Kyushu University Academic Staff Educational and Research Activities Database
List of Presentations
Selyancyn Roman Last modified date:2022.04.06

Associate Professor / Platform for International Collaborations and Partnerships / Kyushu University Platform of Inter/Transdisciplinary Energy Research

1. Roman Selyanchyn, Olena Selyanchyn and Shigenori Fujikawa, Interface-governed, highly efficient CO2/N2 gas separation in thin-film composite nanomembranes, 2020.12, Gas separation membranes suitable for economically feasible post-combustion CO2 capture should combine the moderate CO2/N2 selectivity (20-60) with a substantial values of CO2 permeances (>1000 GPU). Most the membranes tailored to have these properties are so-called thin-film composite membranes (TFCM) containing different layers it structure, each having a specific function (porous support, gutter, selective, protective layer). Due to the highest resistance towards gas transport, selective layers in TFCM are commonly fabricated with thicknesses below 100 nm. In this work, in order to achieve high CO2 permeances in TFCM we have fabricated ultra-thin selective layers (2-20 nm) composed of well-known hydrophilic and CO2-selective block-copolymer (Pebax MH-1657). It was deposited on the O2-plasma-activated surface of a much thicker (~400 nm) gutter layer composed of polydimethylsiloxane (PDMS). The structure was subsequently transferred on the polyacrylonitrile (PAN) microporous support to complete the TFCM. We have found that contrary to the theoretical predictions (resistance in the series model) for the layered membrane, highly selective CO2/N2 separation membrane was achieved in the TFCM with ultra-thin selective layer. The critical role to achieve this selectivity was attributed to the specific interface formed between selective and gutter layers which were controlled by the duration of oxygen plasma treatment (PDMS activation). Permeances of CO2 in the developed TFCM were between 1000-3000 GPU and CO2/N2 selectivities between 30-100, providing the gas separation parameters that are within the optimal range for cost-efficient CO2 capture in post-combustion processes. Detailed characterization of the interface revealed the chemical structure of the outermost membrane surface suggesting the blending of the ultra-thin Pebax-1657 layer with the activated surface of PDMS. This nano-thick blend layer contributed to the overall selectivity of the membrane significantly exceeding the selectivity that can be achieved by Pebax-1657 alone. The formed interface demonstrates stable gas separation with a moderate change of performance over one year..
2. Roman Selyanchyn, Shigenori Fujikawa, In-situ formation of molecularly dispersed ZrO2 in polydimethylsiloxane for highly gas permeable membranes, 2019.03, [URL].
3. Roman Selyanchyn, Risa Okeda, Keisuke Kanakogi, Shigenori Fujikawa, Nobuo Kimizuka, Prussian blue nanomembranes on porous supports: growth mechanism and gas separation, 2019.03, [URL].