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Solvent Density (g cm-3) Boiling point (°C) K b (°C⋅kg/mol) ... –12.5 K b & K f [1] Ethylene glycol: 1.11 197.3 2.26 −12.9 –3.11 K b & K f [1] Formic acid ...
Physically, this is energy cost of compressing the solvents structure when creating a void in the solvent. 2nd term - electrostatic energy; This term deals with the polarization of the solute and solvent. 3rd term - quantum mechanical dispersion energy; can be approximated using an averaging procedure for the solvent charge distribution.
Once the desired conversion is reached, excess solvent must be removed to obtain the pure polymer. Accordingly, solution polymerization is primarily used in applications where the presence of a solvent is desired anyway, as is the case for varnish and adhesives.
Solute atoms should have a smaller radius than 59% of the radius of solvent atoms. [5] [6] The solute and solvent should have similar electronegativity. [7] Valency factor: two elements should have the same valence. The greater the difference in valence between solute and solvent atoms, the lower the solubility.
A solvent dissolves a solute, resulting in a solution Ethyl acetate, a nail polish solvent. [1] A solvent (from the Latin solvō, "loosen, untie, solve") is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid.
The solvent-rich phase is close to pure solvent. This is peculiar to polymers, a mixture of small molecules can be approximated using the Flory–Huggins expression with N = 1 {\displaystyle N=1} , and then ϕ cp = 1 / 2 {\displaystyle \phi _{\text{cp}}=1/2} and both coexisting phases are far from pure.
For example, if there are 10 grams of salt (the solute) dissolved in 1 litre of water (the solvent), this solution has a certain salt concentration . If one adds 1 litre of water to this solution, the salt concentration is reduced. The diluted solution still contains 10 grams of salt (0.171 moles of NaCl).
B reflects the energy of binary interactions between solvent molecules and segments of polymer chain. When B > 0, the solvent is "good," and when B < 0, the solvent is "poor". For a theta solvent, the second virial coefficient is zero because the excess chemical potential is zero; otherwise it would fall outside the definition of a theta solvent.