Facile Fabrication of Energetic Nanocomposite Materials by Polydopamine.

Polydopamine-based materials have been widely investigated for incorporation in energetic nanocomposites due to their outstanding adherence. However, these materials are often prepared in alkaline environments, which negatively affects Al nanoparticles. In this study, a one-pot assembly was devised for the preparation of a polydopamine-based Al/CuO energetic nanocomposite material (Al/PDA/CuO) in a neutral environment. The CuO and Al nanoparticles of the Al/PDA/CuO nanothermite were uniformly dispersed and closely combined. Consequently, the Al/PDA/CuO nanothermite was able to release more heat (2069.7 J/g) than physically mixed Al/CuO (1438.9 J/g). Furthermore, the universality of using polydopamine in the assembly of different types of energetic nanocomposite materials was verified, including an organic energetic material-nanothermit (HMX/PDA/Al/CuO nanothermite) and an inorganic oxidant-metal nanocatalyst (AP/PDA/Fe2O3). This study provides a promising route for the preparation of polydopamine-based energetic nanocomposites in neutral aqueous solutions.

Peptide Assembly of Al/CuO Nanothermite for Enhanced Reactivity of Nanoaluminum Particles.

Biological self-assembly procedures, which are generally carried out in an aqueous solution, have been found to be the most promising method for directing the fabrication of diverse nanothermites, including Al/CuO nanothermite. However, the aqueous environment in which Al nanoparticles self-assemble has an impact on their stability. We show that using a peptide to self-assemble Al or CuO nanoparticles considerably improves their durability in phosphate buffer aqueous solution, with Al and CuO nanoparticles remaining intact in aqueous solution for over 2 weeks with minimal changes in the structure. When peptide-assembled Al/CuO nanothermite was compared with a physically mixed sample in phosphate buffer for 30 min, the energy release of the former was higher by 26%. Furthermore, the energy release of peptide-assembled Al/CuO nanocomposite in phosphate buffer showed a 6% reduction by Day 7, while that of the peptide-assembled Al/CuO nanocomposite in ultrapure water was reduced by 75%. Taken together, our study provides an easy method for keeping the thermal activity of Al/CuO nanothermite assembled in aqueous solution.

Biofunctionalization of HMX with Peptides via Polydopamine Crosslinking for Assembling an HMX@Al@CuO Nanoenergetic Composite.

Biological approaches for the synthesis of a hybrid explosive-nanothermite energetic composite have attracted greater scientific attention because of their advantages, including their moderate reactions and the absence of secondary pollution. In this study, a simple technique was developed to fabricate a hybrid explosive-nanothermite energetic composite based on a peptide and a mussel-inspired surface modification. Polydopamine (PDA) was easily imprinted onto the HMX, where it maintained its reactivity and was capable of reacting with a specific peptide used to introduce Al and CuO NPs to the surface of the HMX via specific recognition. The hybrid explosive-nanothermite energetic composites were characterized using differential scanning calorimetry (TG-DSC), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy(XPS), and a fluorescence microscope. A thermal analysis was utilized to investigate the energy-release properties of the materials. The HMX@Al@CuO, which benefitted from an enhanced interfacial contact in comparison with the physically mixed sample (HMX-Al-CuO), demonstrated a 41% lower HMX activation energy.

A facile approach to preparation of silica double-shell hollow particles, and their application in gel composite electrolytes.

Double-shell hollow particles (DSHPs) have attracted significant attention due to their diverse potential applications. DSHPs are usually obtained by multi-step sacrificial template method which is tedious and inefficient. In this work, a facile synthesis of silica DSHPs has been developed via a novel one-step template method, which is using single-hole hollow particles (SHHPs) as the templates. The shapes and internal structures of the DSHPs were determined by SEM and TEM, and the average diameters of inner and outer shells were about 0.6 and 1.6 µm, respectively. According to FTIR analyses, the compositions of silica DSHPs were identified as well. Furthermore, the silica DSHPs was applied to Li-ion batteries as a modifier of gel polymer electrolyte (GPEs), and the results showed that the gel composite electrolytes (GCEs) could display higher capability, higher ionic conductivity and better rate performance at high current density for GCEs-cell. Properties of the silica DSHPs such as larger specific surface area, more porous structures and Lewis acid-base effect were important for high-performance Li-ion batteries.