A Physical Chemistry Study of Black Powder Materials by Solution Combustion Synthesis Method

A study on the synthesis of black powder (La2NiO4) material using the solution combustion synthesis method at a variation of synthesis temperature of 60, 70, and 80°C was carried out. It produces a mass of black powder of 2 grams by four times of synthesis process. Then, material characterization was performed on the black powder samples obtained by using X-ray Diffraction (XRD) to determine the phases formed, Scanning Electron Microscopy - Energy Dispersive X-ray Spectroscopy (SEM-EDS) to determine the morphology and analyze the composition elemental on the microscale and Fourier Transform Infra-Red (FTIR) to determine chemical bonds. From the whole black powder sample, XRD analysis showed the phases of Dilantanum Nickel Tetraoxide (La2NiO4), Nickel Oxide (NiO), Lanthanum Oxide (La2O3), and Lanthanum Oxide Ht x-form (La2O3 Ht (x-form)). In addition, it was seen from the visible compositions of the phases that the NiO phase looks more dominant and the variation of the synthesis temperature shows that the La2O3 phase was increasing. This was supported by the EDS analysis, which showed that the EDS spectrum contains elements La, Ni, and O where the element O indicates that oxidation occurs in the elements Ni and La. On the other hand, the SEM analysis results confirm that the black powder sample contains the elements La and Ni, based on the high and low electron images contained in the morphology of the black powder sample. In addition, it was also known that the particles in the black powder sample were micron size and had porous morphology. This occurs due to rapid thermal decomposition events and excessive gas development. In addition, FTIR analysis showed that the O-H bond had been reduced and there are still C-O and C-H bonds indicating the presence of organic elements possessed by glycine.

Synthesis of BiF3 and BiF3-Added Plaster of Paris Composites for Photocatalytic Applications

A BiF3 powder sample was prepared from the purchased Bi2O3 powder via the precipitation route. The photocatalytic performance of the prepared BiF3 powder was compared with the Bi2O3 powder and recognized as superior. The prepared BiF3 powder sample was added in a plaster of Paris (POP) matrix in the proportion of 0%, 1%, 5%, and 10% by wt% to form POP–BiF3(0%), POP–BiF3(1%), POP–BiF3(5%), and POP–BiF3(10%) composite pellets, respectively, and activated the photocatalytic property under the UV–light irradiation,in the POP. In this work, Resazurin (Rz) ink was utilized as an indicator to examine the photocatalytic activity and self-cleaning performance of POP–BiF3(0%), POP–BiF3(1%), POP–BiF3(5%), and POP–BiF3(10%) composite pellets. In addition to the digital photographic method, the UV–visible absorption technique was adopted to quantify the rate of the de-colorization of the Rz ink, which is a direct measure of comparative photocatalytic performance of samples.

Karakteristik Fisik Serbuk Ekstrak Buncis (Pheseolus vulgaris L) dengan Variasi Lama Penyimpanan

Research has been carried out on the analysis of physic properties of green bean extract powder (Phaseolus vulgaris L). This study aims to determine the physical characteristics of the bean extract powder that has been stored in a predetermined time variation. The physic properties tested included water content, solubility and organoleptic tests. The results of the sample water content test with storage variations of less than 1, 1, 2 and 3 months respectively were 5.55%, 2.86%, 3.83% and 3.54% and the solubility was 42.67%, 33, 84%, 44.51% and 34.33% for Artificial Gastrid Fluid (AGF) solvents and 31.79%, 35.08%, 43.24 and 34.52% for Water solvents. The results of the organoleptic test showed that the color of the bean extract powder sample with a storage time of ± 2 months was the most preferred by the panelists, Fresh samples had the highest average scores for taste and aroma, of the panelist samples preferred the samples that had been stored for ± 3 months

Determination of the crystallite size and crystal structure of magnesium powder by x-ray diffraction

Magnesium powder has become an important material in the development of science and technology such as alloy and hydrogen storage. In this work, the chemical composition, crystallite size, and crystal structure of the magnesium powder sample have been studied by using x-ray fluorescent and x-ray diffraction. The x-ray diffraction data of the magnesium powder sample was analyzed by using the Rietveld method to obtain the crystal structure. Our results show that the purity of our magnesium powder sample is 93.1%. Our sample has good crystallinity with the average crystallite size of 31 nm. The crystal structure is found to be a hexagonal closed-packed structure with the lattice constants of 3.2100 Å (a and b-axis) and 5.2107 Å (c-axis). Our result revealed that the lattice constant in the c-axis of magnesium powder is influenced by impurity. This finding suggests that the impurity can affect the crystal structure of a material in general.

Antioxidant and Anti-inflammatory activities of the flower extracts of Argemone mexicana L.

To assess the antioxidant and anti-inflammatory activities of the powder sample derived from the ethyl acetate fraction of the floral Argemone mexicana L. For antioxidant efficiency, the floral extract was evaluated using 1, 1–diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging assay and the FRC (Ferric Reduction Capacity) assay. In vitro anti-inflammatory activity was assessed using human peripheral blood mononuclear cells (PBMC) induced by lipopolysaccharide (LPS) and the production method of nitric oxide (NO). The powder sample extracted from ethyl acetate fraction of the floral of Argemone Mexicana L showed good antioxidant activity with the comparative standard sample in scavenging DPPH radicals and in FRC assay. In the cell viability (PBMC influenced by LPS) method and the Nitric oxide (NO) assay, this sample showed even able anti-inflammative activities. Such results indicate a significant antioxidant and anti-inflammatory activity in the powder sample obtained from ethyl acetate fraction in the flower of Argemone mexicana L.