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科研人员实现高质量石墨烯在水相中制备
来源:网络 | 作者:Bungechem | 发布时间: 1651天前 | 575 次浏览 | 分享到:
石墨烯是现有材料中厚度较薄、强度较高、导热性较好的新型二维材料,在智能装备、航空航天、能源储存和环境治理等诸多领域应用潜力巨大,是重要的战略新兴材料。
Graphene is a new type of two-dimensional material with thin thickness, high strength and good thermal conductivity among existing materials. It has great application potential in many fields such as intelligent equipment, aerospace, energy storage and environmental governance. It is an important strategic emerging material.

    从复旦大学获悉,该校与新加坡国立大学研究人员合作,通过在石墨烯表面引入极少量可电离含氧官能团,实现高质量石墨烯在水相中的**率制备,有利于加速石墨烯大规模产业化应用。相关成果近日在线发表于《自然·通讯》杂志。
    石墨烯是现有材料中厚度较薄、强度较高、导热性较好的新型二维材料,在智能装备、航空航天、能源储存和环境治理等诸多领域应用潜力巨大,是重要的战略新兴材料。
    然而,如何实现高质量石墨烯的**率、规模化制备,一直是制约其大规模应用的关键难题。理想解决方案是从天然鳞片石墨出发,将其在液相中剥离成石墨烯。
    据专家介绍,为避免石墨烯的不可逆聚集,液相剥离通常需要在特定溶剂中进行,而溶剂对石墨烯的分散能力则限制了剥离的效率,以致液相剥离很难在高浓度下进行。典型情况下石墨烯含量通常小于1mg/mL,这意味着生产1kg石墨烯至少需要1吨的溶剂用量。此外,石墨烯强烈的聚集倾向也使其难以存储、运输,为后续应用提出挑战。
    如何克服这些难题?研究人员采用一种非稳定分散的策略,通过在石墨烯表面引入极少量的可电离含氧官能团,实现在极高浓度(50mg/mL)下的快速、高产率剥离,剥离产物90%以上为单层石墨烯,且晶格缺陷少。剥离过程中,由于表面双电层被压缩,石墨烯以絮凝方式析出形成沉淀,后者即使浓缩至固含量很高的滤饼,室温储存一月后,仍可再次分散于水溶液中形成均匀稳定的石墨烯悬浮液,从而有效解决石墨烯规模化应用中的储存和运输问题。
    此外,该方法制备的石墨烯水相浆料表现出良好的流变特性,可直接通过3D打印制备各种形状的石墨烯气凝胶,从而为石墨烯在储能、环境治理、多功能复合材料等领域的应用开辟了新途径。

It was learned from Fudan University that the school cooperated with researchers from the National University of Singapore to achieve high-quality graphene in the aqueous phase by introducing a very small amount of ionizable oxygen-containing functional groups on the surface of graphene, which is conducive to accelerating the growth of graphene. Scale industrial application. The results were recently published online in the journal Nature Communications.

    Graphene is a new type of two-dimensional material with thin thickness, high strength and good thermal conductivity among existing materials. It has great application potential in many fields such as intelligent equipment, aerospace, energy storage and environmental management. It is an important strategic emerging material. .

    However, how to achieve high yield and large-scale preparation of high-quality graphene has always been a key problem restricting its large-scale application. The ideal solution is to start with natural flake graphite and exfoliate it into graphene in the liquid phase.

    According to experts, in order to avoid irreversible aggregation of graphene, liquid-phase exfoliation usually needs to be carried out in a specific solvent, and the dispersing ability of the solvent to graphene limits the efficiency of exfoliation, so that liquid-phase exfoliation is difficult to carry out at high concentrations. Typically, the graphene content is less than 1 mg/mL, which means that at least 1 ton of solvent is required to produce 1 kg of graphene. In addition, the strong aggregation tendency of graphene also makes it difficult to store and transport, posing challenges for subsequent applications.

    How to overcome these difficulties? The researchers adopted a non-stable dispersion strategy to achieve fast, high-yield exfoliation at extremely high concentrations (50 mg/mL) by introducing a very small amount of ionizable oxygen-containing functional groups on the graphene surface, exfoliation More than 90% of the products are single-layer graphene with few lattice defects. During the peeling process, due to the compression of the surface electric double layer, graphene is precipitated by flocculation to form a precipitate. Even if the latter is concentrated to a filter cake with a high solid content, it can be re-dispersed in an aqueous solution to form a uniform and stable form after being stored at room temperature for one month. The graphene suspension can effectively solve the storage and transportation problems in the large-scale application of graphene.

    In addition, the graphene aqueous phase slurry prepared by this method exhibits good rheological properties, and graphene aerogels of various shapes can be directly prepared by 3D printing, thus providing graphene's application in energy storage, environmental management, multi-functional composite Applications in fields such as materials have opened up new avenues.