What is the hydrodynamic volume?
Hydrodynamic volume – the volume of a polymer coil when it is in solution. This can vary for a polymer depending on how well it interacts with the solvent, and the polymer’s molecular weight. Ion – an atom or molecule which has a positive or a negative electrical charge.
In which type of polymerization viscosity is high?
The molecular weight of polymer is related to its molecular size, which means that polymers with a larger molecular size have a higher molecular weight. Polymers with a higher molecular weight provide higher viscosity, as shown in Figure p28.
How do you find the viscosity of a polymer?
The viscosity will be determined by the ratio between the flow time of the polymer solution (t) and the flow time of the pure solvent (t0).
Does intrinsic viscosity have a unit?
The units of intrinsic viscosity are typically deciliters per gram (dL/g), or inverse concentration and can also be viewed as an indication of molecular density for a polymer under a given set of conditions (solvent composition and temperature).
Which of these fluids has the highest viscosity?
The correct answer is Honey. Viscosity: S I unit: Pascal seconds (Pa·s) or kg·m−1·s−1. It is the property of a liquid representing the internal resistance of its different layers to motion.
What is hydrodynamic size in DLS?
Note that the diameter that is measured in DLS is a value that refers to how a particle diffuses within a fluid so it is referred to as a hydrodynamic diameter. The diameter that is obtained by this technique is the diameter of a sphere that has the same translational diffusion coefficient as the particle.
How to calculate the viscosity of a solution?
The viscosity is given by ηrel= η/ ηS= 160 / 100 = 1.6 ηsp= ηrel- 1 = 0.6 ηred= ηsp/ c= 0.6 / 0.001 g/ml = 600 ml/g Assuming the concentration is sufficiently close to zero so that [η] ≈ 6.0 102ml/g, the molecular weight can be estimated with the the Mark-Houwink relation:
Is the viscosity equation still applicable to dissolved polymers?
It has been shown that the equation is still applicable to dissolved polymers if the hard sphere radius is replaced by the hydrodynamic radius of the polymer coil. Then the equation can be rewritten in the form [η] = k NA(〈Rh,02〉/M)3/2M1/2αh3= Φ (〈Rh,02〉/M)3/2M1/2αh3
Why do high molecular weight polymers increase viscosity?
High molecular weight polymers greatly increase the viscosity of liquids in which they are dissolved. The increase in viscosity is caused by strong internal friction between the randomly coiled and swollen macromolecules and the surrounding solvent molecules.
How is hydrodynamic volume affected by substituents?
A quantification of this difference reveals that PS overestimates the real molar mass of PPP 10 by a factor of almost 2. Although substituents certainly have an effect on the stiffness and thus the hydrodynamic volume of a polymer chain, it is reasonable to assume that this effect will normally be small.