121st General Meeting of the KCS

Type Poster Presentation
Area Material Chemistry
Room No. Event Hall
Time 4월 20일 (금요일) 11:00~12:30
Code MAT.P-477
Subject Fabrication of carbon nanotube membranes attached on a glass capillary for the detection of individual ions
Authors Hyegi Min, Chang Young Lee*
Chemical engineering, Ulsan National Institute of Science and Technology, Korea
Abstract We developed a nanopore platform with improved reproducibility in terms of both fabrication and the detection of ionic species, using centimeter-long and horizontally aligned carbon nanotubes having average diameter of 4 nm. Carbon nanotubes were embedded into an epoxy matrix and microtomed with 10 μm thickness, resulting in fabrication of hundreds of carbon nanotube membranes having identical pores. The membrane attached on a glass capillary can be directly used for the measurement of pore-blocking events caused by cations, and switching between different analytes is done simply by dipping the capillary into another solution. The noise level was also reduced by using glass capillaries with smaller inner diameter. This platform allows for the statistical prediction of the threshold voltage for the ions to enter the pores, by recording IV-curves based on repeated voltage-ramping protocol. The threshold voltages for K+, Na+, and Li+ were -90 mV, -30 mV, and -10 mV, respectively. The mobility values estimated from the blocking events at each bias were 7.59 x 10-8 m2/Vs, 3.56 x 10-8 m2/Vs, and 4.95 x 10-9 m2/Vs for K+, Na+, and Li+, respectively, which are lower than the values previously reported from the pores of single-walled carbon nanotubes.
E-mail hg_1122@naver.com