In situ self-assembled preparation of the hybrid nanopigment from raw sepiolite with excellent stability and optical performance

A novel nanopigment with excellent stability and optical performance was prepared by installing rhodamine B (Rhb) onto the hexagonally ordered mesoporous silica (Al-MCM-41) using in situ self-assembled method (Rhb@SSA). The Rhb molecules were assembled and enriched in special microenvironment between the template and silica walls by the reconstructed process. Raw sepiolite (Sep) was used as effective and environmentally-friendly source of silicon and aluminum in the synthesis of Al-MCM-41. The structure and performance of nanopigments obtained by different supports and preparation methods were characterized by XRD, BET, SEM-EDX, TEM, FT-IR, TGA, UV-Vis, the excitation spectrum and emission spectrum and colorimetric tests. The cetyl-trimethyl ammonium bromide (CTAB) with dual functions of templating-photosensitizer plays an important role in formation of the Al-MCM-41 and the colour performance enhancement. 0.5% Rhb@SSA prepared via impregnation method shows better performance than those of 0.5% Rhb/Sep and 0.5% Rhb/Al-MCM-41.