Author (Your Name)

Stephanie Mann, Colby College

Date of Award


Document Type

Honors Thesis (Colby Access Only)


Colby College. Chemistry Dept.


Thomas W. Shattuck

Second Advisor

Paul Greenwood

Third Advisor

Tom Poon


The study of PGG was initially begun as a free energy perturbation srudy to determine if PGG preferred to be associated with one cation over another. The cations studied were Na+, K+, and Ca2+, with hopes of also expanding this study to Mg2+. Free energy perturbation was used to calculate the change in Gibbs free energy for the PGG associated with these cations. The studies were not completely conclusive, but seem to indicate that although PGG would prefer Ca2+ in an enthalpicly driven reaction, it would prefer Na+ with regards to entropy. Trial studies conducted on the acetate anion show that acetate prefers Ca2+ with regards to entropy and enthalpy. This indicates that PGG has some unique properties compared to comparable acetate solutions. To understand the enthalpic and entropic origins of the properties of PGG we did studies of the radius of gyration, solvation shell ordering, ion pair types, and Hooke's law. These studies indicate that PGG has the most freedom of motion when associated with potassium and the least flexibility when associated with calcium.


Full-text download restricted to Colby College campus only.


Cations, Gibbs' free energy, Polyelectrolytes, Thermodynamic potentials