X-RAY ABSORPTION IMPROVEMENT OF SINGLE WALL CARBON NANOTUBE THROUGH METAL ENCAPSULATION; PENINGKATAN KEMAMPUAN SERAPAN SINGLE WALL CARBON NANOTUBE TERHADAP SINAR-X MELALUI ENKAPSULASI LOGAM

ALIMIN, Sri Juari Santosa

2015 | Tesis | FMIPA

Since single wall carbon nanotube (SWCNT) has extraordinary properties such as cylindrical structure and relatively high electromagnetic attenuation, it is then projected to be one of the most promising candidates of the electromagnetic radiation protective nanomaterials. In this study, SWCNT-Meijo and SG (super growth)-SWCNT denoted as SWCNT1 and SWCNT2, respectively have been selected. Despite SWCNT is potentially to offer protection against the radiation such as X-ray radiation, the X-ray absorption improvement of SWCNT1 through metal encapsulation is still necessary to be realized. Prior to encapsulation, the appropriate methods for opening the end caps both of SWCNT and purifying SWCNT1 as well as introducing silver (Ag), gadolinium (Gd), and gold (Au) in the internal wall of nanotube need to be studied. Thermal oxidation both of SWCNT has been performed for opening end caps of the nanotube while the remained catalysts of the SWCNT1 have been removed by acid treatment. The treated SWCNTs were then applied for metal encapsulation. A relatively simple liquid phase adsorption technique using ethanol has been employed for metals encapsulation inside the opened end cap of the nanotube. The non-doped and metal doped SWCNT samples were characterized by nitrogen adsorption isotherms, Raman spectroscopy, X-ray Diffraction (XRD), thermal gravimetric analysis-differential thermal analysis (TGA-DTA), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. X-ray absorption improvement of the SWCNT1 after metal encapsulation was examined by X-ray equipment of RIGAKU 2300 SF/RDF using a monochromatic incident X-ray beam of MoK?. The increases of surface area and micropore volume of the treated SWCNT suggest that the end caps of the tubes have been opened successfully by this method. TGA data indicate that nearly all the catalyst remains in the SWCNT1 are removed completely by the acid treatment. The produced metal nanoparticles have been encapsulated successfully in the nanotubes as observed by TEM images. In addition, the supporting evidences of the metal nanoparticles encapsulated inside the nanotube are suggested by the decreases of nitrogen uptake of nitrogen adsorption isotherms and diffraction intensity of 1 0 peaks of XRD, and upshifts of radial breathing mode (RBM) as well as G band of Raman spectra of metal doped SWCNT (M@SWCNT) specimens. It was found that the mass attenuation coefficient (?) of the SWCNT increases significantly about 2.4, 3.0 and 14.0-fold after encapsulating with Ag, Gd and Au, respectively.

Kata Kunci : X-ray absorption; mass attenuation coefficient; silver; gold; gadolinium; nanoparticles; SWCNT