Tuyển tập các báo cáo nghiên cứu về hóa học được đăng trên tạp chí hóa hoc quốc tế đề tài : A study on the effect of different chemical routes on functionalization of MWCNTs by various groups (-COOH, -SO3H, -PO3H2) | Kumar et al. Nanoscale Research Letters 2011 6 583 http content 6 1 583 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access A study on the effect of different chemical routes on functionalization of MWCNTs by various groups -COOH -SO3H -PO3H2 1 2 1 1 2 Pawan Kumar Jin-Soo Park Prabhsharan Randhawa Sandeep Sharma Mun-Sik Shin and Satpal Singh Sekhon1 Abstract Pristine multiwall carbon nanotubes MWCNTs have been functionalized with various groups -COOH -SO3H -PO3H2 using different single- and double-step chemical routes. Various chemical treatments were given to MWCNTs using hydrochloric nitric phosphoric and sulphuric acids followed by a microwave treatment. The effect of the various chemical treatments and the dispersion using a surfactant via ultrasonication on the functionalization of MWCNTs has been studied. The results obtained have been compared with pristine MWCNTs. Scanning electron microscopy energy dispersive X-ray EDX spectroscopy and transmission electron microscopy confirm the dispersion and functionalization of MWCNTs. Their extent of functionalization with -SO3H and -PO3H2 groups from the EDX spectra has been observed to be higher for the samples functionalized with a double-step chemical route and a single-step chemical route respectively. The D G ratio calculated from Raman data shows a maximum defect concentration for the sample functionalized with the single-step chemical treatment using nitric acid. The dispersion of MWCNTs with the surfactant Triton X-100 via ultrasonication helps in their unbundling but the extent of functionalization mainly depends on the chemical route followed for their treatment. The functionalized carbon nanotubes can be used in proton conducting membranes for fuel cells. Keywords functionalization carbon nanotubes dispersion surfactant Introduction Currently carbon nanotubes CNTs are the state-of-the-art materials actively studied by both experimentalists and theoreticians
