Mathematical modeling of CO2 facilitated transport across polyvinylamine membranes with direct operando observation of amine carrier saturation
Mathematical modeling of CO2 facilitated transport across polyvinylamine membranes with direct operando observation of amine carrier saturation
复制标题
通过直接操作观察胺载体饱和度，二氧化碳的数学模型促进了跨聚乙烯胺膜的运输
DOI：
10.1016/j.cej.2023.141728
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发表时间：
2023
影响因子：
15.1
通讯作者：
O'Brien, Casey P.
中科院分区：
文献类型：
--
作者：
Xu, Hui;Pate, Sarah G.;O'Brien, Casey P.
在这项工作中，我们利用实验测量的CO2跨PVAm膜通量的数学模型，结合OPANDO表面增强拉曼光谱(SERS)和傅立叶变换红外光谱(FTIR)表征，研究了CO2促进通过PVAm膜的动力学和机理。该数学模型适用于CO2分压(2~99kPa)和PVAm膜厚度(1.7~4.1µm)对CO2通量的实验测量。从模型中提取了与CO2传输相关的动力学和热力学参数，如PVAm通过溶液扩散对CO2的渗透性、PVAm对氨基甲酸酯(NHCO-)的促进传输渗透性以及氨基甲酸酯的生成/分解平衡常数。结果表明，PVAm通过促进转运对氨基甲酸酯的渗透率(2200±1200Barrer)比PVAm通过CO2溶液扩散的渗透率(150±20Barrer)大一个数量级。在进料CO2分压为∼10kPa时，利用操纵子表面增强拉曼光谱和傅立叶变换红外光谱直接观察到PVAm的伯胺基团与CO2(氨基甲酸酯)的饱和，这与我们的模型预测是一致的。这项工作定量地描述了二氧化碳在PVAM中的促进输运，并首次从分子角度通过Operando光谱表征提供了载流子饱和现象的直接证据。
In this work, we investigate the kinetics and mechanisms of CO 2 facilitated transport across polyvinylamine (PVAm) membranes using mathematical modeling of experimentally measured CO 2 fluxes across PVAm with operando surface-enhanced Raman spectroscopic (SERS) and Fourier-transform infrared (FTIR) spectroscopy characterization. The mathematical model was fit to experimentally measured CO 2 fluxes as a function of CO 2 partial pressure (2–99 kPa) and PVAm membrane thickness (1.7–4.1 µm). Physically significant kinetic and thermodynamic parameters associated with CO 2 transport were extracted from the model, such as the permeability of PVAm to CO 2 via solution diffusion, the permeability of PVAm to carbamate (NHCO O-) via facilitated transport, and the carbamate formation/decomposition equilibrium constant. Our results show that the permeability of PVAm to carbamate via facilitated transport (2200±1200 Barrer) is about an order of magnitude greater than the permeability of PVAm to CO 2 via solution-diffusion of CO 2 (150±20 Barrer). Using operando SERS and FTIR, we directly observed saturation of the primary amine groups of PVAm with CO 2 (carbamate) at a feed CO 2 partial pressure of∼ 10 kPa, which was in good agreement with our model predictions. This work quantitatively describes CO 2 facilitated transport across PVAm and provides direct evidence of the carrier saturation phenomenon—for the first time to our knowledge—from a molecular perspective through operando spectroscopic characterization.