Size selection of dispersed, exfoliated graphene flakes by controlled centrifugation

By U. Khan, A. O’Neill, H. Porwal, Peter May, K. Nawaz, Jonathan N. Coleman. 2012

314 citations recorded by the source corpus.

Abstract 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 ∼1 μm 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 μm for the highest final centrifugation rate to 3.5 μm for the sample whose final centrifugation rate was 500 rpm.

Subfields: Biomedical Engineering, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/d1e4b6a149258916606e3738d8f3e26bdd78c008

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Biomedical Engineering

1. Jonathan N. Coleman
2. U. Khan
3. A. O’Neill
4. M. Bhattacharya
5. Hongwei Zhu
6. Xiao Li

In Materials Chemistry

1. Jonathan N. Coleman
2. U. Khan
3. A. O’Neill
4. I. Mcgovern
5. W. Maser
6. Ana M. Benito
7. Manuela Cano
8. Zhiming Wang

Citations in the corpus

• Improving the mechanical properties of graphene oxide based materials by covalent attachment of polymer chains (2013, methodology): “In this scenario, the smaller f-(PVA)GO flakes would remain dispersed while the larger flakes would be found in the sediment [35].”