推 荐 人:任博

文献信息1Yang Si, Lihuan Wang, Xueqin Wang, et al. Ultrahigh-water-content, superelastic, and shape-memory nanofiber-assembled hydrogels exhibiting pressure responsive conductivity, Advanced Materials. 2017, 29, 1700339.

推荐理由:水凝胶材料在生物工程、医学和电子元器件等领域具有巨大的应用潜力,然而该类材料的制备方法极为繁琐复杂。本文提出制备一种具有超弹性、多孔结构的水凝胶材料的新方法。该方法通过藻朊酸盐将SiO2纳米纤维组装成具有弹性的大尺寸形状,并且可根据工艺条件调控水凝胶中水的含量。所制备的水凝胶具有超高的水含量(99.8 wt%)、80%应变后的完全回弹能力、优异的形状记忆性能、零泊松比、受压导电性能等;具有较高的压力敏感性(0.24 kPa−1),感知较大范围的压力(>50 Pa)以及优异的耐久性(>100次)。该方法为制备新型多功能的水凝胶材料提供了新的思路。对于多孔材料功能性表征方面的工作值得大家借鉴。

下载地址:https://onlinelibrary.wiley.com/doi/pdf/10.1002/adma.201700339

AbstractHigh-water-content hydrogels that are both mechanically robust and conductive could have wide applications in fields ranging from bioengineering and electronic devices to medicine; however, creating such materials has proven to be extremely challenging. This study presents a scalable methodology to prepare superelastic, cellular-structured nanofibrous hydrogels (NFHs) by combining alginate and flexible SiO2 nanofibers. This approach causes naturally abundant and sustainable alginate to assemble into 3D elastic bulk NFHs with tunable water content and desirable shapes on a large scale. The resultant NFHs exhibit the integrated properties of ultrahigh water content (99.8 wt%), complete recovery from 80% strain, zero Poisson’s ratio, shapememory behavior, injectability, and elastic-responsive conductivity, which can detect dynamic pressure in a wide range (>50 Pa) with robust sensitivity (0.24 kPa−1) and durability (100 cycles). The fabrication of such fascinating materials may provide new insights into the design and development of multifunctional hydrogels for various applications.

文献信息2Hongsheng Yang, Zengling Li, Bing Lu, et al. Reconstruction of inherent graphene oxide liquid crystals for large-scale fabrication of structure-intact graphene aerogel bulk toward practical applications, ACS Nano, 2018, 12, 11407-11416.

推荐理由:石墨烯气凝胶作为近年来最具吸引力的碳材料之一,在储能转换、环境修复、高性能传感器、超轻型阻燃剂、电磁干扰屏蔽、吸声、高效太阳能热转换等领域显示出巨大的潜力。在以往的研究中,溶胶-凝胶法和空气干燥法被认为是实现超弹性(>90%应变)和超低密度(小于10 mg·cm-3)石墨烯气凝胶的低成本、大规模商业化生产的重要方法。化学还原或交联驱动的氧化石墨烯(GO)的凝胶化过程是其中的关键步骤。液晶(LC)相通常在GO水分散体中自发形成,当不存在特殊控制时,其通常显示常规的向列相或层状相。然而,向列相或层状相GO LCs在微观上有序,但宏观上(特别是米级的大尺寸)是严重无序,这将严重破坏大尺寸样品石墨烯水凝胶的均匀性和完整性,进一步阻碍了干燥后大块石墨烯气凝胶的成功制备。因此,建立适合工业应用的方法制备大尺寸、结构完整的石墨烯气凝胶仍然是一个重大挑战。本文作者通过微泡模板有效地破坏和重建分散体系中的氧化石墨烯液晶,从而获得大尺寸、结构完整的石墨烯水凝胶块(GHB)。经过简单冷冻和风干后,得到的石墨烯气凝胶块(GAB)表现出结构完整的尺寸约为1 m2,超弹性高达99%压缩应变,超低密度2.8 mg·cm-3,具有快速的太阳能热转换能力。这些优异的性能使GABs在许多实际应用中具有潜力,例如可以作为高压缩力吸收器、高吸油或危险溶剂的吸收材料、快速加热器或控制遮蔽物的优质太阳能热管理材料以及高效的耐火保温材料。整个制备过程易于扩展,具有成本效益,适用于大规模生产。本文写作角度新颖,具有较高的创新性,对于采用发泡法制备超轻气凝胶材料提供了新思路。

下载地址:https://pubs.acs.org.ccindex.cn/doi/10.1021/acsnano.8b06380

AbstractThe inherently formed liquid crystals (LCs) of graphene oxide (GO) in aqueous dispersions severely restrict the fabrication of large-size and structure-intact graphene aerogel bulk by an industry-applicable method. Herein, by developing a surfactant-foaming sol−gel method to effectively disrupt and reconstruct the inherent GO LCs via microbubbles as templates, we achieve the large-size and structure-intact graphene hydrogel bulk (GHB). After simple freezing and air-drying, the resulting graphene aerogel bulk (GAB) with a structure-intact size of about 1 m2 exhibits a superelasticity of up to 99% compressive strain, ultralow density of 2.8 mg cm−3, and quick solar-thermal conversion ability. The modified GAB (GABTP) shows a high decomposition temperature (Tmax) of 735°C in air and a low heat storage capacity. These excellent performances make the GABs suitable for many practical applications, as proven in this work, including as high compressive force absorbers, high absorption materials for oils or dangerous solvents, superior solar-thermal management materials for rapid heater or controlled shelter, and high-efficiency fire-resistant and thermal insulation materials. The whole preparation process is easily scalable and cost-effective for mass production of structureintact multifunctional graphene aerogel bulk toward practical applications.


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