Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Determination of the volume-specific surface area by using transmission electron tomography for characterization and definition of nanomaterials | Van Doren et al. Journal of Nanobiotechnology 2011 9 17 http content 9 1 17 JOURNAL OF NANOBIOTECHNOLOGY RESEARCH Open Access Determination of the volume-specific surface area by using transmission electron tomography for characterization and definition of nanomaterials Elke AF Van Doren Pieter-Jan RH De Temmerman Michel Abi Daoud Francisco and Jan Mast Abstract Background Transmission electron microscopy TEM remains an important technique to investigate the size shape and surface characteristics of particles at the nanometer scale. Resulting micrographs are two dimensional projections of objects and their interpretation can be difficult. Recently electron tomography ET is increasingly used to reveal the morphology of nanomaterials NM in 3D. In this study we examined the feasibility to visualize and measure silica and gold NM in suspension using conventional bright field electron tomography. Results The general morphology of gold and silica NM was visualized in 3D by conventional TEM in bright field mode. In orthoslices of the examined NM the surface features of a NM could be seen and measured without interference of higher or lower lying structures inherent to conventional TEM. Segmentation by isosurface rendering allowed visualizing the 3D information of an electron tomographic reconstruction in greater detail than digital slicing. From the 3D reconstructions the surface area and the volume of the examined NM could be estimated directly and the volume-specific surface area VSSA was calculated. The mean VSSA of all examined NM was significantly larger than the threshold of 60 m2 cm3. The high correlation between the measured values of area and volume gold nanoparticles with a known spherical morphology and the areas and volumes calculated from the equivalent circle diameter ECD of projected nanoparticles NP indicates that the values measured from electron tomographic reconstructions are valid for these gold particles. Conclusion The .
