Interactive multiple goal programming: Applications to financial planning

Abstract

The phase behavior and physicochemical properties (dynamic light scattering, electrical conductivity, interfacial tension, heats of transition, etc.) of various phosphatidylcholine (PC)/n-alkane/1-alcohol/water systems are investigated. When the concentration of 1-butanol increases, the phase behavior changes from lower-phase microemulsion (O/W-type) to upper-phase microemulsion (W/O-type) by way of the middle-phase microemulsion; this transition is not observed with higher or lower 1-alcohols; we propose, therefore, that 1-butanol just balances the hydrophilic-lipophilic interactions of PC with water and alkanes and thereby weakens the molecular interaction between the phosphatidylcholine molecules. Both the hydrodynamic diameter (HD) and solubilization parameter (SP) of the middle-phase microemulsion increase with a decrease in alkyl carbon number (ACN) of n-alkane, but interfacial tension (γ) decreases with decreasing ACN. Furthermore, the hydrophilic-lipophilic properties of the PC microemulsions are found to be just balanced by the addition of an n-alkane whose melting point is close to the chainmelting transition temperature (Tc) of the respective PC.