Nanosilica periodic acid (nano-SPIA) is found to be a new, powerful, and reusable heterogeneous catalyst for the rapid synthesis of 2-naphtholazo dyes via diazotization of aromatic amines and followsazo coupling with 2-naphthol under solvent-free conditions at room temperature by grinding. Eco-friendly, heterogeneous reaction conditions, high stability of diazonium salt, simple experimental pro...

A method for the polymerization modification of nanoscale fumed silica by crosslinking a lignin layer adsorbed on nanosilica surface under gas dispersion medium is described. mixture phenol and formaldehyde in presence HCl proved to be most effective agent. It has been suggested that molecules occurs mechanism similar production phenol-formaldehyde resins.