Organically modified superhydrophobic CaCO3, CaCO3 : La3+ and CaCO3 : Tb3+ - Synthesis, characterization, absorption and photoluminescence behaviour

Synthesis of superhydrophobic CaCO3, CaCO3 : La3+ and CaCO3 : Tb3+ with complex morphologies under the influence of lauric acid in methanol medium was investigated. Laurie acid directed the transformation of thermodynamically stable broken sponge-like calcite CaCO3 to ellipsoid-like vaterite. Further, flower shaped amorphous CaCO3: La3+ and CaCO3 : Tb3+ resulted after doping the lanthanide elements to CaCO3. The morphology, composition and phases of the synthesized compounds was characterized with scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA). Water contact angle of 140 degrees indicates superhydrophobic behavior of lauric acid modified CaCO3. More importantly, these materials also displayed high absorption for oils, dyes and genotoxic solvents such as xylene and toluene. The room temperature photoluminescence (PL) measurements of CaCO3 : La3+ and CaCO3 : Tb3+ showed emission at 484 nm (blue) and 545 nin (green), respectively.