Highly Concentrated Aqueous Suspensions of Graphene through Ultrasonic Exfoliation with Continuous Surfactant Addition
Highly Concentrated Aqueous Suspensions of Graphene through Ultrasonic Exfoliation with Continuous Surfactant Addition
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DOI：
10.1021/la302750e
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发表时间：
2012-10-09
期刊：
影响因子：
3.9
通讯作者：
Notley, Shannon M.
中科院分区：
文献类型：
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作者：
Notley, Shannon M.
使用超声剥离制备用表面活性剂稳定的石墨烯的高度浓缩的悬浮液。通过在剥离过程中连续添加表面活性剂，达到了高达1.5%w/w（15 mg/mL）的浓度。先前的方法通常在超声处理开始之前仅添加表面活性剂一次。通过分层可获得的固-液界面面积的巨大增加导致表面活性剂通过吸附从溶液中快速耗尽。这导致液体-蒸气表面张力的变化超出用于有效生产石墨烯片的最佳范围。通过在超声处理和石墨烯表面积的产生期间连续更换表面活性剂以降低表面张力，颗粒的浓度显著增加。研究了阳离子、阴离子和非离子表面活性剂，并且所有表面活性剂都显示出使用这种连续添加方法生产的石墨烯的浓度显著增加。
Highly concentrated suspensions of graphene stabilized with surfactant were prepared using ultrasonic exfoliation. Concentrations of up to 1.5% w/w (15 mg/mL) were achieved through the continuous addition of the surfactant during the exfoliation process. Previous methods typically add the surfactant only once, prior to the commencement of sonication. The vast increase in the available solid-liquid interfacial area through delamination results in the rapid depletion of the surfactant from solution through adsorption. This leads to a change in the liquid-vapor surface tension outside of the optimum range for the efficient production of graphene sheets. By continuously replacing the surfactant to lower the surface tension during sonication and the production of the graphene surface area, the concentration of particles was significantly increased. Cationic, anionic, and nonionic surfactants were studied and all showed significant increases in the concentration of graphene produced using this continuous addition method.