High‐Throughput Continuous Production of Shear‐Exfoliated 2D Layered Materials using Compressible Flows. Issue 30 (14th June 2018)

• Record Type: Journal Article
• Authors: Rizvi, Reza; Nguyen, Emily P.; Kowal, Matthew D.; Mak, Wai H.; Rasel, Sheikh; Islam, Md Akibul; Abdelaal, Ahmed; Joshi, Anup S.; Zekriardehani, Shahab; Coleman, Maria R.; Kaner, Richard B.
• Is Part Of: Advanced materials. Volume 30:Issue 30(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-06-14
• Subjects: 2D materials -- boron nitride -- compressible flow -- exfoliation -- graphene; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.201800200
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: 2D nanomaterials are finding numerous applications in next‐generation electronics, consumer goods, energy generation and storage, and healthcare. The rapid rise of utility and applications for 2D nanomaterials necessitates developing means for their mass production. This study details a new compressible flow exfoliation method for producing 2D nanomaterials using a multiphase flow of 2D layered materials suspended in a high‐pressure gas undergoing expansion. The expanded gas–solid mixture is sprayed in a suitable solvent, where a significant portion (up to 10% yield) of the initial hexagonal boron nitride material is found to be exfoliated with a mean thickness of 4.2 nm. The exfoliation is attributed to the high shear rates ( γ ˙ > 10 5 s −1 ) generated by supersonic flow of compressible gases inside narrow orifices and converging‐diverging channels. This method has significant advantages over current 2D material exfoliation methods, such as chemical intercalation and exfoliation, as well as liquid phase shear exfoliation, with the most obvious benefit being the fast, continuous nature of the process. Other advantages include environmentally friendly processing, reduced occurrence of defects, and the versatility to be applied to any 2D layered material using any gaseous medium. Scaling this process to industrial production has a strong possibility of reducing the cost of creating 2D nanomaterials. Abstract : A new method for continuously exfoliating 2D layered nanomaterials (graphite, boron nitride, molybdenum disulfide), compressible flow exfoliation (CFE), is introduced. CFE uses a multiphase flow of 2D layered materials suspended in a high‐pressure gas undergoing expansion through a fine orifice, where sufficient shear rates ( γ ˙ > 10 5 s −1 ) are generated to cause layer reduction.