An Investigations Into The Fabrication And Combustion Properties Of Porous Silicon Nano-Energetic Materials&Nano-Energetic Array Chips

Porous silicon (PS) has been widely researched and applied in fields of sensor, optoelectronics, micro-optics, MEMS devices&technology, energetic conversion and biomedicine, since the PS has been discovered by J. A. Uhlir in1950s. PS has been introduced into a new field of nano-energetic materials (nEMs), because of the new discoveries on explosion of PS and concentrated nitric acid in1992.For fabrications of PS nEMs, this thesis investigated the law in fabrications of PS, experiment results indicated that the fabrication of PS was affected by the concentration of electrolyte, current density and etching time in electrochemical etching technology.The cracking factors and mechanism of PS were studied, and the experiment results proved that the growth condition of PS was the elementary factor for fabrications of uncracked PS films, and the surface tension of electrolyte in nano-holes of PS was not the ignored factor resulted in the cracks of PS. Based on this researches, this thesis developed a new method to fabricate uncracked PS thick films (the max thickness of PS can be up to205μm).The stabilization of fresh PS was researched to be modified by KH550, KH560and KH570, because the oxidation of fresh PS is very easy in air. The experiment results showed that this stabilizing method could replace the unstable-Si-H with more stable organic groups (such as-R and-CHx) originated from silane coupling agents. The testing results indicated that silane coupling agents could enhance the stabilization of PS at room temperature, and the releasing energy was not decreased obviously in combustions of PS and Pb3O4. So, it’s feasible to stabilize PS atmospheric temperature.The thesis developed a new method (ultrasonic filling method) by filling oxidant into nanoholes of PS to fabricate PS nEMs. This method enhanced the mass transfer process to improve the efficiency to fill oxidant into PS in fabrications of PS nEMs.This thesis studied the ignitions and self-sustained chemical reactions of PS nEMs ignited by pulsed laser and pyrogenation in atmosphere, and these researched realized the stable combustion and denotation of PS nEMs under different igniting conditions and fabricating conditions. Otherwise, the secondary combustions and multiple combustions were discoveried when PS nEMs were ignited by pulsed laser in atmosphere. These results indicated that the ignition mechanism of PS nEMs was pyrogenation. Additionally, the strong explosion of PS nEMs was detected when PS nEMs were ignited by the plasma at vacuum environments (5×10-3P and8Pa, respectively). This phenomenon exploited the applications of PS nEMs from the atmospheric conditions to the vacuum environment.PS nECs were fabricated by integrated the Cr-microbridge-foils on the surfaces of PS arrays with MEMS technologies, and the credible ignitions of PS nECs were realized under the electrical explosion effect and electrothermal effect of Cr-microbridge-foils, respectively. The delay time was as low as8.0×10-5s when the ignitions of PE nECs by electrical explosion effects of Cr-microbridge-foils, and the ignition energy was less than0.2mJ. Differently, the delay time of ignitions was in a scale of ms when PS nECs was ignited by of Cr-microbridge-foils, but this method could ignite the combustion of PS nECs under an igniting voltage of10V. It’s suitable to be used in low-voltage ignitions.