Combined molecular dynamics simulations and experimental studies of the removal of cationic dyes on the eco-friendly adsorbent of activated carbon decorated montmorillonite Mt@AC.

In recent years, the combination of experimental and theoretical study to explain adsorbate/adsorbent interactions has attracted the attention of researchers. In this context, this work aims to study the adsorption of two cationic dyes, namely methylene blue (MB) and crystal violet (CV), on a green adsorbent Montmorillonite@activated carbon (Mt@AC) composite and to explain the adsorption behavior of each dye by the molecular dynamics (MD) simulation method. The eco-friendly nanocomposite Mt@AC is synthesized and characterized by the analysis methods: XRD, FTIR, BET, TGA/DTA, SEM-EDS, EDS-mapping and zeta potential. The experimental results of adsorption equilibrium show that the adsorption of the two dyes is well suited to the Langmuir adsorption model. The maximum adsorption capacity of the two dyes reaches 801.7 mg g-1 for methylene blue and 1110.8 mg g-1 for crystal violet. The experimental kinetics data fit well with a pseudo-first order kinetic model for the two dyes with coefficient of determination R 2 close to unity, non-linear chi-square χ 2 close to zero and lower Root Mean Square Error RMSE (R 2 → 1 and χ 2 → 0, RMSE lower). Molecular dynamic simulations are run to gain insights on the adsorption process. According to the RDF analysis and interaction energy calculations, the obtained results reveal a better affinity of the CV molecule with both the AC sheet and montmorillonite framework as compared with MB. This finding suggests that CV is adsorbed to a larger extent onto the nanocomposite material which is in good agreement with the adsorption isothermal experiment observations.

Synthesis, Antimicrobial Screening, Homology Modeling, and Molecular Docking Studies of a New Series of Schiff Base Derivatives as Prospective Fungal Inhibitor Candidates.

Twelve new Schiff base derivatives have been prepared by the condensation reaction of different amino substituted compounds (aniline, pyridin-2-amine, o-toluidine, 2-nitrobenzenamine, 4-aminophenol, and 3-aminopropanol) and substituted aldehydes such as nicotinaldehyde, o,m,p-nitrobenzaldehyde, and picolinaldehyde in ethanol using acetic acid as a catalyst. The envisaged structures of the all the synthesized ligands have been confirmed on the basis of their spectral analysis FT-IR, mass spectroscopy, 1H- and 13C-NMR. In vitro screening of their antibacterial and antifungal potential against Escherichia coli bacterium and Fusarium oxysporum f.sp albedinis (F.o.a) fungus, respectively, revealed that all the ligands showed no significant antibacterial activity, whereas most of them displayed good antifungal activity. Homology modeling and docking analysis were performed to explain the antifungal effect of the most and least active compound against two F.o.a fungus proteins.

Polysiloxane surface modified with bipyrazolic tripodal receptor for quantitative lead adsorption.

A new silica gel compound modified N,N-bis(3,5-dimethylpyrazol-1-ylmethyl) amine (SiN(2)Pz) was synthesized and characterized by elemental analysis, FT-IR, (13)C NMR of the solid state, nitrogen adsorption-desorption isotherm, BET surface area and BJH pore sizes. The new surface exhibits good chemical and thermal stability determined by thermogravimetry curves (TGA). The effect of pH and stirring time on the adsorption of Pb(II) were studied. The process of metal retention was followed by batch method and the optimum pH value for the quantitative adsorption of this toxic metal ion was 7. At this pH value, the new functionalized polysiloxane presents further improvements and shows higher affinity (123mg of Pb(2+)/g of silica) for the effective adsorption of Pb(II) compared to others described sorbents. The extracted amounts of Pb(II) were determined by atomic absorption measurements.

Ni(2)Si(P(2)O(7))(2).

Dinickel(II) silicon bis-[diphosphate(4-)], Ni(2)Si(P(2)O(7))(2), is isotypic with other phosphates of the formula M(2)Si(P(2)O(7))(2) (M = Co, Cd). All atoms except Si (site symmetry 2) are found in general positions. Ni(2)O(10) dimers formed from edge-sharing NiO(6) octa-hedra are linked by corners and O-P-O bridges, forming slabs parallel to (100), which are in turn inter-connected by O-Si-O contacts.