Physical properties of halloysite nanotubes-polyvinyl alcohol nanocomposites using malonic acid crosslinked

Halloysite nanotubes (HNTs) based nanocomposites were produced by blending individualized HNTs dispersion with polyvinyl alcohol (PVA). Several sequential separation techniques were applied to obtain stable individualized HNTs dispersion. The preparation of PVA-crosslinked-HNTs nanocomposite has not been developed and, to the best of our knowledge, there was no published report indicating the use of neither dispersion nor crosslinker agent. In addition, PVA was crosslinked using the crosslinker malonic acid (MA) and sulfuric acid as a catalyst. This individualization increases the mechanical and thermal properties of HNTs-PVA nanocomposites. As a side result, crosslinking was employed to make PVA water-insoluble and hence to become more useful in biomedical applications. Examination of the nanocomposites indicated that HNTs were uniformly dispersed in both PVA as well as crosslinked PVA. These nanocomposites could be composted easily and hence would be good candidates to\replace some of today’s traditional non-biodegradable plastics that end up in landfills

Preparation and Spectral Study of New Complexes of Some Metal Ions with 3,5-Dimethyl-1H-Pyrazol-1-yl Phenyl Methanone

Many complexes of 3,5-dimethyl-1H-pyrazol-1-yl phenyl methanone with Cr(III), Co(II), Ni(II), Cu(II) and Cd(II) were synthesized and characterized by FT-IR, UV/visible spectra, elemental analysis, room temperature magnetic susceptibility and molar conductivity. Cd(II) complex was expected to have tetrahedral structure while all the other complexes were expected to have an octahedral structure

Antifungal and Antioxidant Activities of Pyrrolidone Thiosemicarbazone Complexes

Metal complexes of (Z)-2-(pyrrolidin-2-ylidene)hydrazinecarbothioamide (L) with Cu(II), Co(II), and Ni(II) chlorides were tested against selected types of fungi and were found to have significant antifungal activities. The free-radical-scavenging ability of the metal complexes was determined by their interaction with the stable free radical 2,2′′-diphenyl-1-picrylhydrazyl, and all the compounds showed encouraging antioxidant activities. DFT calculations of the Cu complex were performed using molecular structures with optimized geometries. Molecular orbital calculations provide a detailed description of the orbitals, including spatial characteristics, nodal patterns, and the contributions of individual atoms

Inhibition Effect of Hydrazine-Derived Coumarin on a Mild Steel Surface in Hydrochloric acid

In this work, economy novel hydrazine-derived coumarin 4-(6-methylcoumarin)acetohydrazide (MCA) were synthesized, characterized, and tested as an inhibitor for the corrosion of a surface of mild steel in an acidic environment through weight loss and Scanning electron microscopy (SEM) techniques. Results showed that the synthesized inhibitor can inhibit the corrosion of mild steel surface in a 1 M hydrochloric acid environment. The corrosion inhibition efficiency of MCA increases with increasing MCA concentration and decreases with increasing temperature. SEM analysis showed the formation of a film as a protective layer from MCA molecules on the surface of mild steel. Adsorption of the MCA molecules on the mild steel surface in the presence of hydrochloric acid environment was obeyed Langmuir isotherm. The density functional theory (DFT) calculations were used to study the relationship between molecular structure and inhibition efficiency and they found in good agreement

Experimental Study of 2-Amino-5-(4- nitrophenyl)-1, 3, 4-Thiadiazole for MS in HCl Solution

The present work aims to study the inhibition performance of new organic inhibitor namely ANTD “2-amino-5-(4-nitrophenyl)-1,3,4- thiadiazole” on corrosion of mild steel (MS) in HCl environment at the concentration of 1.0 M through using weight loss techniques. Weight lost measurements demonstrates the presence of a film on MS surface in existence of organic substance. The inhibition performance of ANTD at various concentrations for mild steel increases with increasing concentration and with an increased in the immersion time and decreased with raising temperatures degrees. The optimal inhibition efficiency of (ANTD), 82%, was achieved for mild steel when immersed with the highest utilized concentration for 6 hrs

The Antioxidant Activity of New Coumarin Derivatives

The antioxidant activity of two synthesized coumarins namely, N-(4,7-dioxo-2- phenyl-1,3-oxazepin-3(2H,4H,7H)-yl)-2-(2-oxo-2H-chromen-4-yloxy)acetamide 5 and N-(4-oxo-2-phenylthiazolidin-3-yl)-2-(2-oxo-2H-chromen-4-yloxy)acetamide 6 were studied with the DPPH, hydrogen peroxide and nitric oxide radical methods and compared with the known antioxidant ascorbic acid. Compounds 5 and 6 were synthesized in a good yield from the addition reaction of maleic anhydride or mercaptoacetic acid to compound 4, namely N′-benzylidene-2-(2-oxo-2H-chromen-4-yloxy)acetohydrazide. Compound 4 was synthesized by the condensation of compound 3, namely 2-(2-oxo-2H-chromen-4-yloxy) acetohydrazide, with benzaldehyde. Compound 3, however, was synthesized from the addition of hydrazine to compound 2, namely ethyl 2-(2-oxo-2H-chromen-4-yloxy)acetate, which was synthesized from the reaction of ethyl bromoacetate with 4-hydroxycoumarin 1. Structures for the synthesized coumarins 2–6 are proposed on the basis of spectroscopic evidence

Novel quinazolinone derivatives: Synthesis and Antimicrobial Activity

Abstract: This work involves to synthesis novel organic compounds and studies their pharmacological. Approach: The title compound quinazolinone derivatives were prepared by reacting 3 amino of 3-amino-2-methylquinazolin-4(3H)-one (first) with various aldehydes and ketones, and second coupling through diazonium salts with resorcinol or with ethylacetoacetate then cyclized with hydrazine. The starting material 3-amino-2-methylquinazolin-4(3H)-one was synthesized by reacting hydrazine with 2-methyl-4H-benzo[d

Analysis and Parametric Study of Reinforced Concrete Two-Way Ribbed Slabs by using ANSYS

This paper presents the results of finite element analysis for two experimental works (taken from other research works). The aim of this study is to use finite element method (FEM) by using ANSYS (v.15) software to analyse the specimens of experimental work to verify the validity of FEM by comparison with experimental results. In addition, some parametric studies on these works are done to cover the effect of some important variables on the ultimate load capacity and deflection which were not covered in the experimental work. The results of ANSYS software for chosen examples shows good agreement with the experimental results. Load-deflection curves for ANSYS models are higher than the experimental curves. The average value of correlation factor is (98.85%)for first example and (73.7%) for the second one. Results have shown that the percentage of increase in stiffness increases with increasing of slab thickness, but this increase is governed by the spacing between ribs

Evaluation of Green Corrosion Inhibition by Extracts of Citrus aurantium Leaves Against Carbon Steel in 1 M HCl Medium Complemented with Quantum Chemical Assessment

Employing plants as corrosion inhibitors is a physical direction to detect less expensive green friendly inhibitors. Researchers found that the Citrus aurantium leaves extracts are mixtures containing vitamins, minerals, phenolic compounds and terpenoids. The flavonoids contained in C. aurantium can be divided into four groups, including flavones, flavanones, flavonols, and anthocyanins. These compounds indicate the extracts of Citrus aurantium leaves are appropriate to be applied as green corrosion inhibitors. Extracts of Citrus aurantium leaves have been researched by utilizing EIS, gravimetric and SEM techniques as novel eco-friendly corrosion inhibitors for carbon steel in corrosive environments. Inhibition effectiveness of tested extract depends on different concentrations of extract, starting from 0 to 40% v/v. Inhibition effectiveness of 81.2% is reached at the concentration of 20% v/v of the extract in 1 M corrosive solution for three hours at 25℃. Temperature effects and activation parameters have been investigated. A theoretical investigation of Citrus aurantium leaves extract isomers as corrosion inhibitors have been done using DFT/ B3LYP density functional theory. The results shows that, in general, Citrus aurantium leaves have good inhibiting activities at relatively low concentrations. Phenolic groups of Citrus aurantium leaves were picked for examination as substituents of the four inhibitors. Hydroxyl groups of the studied extract compounds result in an increase in inhibition effectiveness, while methylation of the hydroxyl group leads to decrease in inhibitive effectiveness. Citrus aurantium leaves extracted isomers symbolize a considerable enhancement in the inhibition performance