The density (rho) of Tergitol is not 1, its specific gravity is essentially 1, so it's the same as freshwater which is 62.4-lbs/ft^3, convert to mg/cm^3 = 28,304,164-mg/28,316.85-cm^3 = ~1-g/cm^3 = 28,316,846-mg/ft^3.
How did you get only a surface area if 20-cm^2. The record is 12"-D (113.1-in^2) minus the 4" D label area (12.6-in^2) = 100.5-in^2 = 648.4-cm^2. Plus, you have to add the area of the grooves.
1-micron (0.0001-cm) thickness across a 1-cm^2 surface = 0.0001-cm^3.
1-micron (0.00000328-ft) thickness across a 1-ft^2 surface =0.00000328-ft^3.
1-micron of surfactant with density of 1000-mg/cm^3 spread across 1-cm^2 surface = (1000-mg/cm^3 x 0.0001-cm^3) = 0.1-mg.
1-micron of surfactant with density of 28,316,846-mg/ft^3 spread across 1-ft^2 = (28,316,846-mg/ft^3 x 0.00000328-ft^3) = 92.879-mg.
So, my calculation is off by a factor of ~10. In my book, I show 1-micron to be 10-mg/ft^2, when in fact is ~100-mg/ft^2. So, 1-mg/ft^2 is not 0.1-micron but 0.01-micron. Reviewing the NASA document I found my error. They show 1-ug/cm^2 (1-mg/0.1-m^2) for contaminant 1-g/cm^3 = 10-nanometers = 0.01-micron; and 1-mg/0.1-m^2 = 1-mg/ft^2.
Take care,
Neil

