No abstract

The aim of this research was to study the adsorption progress of Benalaxyl from natural and activated clays of Brari and Dardha, so that these clays can be used for practical purposes fof soil and water purification. The natural clay materials originated from the regions of Brari (Tirana) 41 ° 21′14.49 ″ N; 19 ° 50′17.74.E and Dardha (Korça) 40 ° 31′16.59 ″ N; 20 ° 49′33.69 ″ E. SEM images of Dardha clay show a finer dispersity than Brari clay. Powder XRD analysis of reveal remarkable differences in their composition. Dardha clay shows a higher content of SiO2, Al2O3 and CaO than Brari clay. The adsorption dependence of Benalaxyl on Brari and Dardha clays was studied at t = 20ºC and contact time: 12h; 24h; 48h; 72h, considering Benalaxyl concentrations of 0.1 g/l and 0.3 g/l. Based on the time of contact clay-aqueous solution of benalaxyl, 48h to 72h showed significant adsorption of Benalaxyl onto clays, therefore this time interval is presented and oriented further studies in this time interval. Time intervals longer than 72h showed no interest because the rate of hydrolysis increased. Most of Benalaxyl is desorbed from both clays within the first 2 hours. Dardha clay desorbs better than Brari clay.

It is imperative to study the long term corrosion problems of nickel alloys in acidic medium due to breakdown of their passitive oxide. Focus of this work is to enhance the knowledge of adsorption of organic additives (OPD & PPD) onto the Ni-W alloy surface. Deducing the scenario of competitive adsorption of salen-type symmetrical Schiff bases (OPD, and PPD) as additive molecules on Ni-W alloy surface at molecular level was studied by Density Functional Theory (DFT), Monte Carlo simulation (MC), Molecular Dynamics simulation (MD) and Radial Distribution Function (RDF) analysis. Obtained intrinsic molecular parmaters from DFT shows a strong conformity to the corrosion effeciencies of experimental results. Higher polarization value of 650.707 a.u (PPD) explicates its electron donating ability onto the alloy surface. Higher binding energy (Ebinding=1132.241 kJ/mol) and spatial orientation of PPD molecule portrays the closest contacts between active atoms and alloy surface. Significant findings from DFT global descriptors, MC, MD and RDF analysis ratifies the corrosion effeciencies (PPD>OPD) of experimental outcomes, which correlates positively with the larger isomeric spacer. Overall, the present study, reports offers the corrosion inhibition resistance impact of OPD & PPD additives, revealing the fact of PPD as effective one and OPD as moderate ones for Ni-W alloys.

Phenolic acid grafted chitosan has widespread drug delivery applications, as bio adsorbent, packing material, etc., due to its excellent antioxidant and antimicrobial properties. However, for the first time, the anticorrosive efficiency of ferulic acid modified chitosan has been investigated. The prepared chitosan derivative is characterized using spectral methods, thermal analytical methods, surface charge, and particle size analysis. The evaluation of corrosion inhibition potential showed a highest value of 95.96 % at 303 K. Thermodynamic activation and adsorption parameters endorse a mixed adsorption process involving an initial electrostatic interaction followed by chemisorption. Electrochemical studies gave results which agreed well with the gravimetric studies. Surface morphological studies were performed using contact angle measurements, FESEM, EDAX, AFM, optical profilometric and UV spectral techniques. Computational studies involving quantum chemical calculations, Monte Carlo and molecular dynamic simulation studies, and radial distribution function analysis are further done to validate the experimental results.

Imines represent an important class of molecules that are widely used (as intermediates) in the synthesis of a number of Nheterocyclic compounds [1]. These molecules are a product of reversible condensation of an amine and an aldehyde formed through the dynamic bond (a thermodynamically favored product). General procedure for the synthesis of new carbazole substituted imines: 14.26 mmol of 3-amino-9-ethylcarbazole were dissolved in ethanol (30 ml) and added to 14.26 mmol Na2CO3 and 14.26 mmol aldehydes derivates. The reaction mixture was then refluxed for 24 hours at 90°C. The solution was extracted with AcOEt with an aqueous phase. The organic phase was washed three times with water, dried with anhydrous magnesium sulphate, and evaporated under reduced pressure. The X-ray diffraction (XRD) data for the imines samples were collected using a Bruker-Nonius KappaCCD single-crystal diffractometer (Mo Ka radiation, l = 0.71073 Å), installed at IC-CNR, Bari, Italy The structures were solved by Direct Methods implemented in SIR2014 [2] and refined by SHELXL2014 [3] using a fullmatrix least-squares method based on F2. The non-hydrogen atoms were refined anisotropically. All the structures were characterized by non-negligible hydrogen bonds. In Figure the molecular structure of one of the imine compounds [N-(5-nitrobenzylidene)-9-ethyl-9H-carbazol-3-amine (C21H17N3O2)] is shown. The steps of imines synthesis and the main crystallographic results of the single crystal XRD study of the imines compounds will be described.[1] Eicher, T