Assessing CO Adsorption Behavior onto Free-Standing, Flexible Organic Framework-PVDF Composite Membrane: An Empirical Modeling and Validation of an Experimental Data Set.

Covalent organic framework (COF) materials have greatly expanded their range in a variety of applications since the cognitive goal of a highly organized and durable adsorbent is quite rational. The characteristics of a conjugated organic framework are combined with an industrially relevant polymer to produce a composite membrane optimized for selectively adsorbing carbon dioxide (CO) gas across a wide temperature range. Additionally, treatment of the composite membrane with cold atmospheric plasma (CAP) that specifically enhanced the parent membrane's surface area by 36% is established. Following CAP treatment, the membrane accelerates the CO uptake by as much as 66%. This is primarily due to a Lewis acid-base interaction between the electron-deficient carbon atom of CO and the newly acquired functionalities on the COFs@PVDF membrane's surface. In particular, the C-N bonds, which appear to be a higher electron density site, play a key role in this interaction. Moreover, the empirical model proposed here has confirmed CO adsorption phenomena in the COF@PVDF composite membrane, which closely matches the findings from the experimental data set under designated operating conditions. As a result, the current study may pave the way for future design work as well as refine the covalent framework polymer composite membrane's features, revealing a more sophisticated approach to addressing CO capture problems.