Nanoparticle-Stabilized Liquid Foam for Uniform Gas Pore Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing air void-forming agents in mineral binder compositions produce pores of uneven size and distribution, affecting mechanical properties and freeze-thaw resistance, and are sensitive to mixing conditions and other additives.
Innovation Solution
A method to produce a liquid foam with stable gas pores by subjecting a suspension of nanoparticles to underpressure, allowing for uniform gas pores of 1-50 µm surrounded by a nanoparticle shell, which remains stable for up to 6 months.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional air void-forming agents are used to produce pores in mineral binder compositions, then freeze-thaw resistance is improved, but pore size and distribution become uneven and mechanical properties deteriorate
Solution Approach 1:
The invention changes the physical parameters of the system by applying pressure reduction (from 1 bar to 0.8-0.95 bar) to control gas pore formation. This pressure parameter change enables uniform pore sizes of 10-50 μm while maintaining freeze-thaw resistance, resolving the contradiction between reliability and manufacturing precision.
Solution Approach 2:
The invention performs preliminary action by pre-forming uniform gas pores in a liquid foam before incorporating them into the mineral binder composition. The gas pores are stabilized with surfactant and nanoparticles prior to mixing, ensuring uniform distribution and size control, which prevents mechanical property deterioration while achieving adequate freeze-thaw resistance.
2Reliability
If mixing duration and mixing type are increased to improve pore distribution, then freeze-thaw resistance improves, but mechanical properties are reduced due to excessive or uneven pore formation
Solution Approach 1:
The gas pores are pre-formed and stabilized in the liquid foam before mixing with the mineral binder composition. This preliminary action eliminates the need for extended mixing to achieve uniform pore distribution, as the pores are already uniformly distributed at 10-50 μm sizes. Consequently, mechanical properties are preserved while freeze-thaw resistance is achieved.
Solution Approach 2:
The invention uses pressure reduction as a controlling parameter to limit pore size to 10-50 μm during foam formation. This parameter control prevents the formation of excessively large pores that would occur with prolonged mixing, thereby maintaining mechanical strength while ensuring adequate pore distribution for freeze-thaw resistance.
3Reliability
If hollow particles are used as air-void forming agents, then freeze-thaw resistance is achieved, but pumping and dosing become difficult
Solution Approach 1:
The invention uses a liquid foam with temporarily stabilized gas pores that is incorporated into the mineral binder composition during mixing. Unlike durable hollow particles that are difficult to pump and dose, the liquid foam is easily pumpable and doseable as a fluid, while still providing the necessary air voids for freeze-thaw resistance once mixed.
Solution Approach 2:
The invention changes the physical state of the air-void forming agent from solid hollow particles to a liquid foam system. This parameter change from solid to liquid phase improves pumpability and dosing ease significantly, while the gas pores within the liquid foam still provide the necessary air void content for freeze-thaw resistance.
4Reliability
If air voids are entrapped during hardening, then freeze-thaw resistance is achieved, but pore size becomes uncontrolled and mechanical properties are compromised
Solution Approach 1:
The invention applies pressure reduction (from 1 bar to 0.8-0.95 bar) as a controlling parameter during gas pore formation to limit pore sizes to 10-50 μm. This parameter control is applied before the mineral binder hardens, ensuring uniform pore sizes are achieved and maintained, thereby improving both manufacturing precision and mechanical properties while achieving freeze-thaw resistance.
Solution Approach 2:
The gas pores are pre-formed with controlled sizes in the liquid foam before the mineral binder composition hardens. This preliminary action ensures that pore sizes are determined by the pressure-controlled foam formation process rather than by uncontrolled entrapment during hardening, achieving both uniform pore distribution and adequate freeze-thaw resistance.
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 method ensures uniform and stable gas pores that enhance freeze-thaw resistance and mechanical properties of mineral binder compositions, with improved mixing and dosing ease, and reduced sensitivity to mixing conditions and additives.
Implementation Method 1
b) Subjecting the suspension to an underpressure, whereby the underpressure is a pressure lower than the first pressure; c) Foaming the suspension for producing gas bubbles in the suspension while the suspension is kept at the underpressure
Implementation Method 2
gas pores comprising a gas volume surrounded by nanoparticles at the gas-liquid interface
Data Source
Figure 1~2
AI summary
A method for producing a liquid foam with gas pores, comprises the steps of: a) Providing a suspension at a first pressure, whereby the suspension comprises suspended nanoparticles in a liquid; b) Subjecting the suspension to an underpressure, whereby the underpressure is a pressure lower than the first pressure; c) Foaming the suspension for producing gas bubbles in the suspension while the suspension is kept at the underpressure, such that gas pores comprising a gas volume surrounded by nanoparticles at the gas-liquid interface are produced; d) Releasing the underpressure in order to obtain the liquid foam with suspended gas pores.