Barrier kinetics of adsorption–desorption of alcohol monolayers on water under constant surface tension

Abstract

The desorption rate stands between the theoretical curves for pure barrier control (intensive convection) and mixed barrier + diffusion control (no convection).

Prediction of Kinetically Stable Nanotheranostic Superstructures: Integral of First-Passage Times from Constrained Simulations

“…Once all the adsorbed arms of one star are desorbed from the planet NP surface, the star polymer can escape from the shell. Therefore, the desorption rate of short and long stars can be expressed as where c ads,s and c ads,l represent the arm-end concentrations of the adsorbed short and long stars within the shell between r = R np and r = r max i ( i = s, l), which are related to the adsorption densities by The factors β s and β l account for the significant reduction of the desorption rate due to the adsorption–desorption barrier and the multiarm attachment. , …”

“…where c ads,s and c ads,l represent the arm-end concentrations of the adsorbed short and long stars within the shell between r = R np and r = r max i (i = s, l), which are related to the adsorption densities by The factors β s and β l account for the significant reduction of the desorption rate due to the adsorption−desorption barrier and the multiarm attachment. 43,44 Integration of Rate Equations for σ s (t) and σ l (t). The rate equations for the adsorbed densities of short and long stars become…”

Characterization of capillary waves: A review and a new optical method

“…Gravity also has non-negligible effect on  (+6 m at 300 Hz) and has to be accounted for. In comparison, the diffusion correction in the dispersion condition ( 11)-( 12) has effect smaller than the uncertainty limits: the diffusion coefficient of octanol is 7×10 -10 m 2 /s [79], and taking it into account leads to increase in the theoretical values of  by ~2 m and of Ld by ~0.02 mm in the studied frequency range. Therefore, a more accurate approach for the determination of E from Laplace wave characterization would take into account the data for both  and Ld.…”

“…The oscillation of  and c is experimentally accessible for fluorescent surfactants [48]. Let the barrier adsorptiondesorption kinetics have negligible effect on the capillary wave characteristics (this is valid for octanol; for alcohols higher than decanol, we expect considerable role of the barrier adsorptiondesorption [79]). Under this assumption, local equilibrium is established between the adsorbed monolayer and the subsurface solution, and the amplitudes C and a are related as:…”

“…Octanol is of low volatility (the evaporation of hexanol can affect the wave properties significantly). The barrier resistance for adsorption-desorption can be neglected [4] (for higher alcohols, the flip-flop process can be expected to affect the viscoelastic properties of the monolayer [79]). The chosen concentration corresponds to coverage of ~3.3 mol/m 2 , which is about 50% of the collapse value (~6.8 mol/m 2 for normal alkanols).…”