Immobilization of Exfoliated g-C3N4 for Photocatalytical Removal of Organic Pollutants from Water

Graphitic carbon nitride (g-C3N4) was synthesized from melamine and exfoliated by thermal treatment. Exfoliated g-C3N4 particles were immobilized by electrophoretic deposition from an ultrasonically treated ethanolic suspension aged up to 12 weeks. During the aging of the suspension, the separation of particles bigger than 10 μm was observed. The separated stable part of the suspension contained particles with a relatively uniform size distribution, enabling the fabrication of g-C3N4 films that were stable in a stirred aqueous solution. Such stable immobilized particles of exfoliated g-C3N4 are reported for the first time. The photocatalytic activity of such layers was evaluated using aqueous solutions of Acid Orange 7 (AO7) and 4-chlorophenol (4-CP). The photocatalytic decomposition of AO7 was faster in comparison with the decomposition of 4-CP. Mineralization was observed in the case of AO7, but not in the case of 4-CP, where the decrease of 4-CP concentration is due to 4-CP polymerization and the formation of a dimer, C12H8Cl2O2. This indicates that the use of g-C3N4 as a photocatalyst for oxidative degradation of organic compounds in water is limited.

Quality Control of Nanoemulsion: by PDCA Cycle and 7QC Tools

Despite several quality management tools, none or very few systematic operations are taken into account to assure the quality of the pharmaceutical products. Plan Do Check Act (PDCA) analysis is performed based on the problems encountered during the product development. In each step, some of the quality control tools are used for better maintenance of corrective and preventive actions. However, systematic use of these tools is still not made. Here we portray an example of nanoemulsion that will help justify the correct or systematic use of all the seven quality control tools in each section of PDCA cycle for better maintenance of Corrective and Preventive Actions (CAPA). The major limitations associated with the nanoemulsion i.e. non-uniform size distribution, lower encapsulation efficiency, lower magnitude of zeta potential, non-scalable and expensive synthesis procedures have taken into consideration for this portray. This review summarizes the productive use of 7 QC tools in PDCA cycle to ensure the optimum quality of nanoemulsion in an industry.

Multi-Antigenic Virus-like Particle of SARS CoV-2 produced in Saccharomyces cerevisiae as a vaccine candidate

Spike, Envelope and Membrane proteins from the SARS CoV-2 virus surface coat are important vaccine targets. We hereby report recombinant co-expression of the three proteins (Spike, Envelope and Membrane) in a engineered Saccharomyces cerevisiae platform (D-Crypt™) and their self-assembly as Virus-like particle (VLP). This design as a multi-antigenic VLP for SARS CoV-2 has the potential to be a scalable vaccine candidate. The VLP is confirmed by transmission electron microscopy (TEM) images of the SARS CoV-2, along with supportive HPLC, Dynamic Light Scattering (DLS) and allied analytical data. The images clearly outline the presence of a “Corona” like morphology, and uniform size distribution.

Synthesis of LiCoO2 particles with tunable sizes by a urea-based-homogeneous-precipitation method

This paper reports the synthesis of monodisperse spherical LiCoO2 particles in a wide range of average diameter using a urea-based-uniform-precipitation method. The average diameter of LiCoO2 particles can be varied from 2 to 14 lm with a uniform size distribution. The effective approach to maintain the size uniformity while changing the average size of LiCoO2 particles is to keep the ratio of [CO(NH2)2] to [CoSO4] at 8 even when the CoSO4 and urea concentrations are changed.

Synthesis of α-Fe2O3 nanoparticles and analyzing the effect of annealing temperature on its properties

Abstractα-Fe2O3 nanoparticles were synthesized via co-precipitation technique using ferric and ferrous salts and potassium hydroxide as precipitation agents. The samples were calcined at 350 °C, 550 °C and 750 °C for 3 hours. The obtained iron oxide was characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and dynamic light scattering (DLS). Crystallinity of the sample was studied by X-ray diffraction. SEM micrographs showed nonuniform size distribution of the particles forming agglomerates. TGA analysis revealed trace amount of weight loss and material stability for the samples calcined at temperatures above 500 °C. DLS results indicated that increasing of annealing temperature resulted in reduction of the particle size and more uniform size distribution. At the maximum annealing temperature of 750 °C, the mean diameter of the particles of 100 nm was observed.

PREPARATION OF MnO2 NANOPARTICLES BY A SOLUTION BASED APPROACH FOR ELECTROCHEMICAL CAPACITOR

We report here the development of MnO2 nanostructure electrode for electrochemical energy storage application. MnO2 nanoparticles synthesized by a facile and efficient precipitation approach have been investigated for supercapacitor application. The structures and morphologies of MnO2 nanoparticles were systematically studied using X-ray diffraction, Raman spectroscopy and transmission electron microscopy. The synthesized nanoparticles are observed spherical in shape with uniform size distribution. The electrochemical properties were studied in two-electrode configuration by cyclic voltammetry process. A specific capacitance of 52.8[Formula: see text]F/g has been obtained for MnO2 nanoparticles at scan rate of 100[Formula: see text]mV/s. The electrode is able to deliver a power density of 0.66[Formula: see text]kW/kg and energy density of 1.8[Formula: see text]Wh/kg.

Preparation of hexagonal micro-sized α-Al2O3 platelets from a milled Al(OH)3 precursor with NH4F and NH4Cl additives

Hexagonal α-Al2O3 platelets with about 1-μm diameter and 0.2-μm thickness are prepared by the calcination of a milled Al(OH)3 precursor with NH4F and NH4Cl additives. The influences of the ball milling treatment and the composite additive on the microstructure of α-Al2O3 micro-powders are studied. The results indicate that the particle size distribution of α-Al2O3 is highly dependent on the aggregate size of the Al(OH)3 precursor and that the morphology of α-Al2O3 can be significantly favored by the addition of 5 wt.% NH4F and 5 wt.% NH4Cl as additives. The growth velocity of the (0001) plane is significantly reduced because of the accelerated growth rate of other crystal faces caused by the increase of gas phase mass transfer. The combined effect of composite additives and precursor ball milling treatment leads to the generation of well-developed α-Al2O3 platelets with uniform size distribution.

Floc-Flotation of Malachite Fines with an Octyl Hydroxamate and Kerosene Mixture

Malachite fines are easily produced in the grinding process, leading to low malachite flotation recovery. Floc-flotation of malachite fines with an octyl hydroxamate and kerosene mixture was studied to improve the flotation recovery, using microflotation, microscopy image observations, contact angle measurements, and Extended Derjguin–Landau–Verwey–Overbeek (EDLVO) analysis. The results showed that the addition of octyl hydroxamate as an emulsifier of kerosene enhanced the aggregation of malachite fines and improved malachite flotation recovery. In addition, when kerosene droplets were smaller and of uniform size distribution, the spreading of kerosene droplets on the malachite surface improved. The enhanced spreading of kerosene droplets led to higher coverage of kerosene on the malachite surface, resulting in improved hydrophobic aggregation and flotation recovery.