Aluminum Nanopowder Polymer Coating for Combustion

Solution Overview

Problem

Existing methods for producing aluminum nanopowders result in agglomerated nanoparticles, which are difficult to process and have limited active aluminum content due to native oxide coatings, leading to suboptimal combustion performance and energy density in energetic materials.

Innovation Solution

A powder comprising primary nanoparticles of aluminum and/or aluminum oxide separated by an organic or polymeric material, formed into secondary particles that are substantially larger than the primary nanoparticles, enhancing processing characteristics and active aluminum content.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If aluminum nanopowders are produced by conventional methods (electro-explosion, plasma synthesis), then particle size is reduced to nanoscale, but the aluminum oxide layer encompasses a large fraction of the overall particle mass, leaving little remaining reactive aluminum

Engineering Contradiction:

Improveparticle sizeVSAvoidreactive aluminum content

Core Design Contradiction:

Volume of moving objectVSQuantity of substance

Solution Approach 1:

The patent applies preliminary action by pre-coating aluminum particles with a polymer layer before reducing them to nanoscale. This polymer coating prevents oxide formation during the size reduction process, ensuring that when the particles reach nanoscale dimensions, they still maintain high reactive aluminum content rather than being enveloped by oxide layers.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent employs an inert atmosphere approach by using a polymer coating that creates a protective barrier around the aluminum particles, effectively isolating them from oxygen during processing and storage. This prevents the formation of aluminum oxide layers that would otherwise consume reactive aluminum content in conventional production methods.

Inventive Principle:

Principle #39Inert atmosphere (Inert environment)

2Volume of moving object

If aluminum nanopowders are produced by conventional methods, then nanoscale particle size is achieved, but the powders consist of agglomerated nanoparticles that are impossible to re-disperse when combining with polymer

Engineering Contradiction:

Improveparticle sizeVSAvoidprocessability

Core Design Contradiction:

Volume of moving objectVSEase of manufacture

Solution Approach 1:

The patent applies preliminary action by pre-coating aluminum particles with a polymer layer before reducing them to nanoscale. This polymer coating prevents oxide formation during the size reduction process, ensuring that when the particles reach nanoscale dimensions, they still maintain high reactive aluminum content rather than being enveloped by oxide layers.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses a polymer coating as an intermediary substance that mediates between the aluminum particles and the surrounding environment. This coating layer prevents agglomeration by providing steric stabilization, allowing the nanoparticles to remain dispersed when combined with polymer matrices in propellant formulations.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Productivity

If ultrafine or nanoparticulate aluminum is used to increase combustion rates, then surface-to-volume ratio increases, but manufacturing difficulties and safety hazards increase

Engineering Contradiction:

Improvecombustion rateVSAvoidmanufacturing difficulty

Core Design Contradiction:

ProductivityVSEase of manufacture

Solution Approach 1:

The patent uses a polymer coating as an intermediary substance that mediates between the aluminum particles and the surrounding environment. This coating layer prevents agglomeration by providing steric stabilization, allowing the nanoparticles to remain dispersed when combined with polymer matrices in propellant formulations.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent employs an inert atmosphere approach by using a polymer coating that creates a protective barrier around the aluminum particles, effectively isolating them from oxygen during processing and storage. This prevents the formation of aluminum oxide layers that would otherwise consume reactive aluminum content in conventional production methods.

Inventive Principle:

Principle #39Inert atmosphere (Inert environment)

4Ease of manufacture

If agglomerated nanoparticles are used in propellant formulations, then processing is simplified, but composition homogeneity and uniform dispersion are not achieved

Engineering Contradiction:

Improveprocessing easeVSAvoidcomposition homogeneity

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent uses a polymer coating as an intermediary substance that mediates between the aluminum particles and the surrounding environment. This coating layer prevents agglomeration by providing steric stabilization, allowing the nanoparticles to remain dispersed when combined with polymer matrices in propellant formulations.

Inventive Principle:

Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The described powder improves combustion performance by achieving faster reaction rates, higher combustion efficiency, and reduced porosity, leading to enhanced energy density and processing characteristics in energetic materials.

Implementation Method 1

primary nanoparticles of aluminum and/or aluminum oxide, each nanoparticle being separated from the others by an intervening organic or polymeric material

Methodology Applied

Scientific EffectPhysical separation by intervening material:

Implementation Method 2

Due to the strongly exothermic aluminum (Al) to aluminum oxide (Al2O3) reaction

Methodology Applied

Scientific EffectOxidation: Oxidation

Implementation Method 3

Powdered aluminum has long found use in energetic materials including solid propellants. The rate of reaction is proportional to the surface area available for oxidation

Methodology Applied

Scientific EffectCombustion: Combustion

Data Source

PatentUS20250162959A1Composite powder containing primary nanoparticles of aluminum or aluminum oxide

Publication Date: 2025.05.22 HELICON CHEM CO

AI summary

This present invention is directed to a powder comprising a composite of primary nanoparticles of aluminum and/or aluminum oxide, the nanoparticle being separated from the others by an intervening organic or polymeric material, and formed into secondary particles that are substantially larger than the primary nanoparticles.