Example 12
Solutions of concentration 1000 ppm w/v of poly(propylene glycol) with Mn 1000 (PPG1000, Sigma Aldrich, St. Louis, Mo.), poly(2-ethyl-2-oxazoline) with Mn 5000 and PDI≤1.2 (POX5000, Sigma Aldrich, St. Louis, Mo.), Methocel E3LV (Dow Chemical Company, Midland, Mich.), polysorbate 80 (PS80, Sigma Aldrich, St. Louis, Mo.), and Pluronic F68 (F68, BASF Corporation) were prepared using ultrapure deionized water (18.2 MΩ·cm at 25° C.). 3 mL of each solution was placed into a 5-mL polypropylene tube and vortexed on a Mini Vortex Mixer (VWR, Radnor, Pa.) on mixer setting #8 for 15 seconds. The foam heights were measured after vortexing and are listed in Table 20. The times for the foams to dissipate were also recorded and are listed in Table 20. The foams for the POX5000 and F68 samples did not dissipate over the course of the experiment. The stopping points are listed in Table 20.