Antimicrobial Silver Solutions via Citric Acid Complexation
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Solution Overview
Problem
There is a need for economical methods to produce stable aqueous solutions with high concentrations of silver ions for antimicrobial applications, as existing methods face challenges in maintaining silver ions in their ionic form and achieving high concentrations.
Innovation Solution
The use of citric acid and trisilver citrate in aqueous solutions, where the solubility of silver ions increases linearly with citric acid concentration, allowing for the creation of concentrated solutions with up to 25 grams of silver ions per liter, and diluted solutions with stable silver ion concentrations, potentially enhanced by adding stabilizing agents like glycerol.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional methods are used to produce silver ion solutions, then the production cost is reduced, but the stability of silver ions and their concentration cannot be maintained at high levels
Solution Approach 1:
The patent introduces organic ligands (such as citric acid, EDTA, or amino acids) as intermediary substances that mediate between silver ions and water molecules. These ligands form stable coordination complexes with silver ions, preventing their precipitation or reduction while maintaining high concentrations in aqueous solution. The ligand acts as a bridge that stabilizes the silver ions without requiring extreme conditions.
Solution Approach 2:
The invention creates composite aqueous solutions containing multiple components: water, silver ions, and organic ligands. This composite system leverages the stabilizing effect of the ligand-metall complex to maintain high silver ion concentrations. The synergistic interaction between components allows the solution to achieve both high concentration and long-term stability, resolving the contradiction between quantity and reliability.
2Quantity of substance
If electrolytic methods are used to generate silver ions, then high concentrations can be achieved, but the production process becomes complex and costly
Solution Approach 1:
The patent replaces the electrolytic method (which requires electrical equipment, power supply, and complex control systems) with a simple chemical dissolution process. Silver salts are directly dissolved in aqueous solutions containing organic ligands, eliminating the need for electrolytic cells, electrodes, and electrical power. This substitution dramatically simplifies the preparation process while maintaining high silver ion concentrations through the stabilizing effect of ligand complexes.
Solution Approach 2:
The invention changes the chemical parameters of the solution by introducing organic ligands that alter the solubility and stability characteristics of silver salts. By adjusting parameters such as ligand concentration, pH, and temperature, the system achieves high silver ion concentrations through simple dissolution rather than complex electrolytic processes. This parameter optimization allows straightforward preparation while maintaining high effectiveness.
3Ease of manufacture
If silver nitrate is used as the silver source, then the solution can be prepared simply, but the stability of silver ions deteriorates over time
Solution Approach 1:
The patent introduces organic ligands as intermediary substances that mediate between silver nitrate and the aqueous environment. These ligands form stable coordination complexes with silver ions, preventing their precipitation or reduction over time. The ligand acts as a protective intermediary that maintains silver ion stability without complicating the preparation process, as the ligands are readily soluble and require simple mixing.
Solution Approach 2:
The invention uses small molecules of organic ligands (such as citric acid, EDTA, or amino acids) that are inexpensive, readily available, and easily soluble. These small molecular weight ligands provide stable complexation with silver ions without requiring complex or expensive additives. Their simplicity and low cost allow them to be added directly to silver nitrate solutions to enhance stability while maintaining ease of manufacture.
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
This approach results in stable solutions with high silver ion concentrations, suitable for various antimicrobial applications, maintaining silver ion stability over time and providing both antimicrobial and anti-oxidative benefits.
Implementation Method 1
the solubility of silver ions increases linearly with citric acid concentration
Implementation Method 2
potentially enhanced by adding stabilizing agents like glycerol
Data Source
AI summary
A method for preparing a concentrated solution containing water, citrate ions and silver ions, including providing an amount of trisilver citrate, providing an amount of citric acid, wherein the amount of the citric acid is at least 19 times the amount of the trisilver citrate by weight, and mixing the trisilver citrate and the citric acid in an amount of water to produce the concentrated solution, wherein the amount of water is selected so that the concentrated solution has a citrate ion concentration which is at least 300 grams per liter. A concentrated solution containing water, citrate ions and silver ions, wherein the concentrated solution has a silver ion concentration which is at least 10 grams per liter. A diluted solution prepared by adding water to a concentrated solution containing water, citrate ions and silver ions.