onto a glassy carbon electrode (GCE) modified with coating binders. Using electrochemical techniques were measured to develop a sensitive sensor for glucose. Cyclic voltammetry (CV), linear sweep voltammetry (LSV), chronoamperometry and electrochemical impedance spectroscopy (EIS) were carried out to investigate the electrochemical behavior of the prepared poly(OT-Co-MA)@MWCNT/GOx biosensor. Hence, the strategy may prove useful as a route to specific recognition of glucose sensor using the poly(OT-Co-MA)@MWCNT nanocomposites. This novel methodology is presented here as an example of a complete development methodology for a glucose sensor for use in healthcare fields.

MELOXICAM-PECTIN-β-CYCLODEXTRIN TERNARY COMPLEX BY KNEADING FOR ENHANCEMENT OF SOLUBILITY AND DISSOLUTION RATE

Objective: The objective of the present investigation was to improve the solubility and dissolution rate of poorly soluble drug meloxicam by its ternary inclusion complexation with natural polymers and beta-cyclodextrin (β-CD) by kneading.
 Methods: Equimolar physical mixture (1:1) was prepared by homogeneously kneading drug and β-CD using a solution of agar and pectin in water to get a paste, then paste was dried overnight to get inclusion complex. Inclusion complex was evaluated for drug content, the yield of the adsorption process, Fourier-transform infrared (FTIR), differential scanning calorimeter (DSC), powder X-ray diffractometry (PXRD), scanning electron microscopy (SEM), dissolution, and stability studies.
 Results: The phase solubility diagrams exhibit AL showing a linear increase of drug solubility and indicating the formation of soluble complexes. The FTIR and DSC show compatibility between meloxicam and β-CD, while slight broadening in the peak with a reduction in intensity and early onset indicates the reduction in drug crystallinity which confirms in PXRD pattern. The SEM of binary, as well as ternary, showed no aggregation, and there was a gap between the particles also indicating good redispersibility. The dissolution rate of the drug from the kneaded ternary complex with pectin was significantly rapid compared with the pure drug. The maximum drug release was observed at 85.21±1.84% at the end of 60 min. The ternary complex was found stable after 3 months stability studies.
 Conclusion: The results indicated that ternary inclusion complexation with natural polymers and β-CD was most useful for enhancement of solubility and dissolution rate of a poorly soluble drug like meloxicam.

Dual UV irradiation-based metal oxide nanoparticles for enhanced antimicrobial activity in Escherichia coli and M13 bacteriophage.

Metal oxide (MO) nanoparticles have been studied as nano-antibiotics due to their antimicrobial activities even in antibiotic-resistant microorganisms. We hypothesized that a hybrid system of dual UV irradiation and MO nanoparticles would have enhanced antimicrobial activities compared with UV or MO nanoparticles alone. In this study, nanoparticles of ZnO, ZnTiO3, MgO, and CuO were selected as model nanoparticles. A dual UV collimated beam device of UV-A and UV-C was developed depending upon the lamp divided by coating. Physicochemical properties of MO nanoparticles were determined using powder X-ray diffractometry (PXRD), Brunauer-Emmett-Teller analysis, and field emission-scanning electron microscopy with energy-dispersive X-ray spectroscopy. Atomic force microscopy with an electrostatic force microscopy mode was used to confirm the surface topology and electrostatic characteristics after dual UV irradiation. For antimicrobial activity test, MO nanoparticles under dual UV irradiation were applied to Escherichia coli and M13 bacteriophage (phage). The UV-A and UV-C showed differential intensities in the coated and uncoated areas (UV-A, coated = uncoated; UV-C, coated ≪ uncoated). MO nanoparticles showed sharp peaks in PXRD patterns, matched to pure materials. Their primary particle sizes were less than 100 nm with irregular shapes, which had an 8.6~25.6 m2/g of specific surface area with mesopores of 22~262 nm. The electrostatic properties of MO nanoparticles were modulated after UV irradiation. ZnO, MgO, and CuO nanoparticles, except ZnTiO3 nanoparticles, showed antibacterial effects on E. coli. Antimicrobial effects on E. coli and phages were also enhanced after cyclic exposure of dual UV and MO nanoparticle treatment using the uncoated area, except ZnO nanoparticles. Our results demonstrate that dual UV-MO nanoparticle hybrid system has a potential for disinfection. We anticipate that it can be developed as a next-generation disinfection system in pharmaceutical industries and water purification systems.

Formation of Ketoprofen-Malonic Acid Cocrystal by Solvent Evaporation Method

The purpose of this work was to explore the formation of ketoprofen-malonic acid cocrystal by solvent evaporation method. Early detection of cocrystal formation was conducted by hot stage microscopy and solid-liquid phase diagram. Cocrystal were prepared by solvent evaporation method by using isopropyl alcohol as solvent. Characterization of cocrystal was done by Powder X-Ray Diffractometry (PXRD), Differential Scanning Calorimetry (DSC), Fourier Transform Infrared (FTIR) Spectroscopy and Scanning Electron Microscopy (SEM). The results of hot stage microscopic and solid-liquid phase diagram indicated formation of ketoprofen-malonic acid cocrystal. PXRD and DSC measurements showed stoichiometric ratio of cocrystal ketoprofen-malonic acid (2:1). The ketoprofen-malonic acid cocrystal had melting point at 86.2 °C and unique peaks of PXRD pattern at 2θ of 6.1°, 17.8°, 23.2° and 28.6°. FTIR spectra indicated the formation of cocrystal due to interaction of C=O ketone group of ketoprofen with MA molecule. SEM images show that ketoprofen-malonic acid cocrystal have multi-shaped particles with rough surfaces.

Formulation and Evaluation of Naringenin Nanosuspensions for Bioavailability Enhancement.

The clinical potential of naringenin (NRG) is compromised due to its poor aqueous solubility and low oral bioavailability. The study is aimed at addressing these issues by means of naringenin nanosuspensions (NRG-NS) formulated using polyvinylpyrrolidone (PVP K-90) as stabiliser via antisolvent sonoprecipitation method. Optimisation of sonication time, drug concentration and stabilisers was done based on particle size. Characterisation of pure NRG and NRG-NS was carried out by scanning electron microscopy, differential scanning calorimetry (DSC), x-ray powder diffractometry (XRD) and Fourier transform infrared spectroscopy (FTIR). In vitro dissolution, intestinal absorption by non-everted rat intestinal sac model and in situ single pass intestinal perfusion techniques were performed for further investigation. Nanosuspensions prepared using PVP K-90 lead to minimum particle size (117±5nm) with zeta potential of -14.6±5.6mV. The particle size was affected by increasing sonication time, concentration of stabiliser and drug. Nanosizing process converted the crystalline drug into amorphous form as predicted from DSC and XRD patterns. FTIR demonstrated the formation of hydrogen bonds between drug and polymer. NRG-NS displayed a higher dissolution amount (91±4.4% during 60min) compared to NRG powder (42±0.41%). The apparent and effective permeability of NRG-NS was increased as compared to the pure NRG. The in vivo pharmacokinetics demonstrated that the C max and AUC0-24h values of NRG-NS were approximately 2- and 1.8-fold superior than the pure drug. Hence, overall results confirmed nanosuspensions as promising approach for NRG delivery with high absorption in gastrointestinal tract, improved dissolution and oral bioavailability.

Development and characterization of nifedipine-amino methacrylate copolymer solid dispersion powders with various adsorbents

Solid dispersions of nifedipine (NDP), a poorly water-soluble drug, and amino methacrylate copolymer (AMCP) with aid of adsorbent, that is, fumed silica, talcum, calcium carbonate, titanium dioxide, and mesoporous silica from rice husks (SRH), were prepared by solvent method. The physicochemical properties of solid dispersions, compared to their physical mixtures, were determined using powder X-ray diffractometry (PXRD) and differential scanning calorimetry (DSC). The surface morphology of the prepared solid dispersions was examined by scanning electron microscopy (SEM). The dissolution of NDP from solid dispersions was compared to NDP powders. The effect of adsorbent type on NDP dissolution was also examined. The dissolution of NDP increased with the ratio of NDP:AMCP:adsorbent of 1:4:1 when compared to the other formulations. As indicated from PXRD patterns, DSC thermograms and SEM images, NDP was molecularly dispersed within polymer carrier or in an amorphous form, which confirmed the better dissolution of solid dispersions. Solid dispersions containing SRH provided the highest NDP dissolution, due to a porous nature of SRH, allowing dissolved drug to fill in the pores and consequently dissolve in the medium. The results suggested that solid dispersions containing adsorbents (SRH in particular) demonstrated improved dissolution of poorly water-soluble drug when compared to NDP powder.

Structural characterization of inclusion complex of arbutin and hydroxypropyl-β-cyclodextrin

Purpose: To improve the solubility and stability of arbutin and to expand its application by preparing its inclusion complex with hydroxypropyl-β- cyclodextrin (HP-β-CD). Methods: An inclusion complex made of arbutin and hydroxypropyl-β-cyclodextrin (HP-β-CD) was prepared by freeze-drying method. Various analytical techniques, including ultraviolet-visible spectroscopy (UV), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), x-ray diffractometry (XRD) and thermo-gravimetric/differential scanning calorimetry (TG/DSC), were used to characterize the inclusion complex. Results: UV spectra indicated that no new unsaturated bond was formed in the inclusion complex. Infrared analysis showed that the smaller peaks in the proximity of 1450 - 1600 cm-1 were characteristic of the aromatic nucleus, indicating that the phenyl ring of arbutin was involved in the formation of the inclusion complex. Scanning electron micrographs of the inclusion complex showed that the original morphology of both components disappeared, and some tiny aggregates of amorphous areas of irregular size were present, revealing that the arbutin was dispersed in HP-β-CD. The powder XRD pattern of the inclusion complex was more similar to that of amorphous HP-β-CD and did not exhibit the characteristic peaks of arbutin which suggest that arbutin in HP-β-CD matrix was molecularly dispersed, and existed in an amorphous state. The TG curve of the inclusion complex was a one-step process, partly proving the formation of the complex. Complex formation with HP-β-CD remarkably improved the physical and chemical stabilities of arbutin. Conclusion: Inclusion complex of arbutin with HP-β-CD improves the heat stability of arbutin remarkably. This has a potential for expanding the application of arbutin to pharmaceuticals and food. Keywords: Arbutin, Hydroxypropyl-β-cyclodextrin, Inclusion complex, Physicochemical properties, Stability, Solubility

Crystal forms of a new 5-HT4 receptor agonist DA-6886

DA-6886 is a new 5-HT4 receptor agonist under development for the treatment of constipation-predominant irritable bowel syndrome. The objective of this work was to investigate the existence of polymorphs and pseudopolymorphs of DA-6886. Five crystal forms of DA-6886 have been isolated by recrystallization and characterized by differential scanning calorimetry (DSC), thermogravimetric (TG) analysis, and powder X-ray diffractometry (PXRD). From the DSC and TG data, it was confirmed that Form 2 is \( {\raise0.5ex\hbox{$\scriptstyle 1$} \kern-0.1em/\kern-0.15em \lower0.25ex\hbox{$\scriptstyle 3$}} \) methanol solvate, Form 3 is 1 methanol solvate, Form 4 is \( 1{\raise0.5ex\hbox{$\scriptstyle 1$} \kern-0.1em/\kern-0.15em \lower0.25ex\hbox{$\scriptstyle 3$}} \) ethanol solvate, and Form 5 is \( 3{\raise0.5ex\hbox{$\scriptstyle 2$} \kern-0.1em/\kern-0.15em \lower0.25ex\hbox{$\scriptstyle 3$}} \) hydrate. The PXRD patterns of five crystal forms were different, respectively. In the dissolution studies in pH 6.8 ± 0.05 buffer at 37 ± 0.5 °C, the solubility of Form 2 was the highest. And the dissolution rate at 5 min in water decreased in rank order: Form 2 > Form 4 > Form 1 > Form 3 > Form 5. After storage of 3 months at 2 °C, 24 % relative humidity, Form 1, Form 2, Form 3, and Form 4 were not transformed, but Form 5 (\( 3{\raise0.5ex\hbox{$\scriptstyle 2$} \kern-0.1em/\kern-0.15em \lower0.25ex\hbox{$\scriptstyle 3$}} \) hydrate) was transformed to dihydrate.

Solid-State Characterization of Novel Propylene Glycol Ester Solvates Isolated from Lipid Formulations.

The purpose of this study was to identify and characterize precipitates obtained from a liquid formulation of GNE068.HCl, a Genentech developmental compound, and lipophilic excipients, such as propylene glycol monocaprylate, and monolaurate. Precipitates were characterized using powder X-ray diffractometry (PXRD), differential scanning calorimetry, thermogravimetry, microscopy, nuclear magnetic resonance spectroscopy (NMR; solution and solid-state) and water sorption analysis. PXRD and NMR revealed the precipitates to be crystalline solvates of propylene glycol esters. The solvates (capryolate and lauroglycolate) were isomorphic and stable up to 70 °C, beyond which melting of the lattice occurred with subsequent dissolution of the active ingredient in the melt (microscopy and variable temperature PXRD). They were found to be mechanically stable (no change in PXRD pattern upon compression) and were nonhygroscopic up to ∼70% RH (25 °C). Our results highlight the outcome of inadvertent drug-excipient interactions in two separate lipid solution formulations with good solid-state properties and, thus, potential for further development.

Nanostructure Cu–Zn mixed-oxide supported photocatalyst fabricated by impregnation method for the photocatalytic degradation of C.I. Reactive Orange 16 (V3R) in water

Nanostructure Cu–Zn mixed-oxide (CZMO) have been prepared by an impregnation method using copper nitrate and zinc oxide tetrapod precursors. X-ray powder diffractometry (XRD) and field emission scanning electron microscopy (FESEM) were used to characterize the structural of CZMO. The XRD patterns confirmed metal oxides formation and their good crystallinity. In agreement with XRD results, FESEM images also illustrated nanosized particles with an average nanocrystallite size of 33nm. The photocatalytic activity of CZMO was studied using the photocatalytic decolorization of C.I. Reactive Orange 16 (V3R) in aqueous environment. The results indicated that the CZMO display good photocatalytic efficiency. The related photocatalytic mechanism was discussed based on the coupling of zinc–copper oxide.

Sol–gel combustion synthesis and characterization of nanostructure copper chromite spinel

Nanocomposite copper chromite spinel was fabricated by sol–gel process using copper nitrate trihydrate, chromium nitrate nonahydrate, ethylene glycol, diethyl ether, and citric acid. The thermoanalytical measurements (TG–DTG), X-ray powder diffractometry (XRD), field emission scanning electron microscopy (FESEM), and energy dispersive X-ray analysis were used to characterize the structural and the chemical features of the nanocomposites. TG–DTG results showed that the major mass loss for copper(II) nitrate, chromium(III) nitrate as precursors occur at 258 and 140 °C, respectively. The major mass loss for dried gel of copper chromite occurs at 310 °C. XRD data revealed the formation of pure copper chromite after thermal decomposition at 1,000 °C for 2 h. The observation of XRD patterns reveals the presence of single-phase tetragonal spinel CuCr2O4. FESEM analysis of calcined composite was found to be in the range of 20–30 nm.

Solid state of a new flavonoid derivative DA-6034

DA-6034 is a new synthetic flavonoid known to possess anti-inflammatory activity. The objective of this work was to investigate the existence of polymorphs and pseudopolymorphs of DA-6034. Six crystal forms, one hydrate form and five solvates, of DA-6034 have been isolated by recrystallization and characterized by differential scanning calorimetry (DSC), thermogravimetric analysis (TG), and powder X-ray diffractometry (PXRD). From the DSC and TG data it was confirmed that Form 1 is monohydrate; Form 2 is DMSO solvate; Form 3 is 1/2 DMSO solvate; Form 4 is 1/2 methyl ethyl ketone solvate; Form 5 is 1.5 H2O, 1/2 acetic acid solvate; Form 6 is 1/2 H2O, 1/4 butanol solvate. The PXRD patterns of the six crystal forms were different respectively. In the dissolution studies in pH 6.8 ± 0.05 buffer at 37 ± 0.5 °C, the solubility of solvates was higher than that of Form 1.

Magnetic cobalt-zinc ferrite/PVAc nanocomposite: synthesis and characterization

Metal oxide nanoparticles are the subject of current interest because of their unusual optical, electronic, and magnetic properties. In this work, cobalt zinc ferrite (\( {\text{Co}}_{0.3} {\text{Zn}}_{0.7} {\text{Fe}}_{2} {\text{O}}_{4} \)) nanoparticles have been synthesized successfully through redox chemical reaction in aqueous solution. The synthesized \( {\text{Co}}_{0.3} {\text{Zn}}_{0.7} {\text{Fe}}_{2} {\text{O}}_{4} \) nanoparticles have been used for the preparation of homogenous polyvinyl acetate-based nanocomposite (\( {\text{Co}}_{0.3} {\text{Zn}}_{0.7} {\text{Fe}}_{2} {\text{O}}_{4} /{\text{PVAc}} \)) via in situ emulsion polymerization method. Structural, morphological and magnetic properties of the products were determined and characterized in detail by X-ray powder diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). The XRD patterns of the \( {\text{Co}}_{0.3} {\text{Zn}}_{0.7} {\text{Fe}}_{2} {\text{O}}_{4} \) confirmed that the formed nanoparticles are single crystalline. According to TEM micrographs, the synthesized \( {\text{Co}}_{0.3} {\text{Zn}}_{0.7} {\text{Fe}}_{2} {\text{O}}_{4} \) nanoparticles had nano-needle morphology with an average particle size of 20 nm. The calculated coefficient of variation (CV) of nanoparticles diameters obtained by TEM micrographs was 16.77. The \( {\text{Co}}_{0.3} {\text{Zn}}_{0.7} {\text{Fe}}_{2} {\text{O}}_{4} \) nanoparticles were dispersed almost uniformly in the polymer matrix as was proved by SEM technique. The magnetic parameters of the samples, such as saturation magnetization (Ms) and coercivity (Hc) were measured, as well. Magnetization measurements indicated that the saturation magnetization of synthesized \( {\text{Co}}_{0.3} {\text{Zn}}_{0.7} {\text{Fe}}_{2} {\text{O}}_{4} /{\text{PVAc}} \) nanocomposites was markedly less than that of \( {\text{Co}}_{0.3} {\text{Zn}}_{0.7} {\text{Fe}}_{2} {\text{O}}_{4} \) magnetic nanoparticles. However, the nanocompoites exhibited super-paramagnetic behavior at room temperature under an applied magnetic field.