Blue Silver Nanoparticle Dispersion for Non-Yellowing Antimicrobial Textiles
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Solution Overview
Problem
Current antimicrobial silver nanoparticle finishes for textiles suffer from issues such as yellowing of fabrics, instability of aqueous dispersions, high concentration requirements for effectiveness, and poor wash durability, which affect their aesthetic appeal and longevity.
Innovation Solution
A blue-colored aqueous dispersion of silver nanoparticles with particle sizes ranging from 0.5 to 6 nm, characterized by specific plasmonic peaks and high molar extinction coefficients, is developed using a direct one-step synthesis method involving a protecting agent, stabilizer, and hydrogen peroxide, along with a reducing agent, providing enhanced stability and antimicrobial activity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional silver nanoparticle dispersions are applied to textiles, then antimicrobial activity is achieved, but yellowing of fabrics occurs and aesthetics deteriorate
Solution Approach 1:
The patent applies color changes by synthesizing silver nanoparticles with controlled sizes (2-10 nm) that exhibit blue coloration instead of the conventional yellow-brown color. This is achieved through precise control of particle size during synthesis, resulting in a blue-colored dispersion that does not cause yellowing of fabrics while maintaining antimicrobial activity.
2Reliability
If high concentration of silver nanoparticles is applied, then effective antimicrobial activity is achieved, but cost increases and yellowing worsens
Solution Approach 1:
The patent applies parameter changes by optimizing the particle size parameter to 2-10 nm, which significantly enhances the antimicrobial activity per unit concentration. This allows effective antimicrobial protection at lower silver concentrations (0.1-10 ppm), reducing both cost and yellowing effects compared to conventional formulations requiring 5-1000 ppm.
3Reliability
If conventional nanosilver dispersions are stored, then initial antimicrobial activity is present, but stability deteriorates and particles agglomerate
Solution Approach 1:
The patent applies intermediary by introducing stabilizing agents during the synthesis process that prevent agglomeration of silver nanoparticles. These intermediaries maintain colloidal stability of the blue-colored dispersion over time, preventing particle aggregation and settling, thereby preserving antimicrobial activity during storage.
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 blue-colored silver nanoparticle dispersion exhibits 99.99% antimicrobial activity at low concentrations, remains stable for 15-24 months, and provides wash durability with heat treatment or binders, maintaining whiteness and preventing yellowing of fabrics.
Implementation Method 1
Chemical reduction method. This involves the dissolution of silver salt into a solvent (aqueous or non-aqueous) and subsequent addition of a suitable reducing agent e.g. chemical reduction of silver ion in aqueous solutions
Implementation Method 2
characterized by specific plasmonic peaks and high molar extinction coefficients
Implementation Method 3
adding a stabilizer and hydrogen peroxide
Data Source
AI summary
The present invention provides blue colored aqueous dispersion of silver nanoparticles and process for preparation thereof. The present invention also provides compositions comprising blue colored dispersion of silver nanoparticles. The blue colored aqueous dispersion comprising silver nanoparticles wherein dispersion is characterized by —having plasmonic peaks in the range 330-335 nm and 650-720 nm combined with missing plasmonic peaks in the range 390 to 410 nm and 410-500 nm in UV-Vis spectrum, —the dispersion having silver nanoparticles of anisotropic shape with majority of particles (>65%) having equivalent diameter in range of 0.5 to 6 nm, —Molar extinction coefficient greater than 10.1 preferably in the range of 10.1 to 15.7 mM−1 cm−1 at wavelength of maximum absorption in the range of 650-720 nm, —Dispersion stability of at least 15 months, —Minimum Bactericidal Concentration (MBC) lower than 0.10 ppm preferably in the range of 0.055-0.099 ppm.