Investigation on unidirectional growth of 1,3,5-Triphenylbenzene by Sankaranarayanan-Ramasamy method and its characterization of lifetime, thermal analysis, hardness and etching studies

An organic single crystal of 1,3,5-Triphenylbenzene (3PB) has been grown from solution by unidirectional Sankaranarayanan-Ramasamy (SR) method within a period of 72 days. The size of grown crystal was 40 mm length and 30 mm diameter. The solubility of 3PB material was determined in five various solvents with different temperatures and tetrahydrofuran (THF) was used as a suitable solvent for bulk crystallization. Metastable zone width of the solution was determined to optimize the growth period. Cell parameters of the grown 3PB crystal were confirmed by single crystal X-ray diffraction and it belongs to orthorhombic crystal system. The density of the grown 3PB crystal was found to be 1.240 g/cm³ by floatation method. Optical studies reflect the transmittance ability of crystal in entire visible and NIR region. The refractive index of the grown 3PB crystal was found to be 1.618. Fluorescence emission spectrum was recorded and emission peak observed at 360 nm. Prompt and delayed fluorescence lifetime of 3PB single crystal has been calculated at 12 ns and 30 ns respectively. Thermogravimetric/Differential thermal analysis (TG/DTA) measurement was performed to the grown crystal and it was stable up to 164 °C. Vicker's microhardness value (H_v) was calculated with varying load ranging from 25 to 100 g and the Mayer's index was found to be 4.5, showing that the grown crystal belongs to a soft material category. Growth pattern and the surface defect were examined by the optical microscope. The microstructure of the crystal surface shows the regular shapes of etch pits which are in triangular shape. - Highlights: • The solubility of 3PB material was determined by five different solvents. THF has high solubility compare to other solvents. • Unidirectional 〈100〉 plane of 3PB single crystal was grown by Sankaranarayanan-Ramasamy method. • Fluorescence lifetime was analyzed, prompt and delayed lifetime was obtained at 12 ns and 30 ns respectively. • The grown crystal was analyzed TG/DTA and it was stable up to 164 °C.