Curvature Effect in Polydimethylsiloxane Interaction with CO2. Insights from Theory

Anant Vaishnav; Shigenori Fujikawa; Aleksandar Staykov

doi:10.1021/acs.jpca.2c07001

Curvature Effect in Polydimethylsiloxane Interaction with CO₂. Insights from Theory

J Phys Chem A. 2023 Feb 2;127(4):876-885. doi: 10.1021/acs.jpca.2c07001. Epub 2023 Jan 20.

Authors

Anant Vaishnav¹, Shigenori Fujikawa^{1

2

3}, Aleksandar Staykov^{1

2

3}

Affiliations

¹ Department of Applied Chemistry, Faculty of Engineering, Kyushu University, Motooka 744, Nishi-ku, Fukuoka 6-10-1, Japan.
² International Institute for Carbon Neutral Energy Research I2CNER, Kyushu University, Motooka 744, Nishi-ku, Fukuoka 6-10-1, Japan.
³ Research Center for Negative Emission Technologies K-NETs, Kyushu University, Motooka 744, Nishi-ku, Fukuoka 6-10-1, Japan.

PMID: 36668674
DOI: 10.1021/acs.jpca.2c07001

Abstract

In this study we employ density functional theory to investigate the binding interaction between polydimethylsiloxane and CO₂ for application in gas separation membranes. The binding strength has been studied systematically as a function of the monomer conformational rotations in the polymer chain. Our work identified major differences between the CO₂ interaction with the helical conformation and the linear conformation of polydimethylsiloxane polymer chains. We have further estimated dependence between the CO₂ binding strength and the polydimethylsiloxane polymer chain curvature by systematically evaluating the CO₂ binding to cyclic polydimethylsiloxane oligomers. The enhanced CO₂ interaction with helical chains and cyclic oligomers was attributed to cooperative, confinement effects, and local electron density distribution at the Si-O-Si fragments. The binding modes were identified using vibration frequency analysis.