• Source: Huggins equation

The Huggins Equation is an empirical equation used to relate the reduced viscosity of a dilute polymer solution to the concentration of the polymer in solution. It is named after Maurice L. Huggins. The Huggins equation states:







η

s


c


=
[
η
]
+

k

H


[
η

]

2


c


{\displaystyle {\frac {\eta _{s}}{c}}=[\eta ]+k_{H}[\eta ]^{2}c}


Where





η

s





{\displaystyle {\eta _{s}}}

is the specific viscosity of a solution at a given concentration of a polymer in solution,



[
η
]


{\displaystyle [\eta ]}

is the intrinsic viscosity of the solution,




k

H




{\displaystyle k_{H}}

is the Huggins coefficient, and



c


{\displaystyle c}

is the concentration of the polymer in solution. In isolation,




n

s




{\displaystyle n_{s}}

is the specific viscosity of a solution at a given concentration.
The Huggins equation is valid when



[
η
]
c


{\displaystyle [\eta ]c}

is much smaller than 1, indicating that it is a dilute solution. The Huggins coefficient used in this equation is an indicator of the strength of a solvent. The coefficient typically ranges from about



0.3


{\displaystyle 0.3}

(for strong solvents) to



0.5


{\displaystyle 0.5}

(for poor solvents).
The Huggins equation is a useful tool because it can be used to determine the intrinsic viscosity,



[
η
]


{\displaystyle [\eta ]}

, from experimental data by plotting






η

s


c




{\displaystyle {\frac {\eta _{s}}{c}}}

versus the concentration of the solution,



c


{\displaystyle c}

.




See also


Viscosity
Rheology




References

Kata Kunci Pencarian:

• Huggins equation
• Reduced viscosity
• Flory–Huggins solution theory
• Robert Huggins
• Mark–Houwink equation
• Van der Waals equation
• Flory–Rehner equation
• Paul Flory
• Solvation shell
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