Chitosan Biopolymer Filter for Stable Bactericidal Metal Binding

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Solution Overview

Problem

Existing air filters for HVAC systems lack stability and reliability in maintaining bactericidal efficiency without compromising the functioning parameters of the air circuit, risking the introduction of toxic metals into the air-conditioned space.

Innovation Solution

A filter with a chitosan-based biopolymer support stably associated with ionic metals like silver, gold, or quaternary ammonium salts, such as Cetyl trimethylammonium bromide, ensuring a strong chemical bond that prevents metal migration into the air circuit, while maintaining bactericidal efficacy and adhering to HVAC standards.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If bactericidal metals are applied on the filtering support surface, then bactericidal action is achieved, but metal stability and reliability deteriorate causing metal migration into the air circuit

Engineering Contradiction:
Improvebactericidal actionVSAvoidmetal stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent introduces a polymeric material as an intermediary between the filtering support and the bactericidal metals. This polymer acts as a binding matrix that securely holds metal particles (silver, copper, zinc, etc.) in place while allowing their bactericidal properties to manifest. The polymer prevents direct contact and potential migration of metals into the air circuit, thus resolving the contradiction between maintaining bactericidal efficacy and ensuring metal stability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention creates a composite material structure consisting of three components: the filtering support, the polymeric binding material, and the bactericidal metal particles. This composite approach integrates the filtration function with the bactericidal function while using the polymer to stabilize the metal particles. The composite structure ensures that metals remain fixed in the filter matrix, preventing migration while maintaining their antimicrobial effectiveness.

Inventive Principle:
Principle #40Composite materials

2Reliability

If bactericidal metals are applied on the filtering support, then bactericidal efficiency is improved, but toxicity to humans worsens due to potential metal introduction into the air

Engineering Contradiction:
Improvebactericidal efficiencyVSAvoidtoxicity
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The polymeric material serves as a protective intermediary that prevents bactericidal metals from migrating into the air circuit and being inhaled by occupants. The polymer encapsulates or binds the metal particles securely within the filter structure, allowing the metals to exert their antimicrobial effect on passing air and contaminants while blocking their direct release into the breathable air stream, thus eliminating the toxicity hazard.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of manufacture

If standard filtering supports are used, then manufacturing simplicity is maintained, but stable association with bactericidal metals deteriorates

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidmetal association stability
Core Design Contradiction:
Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The patent applies a polymeric material to the filtering support as a preliminary action before introducing the bactericidal metals. This pre-applied polymer layer creates ready-made binding sites and a suitable matrix for incorporating metal particles. By preparing the support surface in advance with the polymeric material, the subsequent metal application becomes simpler and more effective, achieving stable metal association without complicating the overall manufacturing process.

Inventive Principle:
Principle #10Preliminary action

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 filter achieves a stable bactericidal effect with high adsorption yields, maintaining air circuit efficiency and preventing metal introduction into the air, thus ensuring safe and effective air purification without altering the HVAC system's performance.

Implementation Method 1

A filter with a chitosan-based biopolymer support stably associated with ionic metals like silver, gold, or quaternary ammonium salts, such as Cetyl trimethylammonium bromide, ensuring a strong chemical bond that prevents metal migration into the air circuit

Methodology Applied
Scientific EffectChemical bonding: Chemical Bonding

Implementation Method 2

The filter achieves a stable bactericidal effect with high adsorption yields

Methodology Applied
Scientific EffectAdsorption: Adsorption

Data Source

PatentEP2627429B1Filter and method for its production
Publication Date: 2015.09.09 LABIOTEST
  • EP2627429B1 patent drawingFigure 1~2
  • EP2627429B1 patent drawingFigure 3
  • EP2627429B1 patent drawingFigure 4

AI summary

A filter (10) for cooling, ventilation, air-conditioning, heating and air purifying plants comprises a filtering support (12) with which one or more bactericidal metals (14) are stably associated, chosen from a group comprising: noble metals such as silver, gold, platinum, or heavy metals such as iron, copper, manganese, zinc, lithium, or an organic bactericidal molecule chosen from quaternary ammonium salts. The metals (14) are taken individually or in a mixture with each other, or individually or mixed with the quaternary ammonium salt. The filtering support (12) comprises, in concentration in weight higher than or equal to about 15%, a chitosan- based biopolymer to which said metals (14) and/or said quaternary ammonium salt are chemically bonded, both inside the biopolymer and on its surface.