风琴状超弹性CS/CP石墨烯复合气凝胶，用全天候高效清理原油泄漏

摘要：原油泄漏是海洋生态系统中的一大环境灾难。原油的高粘度极大地阻碍了其渗入传统多孔吸附材料的能力。幸运的是，原油的粘度对温度非常敏感。本文，福建理工大学Sen Zeng、 Xiaolong Liu、Zhixiang Cui 等研究人员在《Separation an

1成果简介

原油泄漏是海洋生态系统中的一大环境灾难。原油的高粘度极大地阻碍了其渗入传统多孔吸附材料的能力。幸运的是，原油的粘度对温度非常敏感。本文，福建理工大学Sen Zeng、 Xiaolong Liu、Zhixiang Cui 等研究人员在《Separation and Purification Technology》期刊发表名为“Super-elastic compressible chitosan/chlorella pyrenoidosa-graphene biomass aerogel with accordion-like structure for all-weather and high-efficiency cleanup of crude oil spills”的论文，研究设计了一种由太阳能和焦耳加热提供动力的自加热气凝胶，通过显著降低原油粘度，将其作为一种全天候吸附剂，用于持续吸收原油。壳聚糖（CS）/小球藻（CP）-石墨烯（GO）生物质气凝胶具有风琴状结构和超弹性可压缩性。然后用GO/碳纳米管（CNTs）和甲基三甲氧基硅烷（MTMS）对其进行表面处理，分别赋予焦耳加热效应和疏水性（命名为 H-CS/CP-G）。

H-CS/CP-G 生物质气凝胶的特殊风琴状结构使其具有优异的机械性能，经过 10 次循环压缩实验后，其高度恢复率可达 95%。在阳光照射下，H-CS/CP-G 生物质气凝胶可迅速达到 79.4 °C，同样，在施加 6 V 电压时，它也能迅速升温至 79.6 °C。这种温度响应能力可实现全天候高效原油净化。更重要的是，H-CS/CP-G 生物质气凝胶吸收原油的能力可达其自身重量的 25 倍，在经过 10 次吸收-挤压循环后，其可回收性高达 90.7%。与真空泵系统集成后，生物质气凝胶有助于从水面上持续提取原油。因此，H-CS/CP-G 气凝胶通过光热和焦耳加热的协同作用，加上独特的风琴状结构，在泵吸装置的辅助下，可以在任何天气条件下实现高粘度原油的高效连续分离。所制备的全天候生物质气凝胶具有成本低、制备简单、环保和高效等特点，为原油泄漏的清理提供了一种可持续的有效解决方案。

2图文导读

图1. Schematic diagram of the preparation process for H-CS/CP-Gx-y biomass aerogels.

图2. Photothermal conversion and Joule heating performance of the H-CS/CP-G4/1-y aerogel. (a) The change of the surface temperatures of the H-CS/CP-G4/1-y aerogels under one sun irradiation. (b) The change of the surface temperatures of the H-CS/CP-G4/1-y aerogels during the light off/on cycling experiment under one sun irradiation. Time-surface temperature curves of the aerogel under different voltages (c) 2 V, (d) 4 V, (e) 6 V, and (f) 8 V.

图3. Morphology of biomass aerogel prepared using different freezing methods. (a1-c1) schematic diagram of conventional freezing, unidirectional freezing, and bidirectional freezing; (a2-c2) microstructure of the cross section (the plane formed by XY) for biomass aerogel prepared under different freezing methods; (a3-c3) microstructure of the longitudinal section (the plane formed by YZ) for biomass aerogel prepared under different freezing methods. (a4-c4) digital image of the biomass aerogel standing on a leaf prepared under different freezing methods.

图4. (a) XRD spectra and (b) FTIR spectra of CS/CP, CS/CP-G4/1 and H-CS/CP-G4/1–2 biomass aerogel. (c) XPS spectrum of CS/CP-G4/1 and H-CS/CP-G4/1–2 biomass aerogels. Spectrum of (d) C 1s, (e) O 1s, and (f) Si 2p for H-CS/CP-G4/1–2 biomass aerogels.

图5. Stress–strain curves of H-CS/CP-G biomass aerogel during 10 compression-release cycles at a strain of 40% under different freezing methods of (a) conventional freezing, (b) unidirectional freezing, and (c) bidirectional freezing. (d) recovery rates of H-CS/CP-G biomass aerogel under 10 compression-release cycles. (e) digital images of the bidirectional H-CS/CP-G biomass aerogel before and after compression.

图6、 (a) Water contact angle of H-CS/CP-G biomass aerogel under different MTMS coating time. (b) The H-CS/CP-G biomass aerogel selectively adsorbs n-hexane (stained with oil red O) from the water surface. (c) The H-CS/CP-G biomass aerogel selectively adsorbs chloroform (stained with oil red O) from the bottom of water. (d) Adsorption capacity of H-CS/CP-G biomass aerogels for different types of oils and organic solvents. (e) The cyclic absorption capacity of H-CS/CP-G biomass Aerogel for petroleum ether. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

图7. (a) The variation of crude oil viscosity with temperature. (b) The oil absorption capacity of the H-CS/CP-G biomass aerogel at different temperatures. (c) The recycling performance of the H-CS/CP-G biomass aerogel under solar irradiation with an intensity of 1.0 kW m−2. (d) Comparison of saturated absorption capacity of the H-CS/CP-G biomass aerogel for high-viscosity crude oil with other reported aerogels under one-sun irradiation.

图8. (a) Temperature-time curve of the H-CS/CP-G biomass aerogel under real sunlight (before 5:00 pm) and under a voltage of 6 V. (b) The solar intensity and surface temperature of the H-CS/CP-G biomass aerogel under real sunlight irradiation. (c) The temperature of the H-CS/CP-G biomass aerogel under a 6 voltage at night. (d) The relationship between the saturated oil absorption capacity and temperature of the H-CS/CP-G biomass aerogel from 8:00 am to 5:00 pm and from 8 pm to 02:00 am. (e) Schematic diagram of the energy converter for continuous crude oil/water separation all day through solar heating and Joule heating effects.

3小结

总之，H-CS/CP-G 生物质气凝胶的开发，实现了全天候高效原油修复。这种气凝胶以小球藻、壳聚糖和石墨烯为主要骨架，通过双向冷冻形成独特的风琴状结构，并结合了石墨烯和碳纳米管的优点。这种气凝胶具有显著的焦耳加热和太阳能加热性能。在1.0kW/m2 的太阳辐射和6V的外加电压下，气凝胶的温度分别达到79.4 ℃ 和 79.6 ℃，这突出表明了它在全天候高效原油泄漏清理方面的有效性。在1.0 kW/m2的太阳辐射下，H-CS/CP-G气凝胶吸收的高粘度原油可达其自身重量的25倍。值得注意的是，这项研究证实，H-CS/CP-G生物质气凝胶即使在全天候户外自然阳光条件下也能保持出色的光热性能。这种利用太阳能和焦耳热的复合气凝胶在原油泄漏回收的实际应用中大有可为。

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