A Novel Impregnation Process: Application to Carbon/Carbon Composites

<title>Supercritical fluid processing: a new dry technique for photoresist developing</title>

“…The phenomenon of SCF solubility was first reported over one hundred years ago by Hannay and Hogarth.5 As a demonstration of the pressure dependent dissolving power of SCF solvents, Figure 1 shows the solubiity of a simple compound, naphthalene, in carbon dioxide and ethylene.6 16 14 12 Pressure, MPa Above the critical pressure of each gas, 50 atm for ethylene and 73 atm for carbon dioxide, it is seen that increases in pressure result in large increases in solubiity of naphthalene. Because of such dissolving characteristics, it is possible to design industrial processes to extract, purify, and fractionate materials based on changes in pressure of a supercritical fluid solvent.7 At high pressure an extraction can be carried out, for example at Point 1 on the ethylene solubiity curve and by lowering the pressure to Point 2 a separation of the dissolved material from the gas can be made to occur; the solvent can then be recycled to the extractor to carry out more extraction.…”