Precise Single‐Step Electrophoretic Multi‐Sized Fractionation of Liquid‐Exfoliated Nanosheets

• Published in: Advanced functional materials 2018-07, Vol.28 (29), p.n/a
• Main Authors: Tay, Dousabel M. Y., Li, Bang Lin, Tan, Eveline S. L., Loh, Kian Ping, Leong, David Tai
• Format: Article
• Language: English
• Subjects: agarose gel electrophoresis; Banding; bioapplications, exfoliation; Dependence; Electrophoresis; Exfoliation; few‐layer nanoflakes; Fractionation; Materials science; Molybdenum disulfide; Nanomaterials; nanomedicine, size fractionation; Nanosheets; Size distribution; transition metal dichalogenides
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.201801622

Transition metal dichalcogenides (TMDs) 2D nanomaterials' integration into the industry has been hampered by the ability to mass produce nanosheets of designed sizes. Large‐scale exfoliation is possible with liquid‐phase exfoliation, but precise subsequent isolation of a specified size dimension has yet to be realized. Herein, a precise and efficient method for both size fractionation and nanosheet retrieval is demonstrated using electrophoretic isolation of MoS2 nanosheets in low melting agarose. This can be applied to find out the relative size distribution and sizes within a sample of MoS2. Fractionation can be estimated visually by the relative spread of sizes based on their banding within the agarose. The additional degrees of freedom conferred by the agarose allow for more precise design and control over the size selection process. This serves as a quick and easy method of discerning and isolating the desired size range of MoS2 for further downstream applications in a single step. Nanosheets separated by the procedure retain their structural properties and display size dependency shown empirically and theoretically. This technique is versatile and can be varied according to the needs. It may truly bring large‐scale isolation that much needed step closer to industrial scale production. Electrophoretic migration of 2D nanosheets in a gel matrix is exploited to achieve effectual size selection with tunable precision. Driven by bovine serum albumin, nanosheets exhibit exponential increases in mobility with decreasing size like DNA electrophoresis. Such understanding paves the way for predictive models and subsequently powerful tools for simultaneous isolation and identification of size fractions.