수성 그래핀 박리
Ultrasonic exfoliation allows to produce few-layer graphene without the use of harsh solvents using pure water only. High-power sonication delaminates graphene sheets within a short treatment. The avoidance of solvents turns graphene exfoliation in a green, sustainable process.
Graphene Production via Liquid Phase Exfoliation
Graphene is commercially manufactured via so-called liquid phase exfoliation. Liquid phase exfoliation of graphene requires the use of toxic, environmentally harmful, and expensive solvents, which is used as chemical pre-treatment or in combination to/with a mechanical dispersion technique. For mechanical dispersion of the graphene sheets, ultrasonication has been established as highly reliable, efficient and safe technique to produce high-quality graphene sheets in large quantities on fully-industrial level. Since the use of harsh solvents is always accompanied with costs, contamination, complex removal and disposal, safety concerns as well as environmental burden, a non-toxic and safer alternative is significantly advantageous. Graphene exfoliation using water as solvent and power ultrasound for mechanical delamination of few layer graphene sheets is therefore a highly promising technique for a green graphene manufacturing.
Common solvents, which are often used as liquid phase to disperse graphene nanosheets, include Dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), N-methyl-2-pyrrolidone (NMP), Tetramethylurea (TMU), Tetrahydrofuran (THF), propylene carbonateacetone (PC), ethanol, and formamide.
As an already long-term established technique for graphene exfoliation on commercial scale, ultrasonication enables to produce high-quality graphene of high purity at low cost. As ultrasonic graphene exfoliation can be completely linear scaled to any volume, the production yield of high-quality graphene flakes can be easily implemented for mass production of graphene.
The UIP2000hdT is a 2kW powerful ultrasonic disperser for graphene exfoliation and dispersion.
Ultrasonic Exfoliation of Graphene in Water
Tyurnina et al. (2020) investigated the effects of amplitude and sonication intensity on pure water-graphite solutions and the resulting graphene exfoliation. In the study, they used a Hielscher UP200S (200W, 24kHz). Ultrasonic exfoliation using water was applied as a single step process for few layer graphene delamination. A short treatment of 2h was sufficient to produce few-layer graphene in an open beaker sonication setup.
물에서 흑연 플레이크의 음파 기계적 박리를 보여주는 프레임의 고속 시퀀스(a에서 f까지) using the UP200s, a 24 kHz ultrasonicator with 3-mm sonotrode. 화살표는 캐비테이션 버블이 분할을 관통하는 분할(박리) 위치를 보여줍니다.
© Tyurnina et al., 2020
Optimization of Ultrasonic Graphene Exfoliation
The ultrasonic setup used by Tyurnina et al. (2020) can be easily optimized for more efficiency and faster exfoliation by using a closed ultrasonic reactor in flow-through mode. Ultrasonic inline treatment allows for a significantly more uniform ultrasonic treatment of all graphite raw material: feeding the graphite / water solution directly into the confined space of ultrasonic cavitation, all graphite becomes uniformly sonicated resulting in a high yield of high-quality graphene flakes.
Hielscher Ultrasonics systems allow for precise control over all important processing parameters such as amplitude, time / retention, energy input (Ws/mL), pressure, and temperature. Setting the optimum ultrasonic parameters results in highest yield, quality and overall efficiency.
How Does Ultrasonication Promote Graphene Exfoliation
When high-power ultrasound waves are coupled into a slurry of graphite powder and water or any solvent, sonomechanical forces such as high-shear, intense turbulences and high pressure and temperature differentials create energy-intense conditions. These energy-intense conditions are the result of the phenomenon of acoustic cavitation.
Read more about ultrasonic cavitation here!
The power ultrasound initiates the expanding of the graphite powder, since fluids are pressed between the graphene layers, of which graphite is composed. The ultrasonic shear forces delaminate the single sheets of graphene and disperse them as graphene flakes in the solution. To obtain long-term stability of graphene in water, a surfactant is required.
Mechnism of ultrasonic liquid phase exfoliation of graphene exfoliation.
Study and picture by Tyurnina et al., 2021.
High-Performance Ultrasonicators for Graphene Exfoliation
The smart features of Hielscher ultrasonicators are designed to guarantee reliable operation, reproducible outcomes and user-friendliness. Operational settings can be easily accessed and dialled via intuitive menu, which can be accessed via digital colour touch-display and browser remote control. Therefore, all processing conditions such as net energy, total energy, amplitude, time, pressure and temperature are automatically recorded on a built-in SD-card. This allows you to revise and compare previous sonication runs and to optimize the graphene exfoliation process to highest efficiency.
Hielscher Ultrasonics systems are used worldwide for the manufacturing of high-quality graphene sheets and graphene oxides. Hielscher industrial ultrasonicators can easily run high amplitudes in continuous operation (24/7/365). Amplitudes of up to 200µm can be easily continuously generated with standard sonotrodes (ultrasonic probes / horns and 캐스캐트로데스™). For even higher amplitudes, customized ultrasonic sonotrodes are available. Due to their robustness and low maintenance, our ultrasonic exfoliation systems are commonly installed for heavy duty applications and in demanding environments.
Hielscher ultrasonic processors for graphene exfoliation are already installed worldwide on commercial scale. Contact us now to discuss your graphene manufacturing process! Our well-experienced staff will be glad to share more information on the exfoliation process, ultrasonic systems and pricing!
To learn more about ultrasonic graphene synthesis, dispersion and functionalization, please click here:
| 배치 볼륨(Batch Volume) | 유량 | 권장 장치 |
|---|---|---|
| 1 내지 500mL | 10 내지 200mL/분 | 업100H |
| 10 내지 2000mL | 20 내지 400mL/분 | UP200HT, UP400ST |
| 0.1 내지 20L | 0.2 내지 4L/min | UIP2000hdT 님 |
| 10에서 100L | 2 내지 10L/min | UIP4000hdt 님 |
| N.A. 개시 | 10 내지 100L/min | UIP16000 |
| N.A. 개시 | 큰 | 의 클러스터 UIP16000 |
문의! / 저희에게 물어보세요!
Hielscher 초음파는 실험실, 파일럿 및 산업 규모에서 혼합 응용 분야, 분산, 유화 및 추출을위한 고성능 초음파 균질화기를 제조합니다.
문헌 / 참고문헌
- FactSheet: Ultrasonic Graphene Exfoliation and Dispersion – Hielscher Ultrasonics – english version
- FactSheet: Exfoliación y Dispersión de Grafeno por Ultrasonidos – Hielscher Ultrasonics – spanish version
- Anastasia V. Tyurnina, Iakovos Tzanakis, Justin Morton, Jiawei Mi, Kyriakos Porfyrakis, Barbara M. Maciejewska, Nicole Grobert, Dmitry G. Eskin (2020): Ultrasonic exfoliation of graphene in water: A key parameter study. Carbon Vol. 168, 2020. 737-747.
(Available under a Creative Commons Attribution 4.0: CC BY-NC-ND 4.0. See full terms here.) - Štengl V., Henych J., Slušná M., Ecorchard P. (2014): Ultrasound exfoliation of inorganic analogues of graphene. Nanoscale Research Letters 9(1), 2014.
- Unalan I.U., Wan C., Trabattoni S., Piergiovannia L., Farris S. (2015): Polysaccharide-assisted rapid exfoliation of graphite platelets into high quality water-dispersible graphene sheets. RSC Advances 5, 2015. 26482–26490.
- Bang, J. H.; Suslick, K. S. (2010): Applications of Ultrasound to the Synthesis of Nanostructured Materials. Advanced Materials 22/2010. pp. 1039-1059.
- Štengl, V.; Popelková, D.; Vlácil, P. (2011): TiO2-Graphene Nanocomposite as High Performance Photocatalysts. In: Journal of Physical Chemistry C 115/2011. pp. 25209-25218.
알아 둘 만한 가치가 있는 사실
What is Graphene?
그래핀은 sp의 단층입니다.2-결합 된 탄소 원자. 그래핀은 매우 큰 비표면적(2620m)과 같은 독특한 재료 특성을 제공합니다.2g-1), 1 TPa의 영률 및 130 GPa의 고유 강도, 매우 높은 전자 전도성(2.5 × 105cm의 실온 전자 이동도)을 가진 우수한 기계적 특성2 V-1s-1), 매우 높은 열전도율(3000W m K 이상)-1)을 사용하여 가장 중요한 속성의 이름을 지정할 수 있습니다. 그래핀은 우수한 재료 특성으로 인해 고성능 배터리, 연료 전지, 태양 전지, 슈퍼 커패시터, 수소 저장, 전자기 차폐 및 전자 장치의 개발 및 생산에 많이 사용됩니다. 또한, 그래핀은 폴리머, 세라믹 및 금속 매트릭스와 같은 강화 첨가제로 많은 나노 복합 재료 및 복합 재료에 통합됩니다. 높은 전도성으로 인해 그래핀은 전도성 페인트와 잉크의 중요한 구성 요소입니다.
The rapid and safe ultrasonic preparation of defect-free graphene at large volumes at low costs allows for widening the applications of graphene to more and more industries.
Graphene is a one-atom-thick layer of carbon, which can be described as a single-layer or 2D structure of graphene (single layer graphene = SLG). Graphene has an extraordinarily large specific surface area and superior mechanical properties (Young’s modulus of 1 TPa and intrinsic strength of 130 GPa), offers great electronic and thermal conductivity, charge carrier mobility, transparency, and is impermeable to gases. Due to these material characteristics, graphene is used as reinforcing additive to give composites its strength, conductivity, etc. In order to combine the characteristics of graphene with other materials, graphene must be dispersed into the compound or is applied as a thin-film coating onto a substrate.
고성능 초음파! Hielscher의 제품 범위는 벤치 탑 장치를 통한 소형 실험실 초음파에서 전체 산업용 초음파 시스템에 이르기까지 전체 스펙트럼을 포괄합니다.