17 mL of solution of 2NapFF-Na at a concentration of 40 mg/mL and 9 mL of 2NapFF solutions prepared at concentrations of 10 and 100 mg/mL were prepared using the quantities in Section 1.3. Solutions were made in 50 mL Falcon tubes, stirred with the same (25 x 8 mm) stirrer bars, and wrapped in Parafilm. Three different stirring methods were used on each sample over a seven-day period to establish if sample preparation history could affect the data collected. Samples were either stirred continuously at 400 rpm for seven days; stirred at 1000 rpm for seven days; or stirred overnight at 400 rpm and then left to stand undisturbed for the remaining six of the seven-day period. Viscosity measurements were performed every day for seven days, with day 1 representing the day following the creation of the samples. The sample was discarded after viscosity measurement. The pH was adjusted every day to 10.5 ± 0.1 using 0.1 M, 1 M and 2M NaOH; or 1 M and 2 M HCl as required for each solution. This did not affect the overall concentration of the solutions as no more than 3 µL of base was added each day.