Abstract:
Abstract: The aim of this dissertation is to study the effect of surface functionalization of
multiwalled carbon nanotubes (MWCNT) on their adsorption properties toward phenol. The
functionalization process was carried out by oxidation and silanization using nitric acid and
silane 3-Amino propyl triethoxy silane (APTES) coupling agent, respectively. The materials
were characterized by FTIR, XRD and TGA which have proven the good functionalization of
carbon nanotubes. We used untreated MWCNT, MWCNT-COOH, and MWCNT-APTES as
adsorbent for the removal of phenol from an aqueous solution. The adsorption property of
activated carbon was also investigated for a comparative study. The adsorption results showed
that the untreated MWCNT has negligible adsorption efficiency, however after the oxidation
with the nitric acid, the MWCNT-COOH showed an increment of the adsorption capacity up
to 45.78 mg g
-1
. Furthermore, the MWCNT grafted with APTES coupling agent present the
highest adsorption efficiency for phenol. Their maximum absorption capacity was up to
147.35 mg g
-1 with a removal of absorbent by 55.17%. The adsorption capacity of MWCNTAPTES is three times that of MWCNT-COOH, which could be explained by the increase of
the number of OH functional groups on the surface of MWCNTs grafted APTES. Finally, the
result of this work reveals that the treated MWCNT-APTES has a higher adsorption capacity
of phenol than activated carbon.
