Size selection of dispersed, exfoliated graphene flakes by controlled centrifugation
Size selection of dispersed, exfoliated graphene flakes by controlled centrifugation
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DOI：
10.1016/j.carbon.2011.09.001
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发表时间：
2012-02-01
期刊：
影响因子：
10.9
通讯作者：
Coleman, Jonathan N.
中科院分区：
文献类型：
--
作者：
Khan, Umar;O'Neill, Arlene;Coleman, Jonathan N.
石墨烯的液体剥离通常会产生横向尺寸平均为1微米或更小的薄片，对于许多应用来说太小了。本文描述了一种将平均片状长度接近1微米的分散体分离成不同平均片状尺寸的碎片的方法。最初的分散体以高离心率离心，将上清液中的小薄片与沉积物中的大薄片分离。沉淀物的再分散，然后是连续的离心、分离和再分散循环可以用来按大小分离鳞片，只要离心率随着每个循环而降低。这一过程产生的分散体的平均片长从最高最终离心率的1微米到最终离心率为500转/分的样品的3.5微米不等。(C)2011爱思唯尔有限公司。保留所有权利。
Liquid exfoliation of graphene generally results in flakes with lateral size of one micron or less on average, too small for many applications. In this paper we describe a method to separate an existing dispersion with mean flake length of similar to 1 mu m into fractions, each with different mean flake size. The initial dispersion is centrifuged at a high centrifugation rate, separating small flakes in the supernatant from large flakes in the sediment. Redispersion of the sediment, followed by successive centrifugation, separation and redispersion cycles can be used to separate the flakes by size so long as the centrifugation rate is decreased with each cycle. This procedure results in a range of dispersions with mean flake length varying from 1 mu m for the highest final centrifugation rate to 3.5 mu m for the sample whose final centrifugation rate was 500 rpm. (C) 2011 Elsevier Ltd. All rights reserved.