School of Chemistry and Chemical Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
Key Laboratory of Wuliangye-flavor Liquor Solid-state Fermentation, China National Light Industry, Yibin 644000, China.
ACS Appl Mater Interfaces. 2023 Mar 8;15(9):12294-12304. doi: 10.1021/acsami.2c20553. Epub 2023 Feb 22.
Ethanol separation via the pervaporation process has shown growing application potential in solvent recovery and the bioethanol industry. In the continuous pervaporation process, polymeric membranes such as hydrophobic polydimethylsiloxane (PDMS) have been developed to enrich/separate ethanol from dilute aqueous solutions. However, its practical application remains largely limited due to the relatively low separation efficiency, especially in selectivity. In view of this, hydrophobic carbon nanotube (CNT) filled PDMS mixed matrix membranes (MMMs) aimed at high-efficiency ethanol recovery were fabricated in this work. The filler K-MWCNTs was prepared by functionalizing MWCNT-NH with epoxy-containing silane coupling agent (KH560) to improve the affinity between fillers and PDMS matrix. With K-MWCNT loading increased from 1 wt % to 10 wt %, membranes showed higher surface roughness and water contact angle was improved from 115° to 130°. The swelling degree of K-MWCNT/PDMS MMMs (2 wt %) in water were also reduced from 10 wt % to 2.5 wt %. Pervaporation performance for K-MWCNT/PDMS MMMs under varied feed concentrations and temperatures were evaluated. The results supported that the K-MWCNT/PDMS MMMs at 2 wt % K-MWCNT loading showed the optimum separation performance (compared with pure PDMS membranes), with the separation factor improved from 9.1 to 10.4, and the permeate flux increased by 50% (40-60 °C, at 6 wt % feed ethanol concentration). This work provides a promising method for preparing a PDMS composite with both high permeate flux and selectivity, which showed great potential for bioethanol production and alcohol separation in industry.
通过渗透蒸发过程分离乙醇在溶剂回收和生物乙醇工业中显示出越来越大的应用潜力。在连续渗透蒸发过程中，已经开发出了疏水性聚二甲基硅氧烷（PDMS）等聚合物膜，以从稀水溶液中浓缩/分离乙醇。然而，由于分离效率相对较低，特别是选择性方面，其实际应用仍然受到很大限制。有鉴于此，本工作制备了旨在实现高效乙醇回收的疏水性碳纳米管（CNT）填充 PDMS 混合基质膜（MMM）。通过用含环氧的硅烷偶联剂（KH560）对 MWCNT-NH 进行功能化制备填料 K-MWCNT，以提高填料与 PDMS 基体之间的亲和力。随着 K-MWCNT 负载量从 1wt%增加到 10wt%，膜的表面粗糙度增加，水接触角从 115°提高到 130°。K-MWCNT/PDMS MMMs 在水中的溶胀度（2wt%）也从 10wt%降低到 2.5wt%。在不同进料浓度和温度下，评估了 K-MWCNT/PDMS MMMs 的渗透蒸发性能。结果表明，在 2wt%K-MWCNT 负载量下，K-MWCNT/PDMS MMMs 表现出最佳的分离性能（与纯 PDMS 膜相比），分离因子从 9.1提高到 10.4，渗透通量提高了 50%（在 6wt%进料乙醇浓度下，40-60°C）。这项工作为制备具有高通量和高选择性的 PDMS 复合材料提供了一种有前景的方法，这在生物乙醇生产和工业中酒精分离方面具有很大的潜力。
