Powerful Surface Chemistry Approach for the Grafting of Alkyl Multilayers on Aluminum Nanoparticles

Abstract

The synthesis of aluminum nanoparticles (Alnp) has raised promising perspectives these past few years for applications in energetic materials. However, because of their high reactivity, it is crucial to functionalize them before their use. In this work, we propose an original and simple chemical approach to graft spontaneously alkyl layers derived from alkyl halides at the surface of Alnp, by relying on the highly reductive character of these nanoparticles, when they are in the unoxidized form. Alnp were prepared in a glovebox and reacted with alkyl halides (RI and RBr) to give modified Alnp-R, as shown by infrared spectroscopy (IR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction, thermogravimetric analysis (TGA), and microscopy. The coating is made of alkyl multilayers, which were found to be strongly anchored at the Alnp surface, as it resisted 2 h of rinsing in toluene. An electrocatalytic electron transfer promoted by Alnp is proposed to describe the mechanism of this grafting reaction.

Influence of passivation on ageing of nano-aluminum: Heat flux calorimetry and microstructural studies

“…The XPS wide scan spectrum of bare n-Al is shown in Figure 2(a). The representative peaks corresponding to Al 2s (118 eV) and Al 2p (74 eV) [14,15] are observed. The higher resolution Al 2P spectra of n-Al, shown in Figure 2(b), exhibits a shoulder peak at 72.5 eV along with the main peak at 74.5 eV.…”

“…The samples were heated at a rate of 20 °C/min from room temperature to 470 0 C, subsequently at the rate of 3 0 C/min until 550 0 C and at the rate of 20 °C/min from 550 0 C until 1200 0 C in a constant air flow of 50 ml/min. From the weight gain due to the reaction between aluminum and oxygen, active Al contents (by total mass) was deduced from the TGA curves according to the following equation [14]:…”

Ultrastable Aluminum Nanoparticles with Enhanced Combustion Performance Enabled by a Polydopamine/Polyethyleneimine Nanocoating

“…Great efforts have been made to design protective coatings on the surface of Al NPs via various strategies, e.g., self-assembly, solution polymerization, , and chemical vapor deposition . Compared with the physical methods, chemical modification can form stable coatings on Al NPs via strong chemical bonding and interfacial interactions between them. − Also, various coating materials including metallic oxides, organic acids, carbon materials, and fluoropolymers , have been employed to protect Al NPs. For example, fluoropolymers can enhance the combustion heat of Al NPs by reducing oxidative inactivation and agglomeration, but the interfacial interaction between them is still weak .…”

The Effect of Organic Matter from Sewage Sludge as an Interfacial Layer on the Surface of Nano-Al and Fluoride

“…In order to address the issue, coating is an important method, including physical and chemical methods, which can form stable coatings on n-Al via strong chemical bonding and interfacial interactions between n-Al and coating [ 21 , 22 ]. Various organic matter and inorganic matter coating materials have been used to coat n-Al, especially fluorine polymer [ 23 , 24 ].…”