Among the polymers of this kind, polyvinylpyrrolidone (PVP) is one of the most commonly used as it can be dissolved in both polar and nonpolar solvents
; the polar amide group in polymeric chain of PVP is readily attached to the surface of nanoparticles to protect them from aggregation by the two stabilization mechanisms.
Effect of Aggregation on Electronic Absorption Spectra in Nonpolar Solvents
. It should be noted first that similar spectral changes of solutions of 1 and 2 have been found in polar solvents upon concentration changes; these changes will be considered in more detail in a subsequent section.
No doubt that PL of Psi in some nonpolar solvents
are exhibited and well-dispersed but not stable as listed in Table 1.
These data indicate that the association between pyridine and perfluoroalkyl iodides is more favorable in nonpolar solvents
such as hexane and cyclohexane.
Polar molecules are soluble in polar solvents and nonpolar molecules are soluble in nonpolar solvents
. "Like dissolves like" is a general rule of chemistry.
The most important of these is the omnipresent water, which stabilizes polar species--especially ions--in nonpolar solvents
and hence shifts the acid--base equilibria leading to erroneous results in the measurements of acidity or basicity.
Under these conditions, water must be regarded as a hot, pressurized fluid having a very low dielectric constant, thereby giving it a propensity for dissolving analytes normally extracted by nonpolar solvents
. Thus, two fluids at extreme ends of the solvent polarity spectrum, [CO.sub.2] and [H.sub.2]O, can be made complementary for providing extractions that are both versatile and environmentally benign.
Using computer simulations of water and five nonpolar solvents
, they calculated "the likelihood of finding, at an arbitrary point in the solvent, an atomic-sized cavity that could accommodate the solute." Though water has more overall cavity space than the nonpolar solvents
, its spaces are distributed in smaller, less flexible packets, the chemists report in the June 20 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY.
The nonpolar target chemicals are generally eluted by nonpolar solvents
such as HEX and DCM [19,23,25,34].
Thermodynamic interactions of poly[2-(p- chlorophenyl)-1,3-dioxolane-4-yl] methyl acrylate-co- styrene (PCKPhDMA-co-St) and poly[2-(p-chlorophenyl)-1,3-dioxolane-4-yl] methyl acrylate-co-acrylonitrile (PCKPhDMA-co-AN) with alcohols as polar and alkenes as nonpolar solvents
were investigated between 50 to 180 degC degrees by IGC.