摘要:
This invention is directed to conducting chemical reactions in reverse micelle or microemulsion systems comprising a substantially discontinuous phase including a polar fluid, typically an aqueous fluid, and a microemulsion promoter, typically a surfactant, for facilitating the formation of reverse micelles in the system. The system further includes a substantially continuous phase including a non-polar or low-polarity fluid material which is a gas under standard temperature and pressure and has a critical density, and which is generally a water-insoluble fluid in a near critical or supercritical state. Thus, the microemulsion system is maintained at a pressure and temperature such that the density of the non-polar or low-polarity fluid exceeds the critical density thereof. The method of carrying out chemical reactions generally comprises forming a first reverse micelle system including an aqueous fluid including reverse micelles in a water-insoluble fluid in the supercritical state. Then, a first reactant is introduced into the first reverse micelle system, and a chemical reaction is carried out with the first reactant to form a reaction product. In general, the first reactant can be incorporated into, and the product formed in, the reverse micelles. A second reactant can also be incorporated in the first reverse micelle system which is capable of reacting with the first reactant to form a product.
摘要:
A method of separating solute material from a polar fluid in a first polar fluid phase is provided. The method comprises combining a polar fluid, a second fluid that is a gas at standard temperature and pressure and has a critical density, and a surfactant. The solute material is dissolved in the polar fluid to define the first polar fluid phase. The combined polar and second fluids, surfactant, and solute material dissolved in the polar fluid is maintained under near critical or supercritical temperature and pressure conditions such that the density of the second fluid exceeds the critical density thereof. In this way, a reverse micelle system defining a reverse micelle solvent is formed which comprises a continuous phase in the second fluid and a plurality of reverse micelles dispersed in the continuous phase. The solute material is dissolved in the polar fluid and is in chemical equilibrium with the reverse micelles. The first polar fluid phase and the continuous phase are immiscible. The reverse micelles each comprise a dynamic aggregate of surfactant molecules surrounding a core of the polar fluid. The reverse micelle solvent has a polar fluid-to-surfactant molar ratio W, which can vary over a range having a maximum ratio W.sub.o that determines the maximum size of the reverse micelles. The maximum ratio W.sub.o of the reverse micelle solvent is then varied, and the solute material from the first polar fluid phase is transported into the reverse micelles in the continuous phase at an extraction efficiency determined by the critical or supercritical conditions.
摘要:
The surfactant sodium bis(2-ethylhexyl) sulfosuccinate (AOT) was used to form reverse micelle and microemulsion ethane and propane for systems consisting of 80 to 100 percent alkane by weight. Phase diagrams from view cell studies of microemulsion phases formed in supercritical fluids are reported and shown to be strongly dependent on pressure. The properties of these solutions were also characterized by conductivity, density and surfactant solubility measurements. The solubility of AOT in ethane and propane over a range of pressures shows behavior typical of soilds in supercritical fluids. The maximum water to surfactant ratio (Wo) increased dramatically in both ethane and propane systems as presssure was increased. At 300 bar and 103 DEG C., the supercritical propane-surfactant system is capable of solubilizing much more water (Wo=12) than the supercritical ethane-surfactant system (Wo=4) at 300 bar and 37 DEG C. Some of the important thermodynamic contributions which are likely responsible for this pressure dependent phase behavior are discussed and potential applications of this new class of solvents are considered.
摘要:
This invention is directed to a microemulsion system comprising a first phase including a low-polarity fluid material which is a gas at standard temperature and pressure, and which has a cloud-point density. It also includes a second phase including a polar fluid, typically water, a monomer, preferably a monomer soluble in the polar fluid, and a microemulsion promoter for facilitating the formation of micelles including the monomer in the system. In the subject process, micelles including the monomer are formed in the first phase. A polymerization initiator is introduced into the micelles in the microemulsion system. The monomer is then polymerized in the micelles, preferably in the core of the micelle, to produce a polymeric material having a relatively high molecular weight.
摘要:
An ion funnel device is disclosed. A first pair of electrodes is positioned in a first direction. A second pair of electrodes is positioned in a second direction. The device includes an RF voltage source and a DC voltage source. A RF voltage with a superimposed DC voltage gradient is applied to the first pair of electrodes, and a DC voltage gradient is applied to the second pair of electrodes.
摘要:
A method for raising the resolving power, specificity, and peak capacity of conventional ion mobility spectrometry is disclosed. Ions are separated in a dynamic electric field comprising an oscillatory field wave and opposing static field, or at least two counter propagating waves with different parameters (amplitude, profile, frequency, or speed). As the functional dependencies of mean drift velocity on the ion mobility in a wave and static field or in unequal waves differ, only single species is equilibrated while others drift in either direction and are mobility-separated. An ion mobility spectrum over a limited range is then acquired by measuring ion drift times through a fixed distance inside the gas-filled enclosure. The resolving power in the vicinity of equilibrium mobility substantially exceeds that for known traveling-wave or drift-tube IMS separations, with spectra over wider ranges obtainable by stitching multiple segments. The approach also enables low-cutoff, high-cutoff, and bandpass ion mobility filters.
摘要:
A folding or stacking chair has a seat and a backrest carried between opposite frame sides each with a backrest support, a front leg and a rear leg. One or both of the seat and the backrest has a continuous sheet of flexible and elastic knitted mesh or patterned open texture plastic held across and substantially covering an opening in an open-end hoop coupled between the frame sides. An open-end of the hoop faces in a front or a back orientation for the seat, or a top or a bottom orientation for the backrest, with sides of the hoop attached to the frame sides. The sheet of mesh or textured plastic has a finished edge spanning the open-end of the hoop.
摘要:
A folding mesh chair includes a seat and a backrest carried between opposite frame sides. The chair has an unfolded seating position in which the seat pivots to extend from the frame sides and bottoms of front and rear legs move apart, and a folded position in which the seat pivots toward the frame sides and the front and rear legs move together. One or both of the seat and the backrest have a continuous sheet of flexible and elastic mesh or patterned open texture plastic held across and substantially covering an opening in an all-plastic hoop fixed between the frame sides. The hoop includes inner and outer plastic mating hoops with the mesh extending over an outer perimeter of the inner hoop and into an interface between the inner and outer hoops.
摘要:
A differential ion mobility spectrometry or field asymmetric waveform ion mobility spectrometry (FAIMS) platform is disclosed that utilizes both gas flow and electric field, consecutively or simultaneously, to move ions through the analytical gap. The consecutive combination of flow and field enables rapid and flexible switching of the FAIMS stage “on” (for ion separation) and “off” (for high non-selective transmission) with no hardware modifications. This capability is needed for effective use of multidimensional instrument systems that couple FAIMS to mass spectrometry and/or conventional ion mobility spectrometry. The joint application of flow and field allows controlling the discrimination against high-mobility ions, maximizing it to remove the chemical noise or minimizing it to make the analyses of complex samples more predictable and uniform.
摘要:
A folding mesh chair includes a seat and a backrest carried between opposite frame sides. The chair has an unfolded seating position in which the seat pivots to extend from the frame sides and bottoms of front and rear legs move apart, and a folded position in which the seat pivots toward the frame sides and the front and rear legs move together. One or both of the seat and the backrest have a continuous sheet of flexible and elastic mesh or patterned open texture plastic held across and substantially covering an opening in an all-plastic hoop fixed between the frame sides.