Inverted vortex fluidic exfoliation and scrolling of hexagonal-boron nitride

Abstract

Exfoliation or scrolling of hexagonal boron nitride (h-BN) occurs in a vortex fluidic device (VFD) operating under continuous flow, with a tilt angle of À45 relative to the horizontal position. This new VFD processing strategy is effective in avoiding the build-up of material that occurs when the device is operated using the conventional tilt angle of +45 , where the h-BN precursor and scrolls are centrifugally held against the wall of the tube. At a tilt angle of À45 the downward flow aided by gravity facilitates material exiting the tube with the exfoliation of h-BN and formation of h-BN scrolls then optimized by systematically varying the other VFD operating parameters,including flow rate and rotational speed, along with concentration of h-BN and the choice of solvent. Water was the most effective solvent, which enhances the green chemistry metrics of the processing.

Continuous flow vortex fluidic-mediated exfoliation and fragmentation of two-dimensional MXene

“…7: 192255 electronic supplementary material, figure S4. We note that −45°tilt angle was effective in exfoliating h-BN in water [22]. Varying the different operating parameters of the VFD led to determining the optimal conditions for the exfoliation of MXene and the highest yield of material exiting (collected) the tube under continuous flow.…”

Vortex Fluidic Mediated Synthesis of TiO2 Nanoparticle/MXene Composites

“…The dynamic thin film in VFD is also effective in exfoliating other 2D materials including graphene and h ‐BN, with and without scrolling . In the present study, treating MXene with aqueous H 2 O 2 prior to VFD processing (batch processing) reduced the thickness of the MXene starting material from 10 μm to a few hundred nanometres, presumably driven by surface oxidation along dislocations in the material, Figure S5(d‐f).…”

“…[32] This is a proven approach for then translating any reaction into a continuous flow process, which is the other mode of operation of the VFD, Figure 1. [33] The VFD is a versatile thin film device effective for a growing number of applications, including in situ decorating h-BN with magnetite nanoparticles, [34] fabricating carbon dots from multi-walled carbon nanotubes, [35] chemo selective hydrogenation using cellulose impregnated with Pd NPs lining the VFD tube, [36] organic synthesis, [37][38] probing the structure of self-organised systems, [39][40] exfoliation and scrolling of h-BN and graphite, [41][42][43] slicing CNTs, [44][45] to mention a few. [41,[46][47][48][49][50][51][52][53][54] The VFD typically houses a borosilicate glass tube (O.D.…”

Tuning Surface Morphology of Fluorescent Hydrogels Using a Vortex Fluidic Device

“…One study reported the preparation of silica hydrogel using a VFD without the need for auxiliary reagents (solvent, acid, or base), promoting a new route for green chemistry. It was reported that the condensation of VFD- The VFD is a relatively low-cost research platform assisting efficient micromixing of chemicals and reactions, material synthesis, and both top-down and bottom-up strategies for the manufacture of nanoscale materials with complex structures, suggesting a range of benefits over conventional methods [63][64][65]. We successfully utilized a VFD for one-step fabrication of several physically and ionically crosslinked hydrogels with simultaneous control over their properties and surface morphology [66].…”