Abstract: A separation method includes (a) providing a heterogeneous separation system, the heterogeneous cleaning system comprising CO2 in a first phase and an oil in a separate second phase; (b) entraining a material to be separated in the second phase; (c) wholly or partially solubilizing the second phase in the first phase to produce a separation system in which said material to be separated is insoluble; and then (d) separating the material from the system. The separating step is preferably followed by the step of (e) recovering at least a portion of the oil. The system is useful in a variety of applications, including cleaning (particularly metal cleaning), polymerization, extraction, coating, and particle formation and treatment.

Abstract: A method of treating a substrate comprises contacting a surface of said substrate, with a pressurized fluid comprising carbon dioxide and a surface treatment component, the surface treatment component being entrained in the pressurized fluid and contacting the surface so that the surface treatment component lowers the surface tension of the surface of the substrate and treats the substrate. The contacting step is preferably carried out by immersion, the fluid is preferably a liquid or supercritical fluid, the substrate is preferably a metal or fabric substrate, and the surface treatment component is preferably a fluoroacrylate polymer.

Abstract: A method for dry-cleaning articles such as fabrics and clothing in carbon dioxide comprises contacting an article to be cleaned with a liquid dry cleaning composition for a time sufficient to clean the fabric. The liquid dry-cleaning composition comprises a mixture of carbon dioxide, a surfactant, and an organic co-solvent. After the contacting step, the article is separated from the liquid dry cleaning composition. The method is preferably carried out at ambient temperature. The surfactant is preferably one that does not contain a CO2-philic group. The organic co-solvent is preferably an alkane and has a flash point above 140° F.

Abstract: A method for dry-cleaning garments or fabrics in carbon dioxide comprises contacting a garment or fabric article to be cleaned with a liquid dry cleaning composition for a time sufficient to clean the article, said liquid dry-cleaning composition comprising a mixture of carbon dioxide, water, a first surfactant, and a second surfactant, and then separating the article from the liquid dry cleaning composition. The first surfactant comprises a CO2-philic group covalently joined to a hydrophilic group; and the second surfactant comprising a CO2-philic group covalently joined to a lipophilic group. In the alternative, a single surfactant containing all three of a CO2-philic group, a lipophilic group, and a hydrophilic group covalently joined to one another may also be employed. Systems useful for carrying out the foregoing are also disclosed.

Abstract: A method of treating a substrate comprises contacting a surface of said substrate, with a pressurized fluid comprising carbon dioxide and a surface treatment component, the surface treatment component being entrained in the pressurized fluid and contacting the surface so that the surface treatment component lowers the surface tension of the surface of the substrate and treats the substrate. The contacting step is preferably carried out by immersion, the fluid is preferably a liquid or supercritical fluid, the substrate is preferably a metal or fabric substrate, and the surface treatment component is preferably a fluoroacrylate polymer.

Abstract: A method of treating a substrate comprises contacting a surface of said substrate, with a pressurized fluid comprising carbon dioxide and a surface treatment component, the surface treatment component being entrained in the pressurized fluid and contacting the surface so that the surface treatment component lowers the surface tension of the surface of the substrate and treats the substrate. The contacting step is preferably carried out by immersion, the fluid is preferably a liquid or supercritical fluid, the substrate is preferably a metal or fabric substrate, and the surface treatment component is preferably a fluoroacrylate polymer.

Abstract: A method of treating a substrate comprises contacting a surface of said substrate, with a pressurized fluid comprising carbon dioxide and a surface treatment component, the surface treatment component being entrained in the pressurized fluid and contacting the surface so that the surface treatment component lowers the surface tension of the surface of the substrate and treats the substrate. The contacting step is preferably carried out by immersion, the fluid is preferably a liquid or supercritical fluid, the substrate is preferably a metal or fabric substrate, and the surface treatment component is preferably a fluoroacrylate polymer.

Abstract: A system for the controlled addition of detergent formulations and the like to a carbon dioxide cleaning apparatus comprises: (a) a high pressure wash vessel; (b) an auxiliary vessel; (c) a drain line connecting the auxiliary vessel to the wash vessel; (d) optionally but preferably, a separate vent line connecting the auxiliary vessel to the wash vessel; (e) a detergent reservoir; and (f) a detergent supply line connecting the detergent reservoir to the auxiliary vessel. An advantage of this apparatus is that, because the detergent formulation can be pumped into the auxiliary vessel in a predetermined aliquot or amount, which predetermined aliquot or amount can then be transferred into the wash vessel where it combines with the liquid carbon dioxide cleaning solution, the detergent formulation can be added to the cleaning solution in a more controlled or accurate manner.

Abstract: A wash tank adapted for use with a carbon dioxide cleaning medium has a body member having a front opening formed therein, the body member having side walls and a back wall opposite the front opening. The side walls terminate in a front body member edge portion that defines the front opening. The edge portion serves in the sealing mechanism, as discussed below. A substantially cylindrical basket is disposed within the body member for rotation about a generally horizontal axis. The basket has a front opening formed therein, and has a side wall and a back wall opposite the front opening. The basket side wall terminates in a front basket edge portion defining the basket front opening. The said basket edge portion is spaced forward from the body member edge portion when the basket is positioned in the body member, serving to prevent loose garments or materials placed within the basket from becoming caught in the seal and interfering with seal integrity.

Abstract: A separation method includes (a) providing a heterogeneous separation system, the heterogeneous cleaning system including CO.sub.2 in a first phase and an oil in a separate second phase; (b) entraining a material to be separated in the second phase; (c) wholly or partially solubilizing the second phase in the first phase to produce a separation system in which said material to be separated is insoluble; and then (d) separating the material from the system. The separating step is preferably followed by the step of (e) recovering at least a portion of the oil. The system is useful in a variety of applications, including cleaning (particularly metal cleaning), polymerization, extraction, coating, and particle formation and treatment.

Abstract: A wash tank adapted for use with a carbon dioxide cleaning medium has a body member having a front opening formed therein, the body member having side walls and a back wall opposite the front opening. The side walls terminate in a front body member edge portion that defines the front opening. The edge portion serves in the sealing mechanism, as discussed below. A substantially cylindrical basket is disposed within the body member for rotation about a generally horizontal axis. The basket has a front opening formed therein, and has a side wall and a back wall opposite the front opening. The basket side wall terminates in a front basket edge portion defining the basket front opening. The said basket edge portion is spaced forward from the body member edge portion when the basket is positioned in the body member, serving to prevent loose garments or materials placed within the basket from becoming caught in the seal and interfering with seal integrity.

Abstract: A wash tank adapted for use with a carbon dioxide cleaning medium has a body member having a front opening formed therein, the body member having side walls and a back wall opposite the front opening. The side walls terminate in a front body member edge portion that defines the front opening. The edge portion serves in the sealing mechanism, as discussed below. A substantially cylindrical basket is disposed within the body member for rotation about a generally horizontal axis. The basket has a front opening formed therein, and has a side wall and a back wall opposite the front opening. The basket side wall terminates in a front basket edge portion defining the basket front opening. The said basket edge portion is spaced forward from the body member edge portion when the basket is positioned in the body member, serving to prevent loose garments or materials placed within the basket from becoming caught in the seal and interfering with seal integrity.

Abstract: A wash tank adapted for use with a carbon dioxide cleaning medium has a body member having a front opening formed therein, the body member having side walls and a back wall opposite the front opening. The side walls terminate in a front body member edge portion that defines the front opening. The edge portion serves in the sealing mechanism, as discussed below. A substantially cylindrical basket is disposed within the body member for rotation about a generally horizontal axis. The basket has a front opening formed therein, and has a side wall and a back wall opposite the front opening. The basket side wall terminates in a front basket edge portion defining the basket front opening. The said basket edge portion is spaced forward from the body member edge portion when the basket is positioned in the body member, serving to prevent loose garments or materials placed within the basket from becoming caught in the seal and interfering with seal integrity.

Abstract: A method of treating a substrate comprises contacting a surface of said substrate, with a pressurized fluid comprising carbon dioxide and a surface treatment component, the surface treatment component being entrained in the pressurized fluid and contacting the surface so that the surface treatment component lowers the surface tension of the surface of the substrate and treats the substrate. The contacting step is preferably carried out by immersion, the fluid is preferably a liquid or supercritical fluid, the substrate is preferably a metal or fabric substrate, and the surface treatment component is preferably a fluoroacrylate polymer.

Abstract: A method of dyeing a substrate in carbon dioxide comprises the steps of (a) providing a dye composition comprising carbon dioxide, a dye, and a surfactant, the surfactant included in an amount sufficient to solubilize, emulsify or disperse the dye in the carbon dioxide; and then (b) dyeing said substrate with said dye composition.

Abstract: A method for dry-cleaning articles such as fabrics and clothing in carbon dioxide comprises contacting an article to be cleaned with a liquid dry cleaning composition for a time sufficient to clean the fabric. The liquid dry-cleaning composition comprises a mixture of carbon dioxide, water, and an end-functional polysiloxane surfactant. After the contacting step, the article is separated from the liquid dry cleaning composition. The method is preferably carried out at ambient temperature.

Abstract: A method for dry-cleaning articles such as fabrics and clothing in carbon dioxide comprises contacting an article to be cleaned with a liquid dry cleaning composition for a time sufficient to clean the fabric. The liquid dry-cleaning composition comprises a mixture of carbon dioxide, water, a surfactant, and an organic co-solvent. After the contacting step, the article is separated from the liquid dry cleaning composition. The method is preferably carried out at ambient temperature. The surfactant may be either one that contains a CO.sub.2 -philic group or one that does not contain a CO.sub.2 -philic group. The organic co-solvent is preferably an alkane that has a flash point above 140.degree. F.