MOLECULAR DESIGN OF COLLOIDS IN SUPERCRITICAL FLUIDS

Keith P. Johnston

关键词: CARBON DIOXIDE;    CHEMISTRY;    COLLOIDS;    DESIGN;    ELECTROSTATICS;    GERMANIUM;    SILICON;    SOLVENTS;    STABILIZATION;    SURFACTANTS;    SYNTHESIS;    WATER carbon dioxide;    emulsions;    colloid science;    foams;    surfactants;    interfacial phenomena;    germanium;   

DOI  :  10.2172/950785
RP-ID  :  DOE/ER/15549-1
PID  :  OSTI ID: 950785
Others  :  TRN: US201002%%338

学科分类：工程和技术（综合）

美国|英语

来源: SciTech Connect

【 摘 要 】

The environmentally benign, non-toxic, non-flammable fluids water and carbon dioxide (CO2) are the two most abundant and inexpensive solvents on earth. Emulsions of these fluids are of interest in many industrial processes, as well as CO2 sequestration and enhanced oil recovery. Until recently, formation of these emulsions required stabilization with fluorinated surfactants, which are expensive and often not environmentally friendly. In this work we overcame this severe limitation by developing a fundamental understanding of the properties of surfactants the CO2-water interface and using this knowledge to design and characterize emulsions stabilized with either hydrocarbon-based surfactants or nanoparticle stabilizers. We also discovered a new concept of electrostatic stabilization for CO2-based emulsions and colloids. Finally, we were able to translate our earlier work on the synthesis of silicon and germanium nanocrystals and nanowires from high temperatures and pressures to lower temperatures and ambient pressure to make the chemistry much more accessible.