Katare Aviti, Borgohain Rajashree, Prasad Babul, Mandal Bishnupada
Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India.
William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, OH 43210-1350, USA.
Membranes (Basel). 2023 Apr 29;13(5):487. doi: 10.3390/membranes13050487.
Rubbery polymeric membranes, containing amine carriers, have received much attention in CO separation because of their easy fabrication, low cost, and excellent separation performance. The present study focuses on the versatile aspects of covalent conjugation of L-tyrosine (Tyr) onto the high molecular weight chitosan (CS) accomplished by using carbodiimide as a coupling agent for CO/N separation. The fabricated membrane was subjected to FTIR, XRD, TGA, AFM, FESEM, and moisture retention tests to examine the thermal and physicochemical properties. The defect-free dense layer of tyrosine-conjugated-chitosan, with active layer thickness within the range of ~600 nm, was cast and employed for mixed gas (CO/N) separation study in the temperature range of 25-115 °C in both dry and swollen conditions and compared to that of a neat CS membrane. An enhancement in the thermal stability and amorphousness was displayed by TGA and XRD spectra, respectively, for the prepared membranes. The fabricated membrane showed reasonably good CO permeance of around 103 GPU and CO/N selectivity of 32 by maintaining a sweep/feed moisture flow rate of 0.05/0.03 mL/min, respectively, an operating temperature of 85 °C, and a feed pressure of 32 psi. The composite membrane demonstrated high permeance because of the chemical grafting compared to the bare chitosan. Additionally, the excellent moisture retention capacity of the fabricated membrane accelerates high CO uptake by amine carriers, owing to the reversible zwitterion reaction. All the features make this membrane a potential membrane material for CO capture.
含有胺载体的橡胶状聚合物膜因其易于制备、成本低和分离性能优异，在CO分离方面受到了广泛关注。本研究聚焦于通过使用碳二亚胺作为偶联剂，将L-酪氨酸（Tyr）共价共轭到高分子量壳聚糖（CS）上的多方面应用，用于CO/N分离。对制备的膜进行了傅里叶变换红外光谱（FTIR）、X射线衍射（XRD）、热重分析（TGA）、原子力显微镜（AFM）、场发射扫描电子显微镜（FESEM）和保湿测试，以研究其热性能和物理化学性质。浇铸了酪氨酸共轭壳聚糖的无缺陷致密层，其活性层厚度在约600 nm范围内，并用于在25-115°C温度范围内的干燥和溶胀条件下进行混合气体（CO/N）分离研究，并与纯CS膜进行比较。TGA和XRD光谱分别显示了制备的膜的热稳定性和非晶性增强。制备的膜在吹扫/进料水分流速分别为0.05/0.03 mL/min、操作温度为85°C和进料压力为32 psi的条件下，表现出约103 GPU的合理良好的CO渗透率和32的CO/N选择性。与裸壳聚糖相比，复合膜由于化学接枝而表现出高渗透率。此外，制备的膜优异的保湿能力由于可逆两性离子反应加速了胺载体对CO的高吸收。所有这些特性使该膜成为一种潜在的CO捕获膜材料。
