Green novel multicomponent synthesis and biological evaluation of new oxazolopyrazoloazepines and reduction of nitrophenols in the presence of Ag/Fe3O4/ZnO@MWCNT MNCs.

In this research, new derivatives of oxazolopyrazoloazepines were synthesized in high yields using multicomponent reaction of anilines, oxalylchloride, alkyl bromides, activated acetylenic compounds, hydrazine and ethyl bromopyruvate in the presence of Ag/Fe3O4/ZnO@MWCNT magnetic nanocomposite (MNCs) as a high-performance magnetic catalyst in ionic liquid at room temperature. The Ag/Fe3O4/ZnO@MWCNT magnetic nanocomposites (MNCs) were synthesized using 1-octhyl-3-methyl imidazolium bromide ([OMIM]Br) as a stabilizer and soft template. Also, the catalytic activity of the Ag/Fe3O4/ZnO@MWCNT MNCs was evaluated in reduction of organic pollutants such as 4-nitrophenol (4-NP) in water at mild conditions. The results indicated that the biosynthesized nanocomposites (NCs) have high catalytic activity for organic pollutants within few seconds. Because of having benzazepine nucleus in the synthesized compounds, we investigate antioxidant property of some synthesized oxazolopyrazoloazepines by diphenyl-picrylhydrazine radical trapping and power of ferric reduction experiment. Short time of reaction, high yields of product, easy separation of catalyst and products are some advantages of this procedure.

Efficient removal of lead and arsenic using macromolecule-carbonized rice husks.

The adsorption process using inexpensive adsorbents is one of the methods to remove contaminants from aqueous solutions. Biomass porous carbon based materials are among the most widely used adsorbents in this field. Rice husk is a bio-based adsorbent material for pollutant removal. In this study, the porous carbon material obtained from the rice husk was used for the adsorptive removal of lead (Pb) and arsenic (As) from aqueous solutions. Silica was removed from rice husk structure through the one-step reaction using PTFE. The morphological and crystallographic characteristics of the adsorbent surface were determined by scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. The removal efficiency was investigated under different conditions of pH (3-9), contact time (3-90min), adsorbent amount (0.5-6 g/l) and initially adsorbed concentration (10-100 µg/l) by changing the parameters in the adsorption reactions. The Response Surface Method (RSM), a Box-Behnken design (BBD), was used to optimize adsorption of Lead and Arsenic by Rice husk. The removal efficiency was finally calculated using analysis of variance. According to the adsorption analysis results, the removal efficiency of Pb and As in aqueous solutions increased (up to 97%, 85% for Lead and Arsenic) under optimum conditions.

Efficient dye removal from wastewater by functionalized macromolecule chitosan-SBA-15 nanofibers for biological approaches.

Today, one of the major concerns of environmental health is the purification of colored wastewater due to its high contamination. The present study focused on the synthesis and comprehensive characterization of environmentally friendly electrospinning membranes based on Chitosan cross linked with SBA-15 as a novel adsorbent for dye removal. Unlike most micro structured adsorbents, CTS-SBA-15 nanofibers with their special properties such as density, porosity, high surface-to-volume ratio, small and layered structures, etc. have a very high adsorption capacity to remove macromolecular pollution and microorganisms. Adsorbents were synthesized and functionalized, then produced by electrospinning instrument in the form of nanofibers sheets. In this study, FT-IR, XRD, FE-SEM, TEM, and tensile tests were employed to characterize the functional groups, surface morphology and pore diameter distribution of nanofibers. The influence of different analytical parameters was investigated to obtain the optimum conditions for the adsorption process. The optimum conditions for adsorption process obtained as following: type of adsorbent: CTS-SBA-15-NH2, pH: 2, adsorbent dosage: 0.05 g, initial concentration: 60 and 40 mg/l and contact time: 40 min, which followed from the Langmuir and Freundlich isotherms. So, it was found that CTS-SBA-15 can act as inexpensive and efficient adsorbent for the dye removal from the contaminated water.

Synthesis and characterization of magnetized-PEGylated dendrimer anchored to thermosensitive polymer for letrozole drug delivery.

Letrozole as a target loaded drug on siliceous magnetized Fe3O4 nanoparticles grafted with high-branched dendrimers. Grafted polymer coating contained N-vinyl caprolactam as a stimulus-responsive polymer which functionalized with five generations of dendrimers containing oxime functional group. The precursors underwent PEGylating polymerization to form PEGylated dendrimer coating on the particle surface as the final carrier. The final product has the average size of ˜79 nm. The final product characterized by FT-IR, TGA, VSM, SEM-EDAX to investigate carrier features further. Some characteristic parameters in adsorption process like pH, time, the temperature investigated for letrozole using the final carrier. The physical and chemical properties of the final polymerized generations were also studied. Letrozole releasing process examined in the simulated intestinal fluid (pH = 7.4) revealed 95% of letrozole released during 25 h which also considered by Korsmeyer-Peppas equation to verify Fickian diffusion mechanism.