Amidation of multiwalled carbon nanotubes in mild and efficient conditions.

Functionalization of Multi Walled Carbon Nanotubes (MWCNTs) with amines under a two step reaction is studied. In the first step, maleic anhydride graft to the MWCNT (Mah-g-MWCNTs) surfaces via a polymerization process with benzoylproxide as initiator. Active anhydride groups on the surfaces of MWCNTs, react with amines to give a polyamido chain attached to the MWCNTs surfaces.

Solubilization of multi walled carbon nanotubes under a facile and mild condition.

Multi-walled carbon nanotubes (MWCNTs) functionalized with amino groups was prepared via chemical modification of carboxyl groups introduced on the carbon nanotube surfaces. Oxidation of MWCNTs was performed with ozone in aqueous phase and amidation of generated carboxylic groups, was occurred with amines in the presence of HATU as a coupling agent. Obtained functionalized MWCNTs are soluble in many common organic solvents.

Spectrophotometric study of the effects of surfactants and ethanol on the acidity constants of fluorescein.

In the present paper, a sensitive, fast and suitable method for the calculation of pK(a) values of fluorescein is proposed. The effects of sodium dodecyl sulfate (SDS) and Triton X-100 (TX-100) as a surface-active agent on the acidic and basic forms, and the spectral properties of fluorescein were studied by the spectrophotometric method. The study was performed in sub-micelle surfactant concentration, and absorption spectra at 300-550 nm intervals were recorded.

PVC-membrane ion-selective bulk optode for Ag+ ion based on hexathia-18-crown-6 and 1,2-benzo-3-octadecanoylimino-7-diethylaminophenoxazine.

A silver-selective optode membrane incorporating hexathia-18-crown-6 for cation recognition and a lipophilic chromoionophore 1,2-benzo-3-octadecanoylimino-7-diethylaminophenoxazine for transduction has been prepared. The PVC membrane composition was optimized to result in the largest working concentration range. The response range of the proposed optode is 5.