Synthesis of Polyhedral Magnetite Particles by Hydrothermal Process under High Pressure Condition

Abstract

Abstract. Magnetite particles were successfully generated by hydrothermal synthesis using water at subcritical conditions. By changing the temperature and pressure at subcritical water conditions, the thermodynamics and transport properties of the water can be controlled, thus enabling to manage the way of crystal formation, morphology, and particle size. In this work, the experiments were carried out at temperatures of 250 °C and 290 °C and a pressure of 10 MPa with a reactor made of SUS 316 in a batch system. The synthesized particles were dried in vacuum condition and characterized by SEM and XRD. The XRD patterns showed that magnetite particles were dominantly formed in the particle products with a black color. The results showed that the magnetite particles formed had diameters of around 60 nm in all experiments with irregular polyhedral shaped morphologies.

Recovery of Rutin from Labisia pumila Extract Using Solid Phase Extraction

“…[17][18][19] Nevertheless, recent advancement of extraction technology revealed that subcritical water or ionic liquid which act as a good hydrogen donor solvent, could effectively recover polyphenolic compounds from lignocellulosic biomass or plant material using hydrothermal treatment. [20][21][22] This study was focused on the investigation of rutin recovery from the crude extract of Labisia pumila var. Alata using different percentages of methanol as the eluent in C18 reversed phase SPE.…”