0.2 mg/mL albumin in buffer (NaCl 150mM, NaHCO3 0.2mM and pH=7.0) at room temperature (22°C) held at a fixed surface pressure, Π = 10 mN/m where we plotted (A) trough area, A, versus time, t, and fitted a line A(t) = A0eCt to data after 20 min of equilibration where the exponential constant C = 1/A·dA/dt and (B) the reflectivity, R, versus time, t.