Abstract：
Separating xylene isomers is a challenging task due to their similar physical and chemical properties. In this study, we developed a molecular sieve incorporating a reduced graphene oxide (rGO) membrane for the precise differentiation of xylene isomers. We fabricated GO membranes using a vacuum filtration technique followed by thermal-induced reduction to produce rGO membranes with precisely controllable interlayer spacing. Notably, we could finely tune the interlayer spacing of the rGO membrane from 8.0 to 5.0 Å by simply varying the thermal reduction temperature. We investigated the reverse osmosis separation ability of the rGO membranes for xylene isomers and found that the rGO membrane with an interlayer spacing of 6.1 Å showed a high single component permeance of 0.17 and 0.04 L m-2 h-1 bar-1 for para- and ortho-xylene, respectively, exhibiting clear permselectivity. The separation factor reached 3.4 and 2.8 when 90:10 and 50:50 feed mixtures were used, respectively, with permeance 1 order of magnitude higher than that of current state-of-the-art reverse osmosis membranes. Additionally, the membrane showed negligible permeance and selectivity decay even after continuous operation for more than 5 days, suggesting commendable membrane resistance to solvent swelling and operating pressure.
摘要：
分离二甲苯异构体是一项具有挑战性的任务,因为它们具有相似的物理和化学性质。在这项研究中,我们开发了一种包含还原氧化石墨烯（rGO）膜的分子筛，用于精确区分二甲苯异构体。我们使用真空过滤技术制造GO膜，然后进行热诱导还原，以生产具有精确可控的层间间距的rGO膜。值得注意的是,通过简单地改变热还原温度，我们可以将rGO膜的层间间距从8.0微调到5.0。我们研究了rGO膜对二甲苯异构体的反渗透分离能力，发现层间间距为6.1µ的rGO膜对对二甲苯和邻二甲苯的单组分渗透率高，分别为0.17和0.04Lm-2h-1bar-1，分别,表现出明显的选择透过性。当使用90:10和50:50的进料混合物时，分离因子达到3.4和2.8，分别,渗透率比当前最先进的反渗透膜高1个数量级。此外,即使连续运行超过5天，膜也显示出可忽略不计的渗透性和选择性衰减，表明膜耐溶剂溶胀和操作压力良好。
