Preparation and characterization of a new surface-modified dichromate/triethylamine/silica/iron oxide magnetic hybrid nanomaterial

Ultrasonic-assisted environmentally-friendly synergetic synthesis of nitroaromatic compounds in core/shell nanoreactor: A green protocol

An efficient sonochemical protocol for the nitration of aromatic compounds was described in the presence of a catalytic amount of sulfuric acid-functionalized silica-based core/shell magnetic nanocomposite at room temperature in an eco-friendly and recyclable media, deep eutectic solvent (DES), based on choline chloride and urea. The particle size, morphology and elemental analysis of the core/shell nanocatalyst were carried out by TEM, SEM, EDX and XRD analyses. The nanocatalyst and DES were easily recovered from the reaction mixture quantitatively and reused several times.

Ultrasonic assisted synergetic green synthesis of polycyclic imidazo(thiazolo)pyrimidines by using Fe3O4@clay core-shell

A practical and green approach for the ultrasound-enhanced one-pot multicomponent synthesis of tetraheterocyclic imidazo(thiazolo)pyrimidines is described via the condensation of an 2-aminobenzimidazole or 2-aminobenzothiazole, dimedone and various aldehydes in the presence of Fe₃O₄@clay as an environmentally benign and reusable core/shell nanocomposite catalyst in relatively quantitative yields. This novel eco-friendly protocol includes several advantages such as avoiding hazardous solvents, reusability of the catalyst, easy work-up, short reaction times, room temperature and mild reaction conditions. Furthermore, ultrasonic irradiation and synergistic catalyst showed considerable superiority vs. traditional heating or stirring conditions.

Effect of calcium sulphate nanorods on mechanical properties of chitosan-hydroxyethyl methacrylate (HEMA) copolymer nanocomposites

Copolymers of chitosan and hydroxyetheyl methacrylate (HEMA) were successfully synthesized using ceric ammonium nitrate (CAN) as an initiator, via in situ polymerization method, followed by efficacious preparation of their nanocomposites by incorporating calcium sulphate nanorods via solution blending process. Hydrophilicity studies confirmed that grafting of HEMA in the backbone of the hydrophobic chitosan chains induced the improvement in hydrophilicity of chitosan, while mechanical properties of the nanocomposites were also enhanced significantly up to 20%, due to availability of enlarged surface area and higher aspect ratio of CaSO₄ nanorods. This was supported by FE-SEM and XRD analysis in terms of proper distribution of nanofiller through the copolymer matrix and corresponding rise in percentage crystallanity respectively. Results obtained from biodegradation studies proved the efficiency of CaSO₄ nanofillers to improve biomechanical strength of chitosan nanocomposites, without affecting their normal degradation profile that renders the products to be applicable for biomedical applications.