title: Extremely efficient liquid exfoliation and dispersion of layered materials by unusual acoustic cavitation.
abstract: Layered materials must be exfoliated and dispersed in solvents for diverse applications. Usually, highly energetic probe sonication may be considered to be an unfavourable method for the less defective exfoliation and dispersion of layered materials. Here we show that judicious use of ultrasonic cavitation can produce exfoliated transition metal dichalcogenide nanosheets extraordinarily dispersed in non-toxic solvent by minimising the sonolysis of solvent molecules. Our method can also lead to produce less defective, large graphene oxide nanosheets from graphite oxide in a short time (within 10 min), which show high electrical conductivity (>20,000 S m(-1)) of the printed film. This was achieved by adjusting the ultrasonic probe depth to the liquid surface to generate less energetic cavitation (delivered power ~6 W), while maintaining sufficient acoustic shearing (0.73 m s(-1)) and generating additional microbubbling by aeration at the liquid surface.
authors.affiliation: 1] Multidimensional Nanomaterials Research Group, Korea Electrotechnology Research Institute (KERI), Changwon 642-120, Republic of Korea [2] Department of Electrical Functionality Material Engineering, Korea University of Science and Technology (UST), Daejon, 305-333, Republic of Korea.
authors.forename: Joong Tark
authors.initials: JT
authors.lastname: Han
authors.affiliation: Multidimensional Nanomaterials Research Group, Korea Electrotechnology Research Institute (KERI), Changwon 642-120, Republic of Korea.
authors.forename: Jeong In
authors.initials: JI
authors.lastname: Jang
authors.affiliation: Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 790-784, Republic of Korea.
authors.forename: Haena
authors.initials: H
authors.lastname: Kim
authors.affiliation: Institute of Advanced Composite Materials, Korea Institute of Science and Technology (KIST), Eunha-ri san 101, Bondong-eup, Wanju-gun, Jeolabuk-do, 565-905, Republic of Korea.
authors.forename: Jun Yeon
authors.initials: JY
authors.lastname: Hwang
authors.affiliation: Nanophotonics Laboratory, Advanced Photonics Research Institute, 123 Cheomdan-gwagiro, Buk-gu, Gwangju 500-712, Republic of Korea.
authors.forename: Hyung Keun
authors.initials: HK
authors.lastname: Yoo
authors.affiliation: Nano Carbon Materials Research Group, Korea Electrotechnology Research Institute (KERI), Changwon 642-120, Republic of Korea.
authors.forename: Jong Seok
authors.initials: JS
authors.lastname: Woo
authors.affiliation: Nano Carbon Materials Research Group, Korea Electrotechnology Research Institute (KERI), Changwon 642-120, Republic of Korea.
authors.forename: Sua
authors.initials: S
authors.lastname: Choi
authors.affiliation: Nano Carbon Materials Research Group, Korea Electrotechnology Research Institute (KERI), Changwon 642-120, Republic of Korea.
authors.forename: Ho Young
authors.initials: HY
authors.lastname: Kim
authors.affiliation: Nano Carbon Materials Research Group, Korea Electrotechnology Research Institute (KERI), Changwon 642-120, Republic of Korea.
authors.forename: Hee Jin
authors.initials: HJ
authors.lastname: Jeong
authors.affiliation: Nano Carbon Materials Research Group, Korea Electrotechnology Research Institute (KERI), Changwon 642-120, Republic of Korea.
authors.forename: Seung Yol
authors.initials: SY
authors.lastname: Jeong
authors.affiliation: Nano Carbon Materials Research Group, Korea Electrotechnology Research Institute (KERI), Changwon 642-120, Republic of Korea.
authors.forename: Kang-Jun
authors.initials: KJ
authors.lastname: Baeg
authors.affiliation: Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 790-784, Republic of Korea.
authors.forename: Kilwon
authors.initials: K
authors.lastname: Cho
authors.affiliation: Nano Carbon Materials Research Group, Korea Electrotechnology Research Institute (KERI), Changwon 642-120, Republic of Korea.
authors.forename: Geon-Woong
authors.initials: GW
authors.lastname: Lee