Engineering Chemistry Vol. 3

Abstract: In synthetic organic chemistry, use of catalyst to accelerate the rate of reaction leading to high yield product is a common approach practiced by chemists. Numerous homogenous and heterogenous catalyst are widely used in chemical reactions, particularly metal based catalyst are widely used. The properties of metals and their oxides are fine-tuned by size reduction method bringing down to nano scale. Further hybrid materials are used for more specific applications among which metal organic frame works are listed in more number in last ten years. Herein this review focuses on use of metal organic framework in particular Copper metal based organic framework (Cu-MOF). Cu-MOF synthesis, properties and their applications are discussed. A detailed discussion on the use of Cu-MOF as a heterogeneous catalyst in various organic reactions.

Abstract: Biomaterial products for bone repair are needed to support accelerated tissue healing. This research aimed to synthesize and characterize carbonate hydroxyapatite (CHA) from Pinctada maxima (P. maxima) using the precipitation method with a short aging time, 15 min. CHA was dried with oven-dry at 100°C for 12 h (CHA A) and a furnace-dry at 1000°C for 2 h (CHA B). Short aging time succeeded in producing CHA B-type with lattice parameters and of CHA A is 9.382 and 6.964 , while 9.451 and 6.962 for CHA B. The high temperature treatment made the diffraction peak indicating CHA more detected and crystallinity increased to 97.87%. The appearance of C–O bond and diffraction peaks of CHA verified substituted carbonates hydroxyapatite.

Abstract: Herein, we report synthesis of two new copper metal organic frameworks. The organic linkers were terephthalic acid with 6-Dihydroimidazo[2,1-b]thiazole-2-carbaldehyde and terephthalic acid with 3-benzothiazol-2-yl-malonaldehyde used in the copper nano metal organic framework (MOF). Both the Cu-MOF’s were characterized by XRD, UV-vis spectroscopy and FTIR. XRD crystallographic studies revealed the presence of copper metal at 2θ at 18.4°. Tauc plots were simulated to calculate the band gap of both Cu-MOF’s and result indicated the band gap energy of Cu-MOF 1 at 3.31 eV and for Cu-MOF 2 was at 3.57 eV. The UV-Visible absorption studies indicated two bands for Cu-MOF 1 and Cu-MOF 2 at 326 nm. However, the second band in Cu MOF 1 at 509 nm was slightly shifted to higher wavelength at 516 nm in Cu-MOF 2 due to the extension of π-π* transition. The photoluminescent properties of both Cu-MOF’s indicated a strong band at 505 nm. Thus, the optical properties of both the Cu-MOF’s infers that these can be a promising semiconductor material for various electronic applications.

Abstract: A phycocolloidal hydrogel patch is studied as a potential material for the transdermal delivery device for vitamin B12. The vitamin release kinetics from an agar/κ-carrageenan hydrogel blend as a function of mass ratio and vitamin loading. Concentration measurements were done using a colorimetric method, and the experimental data were fitted into the Korsmeyer-Peppas model, Peppas-Sahlin model, and Berens-Hopfenberg model. From the curve fitting, parameters such as first-order polymer relaxation constant and diffusivity constant were obtained. The results showed that for the Korsmeyer-Peppas model and the Peppas-Sahlin model, the release mechanism followed Fickian diffusion predominantly. On the other hand, the Berens-Hopfenberg model fit shows that the release mechanism predominantly follows non-Fickian diffusion and may need to be modified.

Abstract: Calcium carbonate (CaCO₃) has been taken from sea urchin (Diadema setosum) shell and calcinated at several temperatures to obtain calcium oxide (CaO). X-Ray Fluorescence Spectroscopy (XRF) revealed that the powder from this shell had a high Ca level, which increased at a higher temperature. Fourier Transform Infrared Spectroscopy (FTIR) spectra agreed to an increase in Ca level that showed the presence of CaO at 900 °C and 1100 °C; otherwise, CaCO₃ disappeared. Using Scanning Electron Microscopy (SEM), the powder morphology was more homogeneous at 900 °C and 1100 °C than at lower temperatures. This morphology was encouraged by decreasing particle size, indicating compound decomposition in the powder and Ca leaved. This decomposition was confirmed by an Energy Dispersive X-ray Spectroscopy (EDS) analysis that showed increased Ca content with higher mass and atomic level at a higher temperature.

Abstract: The Covid-19 virus, which started in 2019 and has taken the whole world under its influence has negatively affected normal living conditions and accordingly, increased awareness to prevent anti-microbial diseases transmitted by contact. In almost all sectors, precautions have been taken considering the transmission of diseases by contact. As a requirement of our age, they enrich their product ranges by developing new methods and making innovations for companies whose sector is dominated by industrial locks, hinges, and handles, both in terms of hygienic product design and in terms of the raw material of the part used in production. For example, it is preferable that the products in the air-conditioning sector have anti-microbial properties. The evaluation of the effect of microorganisms on plastic raw materials and the determination of whether this effect causes future deterioration in plastic materials has been examined in our article. Currently, the products supplied to the sectors are products produced from raw materials such as PA6 GFR30, ABS, PA6, which are available on the market. It is aimed to provide anti-microbial properties of products in accordance with the needs of the sector and the era by changing the raw material used or adding additives in certain proportions to the raw material.