Roman Selyanchyn

A Nano-Thin Film-Based Prototype QCM Sensor Array for Monitoring Human Breath and Respiratory Patterns

Quartz crystal microbalance (QCM) sensor array was developed for multi-purpose human respiration assessment. The sensor system was designed to provide feedback for human respiration. Thorough optimization of measurement conditions: air flow, temperature in the QCM chamber, frequency measurement rate, and electrode position regarding to the gas flow—was performed. As shown, acquisition of respiratory parameters (rate and respiratory pattern) could be achieved even with a single electrode used in the system. The prototype system contains eight available QCM channels that can be potentially used for selective responses to certain breath chemicals. At present, the prototype machine is ready for the assessment of respiratory functions in larger populations in order to gain statistical validation. To the best of our knowledge, the developed prototype is the only respiratory assessment system based on surface modified QCM sensors.

Incorporation of CO2 philic moieties into a TiO2 nanomembrane for preferential CO2 separation

Here we report a preferential CO2 separation membrane consisting of a nanometer-thick TiO2 layer incorporated with phtalic acid (PA) molecules on polydimethylsiloxane (PDMS) (PA@TiO2/PDMS). Incorporated PAs in TiO2 act as CO2-philic pores for preferential CO-2 permeation over nitrogen. CO2 binding to the PA incorporated in TiO2 is confirmed by the density functional theory calculation (DFT). As a result, membranes with of PA@TiO2 layer demonstrated much higher selectivity to CO2 for mixed CO2/N2 gas separation compared to a conventional PDMS membrane. The exceptional selectivity of the composite layer alone (>150) was estimated by a resistance model.

Membrane thinning for efficient CO2 capture

Abstract Enhancing the fluxes in gas separation membranes is required for utilizing the membranes on a mass scale for CO2 capture. Membrane thinning is one of the most promising approaches to achieve high fluxes. In addition, sophisticated molecular transport across membranes can boost gas separation performance. In this review, we attempt to summarize the current state of CO2 separation membranes, especially from the viewpoint of thinning the selective layers and the membrane itself. The gas permeation behavior of membranes with ultimate thicknesses and their future directions are discussed.

Characterization of polymer-polymer type charge-transfer (CT) blend membranes for fuel cell application

The data presented in this article are related to polymer-polymer type charge-transfer blend membranes for fuel cell application. The visible spectra of the charge-transfer (CT) blend membranes indicated formation of CT complex in the blend membranes, and behavior of CT complex formation by polymers was clarified by Job plot of the visible spectra. The effect of fluorine for membrane property and fuel cell performance of CT blend membranes were evaluated by 19F NMR and overvoltage analysis, respectively.