سال انتشار: ۱۳۸۸
محل انتشار: سومین کنفرانس نانوساختارها
تعداد صفحات: ۴
Iman Asghari – Chemical and Petroleum Engineering Department, School of Engineering, Shiraz University, Iran
Feridun Esmaeilzadeh – Corresponding Author: Chemical and Petroleum Engineering Department, School of Engineering, Shiraz University
The RESS-process enables the micronization of thermally labile materials and the formation of particles of less than 500nm in diameter. This process consists in solvating the product in the fluid and rapidly depressurizing this solution through an adequate nozzle, causing an extremely rapid nucleation of the product into a highly dispersed material. Known for long, this process is attractive due to the absence of organic solvent use. In this work, a RESS apparatus was set up and attapulgite submicronparticles were prepared successfully with the supercritical carbon dioxide. The attapulgite submicron particles can be used in drilling mud to improve the rheological properties including apparent viscosity, gel strength and yield point. The experiments were carried out to investigate the effect of extraction temperature (308–۳۲۸ K) and pressure (15-20MPa), spray distance (1-3 cm), nozzle diameter 450-850μm) on the size and morphology of the precipitated attapulgite particles. The characterization of the particles was determined by scanning electron microscopy (SEM). The experiments led to average particle size from 0.3 μm to 1.16 μm depending on operating conditions. However, the unprocessed particles sizes were in the range of 1 to 150 μm with an average
particle size of 10 μm.