組裝石墨烯膜 (Assembled graphene membrane) 在氣體分離應用上是一項具有潛力的材料；根據相關的研究，我們設計一系列的實驗條件來觀察堆疊結構的差異，而控制夾層間通道的空間是影響分離表現的關鍵因素；因此，有序的堆疊可以有效的避免無選擇性的空間存在。在這項研究中，最終的任務是從混合氣體中純化氫氣；首先，我們得經由超聲震盪和離心分離等程序製備分散良好的石墨烯懸浮液，進而我們嘗試藉由真空抽濾和噴塗法沉積石墨烯膜在多孔基材上。隨後，分析將著重於堆疊結構的觀察與比較經由調整噴塗條件後氣體分離的表現；加工過程中，我們操作的可控因素包括了控制片層尺寸、噴塗距離、懸浮液濃度和噴槍的進氣壓力。
在此，噴塗中最佳的操作條件建立了無缺陷的堆疊結構擁有出色的氫氣純化表現；在混合氣體的檢測中，氫氣分別從二氧化碳及甲烷中分離出來的選擇性分別高達181.6及39.7左右，同時在這項工作中氫氣的通量分別等於2797.8 GPU與2690.6 GPU。將傳統的真空抽濾法轉換為噴塗法使生產規模能夠擴大而更符合工業趨勢；而用多孔的高分子薄膜取代陽極氧化鋁基板 (Anodic alumina oxide, AAO) 能有效的降低生產成本。

Assembled graphene membrane is a potential material for gas separation application. In according to relevant researches, we designed series of experimental conditions to observe the difference in stacking structure, since it is significant to control channel space between interlayer to impact separation performance. Thus, ordered stacking would effectively prevent the existence of non-selective spacing. In this research, the ultimate goal is to purify hydrogen from mixed gases. First, we prepared well-dispersed graphene suspension by sonication and centrifugation, and then we attempted to deposit graphene membrane onto porous substrate by vacuum filtration and spray-coating approaches. Afterwards, the analyses were focused on observation of stacking construction and comparison of gas separation performance via adjustment of spraying conditions. Among processing, controllable factors we operated included controlling sheets size, spraying distance, suspension concentration and inlet pressure from airbrush.
Herein, optimal operated condition in spray-coating built a defect-free stacking construction with remarkable H2 purification. In mixed gas separation investigation, H2/CO2 and H2/CH4 selectivities are up to around 181.6 and 39.7 respectively as well as H2 permeance equals 2797.8 and 2690.6 GPU respectively in this work. The switching from traditional vacuum filtration method to spray-coating method enables the production process to scale up in line with industrial tendency, and to replace the anodic alumina oxide (AAO) substrate with porous polymer membrane, effectively reducing the cost of production.

1.
Koros, W.J., Evolving beyond the thermal age of separation processes: membranes can lead the way. AIChE Journal, 2004. 50(10): p. 2326-2334.
2.
Castro-Muñoz, R., V. Martin-Gil, M.Z. Ahmad, and V. Fíla, Matrimid® 5218 in preparation of membranes for gas separation: Current state-of-the-art. Chemical Engineering Communications, 2018. 205(2): p. 161-196.
3.
Zhang, Y., X. Feng, S. Yuan, J. Zhou, and B. Wang, Challenges and recent advances in MOF–polymer composite membranes for gas separation. Inorganic Chemistry Frontiers, 2016. 3(7): p. 896-909.
4.
Peng, Y., Y. Li, Y. Ban, and W. Yang, Two‐Dimensional Metal–Organic Framework Nanosheets for Membrane‐Based Gas Separation. Angewandte Chemie International Edition, 2017. 56(33): p. 9757-9761.
5.
Basu, S., A. Cano-Odena, and I.F. Vankelecom, MOF-containing mixed-matrix membranes for CO2/CH4 and CO2/N2 binary gas mixture separations. Separation and Purification Technology, 2011. 81(1): p. 31-40.
6.
Li, C., Z. Xiong, J. Zhang, and C. Wu, The strengthening role of the amino group in metal–organic framework MIL-53 (Al) for methylene blue and malachite green dye adsorption. Journal of Chemical & Engineering Data, 2015. 60(11): p. 3414-3422.
7.
Liu, M., P.A. Gurr, Q. Fu, P.A. Webley, and G.G. Qiao, Two-dimensional nanosheet-based gas separation membranes. Journal of Materials Chemistry A, 2018. 6(46): p. 23169-23196.
8.
Wang, B., A. Kuang, X. Luo, G. Wang, H. Yuan, and H. Chen, Bandgap engineering and charge separation in two-dimensional GaS-based van der Waals heterostructures for photocatalytic water splitting. Applied Surface Science, 2018. 439: p. 374-379.
9.
Kamble, A.R., C.M. Patel, and Z. Murthy, Different 2D materials based polyetherimide mixed matrix membranes for CO2/N2 separation. Journal of Industrial and Engineering Chemistry, 2020. 81: p. 451-463.
10.
Alen, S.K., S. Nam, and S.A. Dastgheib, Recent Advances in Graphene Oxide Membranes for Gas Separation Applications. International journal of molecular sciences, 2019. 20(22): p. 5609.
11.
Xu, Q., H. Xu, J. Chen, Y. Lv, C. Dong, and T.S. Sreeprasad, Graphene and graphene oxide: advanced membranes for gas separation and water purification. Inorganic Chemistry Frontiers, 2015. 2(5): p. 417-424.
12.
Joshi, R., S. Alwarappan, M. Yoshimura, V. Sahajwalla, and Y. Nishina, Graphene oxide: the new membrane material. Applied Materials Today, 2015. 1(1): p. 1-12.
13.
Yu, M. and H. Li, Ultrathin, molecular-sieving graphene oxide membranes for separations along with their methods of formation and use. 2017, Google Patents.
14.
Li, X., L. Ma, H. Zhang, S. Wang, Z. Jiang, R. Guo, H. Wu, X. Cao, J. Yang, and B. Wang, Synergistic effect of combining carbon nanotubes and graphene oxide in mixed matrix membranes for efficient CO2 separation. Journal of Membrane Science, 2015. 479: p. 1-10.
15.
Yoo, B.M., J.E. Shin, H.D. Lee, and H.B. Park, Graphene and graphene oxide membranes for gas separation applications. Current opinion in chemical engineering, 2017. 16: p. 39-47.
16.
Hummers Jr, W.S. and R.E. Offeman, Preparation of graphitic oxide. Journal of the american chemical society, 1958. 80(6): p. 1339-1339.
17.
Xin, Q., Z. Li, C. Li, S. Wang, Z. Jiang, H. Wu, Y. Zhang, J. Yang, and X. Cao, Enhancing the CO 2 separation performance of composite membranes by the incorporation of amino acid-functionalized graphene oxide. Journal of Materials Chemistry A, 2015. 3(12): p. 6629-6641.
18.
Yang, T., H. Lin, K.P. Loh, and B. Jia, Fundamental transport mechanisms and advancements of graphene oxide membranes for molecular separation. Chemistry of Materials, 2019. 31(6): p. 1829-1846.
19.
Sun, C., B. Wen, and B. Bai, Application of nanoporous graphene membranes in natural gas processing: Molecular simulations of CH4/CO2, CH4/H2S and CH4/N2 separation. Chemical Engineering Science, 2015. 138: p. 616-621.
20.
Wang, S., S. Dai, and D.-e. Jiang, Continuously tunable pore size for gas separation via a bilayer nanoporous graphene membrane. ACS Applied Nano Materials, 2018. 2(1): p. 379-384.
21.
Formhals, A., United States: Patent Application Publication. US patent, 1934. 1(975): p. 504.
22.
Shen, J., M. Zhang, G. Liu, and W. Jin, Facile tailoring of the two-dimensional graphene oxide channels for gas separation. RSC advances, 2016. 6(59): p. 54281-54285.
23.
Shieh, J.J. and T.S. Chung, Gas permeability, diffusivity, and solubility of poly (4‐vinylpyridine) film. Journal of Polymer Science Part B: Polymer Physics, 1999. 37(20): p. 2851-2861.
24.
Murugiah, P., P. Oh, and K. Lau. Concatenation of carbonaceous nanofillers for mixed matrix membrane development. in IOP Conference Series: Materials Science and Engineering. 2018. IOP Publishing.
25.
Nigiz, F.U. and N.D. Hilmioglu, Enhanced hydrogen purification by graphene-Poly (Dimethyl siloxane) membrane. International Journal of Hydrogen Energy, 2020. 45(5): p. 3549-3557.
26.
Chen, B., C. Wan, X. Kang, M. Chen, C. Zhang, Y. Bai, and L. Dong, Enhanced CO2 separation of mixed matrix membranes with ZIF-8@ GO composites as fillers: Effect of reaction time of ZIF-8@ GO. Separation and Purification Technology, 2019. 223: p. 113-122.
27.
Yang, K., Y. Dai, W. Zheng, X. Ruan, H. Li, and G. He, ZIFs-modified GO plates for enhanced CO2 separation performance of ethyl cellulose based mixed matrix membranesf. Separation and Purification Technology, 2019. 214: p. 87-94.
28.
Liu, G., W. Jin, and N. Xu, Graphene-based membranes. Chemical Society Reviews, 2015. 44(15): p. 5016-5030.
29.
Ibrahim, A. and Y. Lin, Gas permeation and separation properties of large-sheet stacked graphene oxide membranes. Journal of membrane science, 2018. 550: p. 238-245.
30.
Chi, C., X. Wang, Y. Peng, Y. Qian, Z. Hu, J. Dong, and D. Zhao, Facile preparation of graphene oxide membranes for gas separation. Chemistry of Materials, 2016. 28(9): p. 2921-2927.
31.
Kim, H.W., H.W. Yoon, S.-M. Yoon, B.M. Yoo, B.K. Ahn, Y.H. Cho, H.J. Shin, H. Yang, U. Paik, and S. Kwon, Selective gas transport through few-layered graphene and graphene oxide membranes. Science, 2013. 342(6154): p. 91-95.
32.
Zeynali, R., K. Ghasemzadeh, A.B. Sarand, F. Kheiri, and A. Basile, Performance evaluation of graphene oxide (GO) nanocomposite membrane for hydrogen separation: Effect of dip coating sol concentration. Separation and Purification Technology, 2018. 200: p. 169-176.
33.
Akhtar, F.H., M. Kumar, and K.-V. Peinemann, Pebax® 1657/Graphene oxide composite membranes for improved water vapor separation. Journal of membrane science, 2017. 525: p. 187-194.
34.
Hahn, J., J.I. Clodt, C. Abetz, V. Filiz, and V. Abetz, Thin isoporous block copolymer membranes: it is all about the process. ACS applied materials & interfaces, 2015. 7(38): p. 21130-21137.
35.
Guan, K., J. Shen, G. Liu, J. Zhao, H. Zhou, and W. Jin, Spray-evaporation assembled graphene oxide membranes for selective hydrogen transport. Separation and Purification Technology, 2017. 174: p. 126-135.
36.
Pham, V.H., T.V. Cuong, S.H. Hur, E.W. Shin, J.S. Kim, J.S. Chung, and E.J. Kim, Fast and simple fabrication of a large transparent chemically-converted graphene film by spray-coating. Carbon, 2010. 48(7): p. 1945-1951.
37.
Ibrahim, A.F.M. and Y.S. Lin, Synthesis of graphene oxide membranes on polyester substrate by spray coating for gas separation. Chemical Engineering Science, 2018. 190: p. 312-319.
38.
Kim, S., L. Chen, J.K. Johnson, and E. Marand, Polysulfone and functionalized carbon nanotube mixed matrix membranes for gas separation: theory and experiment. Journal of Membrane Science, 2007. 294(1-2): p. 147-158.
39.
Balandin, A.A., Thermal properties of graphene and nanostructured carbon materials. Nature materials, 2011. 10(8): p. 569-581.
40.
Sircar, S., T. Golden, and M. Rao, Activated carbon for gas separation and storage. Carbon, 1996. 34(1): p. 1-12.
41.
Compton, O.C. and S.T. Nguyen, Graphene oxide, highly reduced graphene oxide, and graphene: versatile building blocks for carbon‐based materials. small, 2010. 6(6): p. 711-723.
42.
Bai, H., C. Li, and G. Shi, Functional composite materials based on chemically converted graphene. Advanced Materials, 2011. 23(9): p. 1089-1115.
43.
Wajid, A.S., S. Das, F. Irin, H.T. Ahmed, J.L. Shelburne, D. Parviz, R.J. Fullerton, A.F. Jankowski, R.C. Hedden, and M.J. Green, Polymer-stabilized graphene dispersions at high concentrations in organic solvents for composite production. Carbon, 2012. 50(2): p. 526-534.
44.
Lotya, M., P.J. King, U. Khan, S. De, and J.N. Coleman, High-concentration, surfactant-stabilized graphene dispersions. ACS nano, 2010. 4(6): p. 3155-3162.
45.
Lotya, M., A. Rakovich, J.F. Donegan, and J.N. Coleman, Measuring the lateral size of liquid-exfoliated nanosheets with dynamic light scattering. Nanotechnology, 2013. 24(26): p. 265703.
46.
Heo, J., M. Choi, J. Chang, D. Ji, S.W. Kang, and J. Hong, Highly permeable graphene oxide/polyelectrolytes hybrid thin films for enhanced CO 2/N 2 separation performance. Scientific reports, 2017. 7(1): p. 1-8.
47.
Stobinski, L., B. Lesiak, A. Malolepszy, M. Mazurkiewicz, B. Mierzwa, J. Zemek, P. Jiricek, and I. Bieloshapka, Graphene oxide and reduced graphene oxide studied by the XRD, TEM and electron spectroscopy methods. Journal of Electron Spectroscopy and Related Phenomena, 2014. 195: p. 145-154.