RESUMO
Aligned CNT mats were prepared by thermal chemical vapor deposition (CVD) method by exposing a mixture of ferrocene and xylene vapor to the SiO2/Si substrates. Aligned CNT mats functionalized with reactive chemicals without disturbing CNT alignment were characterized by SEM, XRD, FT-IR, FT-Raman and XPS. The thermal stability of the CNT, CNT-OH and CNT-NaCIO4 are investigated using TG-DSC analysis. Oxidation and combustion temperatures of CNT mats were found to be decreased by functionalizing the CNT mats with NaClO4.
RESUMO
Porous silicon (PS) films â¼65-95 µm thick composed of pores with diameters less than 3 nm were fabricated using a galvanic etching approach that does not require an external power supply. A highly reactive, nanoenergetic composite was then created by impregnating the nanoscale pores with the strong oxidizer, sodium perchlorate (NaClO(4)). The combustion propagation velocity of the energetic composite was measured using microfabricated diagnostic devices in conjunction with high-speed optical imaging up to 930000 frames per second. Combustion velocities averaging 3050 m/s were observed for PS films with specific surface areas of â¼840 m(2)/g and porosities of 65-67%.
Assuntos
Cristalização/métodos , Galvanoplastia/métodos , Nanoestruturas/química , Nanoestruturas/ultraestrutura , Nanotecnologia/métodos , Silício/química , Temperatura Alta , Substâncias Macromoleculares/química , Teste de Materiais , Conformação Molecular , Tamanho da Partícula , Porosidade , Propriedades de SuperfícieRESUMO
Porous silicon (PS) films up to â¼150 µm thick with specific surface area similar to 700 m(2)/g and pore diameters similar to 3 nm are fabricated using a galvanic corrosion etching mechanism that does not require a power supply. After fabrication, the pores are impregnated with the strong oxidizer sodium perchlorate (NaClO(4)) to create a composite that constitutes a highly energetic system capable of explosion. Using bomb calorimetry, the heat of reaction is determined to be 9.9 ± 1.8 and 27.3 ± 3.2 kJ/g of PS when ignited under N(2) and O(2), respectively. Differential scanning calorimetry (DSC) reveals that the energy output is dependent on the hydrogen termination of the PS.
