弹性石墨烯/碳纳米管/橡胶复合气凝胶,用于油水和乳液分离

发布时间:2025-08-11 16:44  浏览量:1

1成果简介

随着工业化和城市化发展,海洋石油泄漏、工业含油废水污染日益增多,对生态系统和人类健康造成严重威胁,油水分离面临重要挑战。多孔吸附法操作简便、制备工艺简单,相比传统的焚烧法、围栏法具有独特的优势,近年来研究广泛。石墨烯是一种由sp2杂化碳原子组成的二维片状纳米材料,由于其特殊的性质和潜在的应用前景,成为材料科学领域中一个重要的研究领域。石墨烯气凝胶是石墨烯片通过π-π、化学键等作用组装而成的三维材料,具有超高的孔隙率、超大的比表面积在水处理、储能等方面有着广泛的应用潜力。然而,石墨烯气凝胶容易发生过度的内部堆积和团聚,导致多孔结构不可逆的塌陷或变形,导致其弹性、力学强度不足,不能承担高载荷及高吸附含量的油/溶剂,同时高粘度油的低流动性会阻碍其扩散到多孔吸附剂中,吸附受到限制。因此,制备具有高弹高强且具有优异吸附性能的石墨烯基复合气凝胶具有重要意义。由于原油(或硅油、高粘度有机溶剂等)具有黏温特性,粘度随温度会发生变化,随着温度的升高,原油黏度会呈指数趋势降低。因此,可以在气凝胶中引入光热组分,通过光热转换将油/有机溶剂的黏度降低,提高吸附能力。

基于此,江苏海洋大学李成杰副教授团队通过引入羧基化碳纳米管作为增强骨架和光热组分,通过化学还原自组装和冷冻干燥制备了石墨烯/碳纳米管气凝胶,为进一步增强力学强度和弹性、调控表面疏水特性,将其浸渍含有醋酸锌的环氧化三元乙丙橡胶的溶液中,控制浸渍时间和碳纳米管含量,得到系列石墨烯/碳纳米管/EPDM复合气凝胶。高长径比的羧基化碳纳米管与还原氧化石墨烯之间存在π-π共轭和氢键作用,同时羧基化碳纳米管与环氧化EPDM之间发生开环反应形成界面交联,锌离子也可以交联环氧化EPDM分子链发挥交联弹性体网络增强作用。

所得到的复合气凝胶具有超轻、高孔隙率和可调控的疏水性(水接触角128°),同时实现了快速油水分离和破乳效果,在重力驱动下,对油包水乳液的通量高达859 L/m²·h,分离效率达98.8%,此外复合气凝胶在20次循环后仍保持优异的结构稳定性和吸附能力。在1个太阳光照射下,由于其良好的光吸收性能,实现了较高的光热转换效率,可以明显降低高粘度油的黏度,实现快速吸附。该研究通过多孔结构优化和分子尺度交联工程,为设计机械强韧、光热响应的复合气凝胶建立了新方法,为油类/溶剂回收和乳液分离提供了可持续解决方案。

相关研究工作以“Flexible Reduced Graphene Oxide/Carbon Nanotubes/EPDM Composite Aerogel with Superior Photothermal Conversion for Selective Oil Recovery and Emulsion Separation”为题发表在工程技术TOP期刊Separation and Purification Technology(2025,DOI:
10.1016/j.seppur.2025.134586)。江苏海洋大学环境与化学工程学院本科生孙叶为第一作者,研究生郭俊瑕等为论文共同作者,对本文研究测试提供了大量帮助,李成杰副教授为通讯作者。

2图文导读

图1、 Schematic representation for preparation of rGCA and rGCA/eEPDM composite aerogels (a). Photographs of rGA and rGCA at different CCNTs/GO mass ratios (b). Surface wetting of rGCA (c)。

图2、 FTIR spectra of CCNTs, GO@CCNTs, rGA, rGCA and rGCA/eEPDM with different CCNTs/GO mass ratios (a,b). XRD patterns of rGA/eEPDM and rGCA/eEPDM (c). TGA curves of GO, CCNTs, eEPDM, rGA/eEPDM and rGCA/eEPDM composites (d). Schematic illustration for interfacial interactions of rGCA/eEPDM (e)。

图3、 SEM images of rGA (a1,a2, a3), rCGA 2-1 (b1, b2, b3), rCGA 1-2/eEPDM (c1, c2, c3), rCGA 1-1/eEPDM (d1, d2, d3) and rCGA 2-1/eEPDM (e1, e2, e3). The crosslinking structure of eEPDM (f). Scheme for the network structure of rGCA/eEPDM (g)。

图4、 Compressive stress-strain curves for rGCA/eEPDM with different CCNTs/GO mass ratios (a). Compression cycles of rGCA/eEPDM at 50% strain (b). Digital photos of compression resilience for rGCA and rGCA/eEPDM (c,d)

图5、 EMI SE versus frequency (a) andEMI SEA and EMI SER (b) for rGCA/eEPDM composites. Schematic diagram of the electromagnetic shielding mechanism (c)

图7、 Digital photo of the water-in-oil emulsion separation by filtration (a). Optical images (b) and separation efficiency (c) of the surfactant stabilized water-in-oil emulsion separation. Water-in-oil emulsion separation mechanism (d)

图8、 IR thermal images of rGCA2-1/eEPDM under one sun irradiation (a) andduring heating (b). UV-vis light absorption spectra for rGCA/eEPDM (c). Temperature evolution of rGCA/eEPDM with different CCNTs/GO ratios with and without sun irradiation (d) and during heating followed by natural cooling (e)

图9、 Photo of the solar photothermal oil adsorption device (a). Adsorption experiment of rGCA/eEPDM (b) and rGCA (c) with and without light. Comparison of the adsorption amount of rGCA/eEPDM and rGCA (d). Viscosity changes of paraffin oil after xenon lamp irradiation (e,f). High-viscosity oil adsorption by rGCA/eEPDM with light (g) and without light (h), respectively. Time-dependent oil absorption of rGCA/eEPDM under solar irradiations (i)

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来源:材料分析与应用