Microstructural Analysis of Copper Foil Etched and Annealed in ECR Plasma Reactor

Microstructural analysis of commercially available cold-rolled polycrystalline copper foil, etched and annealed in an in-house developed Electron Cyclotron Resonance (ECR) Plasma Enhanced Chemical Vapour Deposition (PE-CVD) reactor, have been carried out using x-ray diffraction (XRD) studies. The annealing experiments were carried out under a vacuum environment, keeping the working pressure of the reactor at 50×10-3 mbar, for three different time spans of 30 mins, 45 mins and 1 hour at 823 K (550 °C) and 923 K (650 °C) respectively in presence of hydrogen plasma. The XRD studies reveal the significance of annealing time at two different temperatures for the determination of physical and microstructural parameters such as the average grain size and micro-strain in copper lattice by Williamson-Hall (W-H) method.

One-pot access to 2-oxazolines via a Castro-Stephens coupling and intramolecular cyclization

Aim: Here, we have reported easy one-pot access to a series of oxazolines using a modified Castro-Stephens coupling protocol. Background: 2-oxazolines have been shown to have significant biological activity and wide-ranging applications in organic chemistry. These properties make oxazolines as heterocyclic compounds of immense importance. Objective: The objective of this study is to synthesize oxazoline derivatives via an economical and one-pot protocol. Method: 2-oxazoline has been synthesized through Cu-powder mediated Castro-Stephens coupling and intramolecular cyclization route. The mechanism involves a rearrangement in which one of the oxygen from the N-acylamino alcohol group is liberated as water and then transferred to alkyne functionality to form 2-oxazoline derivatives. The oxazolines were characterized by NMR, mass, and XRD studies. Result: The protocol is economically viable and uses readily available Cu-powder along with DMF for cross-coupling and cyclization steps.

Characterization of bilayer (FeB/Fe2B) on AISI H13 work tool steel

In this work, the borided layers were produced on AISI H13 steel via solid boriding with a powders mixture containing 90 wt.% B4C and 10 wt.% NaBF4 for treatment times of 2-6 h at 900, 950 and 1000 °C. The microscopic observations revealed a less pronounced toothed interface between the borided layer and the transition zone. The XRD studies indicated the presence of a dual phase boride layer (FeB/Fe2B) besides the chromium and vanadium borides as precipitates inside it. The boronizing kinetics of AISI H13 steel was investigated by using the classical parabolic growth law. The obtained value of boron activation energy in the entire boride layer (FeB + + Fe2B) was found to be 236.34 kJ mol-1. Furthermore, this value of energy has been compared to the literature data. Finally, the nanohardness and reduced modulus of elasticity were measured for FeB, Fe2B and transition zone.

Oxidoborates Templated by Cationic Nickel(II) Complexes and Self-Assembled from B(OH)3

Several oxidoborates, self-assembled from B(OH)3 and templated by cationic Ni(II) coordination compounds, were synthesized by crystallization from aqueous solution. These include the ionic compounds trans-[Ni(NH3)4(H2O)2][B4O5(OH)4].H2O (1), s-[Ni(dien)2][B5O6(OH)4]2 (dien = N-(2-aminoethyl)-1,2-ethanediamine (2), trans-[Ni(dmen)2(H2O)2] [B5O6(OH)4]2.2H2O (dmen = N,N-dimethyl-1,2-diaminoethane) (3), [Ni(HEen)2][B5O6(OH)4]2 (HEen = N-(2-hydroxyethyl)-1,2-diaminoethane) (4), [Ni(AEN)][B5O6(OH)4].H2O (AEN = 1-(3-azapropyl) -2,4-dimethyl-1,5,8-triazaocta-2,4-dienato(1-)) (5), trans-[Ni(dach)2(H2O)2][Ni(dach)2] [B7O9(OH)5]2.4H2O (dach = 1,2-diaminocyclohexane) (6), and the neutral species trans-[Ni(en)(H2O)2{B6O7(OH)6}].H2O (7) (en = 1,2-diaminoethane), and [Ni(dmen)(H2O){B6O7(OH)6}].5H2O (8). Compounds 1–8 were characterized by single-crystal XRD studies and by IR spectroscopy and 2, 4–7 were also characterized by thermal (TGA/DSC) methods and powder XDR studies. The solid-state structures of all compounds show extensive stabilizing H-bond interactions, important for their formation, and also display a range of gross structural features: 1 has an insular tetraborate(2-) anion, 2–5 have insular pentaborate(1-) anions, 6 has an insular heptaborate(2-) anion (‘O+’ isomer), whilst 7 and 8 have hexaborate(2-) anions directly coordinated to their Ni(II) centers, as bidentate or tridentate ligands, respectively. The Ni(II) centers are either octahedral (1–4, 7, 8) or square-planar (5), and compound 6 has both octahedral and square-planar metal geometries present within the structure as a double salt. Magnetic susceptibility measurements were undertaken on all compounds.

Evaluation of spray pyrolysed In:ZnO nanostructures for CO gas sensing at low concentration

Herein, we report the role of indium (In) on the carbon monoxide sensing of ZnO thin films using a low-cost spray pyrolysis technique. The decrease in crystalline size was observed from XRD studies and hexagonal wurtzite structure was confirmed. Photoluminescence and XPS studies proved the presence of various defects in the films. The gas-sensing properties of films toward carbon monoxide (CO) gas indicate that 15 wt% of In in ZnO thin films (IZO) exhibit high response (1.84) to a low concentration of the gas (1 ppm) at 300 °C compared to undoped ZnO (0.53). The observed high response of 15 wt% IZO can be mainly endorsed to the oxygen vacancy defects as observed from the photoluminescence and XPS analysis. Further, the high response is complemented by high surface area and smaller grain size (~ 13.1 nm) with well-defined grain boundaries as evident from SEM analysis as well as XRD studies.

Comparative Evaluation of Amorphous Polymers in Solubility and Bioavailability Enhancement of Famotidine Through Solid Dispersion

The present study aimed to enhance the dissolution rate, therefore bioavailability, of famotidine (FMT) using its solid dispersions (SDs) with polyvinyl pyrrolidone (PVP)-K 30, milk powder, and inulin, both in-vitro and in-vivo. The study was also aimed to compare the effect of different amorphous polymers in enhancing the dissolution rate of FMT. The SDs were prepared with a 1:4 weight ratio by a solvent evaporation technique. Evaluation of the properties of the SDs was performed using dissolution, Fourier-transform infrared (FTIR) spectroscopy, and X-ray diffraction (XRD) studies. The SDs of FMT exhibited an enhanced dissolution rate. The FTIR spectroscopic studies showed the stability of FMT and the absence of well-defined drug excipient interaction. The XRD studies indicated the amorphous state of FMT in SDs. The drug release rate of all SDs formulation was found to be greater than the pure drug. Within one hour of dissolution studies, 99.43%, 92.5%, and 58.93% drug release were obtained, respectively, for PVP K-30, milk powder, and inulin. The first two were showing significantly higher release. SDs were also studied for bioavailability studies in-vivo in rats, which confirms that the SDs prepared by PVP K-30 and milk powder significantly enhancing the bioavailability of FMT. The maximum concentration of 15.05±2.45 μg/ml was achieved in 2 hours, and the area under the curve was found to be 33.78±7.3 μg. hour/ml. Therefore, the study results conclude that SDs of the FMT prepared by PVP K-30 successfully increases the dissolution and in-vivo bioavailability. Keywords – Solid dispersion, Second generation solid dispersions, Famotidine, In-vivo bioavailability, amorphous polymers, dissolution enhancement, solubility enhancement.

Development of Perphenazine-Loaded Solid Lipid Nanoparticles: Statistical Optimization and Cytotoxicity Studies

Objective. Perphenazine (PPZ), as a typical antipsychotic medical substance, has the same effectiveness compared to atypical antipsychotic medications for the treatment of schizophrenia. Despite the lipophilic essence, PPZ encounters limited bioavailability caused by the first-pass metabolism following oral administration. In the present study, PPZ-containing solid lipid nanoparticles (PPZ-SLNs) were prepared and optimized based on different factors, including lipid and surfactant amount, to develop appropriate and safe novel oral dosage forms of PPZ. Methods. The solvent emulsification-evaporation method was utilized to form SLNs by using soybean lecithin, glycerol monostearate (GMS), and Tween 80. Statistical optimization was done by the Box-Behnken design method to achieve formulation with optimized particle size, entrapment efficiency, and zeta potential. Also, transmission electron microscopy, in vitro release behavior, differential scanning calorimetry (DSC), and powder X-ray diffractometry (P-XRD) studies and cytotoxicity studies were assessed. Results. Optimization exhibited the significant effect of various excipients on SLN characteristics. Our finding indicated that the mean particle size, zeta potential, and entrapment efficiency of optimized PPZ-SLN were, respectively, 104 ± 3.92 nm , − 28 ± 2.28 mV , and 83 % ± 1.29 . Drug release of PPZ-SLN was observed to be greater than 90% for 48 h that emphasized a sustained-release pattern. The DSC and P-XRD studies revealed the amorphous state of PPZ-SLN. FTIR spectra showed no incompatibility between the drug and the lipid. Performing cytotoxicity studies indicated no significant cytotoxicity on HT-29 cell culture. Conclusion. Our study suggests that PPZ-SLNs can make a promising vehicle for a suitable therapy of schizophrenia for the oral drug delivery system.