2. Problems
Characterization methods
Vapor pressure osmometry
Theoretical estimation of molecular weight from binding const
ant
Size exclusion chromatography
Viscometry
Mass spectrometry
Scanning probe microscopy and electron microscopy
Others
Contents
3. Problems with Supramolecular Polymers
Characterization
(Chem. Soc. Rev., 2012, 41, 5922-5932)
Dynamic nature of
supramolecular polymer bonding,
Factors that significantly influences the
original molecular organization of a
supramolecular polymer.
Solvent concentration
Temperature
Composition
Stimuli from the surrounding environment
4. Vapor pressure osmometry
“The vapor pressure of a solution is lower than that
of the pure solvent at the same temperature and
pressure”.
Through Raoult's law, the Mn and the vapor
pressure can be related.
Psolution = ΧsolventP0solvent
Psolution is the vapor pressure of the solution
Χsolvent is mole fraction of the solvent
P0solvent is the vapor pressure of the pure solvent
(J. Am. Chem. Soc., 2003, 125, 15935)
7. Theoretical estimation of molecular
weight from binding constant
Self-assembly process with a certain
thermodynamic equilibrium constant.
1. Estimate the average molar mass of
supramolecular polymers through theoretical
models.
DP ≈ (KaC)1/2
Ka is the equilibrium constant, C is the total
monomer concentration,
(J. Am. Chem. Soc., 2003, 125, 15935)
11. Viscometry
To determine a polymer molecular weight distribution.
The relationship between the intrinsic viscosity and the
molecular weight can be expressed by the empirical
Mark–Houwink equation, [η] = KMa, (K and a are both emp
irical constants)
For a given polymer, values of K and a may be obtained
from suitable calibration experiments with a series of
sharp fractions..
(Chem. Soc. Rev., 2012, 41, 5922-5932)