Nucleation and growth of CuSO4·5H2O crystals on the liquid state stearic acid Langmuir–Blodgett film

Oriented crystallization of CuSO4·5H2O on a Langmuir–Blodgett (LB) film of stearic acid has been studied in the temperature ranges of 73–68 °C and 53–20 °C, respectively. This is the first time that the LB film at temperature above its melting point has been served as a template to induce nucleation and growth of crystals. The experimental results demonstrated that the LB film in the liquid state has the ability of directing the nucleation and growth of crystals. Moreover, X-ray diffraction patterns of the as-prepared crystals revealed that the orientation of the attached crystals on the LB film is affected by temperature greatly. The (1¯ 2 2) peak is very strong in crystals grown at higher temperature but absent at lower temperature. These results implied that structural changes in the LB film tuned by temperature determine the orientation of the attached crystals. The morphologies of the crystals showed that the orientation changes of the attached crystals influence the shapes and colors of CuSO4·5H2O crystals strongly.