Activated Carbon Mortar for VOC Adsorption
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Solution Overview
Problem
Existing interior mortars and coatings fail to effectively purify ambient air of volatile organic compounds (VOCs) such as formaldehyde, xylene, toluene, and ethylbenzene, and inadequately regulate humidity, leading to discomfort and health issues in buildings, while current solutions often require additional agents that cause discoloration, odor, or ineffective VOC capture.
Innovation Solution
A mortar composition incorporating granular activated carbon with a specific surface area of 875-1200 m²/g, iodine number of 900 mg/g, and sorption capacity of 7 mg/g of toluene, which is incorporated into a cement-based binder, aggregates, and fillers to provide both VOC purification and humidity regulation without desorption at room temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If photocatalytic oxidation technique with titanium oxide particles is used to purify air, then formaldehyde can be degraded, but the process requires a suitable light source and does not effectively capture other VOCs
Solution Approach 1:
The patent combines activated carbon particles with cement-based mortar to create a composite material that integrates both VOC adsorption and humidity regulation functions. The activated carbon serves as the active component for capturing organic compounds while the cement matrix provides structural support and additional humidity buffering capacity.
Solution Approach 2:
The patent utilizes the porous structure of activated carbon with specific surface area of 875-1200 m²/g to adsorb VOCs from the air. The high porosity and large surface area enable effective capture of various volatile organic compounds including formaldehyde, xylene, toluene, and ethylbenzene without requiring additional light sources or catalysts.
2Object-affected harmful factors
If adsorbents or chemisorbents are incorporated into mortar to capture VOCs, then air purification can be achieved, but the agents cause discoloration, odor, or ineffective VOC capture
Solution Approach 1:
The patent employs activated carbon, a stable and durable material that maintains its adsorption capacity over time without degrading into harmful byproducts. The activated carbon particles remain inert within the cement matrix, preventing discoloration and odor generation while continuously adsorbing VOCs.
Solution Approach 2:
The patent transforms the naturally occurring porous structure of activated carbon into a beneficial adsorption medium that passively captures VOCs without requiring additional energy input or producing harmful side effects. The material's inherent properties are leveraged to achieve air purification while maintaining aesthetic appearance.
3Object-affected harmful factors
If montmorillonite-type minerals are used to regulate humidity, then water molecules can be captured, but these minerals have no effect on trapping non-polar VOCs
Solution Approach 1:
The patent achieves multi-functionality by incorporating activated carbon particles that simultaneously provide both VOC adsorption and humidity regulation capabilities. The activated carbon's porous structure allows it to interact with both polar water molecules and non-polar organic compounds, eliminating the need for separate functional additives.
4Object-affected harmful factors
If additional air-purifying agents are incorporated into mortar compositions, then VOC capture can be enhanced, but the agents quickly lead to ammonia odor and yellow-brown discoloration
Solution Approach 1:
The patent utilizes the intrinsic properties of activated carbon to perform air purification without requiring additional chemical reactions or catalysts that produce harmful byproducts. The activated carbon physically adsorbs VOCs through van der Waals forces, a process that does not generate ammonia odor or discoloration.
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 composition achieves efficient adsorption of VOCs (up to 70% for certain pollutants) and effective humidity regulation, maintaining air quality and comfort without additional agents, and is compatible with existing construction materials.
Implementation Method 1
The present invention relates to a mortar or coating composition for interior coating... said composition being characterized in that it further comprises between 1 and 10% by weight of at least one activated carbon... having a specific surface area greater than or equal to 875 m²/g... The composition has both properties for purifying the ambient air... and for regulating the humidity
Implementation Method 2
The composition also has properties for regulating the humidity of the ambient air... It is known to remedy humidity problems to use other types of compounds that capture water molecules... This type of compound, however, has no effect on trapping a large part of volatile organic compounds
Data Source
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AI summary
The present invention relates to a mortar or coating composition for an inner covering, said composition comprising at least one binder, in particular a mineral binder, and also generally comprising at least granular materials and/or aggregates and/or sands and/or fillers, the composition being characterised in that it further comprises at least one activated carbon, preferably in granular form, having: - a specific surface area greater than or equal to 875 m2/g and less than or equal to 1200 m2/g and/or an iodine index greater than or equal to 900 mg/g and/or a sorption capacity of at least 7 mg of toluene per g of activated carbon, and - a change in average mass Δm(S) in sorption of at least 2% and a change in mass Δm(D4) after four sorption/desorption cycles of at most 1.5%.