The effect of 3-(triethoxy silyl) propyl amine concentration on surface modification of multiwall carbon nanotubes

Abstract

The influence of 3-(triethoxy silyl) propyl amine (TESPA) concentration on Multi Wall Carbon Nanotubes (MWCNTs) modification, is experimentally investigated. The MWCNTs modification were performed by 150, 75 and 25 weight percent (wt.%) of TESPA with respect to MWCNTs weight and the properties of the prepared samples were compared with each other and pristine MWCNTs. The MWCNTs silylation has been confirmed by Fourier Transformation Infrared Spectroscopy due to O-H stretching absorption peak disappearing. The 75 wt.% silyl grafted MWCNTs with increasing at about 26.7% in mean value diameters size owns more uniform morphology among the samples based on Scanning Electron Microscopy images. Also, Thermo Gravimetric Analysis shows that this sample has higher thermal stability because of lower weight loss (9.97%) in coupling agent decomposition temperature range at about 119.5–480 °C. Furthermore, X-Ray Diffraction indicates that the mentioned sample has higher level of amorphous structure with 39% reduction in crystallite size in comparison with the pristine MWCNTs. So, the 75 wt.% of TESPA introduced as the optimal concentration for this type of MWCNTs modification.HighlightsIntroduction of silyl compounds as a proper coupling agent to modify the carbon nanotube surfacesDetermination of optimal silyl compounds concentration to modify the carbon nanotube surfaceCristallinity in XRD pattern can determine the success of CNTs grafted with silyl compounds