HOME

INTRODUCTION

CONCEPTS

EQUATIONS

TOUR

LIBRARY

MATH

VARIABLES

SITE MAP

WHAT'S NEW

Variables


Subscripts

1- solvent

2- polymer (polymer textbooks often write "solute")



Latin

a, a scalar that corresponds to the "stiffness" of polymer chains in the Mark Houwink equation

C, characteristic ratio

c2, polymer concentration in the Zimm Plot

D, molecular diffusion constant in the Buche Cashin Debye equation

k
  • Boltzmann's constant
  • constant used in the Zimm plot to adjust the spacing between points so that a person can use a pencil, ruler, and graph paper to extrapolate the "zero angle" and "zero concentration" points needed to determine the molecular weight. There is also an uppercase K used when working with the Zimm plot.
K
  • constant in the Mark Houwink equation
  • constant used in light scattering equations to group together several constants, including refractive index, the derivative of refractive index with respect to polymer concentration, wavelength in a vacuum, Avogadro's number. There is also a lower case k used when working with the Zimm plot.
l, length of the "line", or the length of the monomer

M, molecular weight
    subscripts: n-number average, w-weight average, v- viscosity average, z-z average
NA, Avogadro's Number (see discussion of variables k, n, R, T, NA)

N0, sum of the number of solvent molecules and the number of polymer segments

N1, number of solvent molecules

N2, number of polymer segments
    For texts that say solvent and solute, solute=polymer
ñ, refractive index

R, real gas law constant (a.k.a. universal gas constant)

R2, mean-square end-to-end distance of a single polymer chain

S, entropy

T, temperature

v1, volume fraction of solvent

v2, volume fraction of polymer

W, number of possible arrangements in space that the molecules may assume, used for Boltzmann's entropy change of mixing




Greek

α (alpha), chain expansion factor

η (eta), viscosity

θ (theta), λ0 (lambda), wavelength in a vacuum in variable K used in the Zimm Plot

п (pi) ρ (rho), density

ψ1 (psi), entropic factor in the equation for chain expansion