Development of a swelling-removal model for the scanning fluid dynamic gauge

A mathematical mechanistic swelling-removal approach has been developed for modelling the cleaning process in dried protein samples using the scanning fluid dynamic gauge (sFDG). The algorithm combines swelling phenomena with removal mechanisms (shear stress removal and soil dissolution). Swelling phenomena were described by applying analytical expressions based on poroelasticity theory. The nonlinear partial differential equation (PDE) describing the thickness swelling ratio was solved numerically, allowing the soil to be divided into theoretical layers. The novelty is presented as the cleaning process is integrated by the elimination of those layers. The model predicts the variation of the soil thickness over time. To describe kinetics of removal, experimental results were considered. Constant removal rates were found after an initial transition period. Removal rates were dependent on the different chemical and physical factors acting: temperature, chemistry concentration (pH, enzyme level), shear stress and frequency of application of shear stress. Soil remaining, total mass or percentage of cleaning over time can also be calculated as outputs. Overall the model has the potential to apply varying cleaning conditions over time and grow to a more theoretical approach in the future by applying enzyme kinetics.