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SrFe12O19 samples were initially prepared using sol-gel auto-combustion method and calcined from 500 to 1100°C (for 6 h). XRD data established the phase formation temperature of SrM phase to be ≈1000°C. Thereafter, the effect of Zn2+-Zr4+ co-dopant on magnetic and structural properties of SrZnxZrxFe12-2xO19 (x = 0.00–1.00) samples calcined between 900–1100°C was investigated. XRD data shows that the cell volume increases (from 690.45Å3 (x = 0.00) to 705.72Å3 (x = 1.00)) while crystallite size decreases (from 123.9 nm (x = 0.00) to 62.3nm (x = 1.00)) calcined at 1000°C. The Rietveld refinement of XRD data confirms a) x = 0.00 sample to be phase pure and b) the presence of ZnFe2O4 (≈2.25) & SrZrO3 (≈2.93%) impurity phases in x = 1.00 sample, calcined at 1000°C. FESEM micrographs revealed that a) grain size decreases for x > 0.20 with `x’ at 900°C and b) increases from 122 nm at 900°C to 443 nm at 1100°C, for x = 0.00. Broadening of Raman bands reveals generation of strain in the lattice with enhancement of Zn2+-Zr4+ concentration. The magnetic studies reveal that the coercivity monotonically decreases (from 5358(x = 0.00) Oe to 690(x = 1.00) Oe at 1000°C) with enhancement of Zn2+-Zr4+ concentration. A maximum Ms value ≈ 70.89 emu/g was observed in x = 0.20 sample at 1100°C. Ms value also decreases for x > 0.20 at each calcination temperature.

The development of high-efficiency and durable bifunctional electrocatalysts is an important and challenging topic in the area of energy storage/conversion. Herein, we prepared metallic cobalt nanoparticle decorated N-doped graphitic sheets (Co@NGr) by adopting facile pyrolysis of a mixed ligand cobalt-based MOF (CoMOF-2) as a sacrificial template displaying good OER and HER activity. The catalytic material harvested at three different pyrolytic temperatures was characterized by various analytical methods such as PXRD, SEM, TEM, Raman, and XPS analyses. The catalytic activity of the obtained hybrid composite materials towards oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) was studied. Co@NGr-900 was found to be an efficient bifunctional electrocatalyst and 10 mA cm−2 current density was afforded at an overpotential of 390 mV for OER and 340 mV for HER respectively. This study provides insight for the development of cost-effective nonprecious element-based electrocatalysts for water splitting which has relevance in energy storage and conversion. Catalytic performance is governed by the synergistic compositional effect of metallic cobalt/nitrogen-doping in the graphitic carbon increasing the electrical conductivity/active sites of the composite material.

The major objective of the present investigation to study the effect of Zn/Zr dopant on M type-barium hexagonal ferrites on structure and properties. During present work, we have synthesized a series of BaZnxZrxFe(12-₂x)O19 ferrites (x=0, 0.1, 0.3, 0.5, 0.7, and 0.9) using sol-gel auto combustion method using citric acid as fuel and precursor was calcined at 900°C for 6 hour. These compounds were characterized by FTIR, XRD, VSM, TEM. XRD data of Barium hexaferrite (BAM) material reveals pure phase and have no traces of intermediate phase such as α/γ –Fe2O3 and BaCO3. The BaM series crystal size ranging from 38.9 to 66.9 nm and average size of particle is 49.7 nm. FTIR analysis give information about the functional groups and molecular bands present in the calcined barium hexaferrite material. Magnetic measurements reveal that the values of coercivity ranges viz Hc 4875Oe (x = 0) to 835Oe (x=0.9). The saturation magnetization (Ms) values are in the range of 58.2 to 33.4 emu/g.

Synthesis of BaZn0.6Zr0.6Fe10.8O19 powder samples using sol–gel-auto-combustion method has been reported. The impact of calcination temperature on the structural, magnetic and surface morphology of these samples has been investigated. XRD data confirms that the samples are phase pure and have no traces of intermediate phase such as α/γ-Fe2O3 and BaCO3 etc. The lattice parameters and cell volume increase slightly with increase in calcination temperature. The c/a parameter is

M-type barium hexaferrite (BHF) is frequently used for permanent magnet preparation. Herein, we have synthesized BHF via sol–gel-auto-combustion route using Jamun pulp which perform multiple functions such as natural fuel, green reducing agent and ecofriendly chelating agent. The effect of Jamun pulp concentration (10–60 g/100 mL of water) on structural, morphological properties, coercivity and the saturation magnetization of BHF has been studied for the first time. The X-ray diffraction (XRD) analysis confirmed phase purity of BHF (i.e. absence of even traces of intermediate phase (α-Fe2O3 and BaFe2O4.) at 50 g/100 mL of water and higher Jamun pulp concentration. Further, the c/a ratio

We report the synthesis of Ba0.5Sr0.5ZnxZrxFe12-2xO19 (x = 0.00–1.00) samples using sol–gel auto combustion method. The Rietveld refinement of XRD data indicates a) pure phase formation, b) increase in lattice parameters with composition and c) the absence of undesirable phases such as α–Fe2O3, BaCO3 and SrCO3. FESEM and TEM micrographs reveal an increase in grain size with ‘x’. The broadening of Raman peaks without any peak shift in all the samples indicates that the Zn2+/Zr4+ions are incorporated into Ba0.5Sr0.5Fe12O19 without altering the local structure. Magnetic measurements reveal that the maximum value of saturation magnetization (Ms) is 67.37 emu/g in x = 0.4 sample. The coercivity (Hc) monotonically decreases from 4.936 KOe to 1.029 KOe with increasing concentration of non-magnetic dopants. The dielectric constant values decreases monotonically as function of frequency for all the samples. The samples because of their superior magnetic properties could be vital for high density perpendicular recording, high density parallel recording EM shielding and permanent magnet applications.

The properties of the heterojunction devices are predetermined based on the bandgap and the extent of dopping of their constituent semiconductors and are not tunable in-situ . Albeit in this manuscript a new concept of in-situ tuning of heterojunction has been introduced. pP heterojunction using conducting polymers, polyaniline (PANI) and poly (3,4-ethylenedioxythiophene) (PEDOT) has been fabricated. The junction was studied by scanning electron microscopy and atomic force microscopy. The rectification behavior was studied through current density (J)–voltage (V) characteristics at various electrochemical potentials by superimposing small voltage steps (bias voltage) over a steady electrochemical potential using bipotentiostat. The rectification was found tunable as a function of electrochemical state of the polymers in in-situ conditions.

The effect of co-doping of Zn2+/Zr4+ ions on surface morphology, structure and magnetic properties of BaZnxZrxFe12-2xO19 (x=0.00, 0.20,0.40,0.60,0.80, 1.00) synthesized using Pechini method has been investigated. XRD data reveals that the samples are phase pure and have no intermittent phase. The c/a parameter is 2+/Zr4+ dopant seen using FE-SEM micrographs. The local crystal structure distortion with increasing Zn2+/Zr4+ dopant composition is confirm by Raman measurements. M vs H plots reveal that all the samples shows magnetic ordering. The highest Ms value has been noticed to be 68.43 emu/g in x=0.20 sample. The Hc value varies from 5350 Oe to 763 Oe with increase in dopant concentration. These materials have strong potential in magnetic recording applications.

An electrochemical method for loading electroactive materials over the TEM grid is reported. The protocol has been demonstrated using polyaniline as an example. The electroactive polymer was directly deposited over the Au TEM grid, used as working electrode in a 3 electrode electrochemical cell. The undisturbed as-deposited morphologies under the influence of various counter ions and ex situ electrochemical states have been studied and compared. Contrary to behaviour in bulk the individual polyaniline fibre was found thinner at anodic potentials. The movement of counter ions as a function of the electrochemical state of the polymer was studied using STEM-EDX elemental mapping.

The structure-property correlation in the Cu-TCNQ organometallic complex is very important for explaining its unusual electrical, optical and magnetic properties. Consequently several morphological studies and their correlation with the properties of these materials can be found in the literature, although no systematic study of various morphologies with growth conditions and their correlation has been reported to the best of our knowledge. Therefore in this manuscript the interconversion of various morphologies is reported using electron and probe microscopies. A conventional Cu TEM grid acted as the copper source to form a Cu-TCNQ complex and the complex, which formed at the surface of the TEM grid. The complex thus prepared was characterized by FTIR and Raman spectroscopic techniques. The shifting of -C N from 2221 cm−1 (TCNQ) to 2201 cm−1 indicates formation of a complex and the identical nature of IR spectra in two phases indicates that they are polymorphs. The morphologies of Cu-TCNQ were followed through FE-SEM and TEM studies. Various morphologies such as needle, square tube, platelet etc. were observed as a function of time. A distinct transition from needle to platelet morphology was observed as the complex grew. The conductance of various morphologies in phase-I as well as phase-II were also measured and compared by Spreading Resistance Imaging (SRI) at different bias voltage i.e. 1 V, 3 V and 5 V.

This work evaluates cationic intercalation of Capecitabine (Xeloda), an antineoplastic agent in interlayer gallery of Na + -MMT, which was further compounded with Poly ( L -Lactide) to form microcomposite spheres, for oral chemotherapy of breast cancer. The XRD, TGA, SEM, TEM and FT-IR analysis indicated the CAP intercalated in interlayer of MMT and stabilized in the longitudinal monolayer mode by electrostatic interface. No significant alteration in fundamental active properties of CAP was found in the MMT efficacy and data from in vitro study showed controlled drug release pattern >72 h. The efficacy of CAP-MMT hybrid/MPs was also confirmed on Human neuroblastoma cell line (IMR32) by in vitro cell culture experiments evaluating cell cytotoxic and oxidative stress marker indices which showed that intercalated drug and MPs, were as effective as pristine drug. In vivo pharmacokinetics of CAP-MMT hybrids in rats was examined and plasma CAP levels were evaluated. Our findings suggest that CAP-MMT hybrids and MPs can be of considerable value in chemotherapy of malignant neoplastic disease with reduced side effects and clearly demonstrated that MMT not only plays a role as a delivery matrix for drug but also facilitates significant increase in the delivery proficiency.

The controlled formation of porous ZnO microtubes via the formation of tubular hydrozincite under ambient conditions from bulk ZnO followed by calcination at 500 °C for 2 h is presented. The tubular structure is a hierarchical assembly of ZnO flowers to form uniform tubes, with ∼30 μm length, ∼2 to 7 μm width and ∼400 to 500 nm wall thickness, where the flowers are made of 3D assembled porous ZnO flakes. The surface area of the tubular ZnO structure is quite good (58 m2 g−1). The developed synthetic procedure is quite flexible, and we have also synthesized nanostructured ZnO of varying morphologies from bulk ZnO just by changing the synthetic conditions. The developed ZnO microtubes showed excellent microstructure-based sensing and catalytic properties. A novel biosensor based on the synthesized porous tubular ZnO exhibited high sensitivity (54.5 mA M−1 cm−2) and low LOD (limit of detection, 0.2 mM (S/N = 3)) of cholesterol at room temperature, superior to that of sensors made of other porous ZnO shapes synthesized by varying the conditions, as well as other sensors reported in the literature. It is superior even in comparison with a nano gold modified sensor. The tubular ZnO structure also showed superior catalytic activity (92%) for the synthesis of 5-benzyl-1H-tetrazole to that of other reported solid catalysts. Thus, it is expected that the developed porous tubular ZnO should find potential industrial application in the sensor as well as the catalysis field. Moreover, the synthesis from bulk ZnO makes the procedure cost effective.

Preparation of a high flux poly(dimethylsiloxane) (PDMS) membrane for separation of organics from water by pervaporation has been a challenging task. For this, the membrane should be as thin as possible since the productivity flux is inversely proportional to the membrane thickness. In an attempt to understand the relationship between the membrane structure and flux, the membranes of different thickness varying from about 0.2 to 150 μm were prepared and studied. The neat PDMS membrane prepared by evaporation casting of the 10% (w/w) polymer solution in n-hexane has an average thickness of 150 μm while a porous support was used for preparing the thinner membranes. ATR-IR, SEM, DSC, XRD and Contact angle measurements showed that the thinner membrane had relatively more crystalline domains and less hydrophobic. The nanostructure of the membranes was investigated using small angle neutron scattering (SANS) measurements. While the SANS data of the neat membrane was fitted well with Debye model of polymer chain, the data of coated membranes was fitted with a combination of Debye chain model and some aggregated structure of polymer chains. Among the coated PDMS films, the thinly coated film exhibited relatively a higher amount of the chain aggregates. This might imply that the thinner membrane had a relatively loose structure responsible for low selectivity but high flux in the separation of organic from water by pervaporation.

Pervaporation membrane technology is commercially successful in the dehydration of organic solvents, and the technology has potential for seawater desalination with high recovery because of its capability to treat highly saline water. But to make the technology advantageous over the other available membrane desalination technologies in terms of productivity flux without additional energy cost, the selective barrier layer is required to be extremely thin, defect-free, hydrophilic, and selective to water. In this work, we prepared an efficient membrane by reinforcing a highly water-permeable but continuous barrier layer of poly(vinyl alcohol)–silica (PVA-SiO2) hybrid material on porous polysulfone hollow fibers. The PVA-SiO2 in acidified and hydrated ethanol was aged at room temperature for a period to allow solvent evaporation to obtain the solution concentration desired for the reinforcement. The reinforced hollow fiber membrane with optimal PVA-SiO2 barrier layer thickness exhibited a performance with a flux of 20.6 L m−2 h−1 and 99.9% salt rejection from a saline feed of 2000 ppm NaCl at 333 K. The effects of PVA-SiO2, temperature, and feed salinity on the pervaporation performance of the membrane were also studied. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45718