The covalent functionalization of multi-walled carbon nanotubes (MWCNTs) with a proline-based derivative is reported. Initially, MWCNTs were oxidized in order to introduce a large number of carboxylic units on their tips followed by N-tert-butoxycarbonyl-2,2'(ethylenedioxy)bis-(ethylamine) conjugation through an amide bond. Then, a proline derivative bearing a carboxylic terminal moiety at the ...

The sorption properties of natural organic matter (NOM) with oxidized multiwalled carbon nanotubes (O-MWCNTs) in simple electrolytes has been studied, as well as the effect that NOM concentration, pH, and O-MWCNT surface chemistry have on CNT stability under environmentally relevant conditions. As O-MWCNT oxygen content increased, NOM sorption decreased in simple electrolytes for a common set o...

Background and purpose:The presence of dyes in wastewaters may cause serious problems for the environment because of their high toxicity to aquatic organisms and unfavorable aesthetical impact. In the present study, multi-walled carbon nanotubes (MWCNTs) were used for removal of anionic dyes Direct Blue 106 (DB106) and Acid Green 25 (AG25), from water samples. Materials and Methods:MWCNTs were ...

The effects of surface modifications of multi-walled carbon nanotubes (MWCNTs) on the morphology, dynamic mechanical and tribological properties of multi-walled carbon nanotube/poly (ether ether ketone) (MWCNT/PEEK) composites have been investigated. MWCNTs were treated with mixed acids to obtain acid-functionalized MWCNTs. Then the acid-functionalized MWCNTs were modified with ethanolamine (na...

This paper provides results from studies of the transport of oxidized multi-walled carbon nanotubes (O-MWCNTs) of varying surface oxygen concentrations under a range of aquatic conditions and through uniform silica glass bead media. In the presence of Na(+), the required ionic strength (IS) for maximum particle attachment efficiency (i.e., the critical deposition concentration, or CDC) increase...

we report the enhanced capacitance of the multi-walled carbon nanotubes (mwcnts) after a chemical unzipping process in concentrated sulfuric acid (h2so4) and potassium permanganate (kmno4). the effects of the test duration and temperature were investigated on the unzipping process of the mwcnts to synthesize the graphene oxide nanoribbons. the sem and tem studies were carried out on untreated a...

In the present study, a surface-active enzyme, lipase was immobilized in polyethyleneimine (PEI) microcapsules and then modified with oxidized multiwall carbon nanotubes (MWCNTs). The resulting lipase microcapsules exhibited higher activity and stability, since the activity of microcapsules was 21.9 folds than that of the free counterpart. Numerous interfaces which were created in polycondensat...

Multiwalled carbon nanotubes (MWCNTs) have a great potential in wide applications but faces limitation in term of dispersion feasibility. The aggregation of MWCNTs floss has restricted its usage and thus, acid treatment is expected to promote the MWCNTs reaggregation. The functionalization process of MWCNTs involves oxidation reaction using mild aqueous acid mixture of HNO3 and H2SO4 (1:3 v/v),...

Background: The presence of heavy metals in the environment especially in water supplies have caused many concerns because of their toxicity and non-degradability. Hexavalent Chromium (Cr) is one of the most toxic metals which is used in many industries, so it is essential to remove it from industrial wastewater. In this study, we made a comparison between different adsorption isotherms in the ...