Boron nitride colloidal solutions, ultralight aerogels and freestanding membranes through one-step exfoliation and functionalization.
Boron nitride colloidal solutions, ultralight aerogels and freestanding membranes through one-step exfoliation and functionalization.
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DOI：
10.1038/ncomms9849
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发表时间：
2015-11-27
影响因子：
16.6
通讯作者：
Chen Y
中科院分区：
文献类型：
--
作者：
Lei W;Mochalin VN;Liu D;Qin S;Gogotsi Y;Chen Y
由六方氮化硼（h-BN）制造气凝胶和膜比由石墨烯或氧化石墨烯制造气凝胶和膜困难得多，因为h-BN在水中的溶解性差，这限制了其剥离和胶体溶液的制备。在这里，一个简单的，一步机械化学过程剥离和功能化h-BN成高度水分散性，少层h-BN含有氨基。少层h-BN的胶体溶液可以具有前所未有的高浓度，高达30 mg ml−1，并且稳定长达数月。它们可用于生产密度为1.4 mg cm−3的超轻气凝胶，比散装h-BN小1,500倍，并分别通过冷冻干燥和过滤简单地生产独立膜。该材料在紫外光激发下，在分散状态和干燥状态下均显示出较强的蓝光发射。 目前，二维六方氮化硼在水中的分散性较差，限制了其剥离和应用。在这里，作者提出了一个一步机械化学过程，以实现前所未有的胶体浓度，这允许制造超轻气凝胶和独立膜。
Manufacturing of aerogels and membranes from hexagonal boron nitride (h-BN) is much more difficult than from graphene or graphene oxides because of the poor dispersibility of h-BN in water, which limits its exfoliation and preparation of colloidal solutions. Here, a simple, one-step mechano-chemical process to exfoliate and functionalize h-BN into highly water-dispersible, few-layer h-BN containing amino groups is presented. The colloidal solutions of few-layer h-BN can have unprecedentedly high concentrations, up to 30 mg ml−1, and are stable for up to several months. They can be used to produce ultralight aerogels with a density of 1.4 mg cm−3, which is ∼1,500 times less than bulk h-BN, and freestanding membranes simply by cryodrying and filtration, respectively. The material shows strong blue light emission under ultraviolet excitation, in both dispersed and dry state. The poor dispersibility of 2D hexagonal boron nitride in water currently limits its exfoliation and applications. Here, the authors present a one-step mechano-chemical process to achieve unprecedented colloidal concentrations, which permits fabrication of ultralight aerogels and freestanding membranes.