An eco-friendly solution for liquid phase exfoliation of graphite under optimised ultrasonication conditions

Morton, Justin A.; Kaur, Amanpreet; Khavari, Mohammad; Tyurnina, Anastasia V.; Priyadarshi, Abhinav; Eskin, Dmitry; Mi, Jiawei; Porfyrakis, Kyriakos; Prentice, Paul; Tzanakis, Iakovos

doi:10.1016/j.carbon.2022.12.070

Cited by 24 publications

(22 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This observation demonstrates the benefits of this liquid combination for producing nanomaterials, where these active tiny bubbles may be a key factor for quality exfoliation as previously seen in Ref. 26.…”

Section: Resultssupporting

confidence: 80%

“…1(b)]. 26 A Photron-SA-Z 2100K camera was used at a frame rate of 100 000 fps over 640 Â 280 pixels. This setup provided the capability to capture longer duration recordings of cavitation events occurring in the liquids.…”

Section: Methodsmentioning

confidence: 99%

“…As previously reported, EtOH produces a larger cavitation cloud than DIW, and the mixture of DIW:EtOH produces a mist like cavitation, which extends the cavitation zone with smaller dispersed cavitation bubbles. 25,26 Glycerol's cavitation zone is localized at the sonotrode tip in both frequency setups with a more homogeneous waveform (indication of continuous contribution from the incident wave) and pressure surges from the DF setup. The higher viscosity of glycerol and the high vapor pressure of EtOH, both inhibiting bubble collapse, may promote bubble oscillation under the DF setup.…”

Section: B Shadowgraphic High-speed Imagingmentioning

confidence: 99%

“…The choice of these liquids was made based on previous fundamental research 25 and on the fact that their physical properties largely vary (refer to the supplementary material, Table S1) while also previously seen to be suitable for exfoliation of graphene. 26,27 It is well documented that improving exfoliation efficiency and quality depends on further analysis of solvent selection and cavitation behavior, which changes with the characteristic properties of liquids. [28][29][30] Previous research [25][26][27]31,32 provides the foundation to expect that cavitation dynamics and SW propagation may vary distinctly due to significantly different density, surface tension, viscosity, vapor pressure, and speed of sound in the studied liquids.…”

Section: Introductionmentioning

confidence: 99%

“…26,27 It is well documented that improving exfoliation efficiency and quality depends on further analysis of solvent selection and cavitation behavior, which changes with the characteristic properties of liquids. [28][29][30] Previous research [25][26][27]31,32 provides the foundation to expect that cavitation dynamics and SW propagation may vary distinctly due to significantly different density, surface tension, viscosity, vapor pressure, and speed of sound in the studied liquids. The results of this work can be applied to a wider range of dual frequency sonoprocesses where different properties are required, such as emulsification, 33 sonochemical synthesis, 34,35 in clinical practice, 36 and most notably the exfoliation of 2D nanomaterials.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Dual frequency ultrasonic cavitation in various liquids: High-speed imaging and acoustic pressure measurements

et al. 2023

Self Cite

View full text Add to dashboard Cite

Ultrasonic cavitation is used in various processes and applications, utilising powerful shock waves and high-speed liquid jets generated by the collapsing bubbles. Typically, a single frequency source is used to produce the desired effects. However, optimisation of the efficiency of ultrasound reactors is necessary to improve cavitation activity in specific applications such as for the exfoliation of two dimensional (2D) materials. This research takes the next step to investigate the effect of a dual frequency transducer system on the bubble dynamics, cavitation zone, pressure fields, acoustic spectra and induced shock waves for four liquids with a range of physical properties. Using ultra-high-speed imaging and synchronised acoustic pressure measurements, the effect of ultrasonic dual frequencies on bubble dynamics was investigated. The addition of a high frequency transducer (1174 kHz) showed that the bubble fragments and satellite bubbles induced from a low frequency transducer (24 kHz) were able to extend their lifecycle, increase spatial distribution, thus, extending the boundaries of the cavitation zone. Furthermore, this combination of ultrasonic frequencies generated higher acoustic pressures (up to 180%) and enhanced the characteristic shock wave peak, indicating more bubble collapses and the generation of additional shock waves. The dual frequency system also enlarged the cavitation cloud size under the sonotrode. These observations specifically delineated the enhancement of cavitation activity using a dual frequency system pivotal for optimisation of existing cavitation-based processing technologies.

show abstract

Section: Resultssupporting

confidence: 80%

Section: Methodsmentioning

confidence: 99%

Section: B Shadowgraphic High-speed Imagingmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Dual frequency ultrasonic cavitation in various liquids: High-speed imaging and acoustic pressure measurements

et al. 2023

Self Cite

View full text Add to dashboard Cite

show abstract

Surfactant‐Free Ultrasonication‐Assisted Synthesis of 2d Tellurium Based on Metastable 1T'‐MoTe₂

Qi,

Dai,

et al. 2023

Advanced Materials

View full text Add to dashboard Cite

Elemental two‐dimensional materials (E2DMs) have been attracting considerable attention owing to their chemical simplicity and excellent/exotic properties. However, the lack of robust chemical synthetic methods seriously limits their potential. Here, we report a surfactant‐free liquid‐phase synthesis of high‐quality 2D tellurium based on ultrasonication‐assisted exfoliation of metastable 1T'‐MoTe2. The as‐grown 2D tellurium nanosheets exhibit excellent single crystallinity, ideal 2D morphology, surfactant‐free surface, and negligible 1D by‐products. Furthermore, a unique growth mechanism based on the atomic escape of Te atoms from metastable transition metal dichalcogenides and guided 2D growth in the liquid phase was proposed and verified. 2D tellurium‐based field‐effect transistors show ultrahigh hole mobility exceeding 1000 cm2·V−1·s−1 at room temperature attributing to the high crystallinity and surfactant‐free surface, and exceptional chemical and operational stability using both solid‐state dielectric and liquid‐state electrical double layer. The facile ultrasonication‐assisted synthesis of high‐quality 2D tellurium paves the way for further exploration of E2DMs and expands the scope of liquid‐phase exfoliation (LPE) methodology towards the controlled wet‐chemical synthesis of functional nanomaterials.This article is protected by copyright. All rights reserved

show abstract

Graphene Exfoliation in Binary NMP/Water Mixtures by Molecular Dynamics Simulations

Gotzias,

Lazarou

2024

ChemPlusChem

View full text Add to dashboard Cite

We investigate the molecular mechanism underlying the liquid‐phase exfoliation of graphene in aqueous/N‐methyl‐2‐pyrrolidone (NMP) solvent mixtures and calculate the associated free energies, considering different NMP concentrations and exfoliation temperatures. We employ steered molecular dynamics to establish a path for the exfoliation of a graphene sheet from graphite within each solvent environment. Then, we conduct umbrella sampling simulations throughout the created paths to compute the potential of mean force (PMF) of the graphene sheet. As the nanosheet disperses into the liquid, it becomes fully covered by a solvent monolayer. We analyze the composition of the monolayer by measuring the contacts of either NMP or water molecules with the carbon surface. The carbon surface exhibits a preference for adsorbing NMP over water. The NMP molecules form a hydrophobic compact monolayer structure, effectively protecting the carbon interface from unfavorable interactions with water. The creation of the hydrophobic monolayer is a key factor in the exfoliation process, as it effectively inhibits the restacking of exfoliated nanosheets. An adequate level of graphene solubility is achieved through the addition of 20% to 30% water to NMP. This finding holds significant importance for improving efficiency and reducing dependence on organic solvents in the industrial manufacturing of graphene.

show abstract

An eco-friendly solution for liquid phase exfoliation of graphite under optimised ultrasonication conditions

Cited by 24 publications

References 51 publications

Dual frequency ultrasonic cavitation in various liquids: High-speed imaging and acoustic pressure measurements

Dual frequency ultrasonic cavitation in various liquids: High-speed imaging and acoustic pressure measurements

Surfactant‐Free Ultrasonication‐Assisted Synthesis of 2d Tellurium Based on Metastable 1T'‐MoTe₂

Graphene Exfoliation in Binary NMP/Water Mixtures by Molecular Dynamics Simulations

Contact Info

Product

Resources

About

An eco-friendly solution for liquid phase exfoliation of graphite under optimised ultrasonication conditions

Cited by 24 publications

References 51 publications

Dual frequency ultrasonic cavitation in various liquids: High-speed imaging and acoustic pressure measurements

Dual frequency ultrasonic cavitation in various liquids: High-speed imaging and acoustic pressure measurements

Surfactant‐Free Ultrasonication‐Assisted Synthesis of 2d Tellurium Based on Metastable 1T'‐MoTe2

Graphene Exfoliation in Binary NMP/Water Mixtures by Molecular Dynamics Simulations

Contact Info

Product

Resources

About

Surfactant‐Free Ultrasonication‐Assisted Synthesis of 2d Tellurium Based on Metastable 1T'‐MoTe₂