A RESS (rapid expansion of supercritical solution) process for the preparation of ultra-fine drug particles with no organic solvent has been developed with supercritical CO 2 . Three drug substances with different solubility in supercritical CO 2 were used, and orifice disks and capillary tubes were adapted as an expansion device. The solubilities of drug substances in supercritical CO 2 and the effects of various operating parameters on the characteristics of the particles prepared by RESS process were experimentally investigated. The solubility of the drug substance in supercritical CO 2 had a major effect on the average diameter of the particle prepared by RESS process, and the particle diameter decreased with the solubility for all the drugs and operating conditions. The particle diameter also decreased with preexpansion temperature and increased with the hole diameter of the orifice nozzle and aspect ratio (L/D) of the capillary tube.

This study attempted to develop a copper-PTFE composite consisting of copper nano-particles homogeneously distributed into PTFE using scCO 2 . The overall synthesis process consisted of impregnation of copper precursor and thermolytic reduction. The impregnation process was performed over a range of temperature from 40 to 160 o C and pressure from 120 to 200 bar. The reduction process was performed at 230 o C and 250 bar for 2 hours consecutively after impregnation. The changes in appearance, mass, and morphology of the PTFE composite were examined by precision balance, SEM, TEM, and EDS. The impregnation ratio increased with temperature up to 120 o C, but decreased above 120 o C. The impregnation ratio increased with the pressure. These results could be explained by dehydration reaction of Cu(hfa) 2 H 2 O and thermodynamical affinity difference of copper precursors for PTFE or scCO 2 . Copper nano-particles impregnated into the PTFE were identified from SEM, TEM and EDS analysis.

In this study, zinc or cerium exchanged zeolite was introduced to develop a novel anti-corrosion pigment. The primer paint was made using them and was coated on galvanized(GI) steel. The anti-corrosion performance was measured using electrochemical impedance spectroscopy(EIS). And scanning vibrating electrode technique(SVET) was employed to observe the cut-edge corrosion process of the coated GI steel. From EIS and SVET results, it could be confirmed that Ce ion-exchanged zeolite showed the anti-corrosion performance higher than Shieldex C303 and Zn ionexchanged zeolite. Finally, it was found that metal ion-exchanged zeolite may provide new possibility as the smart cathodic corrosion inhibitor delivery systems on galvanized steels.