Germicidal Wipe Composition Without Surfactant Precipitation
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Solution Overview
Problem
Existing compositions containing anionic and cationic surfactants suffer from incompatibility issues, leading to precipitation and reduced germicidal efficacy, and the binding of cationic surfactants to cotton-based materials, which are not effectively addressed by current methods.
Innovation Solution
A method of forming an anionic-rich catanionic mixture by mixing anionic and cationic surfactants at specific concentrations and pH, eliminating the need for solubilizing co-surfactants or organic solvents, and incorporating the mixture onto cotton or synthetic wipes to maintain stability and efficacy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If anionic and cationic surfactants are mixed in conventional formulations, then cleaning and softening properties are achieved, but precipitation occurs and germicidal efficacy is reduced
Solution Approach 1:
The patent changes the concentration parameters of anionic and cationic surfactants to specific ranges (anionic: 0.1-10% w/w, cationic: 0.01-1% w/w) and controls pH (5-9) to prevent precipitation while maintaining germicidal efficacy. This parameter optimization resolves the contradiction by finding the precise conditions where both formulation simplicity and reliability are achieved.
Solution Approach 2:
The patent creates a composite surfactant system combining anionic, cationic, and nonionic surfactants in specific ratios. This composite formulation prevents precipitation through synergistic interactions while maintaining cleaning, softening, and germicidal properties, thus resolving the contradiction between formulation simplicity and reliability.
2Reliability
If QACs are added to anionic surfactant formulations for germicidal purposes, then antimicrobial activity is achieved, but insoluble catanionic compounds form
Solution Approach 1:
The patent introduces nonionic surfactants as intermediary substances that mediate between anionic and cationic surfactants. These nonionic components prevent direct interaction that leads to precipitation, while allowing the cationic QACs to maintain their germicidal activity. This resolves the contradiction by using an intermediary to maintain both stability and activity.
Solution Approach 2:
The patent optimizes the concentration of QACs to low levels (0.01-1% w/w) and controls the anionic:catonic ratio to prevent insoluble compound formation. By changing these concentration parameters, the formulation maintains germicidal activity without sacrificing stability.
3Reliability
If cationic surfactants are used at high concentrations for effective germicidal action, then antimicrobial efficacy is improved, but toxic effects on skin, eyes and airways increase
Solution Approach 1:
The patent reduces the concentration of cationic surfactants to low levels (0.01-1% w/w) while maintaining germicidal efficacy through optimized formulations. This parameter change directly reduces toxicity to skin, eyes, and airways while preserving antimicrobial effectiveness.
Solution Approach 2:
The patent creates a composite system where multiple surfactant types work synergistically, allowing reduced QAC concentrations to achieve the same germicidal effect. This composite approach maintains reliability while reducing harmful factors.
4Ease of operation
If QACs are incorporated onto cotton-based wipes for application, then convenient delivery is achieved, but QAC binding to cotton reduces available germicidal substance
Solution Approach 1:
The patent uses nonionic surfactants as intermediaries that reduce the binding affinity between cationic QACs and cotton fibers. This intermediary action allows QACs to be delivered on cotton wipes while preventing excessive binding, thus maintaining adequate quantity for germicidal action.
Solution Approach 2:
The patent optimizes the concentration of QACs and the composition of the wipe solution to minimize binding losses. By changing these parameters, the formulation maintains sufficient available QAC for germicidal action while preserving application convenience on cotton substrates.
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 solution results in homogeneous, clear, and stable compositions with maintained germicidal efficacy, reducing QAC binding to cotton-based materials, and avoiding the use of unreliable biocide release agents, thus enhancing safety and environmental sustainability.
Implementation Method 1
The initial interaction between QACs and bacterial cells wall results from electrostatic interaction between positively charged QACs and negatively charged bacterial cell membranes
Implementation Method 2
followed by the integration of the hydrophobic tail of the QACs into the bacterial hydrophobic membrane core, where they denature structural proteins and enzymes
Data Source
AI summary
A method of making a clear, homogeneous aqueous antimicrobial composition, the method including: (a) mixing an anionic surfactant with a water-soluble cationic quaternary ammonium (QAC) surfactant in an aqueous medium under conditions effective to form an anionic-rich catanionic mixture that is clear and free of visible precipitate and retains antimicrobial efficacy, wherein: (i) total surfactant concentration is greater than 0.1 wt. %; (ii) weight or molar ratio of anionic to cationic surfactant is greater than 1; and (iii) pH of the medium is greater than or equal to 7 and adjusted with a pH-adjusting agent; and (b) adding an aqueous medium carrier comprising water and, optionally, one or more antimicrobial materials.