The impedance characterization of Carbon Nanotubes - Fumed Silica Poly (vinyl alcohol) Composites

International Conference on Chemical and Bioprocess Engineering

地球科学;化学;生物科学

Othman, R.N.^1,2 ; Wilkinson, A.N.^1

Materials Science Centre, School of Materials, University of Manchester, Grosvenor Street, Manchester

M13 9PL, United Kingdom^1

Department of Mechanical Engineering, National Defence University Malaysia, Kem Sungai Besi, Kuala Lumpur

57000, Malaysia^2

关键词: Chemical vapor deposition methods;    Composite processing;    Electrically conductive;    Floating catalyst method;    Impedance characterization;    Impedance measurement;    Impregnation methods;    Percolation thresholds;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/36/1/012010/pdf
DOI  :  10.1088/1755-1315/36/1/012010

学科分类：生物科学（综合）

来源: IOP

【 摘 要 】

Carbon Nanotube (CNT) was grown on the surface of fumed silica via chemical vapor deposition (CVD) method. In this work, silica acted as a site that holds CNT together, which prevents further agglomeration during composite processing. Iron catalyst at different loading (7.5 wt. % up to 25 wt. %) was introduced via impregnation method to synthesize CNT at 1000°C, under methane flow. Floating catalyst method was used where ferrocene (2.5 wt. % and 5 wt. %) was used as starting reactants together with toluene at 760°C. The reaction time was set at 1 hour for both methods. It was later confirmed via SEM images that the floating catalyst method is more suitable to produce a large amount of CNTs. The sample synthesized via floating catalyst method at both 2.5 wt.% and 5 wt. % ferrocene was later used to prepare composites. Composite films of the particles in poly (vinyl alcohol) (PVOH) were cast and their TEM images show that the dispersion is indeed uniform. From impedance measurement, it was found that the particles synthesized via floating catalyst method were found to form an electrically-conductive percolated network with percolation threshold of 1 wt. %, obtained via percolation equation.