tailieunhanh - Báo cáo hóa học: " Effect of Surfactants on the Structure and Morphology of Magnesium Borate Hydroxide Nanowhiskers Synthesized by Hydrothermal Route"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Effect of Surfactants on the Structure and Morphology of Magnesium Borate Hydroxide Nanowhiskers Synthesized by Hydrothermal Route | Nanoscale Res Lett 2010 5 149-157 DOI S11671-009-9457-9 NANO EXPRESS Effect of Surfactants on the Structure and Morphology of Magnesium Borate Hydroxide Nanowhiskers Synthesized by Hydrothermal Route Latha Kumari W. Z. Li Shrinivas Kulkarni K. H. Wu Wei Chen Chunlei Wang Charles H. Vannoy Roger M. Leblanc Received 5 August 2009 Accepted 26 September 2009 Published online 13 October 2009 to the authors 2009 Abstract Magnesium borate hydroxide MBH nanowhiskers were synthesized using a one step hydrothermal process with different surfactants. The effect surfactants have on the structure and morphology of the MBH nanowhiskers has been investigated. The X-ray diffraction profile confirms that the as-synthesized material is of single phase monoclinic MgBO2 OH . The variations in the size and shape of the different MBH nanowhiskers have been discussed based on the surface morphology analysis. The annealing of MBH nanowhiskers at 500 C for 4 h has significant effect on the crystal structure and surface morphology. The UV-vis absorption spectra of the MBH nanowhiskers synthesized with and without surfactants show enhanced absorption in the low-wavelength region and their optical band gaps were estimated from the optical band edge plots. The photoluminescence spectra of the MBH nanowhiskers produced with and without surfactants show broad emission band with the peak maximum at around 400 nm which confirms the dominant contribution from the surface defect states. L. Kumari W. Z. Li El Department of Physics Florida International University Miami FL 33199 USA e-mail S. Kulkarni K. H. Wu W. Chen C. Wang Department of Mechanical and Materials Engineering Florida International University Miami FL 33174 USA C. H. Vannoy R. M. Leblanc Department of Chemistry University of Miami Coral Gables FL 33124 USA Keywords Magnesium borate hydroxide Nanowhiskers Hydrothermal synthesis Surface morphology X-ray diffraction Introduction Nanostructured materials have .