Journal
ACS APPLIED MATERIALS & INTERFACES
Volume 13, Issue 4, Pages 5165-5175Publisher
AMER CHEMICAL SOC
DOI: 10.1021/acsami.0c21338
Keywords
polymer entanglement; carbon membrane; molecular sieving; natural gas purification; hydrogen production
Funding
- Ministry of Science and Technology (MOST), ROC
- MOST [108-2923-E-040-001-MY3]
Ask authors/readers for more resources
In this study, carbon molecular sieving (CMS) membranes were fabricated using three different polymer precursor conformations: dilute, semi-dilute, and concentrated. The effects of the precursor conformation on the microstructure of the resulting CMS membranes were characterized by Raman analysis. A novel method combining HR-TEM and FIB systems was proposed to detect the cutoff size of the CMS membranes. The CMS membrane fabricated with a semi-dilute solution exhibited superior gas separation performance, with a high selectivity of H-2/CH4 and hydrogen permeability, surpassing reported permselectivity of other membranes.
In this study, three polymer precursor conformations, dilute, semi-dilute, and concentrated, were used to fabricate carbon molecular sieving (CMS) membranes via a fixed carbonization protocol. The effects of the precursor conformation on the microstructure of the resultant CMS membranes were characterized by Raman analysis. Their ability to separate light gases, such as H-2/CH4 and H-2/N-2, was assessed with a single-gas system. Additionally, a novel method was proposed to detect the cutoff size of the CMS membranes created in this study. The method combined high-resolution transmission electron microscopy (HR-TEM) and a focused ion beam (FIB) system. Finally, due to the semi-dilute solution's denser polymer chains and lack of severe polymer entanglement, highly graphited CMS membranes with excellent gas separation performance were successfully synthesized using a semi-dilute polyetherimide dope solution. Interlayer distances in the carbon matrix were visualized and measured using our novel probing tool (HR-TEM and FIB) and software. The CMS membrane fabricated with a semi-dilute dope exhibited the best gas separation performance of the tested membranes. It had the most ordered carbon sheet orientation and exhibited a superior selectivity of H-2/CH4 = 293 with a hydrogen permeability of 1138.7 Barrer, far surpassing the reported permselectivity of other membranes. We believe that the high H-2/CH4 selectivity presented here is unprecedented for CMS membranes reported in the literature.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available