Preparation and reactivity analysis of novel perfluoroalkyl coated aluminium nanocomposites

Abstract

Passivation of unpassivated aluminium nanoparticles using C 13 F 27 COOH is reported with materials containing as much as 32 . 95%Al. Characterisation data, including scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and attenuated total reflectance Fourier transform infrared (ATR FTIR) spectrometry, indicate that the C 13 F 27 COOH molecule binds to the surface of the Al particle, protecting the surface from oxidation in ambient air. The fast reaction capability of the Al-C 13 F 27 COOH material was investigated using two different means. Response of the material to strong shock was analysed using the small scale shock reactivity test (SSRT). SSRT results show that the Al-C 13 F 27 COOH material formulated with cyclotetramethylenetetranitramine (HMX) and hydroxyl terminated polybutadiene (HTPB) binder produced a significantly larger dent than comparable conventional Al specimen. Additionally, laser ablation/ignition studies of the prepared Al-C 13 F 27 COOH material demonstrate the fast reaction capability of the material.

Metal-based reactive nanomaterials

“…In both cases, aluminum nanoparticles served as a reducing agent for the transition metal complexes, so that reduced metal films were produced on the aluminum surface. In a different passivation approach, aluminum nanopowders coated with non-metallic self-assembled monolayers (SAMs) were prepared [65,66]. Nanoscale Al particles were prepared in a solution by catalytic decomposition of the Al-methyl pyrrolidine alane adduct by titanium(IV) isopropoxide; followed by in situ coating using organic SAMs (e.g., diethyl ether solutions of perfluorotetradecanoic acid, perfluorononanoic acid or perfluoroundecanoic acid).…”

“…Despite these limitations of the wet chemistry approach, surface passivation remains an important safety and handling issue and current research is focused on preparing high quality and well-passivated powders [64][65][66]. For example, surface layers of transition metals were formed on Al nanoparticles to prevent them from oxidation in surrounding air [64,67].…”

Metal-based Inkjet Inks for Printed Electronics

“…Such inks are already commercially available (at least 10 companies in the United States, Japan, Korea and Israel produce Ag-based conductive inks). The main challenge in replacing Ag by the much cheaper metals, Cu and Al, is in avoiding their oxidation at ambient conditions, which usually requires rather sophisticated reaction conditions -the use of hydrocarbon solvents, low precursor concentration and inert atmosphere [19,[21][22][23][24][25][26][27]. For example, Al undergoes rapid oxidation in air (~100 picoseconds) with formation of a dense thin amorphous Al 2 O 3 layer (2-6 nm) [28,29] that results in loss of electrical conductivity and makes aluminum inapplicable for conductive ink formulations.…”

Stabilization of Metal Nanoparticles – A Chemical Approach

“…The particles of ANPs as well as other metal nanoparticles are passivated, as a rule, with oxide layers having an amorphous or crystal structure [18][19][20]. The oxide layers are formed on the ANPs by slow oxidation in air during the passivation process.…”