Hydrophobic Graphene-Based Aerogels

在最近发表的《开放式杂志》上发表的文章中聚合物研究人员报道了由高度可重复使用，仿生和疏水石墨烯/聚乙烯基醇/纤维素纳米纤维气管制成的动油吸收剂的发展。

学习：Biomimetic, Highly Reusable and Hydrophobic Graphene/Polyvinyl Alcohol/Cellulose Nanofiber Aerogels as Oil-Removing Absorbents.Image Credit: LuYago/Shutterstock.com

背景

由于事故或技术原因，可以在勘探，剥削，运输和加工过程中发生漏油，从而造成重大的环境后果。气凝胶作为出色的吸收剂，可以有效，有选择地吸收油油混合物中的油。

但是，许多气凝胶仍然存在有限的机械强度，油吸收能力和可回收性等问题。由于其全球可用性，生物相容性和柔韧性，研究人员对纤维素作为低成本天然材料的兴趣。长期以来，它已被用来制造超轻吸收性气囊材料。欧洲杯足球竞彩另一方面，大多数基于纤维素的气凝胶具有脆性的机械性能。

许多功能性纳米材料，例如聚酰亚胺，聚异丙欧洲杯足球竞彩丙烯酰胺）和聚乙烯醇（PVA），已被用作增强材料以及纳米纤维素，以增强Aerogels的机械性能，以克服纤维素凝胶的缺点。带有长聚合物链的PVA有助于生产氢与纳米纤维素的高密度键合，从而通过产生强烈的接触来改善气囊的机械质量。

（（一种）B-MGTPA制造过程的示意图。（（b）Schematic of the b-MGTPA with a mineral bridge structure. (C）Photograph of an ultralight b-MGTPA located on a dogstail grass. (d，，，，e）SEM图像显示了不同宏伟的仿生气凝胶的结构。图片来源：Feng，P等，聚合物

关于研究

在本研究中，作者介绍了高度可重复使用的氧化石墨烯（GO）/tempo氧化纤维素纳米纤维（TOCN）/聚乙烯醇（PVA）Aerogels，具有出色的机械性能和类似于Thalia dealbata dealbata茎的结构双向冷冻，冷冻干燥和化学蒸气沉积（CVD）修饰的三步过程。通过CVD修饰，将长碳链接枝到GTPA的表面上，从而导致了修饰的GTPA（MGTPA）疏水性（WCA = 134）。

使用双向冷冻和加强元件的组合创建了高度压缩的石墨烯/PVA/纤维素纳米纤维气凝胶。然后，为了获得疏水性，通过简单的溶解进行了CVD修饰。

Scanning electron microscopy images were used to examine the microstructures of the three different types of aerogels. The sessile drop method was used to measure the contact angle at room temperature. While the quality and size of the aerogel were measured using an electronic and digital caliper, the compressive properties of MGTPA were examined using an Instron 5565 universal material tester to study the mechanical properties of aerogel. The reusability of b-MGTPA was assessed by distilling and squeezing the oil, and the removal rate was calculated after 10 absorption–desorption cycles.

（（一种）R-GTPA和B-GTPA的照片。（（b）Photograph of r-MGTPA and b-MGTPA. Image Credit: Feng, P et al., Polymers

观察

在第10周期测试之后，仿生结构能够保留其初始饱和吸收能力的92％以上。B-MGTPA在周期中的残余油速率约为15–20％。在1 s和180 s时，改性气凝胶与水的接触角分别为136和134.8，表明表面疏水性。还观察到，当应变小于45％时，由于桥梁的弹性弯曲，应力随应变线性增加。

After being compressed for 100 cycles, MG₂₀TPA的初始强度为98.4％，是100和300周期后的最高应力率率，塑性变形很小。由于其具有桥梁的层状层的独特结构，B-MGTPA的恢复速率为98.4％，最大应力为99.3％，从100个周期后的60％应变。此外，B-MGTPA的高吸收能力是其重量的75-151倍。

After 10 cycles, the adsorption capacity of b-MGTPA dropped by less than 10% during squeezing and less than 2% during distillation, showing a high degree of reusability. Simple mechanical extrusion recovered about 80–85% of the absorbed oil.

（（一种）Absorption capacity of d-MG₂₀TPA and b-MG₂₀TPA用于各种溶剂。（（b）使用B-MGTPA在水上吸收选择性油（用苏丹III染色的红色）。（（C）B-GTPA和B-MGTPA的水接触角1 s和3分钟。图片来源：Feng，P等，聚合物

结论

In conclusion, this study demonstrated the development of a biomimetic, compressive, and hydrophobic graphene/PVA/cellulose nanofiber aerogel having unique three-dimensional (3D) linked lamellar layers with bridges by using bidirectional freezing. b-MGTPA had outstanding compressible qualities due to the synergistic effects of the three components and the unique biomimetic structure. For several types of organic solvents, b-MGTPA demonstrated a high adsorption capability. Furthermore, because of its high compressibility, b-MGTPA could recover absorbed oil quickly and efficiently using simple mechanical squeezing, and it had excellent reusable stability.

Furthermore, even after 10 extrusion or distillation cycles, b-MGTPA demonstrated exceptional reusability, retaining a high absorption capacity. Due to its unique biomimetic structure, the b-MGTPA retrieved more than 90% oil by mechanical squeezing.

总体而言，作者认为，由于其疏水性能，低成本，易于准备和一致的性能，B-MGTPA在清洁水溢出物和作为有机溶剂方面具有很大潜力。

资源

Feng，P.，Wang，X.，Yang，J。，仿生，高度可重复使用和疏水的石墨烯/聚乙烯基醇/纤维素纳米纤维气凝胶，作为燃油吸收剂。聚合物14（6），1077（2022）。https://www.mdpi.com/2073-4360/14/6/1077

免责声明：此处表达的观点是以其私人身份表达的作者的观点，不一定代表AZOM.com的观点有限的T/A Azonetwork本网站的所有者和运营商。此免责声明构成了条款和条件使用此网站。