Data underlying the publication: Microgel-based etalon membranes: characterization and properties

We introduce Microgel-based Etalon Membranes (MEM), based on the combination of stimuli-responsive microgels with an etalon, which is an optical device consisting of two reflecting plates and is used to filter specific wavelengths of light The microgels are sandwiched between two reflective layers and, in response to a stimulus (e.g., temperature, pH, or biomarker concentration) swell or de-swell, thereby changing the distance between the two reflective layers, and
generating multiple peaks in the reflectance spectra. This property gives a MEM the unique capability of simultaneous separation and tunable responses to the environmental changes and/or biomarker concentrations. We propose a design
based on gold layers on a silicon nitride wafer membrane. Our comprehensive characterization, employing permeability experiments, in-situ optical reflectance spectroscopy, in-liquid AFM analysis, and captive bubble contact angle measurements, elucidates the dynamic response of MEM to pH, temperature, and glucose stimuli and the corresponding effect of microgel swelling/de-swelling on the membrane properties, e.g., permeability. The AFM results confirm the dynamic changes of the microgel layer’s thickness on the membrane surface in response to the stimuli. Although
the microgel’s swelling/deswelling influences the effective pore radius, the decrease in the membrane’s permeance is limited to less than 10%. In the swollen state of the microgels, the etalon membranes show a prominent hydrophilic behavior, while they become less hydrophilic in the microgels’ de-swollen state