An in situ chemical reaction approach to synthesize zinc picrate energetic thin film upon zinc oxide nanowires array

Abstract

Nanoenergetic materials are the key to great advances in microscale energy-demanding systems as actuation part, igniter, propulsion unit, and power. An important challenge of energetic materials for microelectromechanical system (MEMS) is the compatibility of standard microsystem techniques with technology process employed in preparing energetic materials producing a large amount of gas and heat. Picric acid is known to react with metals to form highly unstable metallic picrate, which are often employed as explosive materials. In this study, films of zinc picrate were successfully produced with an 'in-situ chemical reaction' method by introducing picric acid onto a ZnO nanowire array, which is fully compatible with technology for MEMS. The films were characterized by nuclear magnetic resonance, X-ray diffraction, XPS, and SEM. The results demonstrate that picric acid reacted with ZnO to form zinc picrate thin film. Differential scanning calorimetry and thermogravimetric analysis measurements show that zinc picrate/ZnO films exhibit producing a large amount of gas, high energy output and lower ignition temperature, which will enhance the diversity of functions on MEMS devices. Therefore, this will open the door to integrate this traditional organic energetic material into microsystem, leading to new generation of MEMS devices. Copyright

Microwave-assisted hydrothermal synthesis of UV-emitting carbon dots from tannic acid

“…Typically the static quenching process involves the formation of a non-emissive ground-state complex between the analyte and the fluorophores, leading to the quenching of luminescence intensity. 59,60 In order to probe the possibility of complex formation between the CDs and the analyte PA, the 1 H NMR spectra of picric acid and carbon dots were collected in the presence and absence of the analyte (the concentration of PA was chosen to be 5 mM). The 1 H NMR spectra of all samples were obtained by dissolving the powder in DMSO and are displayed in Fig.…”

“…S13 (ESI †). The NMR spectra of PA displays two peaks, at 5.4 ppm (due to phenolic hydroxyl group) and at 8.573 ppm (ascribed to the H in benzene rings); [60][61][62] meanwhile the spectra of CDs show peaks in the regions: 6-8 ppm due to the presence of sp 2 hybridized aromatic protons which arise from different chemical environments and 3-6 ppm due to the protons attached with hydroxyl and carbonyl groups. 63 The broad peak at 9.207 ppm may be ascribed to the aromatic COOH group.…”

In situ synthesis of [Cu(BODN)·5H2O]n@nano-Al composite energetic films with tunable properties in pyro-MEMS

“…However, they also have some defects such as relatively high ignition temperature and low gas production. 29 In this work, we employ an in situ reaction method to integrate the energetic metal-organic frameworks [Cu(BODN)•5H 2 O] n (BODN = [2,2′-bi(1,3,4-oxadiazole)]-5,5′dinitramide) and nano-Al on the copper substrate in the form of composite energetic films. Although a copper substrate is not the most commonly used in pyro-MEMS, the copper film can be easily deposited on a wafer with good cohesion.…”

“…However, they also have some defects such as relatively high ignition temperature and low gas production. 29…”

Novel Approach to the Preparation of Organic Energetic Film for Microelectromechanical Systems and Microactuator Applications

“…However, limited research has been undertaken into gas-generating materials, especially organic energetic materials that have been added to silicon substrates. Nevertheless, several recent papers addressing this issue indicate that gas generation plays an important role in the altitude control of orbiting microspacecraft and in microscale devices capable of producing tens of milliNewtons (mN) of thrust. , In our work, a silicon microchannel plate (Si-MCP) was prepared by photoelectrochemical etching. A gas-generating explosive, cyclotrimethylene trinitramine (RDX), was then loaded into the pores of the Si-MCP matrix using a sol–gel method.…”