생화학 센서용 탄소나노튜브 내장형 나노웹 전극의 전기적 임피던스 특성

In this study, carbon nanotube (CNT) based nanoweb electrodes were fabricated and their electrical impedance properties were investigated to develop chemical sensors and biosensors. The nanoweb electrodes were fabricated with multi-wall CNT(MWCNT) based on PAN using an electrospinning technique. The morphology of the nanoweb electrode was investigated utilizing SEM and TEM. With various amounts of buffer solution, the electrical impedance of the composite electrodes was measured using an LCR meter. The capacitance values showed drastic increments while the resistance values only changed within a few percent range. It is found that the addition of CNTs to a nanofiber web can improve not only the sensitivity but also the linearity of a nanoweb compared to a no-CNT web electrode. Since CNTs have excellent electrochemical properties, the electrical impedance of nanoweb embedded CNTs may be remarkably changed by the ions produced by a buffer solution, and this improves the sensing response of the nanoweb electrode consequently

Nanotechnology convergence and modeling paradigm of sustainable energy system using polymer electrolyte membrane fuel cell as a benchmark example

Developments in nanotechnology have led to innovative progress and converging technologies in engineering and science. These demand novel methodologies that enable efficient communications from the nanoscale all the way to decision-making criteria for actual production systems. In this paper, we discuss the convergence of nanotechnology and novel multi-scale modeling paradigms by using the fuel cell system as a benchmark example. This approach includes complex multi-phenomena at different time and length scales along with the introduction of an optimization framework for application-driven nanotechnology research trends. The modeling paradigm introduced here covers the novel holistic integration from atomistic/molecular phenomena to meso/continuum scales. System optimization is also discussed with respect to the reduced order parameters for a coarse-graining procedure in multi-scale model integration as well as system design. The development of a hierarchical multi-scale paradigm consolidates the theoretical analysis and enables large-scale decision-making of process level design, based on first-principles, and therefore promotes the convergence of nanotechnology to sustainable energy technologies

The synthesis of crystalline SnO2 whiskers via a metalorganic chemical vapor deposition process

We demonstrate the synthesis of one-dimensional (1D) structures of tin oxide (SnO2) by a reaction of a tetramethyltin (Sn(CH3)4)) and oxygen (O2) mixture at 800 ο C. Scanning electron microscopy showed that the morphology of the products was changed by varying the growth temperature. 1D and 2D structures were favored at 800 and 600 ο C, respectively. We suggest the associated mechanisms by which the temperature controlled the morphology. X-ray energy dispersive spectroscopy revealed that the products contained elements of Sn and O. X-ray diffraction, selected area electron diffraction, and latticeresolved transmission electron microscopy indicated that the SnO2 obtained were crystalline with a tetragonal structure. The Raman spectra exhibited three normal interior phonon modes corresponding to the tetragonal rutile SnO2 structure. The intensity of yellow photoluminescence emission increased with an increasing growth temperature in the range of 700-800 ο C