TY - JOUR
T1 - A Novel Fabrication of 3.6 nm High Graphene Nanochannels for Ultrafast Ion Transport
AU - Jung, Wonsuk
AU - Kim, Jangheon
AU - Kim, Soohyun
AU - Park, Hyung Gyu
AU - Jung, Yousung
AU - Han, Chang Soo
N1 - Funding Information:
This work was supported by a Nano Material Fundamental Research (2012M3A7B4049863), Center for Advanced Soft Electronics and Basic Science Research Program (2015-01005931, 2016R1C1B1014978) through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and future Planning (MSIP) in Korea.
PY - 2017/5/3
Y1 - 2017/5/3
N2 - Graphene-based 2D nanochannels of 3.6, 10, and 50 nm heights and a 2μm width with rectangular shapes were fabricated for the first time, and their ion transport properties were reported. The fabrication options of nanochannel inscription and the novel technique of graphene conformal coating altogether enabled to create graphitic nanoconfinements with no limitation to particular nanomaterials, such as carbon nanotube, thereby leading to diversified investigation of the unique nanofluidic phenomena in the graphitic environment. Thus, prepared 3.6 nm high graphene nanochannels take a clean and smooth surface and show ionic conductance =115 times larger than that in the SiO2/Si nanochannels. As the ion concentration increases, the Debye length decreases to become smaller than the channel height, augmenting electroosmotic ion transport and plug flow. Therefore, as the ion concentration and channel size increase, so does the ionic conductance. In the case of the hydrophilic surface, there is the immobile stern layer having a zero slip length. On the other hand, the hydrophilic SiO2 channels having small slip length present low ion transport rate. In addition, the potential surface effects due to the substrate can affect fluid velocity and ion transport through the nanochannel.
AB - Graphene-based 2D nanochannels of 3.6, 10, and 50 nm heights and a 2μm width with rectangular shapes were fabricated for the first time, and their ion transport properties were reported. The fabrication options of nanochannel inscription and the novel technique of graphene conformal coating altogether enabled to create graphitic nanoconfinements with no limitation to particular nanomaterials, such as carbon nanotube, thereby leading to diversified investigation of the unique nanofluidic phenomena in the graphitic environment. Thus, prepared 3.6 nm high graphene nanochannels take a clean and smooth surface and show ionic conductance =115 times larger than that in the SiO2/Si nanochannels. As the ion concentration increases, the Debye length decreases to become smaller than the channel height, augmenting electroosmotic ion transport and plug flow. Therefore, as the ion concentration and channel size increase, so does the ionic conductance. In the case of the hydrophilic surface, there is the immobile stern layer having a zero slip length. On the other hand, the hydrophilic SiO2 channels having small slip length present low ion transport rate. In addition, the potential surface effects due to the substrate can affect fluid velocity and ion transport through the nanochannel.
KW - graphene nanochannels
KW - hydrophobic surfaces
KW - ion transport
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U2 - 10.1002/adma.201605854
DO - 10.1002/adma.201605854
M3 - Article
C2 - 28220978
AN - SCOPUS:85013428347
VL - 29
JO - Advanced Materials
JF - Advanced Materials
SN - 0935-9648
IS - 17
M1 - 1605854
ER -