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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-22 2:14 |
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Conference: Bucharest University Faculty of Physics 2015 Meeting
Section: Polymer Physics
Title:
FTIR investigation of the ageing process of carbon nanowalls
Authors:
Valentina MARASCU(1,2), Sorin VIZIREANU(2), Silviu-Daniel STOICA(2), Valentin BARNA(1), Andrada LAZEA-STOYANOVA(2), Gheorghe DINESCU(1,2)
Affiliation:
1) Faculty of Physics, University of Bucharest, 405 Atomistilor Street, 077125 Bucharest- Magurele, Romania
2) National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor Street, 077125 Bucharest– Magurele, Romania
E-mail
valentina.marascu@gmail.com
Keywords:
ageing process, carbon nanowalls, FTIR, surface chemical change
Abstract:
Carbon nanowalls layers consists of vertical walls of graphene sheets having thicknesses in the range of tens of nm and lengths of the microns size. In our paper we investigate the changes that occur in the chemical composition of carbon nanowalls samples due to ageing process in open atmosphere. The carbon nanowalls layers were prepared by radiofrequency plasma-enhanced chemical vapour deposition by using different nozzles (graphite and molybdenum). We have used argon as main gas and a mixture of acetylene and hydrogen as precursor. The substrate utilized was thin silicon wafer transparent to infrared radiation. The studied carbon nanowalls had different thicknesses and sizes. The morphology of the samples was investigated by Scanning Electron Microscope, Atomic Force Microscope and their chemical composition by FTIR spectrometer. Ageing process of the carbon nanowalls samples was monitored, for about two years, with the FTIR spectrometer. The ageing behaviour of carbon nanowalls samples is related to the appearance, in time, of deformation and stretching of the sp2 and sp3 vibration bands in three different regions (1000- 1200cm-1 , 1500- 1600 cm-1and 2850-2950 cm-1 respectively). The modification of these bands in time is presented. Unlike the sample obtained with graphite nozzle, the material made with molybdenum nozzle has an earlier ageing.
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