Nguyen Manh-Thuong, Grubel Katarzyna, Zhang Difan, Koech Phillip K, Malhotra Deepika, Allec Sarah, Rousseau Roger, Glezakou Vassiliki-Alexandra, Heldebrant David J
Physical Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, USA.
Energy Processes and Materials Division, Pacific Northwest National Laboratory, Richland, WA 99352, USA.
ChemSusChem. 2021 Dec 6;14(23):5283-5292. doi: 10.1002/cssc.202101350. Epub 2021 Oct 22.
A combined experimental and theoretical study has been carried out on the wetting and reactivity of water-lean carbon capture solvents on the surface of common column packing materials. Paradoxically, these solvents are found to be equally able to wet hydrophobic and hydrophilic surfaces. The solvents are amphiphilic and can adapt to any interfacial environment, owing to their inherent heterogeneous (nonionic/ionic) molecular structure. Ab initio molecular dynamics indicates that these structures enable the formation of a strong adlayer on the surface of hydrophilic surfaces like oxidized steel which promotes solvent decomposition akin to hydrolysis from surface oxides and hydroxides. This decomposition passivates the surface, making it effectively hydrophobic, and the decomposed solvent promotes leaching of the iron into the bulk fluid. This study links the wetting behavior to the observed corrosion of the steels by decomposition of solvent at steel interfaces. The overall affect is strongly dependent on the chemical composition of the solvent in that amines are stable, whereas imines and alcohols are not. Moreover, plastic packing shows little to no solvent degradation, but an equal degree of wetting.
针对贫水碳捕集溶剂在常见柱填料材料表面的润湿性和反应性开展了一项实验与理论相结合的研究。矛盾的是，发现这些溶剂在润湿疏水和亲水表面方面能力相当。这些溶剂具有两亲性，由于其固有的非均相（非离子/离子）分子结构，能够适应任何界面环境。从头算分子动力学表明，这些结构能够在诸如氧化钢等亲水性表面形成强吸附层，这促进了溶剂的分解，类似于表面氧化物和氢氧化物的水解。这种分解使表面钝化，使其实际上具有疏水性，并且分解后的溶剂促进铁向主体流体中的浸出。该研究将润湿性行为与在钢界面处溶剂分解导致的钢腐蚀现象联系起来。总体影响在很大程度上取决于溶剂的化学成分，胺类是稳定的，而亚胺类和醇类则不然。此外，塑料填料几乎没有溶剂降解，但具有相同程度的润湿性。
