Gold Nanoparticle Gel Ink Composition for UV-Stable Fixed Color
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Solution Overview
Problem
Existing aqueous gel inks contain dyes and pigments that are expensive, irritating to biological membranes, and lack UV light stability, posing ecological and health risks.
Innovation Solution
A process to prepare aqueous gel inks using citric acid derivatives and gold nanoparticles, which are synthesized in situ, replacing traditional dyes and pigments, and incorporating iron powder to achieve fixed color and UV resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If traditional dyes and pigments are used in aqueous gel inks, then color intensity is achieved, but production costs increase and biological irritation occurs
Solution Approach 1:
The patent changes the chemical composition parameters by replacing traditional dyes and pigments with gold nanoparticles of specific sizes (10-100 nm). This parameter change achieves color through plasmon resonance rather than chemical dyes, eliminating biological irritation while maintaining color intensity and reducing production costs through in situ synthesis
Solution Approach 2:
The patent creates a composite ink formulation combining gold nanoparticles with gel matrix components (hydrocolloids, plasticizers, solvents). This composite approach integrates the color-generating nanoparticles within a gel structure, achieving both safety benefits and functional performance while controlling production costs through a unified synthesis process
2Reliability
If traditional dyes and pigments are used in aqueous gel inks, then color is achieved, but UV light stability deteriorates
Solution Approach 1:
The patent changes the chromophore parameter from organic dyes to metallic gold nanoparticles. Gold nanoparticles exhibit plasmon resonance that provides inherent UV stability, preventing degradation under UV exposure while maintaining color. This eliminates the need for UV-sensitive organic compounds, simultaneously improving UV stability and reducing ecological/health risks
Solution Approach 2:
The patent uses inherently stable gold nanoparticles that do not degrade or leach like traditional dyes. The nanoparticles maintain their color-generating properties indefinitely under UV exposure, eliminating the need for replenishment or replacement and avoiding the release of harmful degradation products into the environment
3Ease of manufacture
If gold nanoparticles are synthesized in situ, then production cost is reduced, but manufacturing process complexity increases
Solution Approach 1:
The patent merges the nanoparticle synthesis step with the ink formulation process. By incorporating reducing agents and stabilizing agents directly into the gel matrix before adding gold salts, the synthesis occurs in situ within the final product matrix. This combines multiple steps (synthesis, purification, formulation) into one integrated process, reducing overall complexity while eliminating separate purification equipment requirements
Solution Approach 2:
The gel matrix components serve dual functions: they act as both the final ink vehicle and the synthesis environment. The reducing agents and stabilizing agents already present in the gel formulation automatically perform the synthesis function when gold salts are added, eliminating the need for separate synthesis equipment, reagents, and purification steps
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 new inks are cost-effective, environmentally friendly, non-irritating, and maintain color stability over time, suitable for writing instruments, and meet ecological requirements.
Implementation Method 1
preparing a gel-based matrix of aqueous ink comprising reducing agent chosen in the group consisting of citric acid and/or derivatives of citric acid... adding a solution of gold salts (Au3+)... adding polyvinylpyrrolidone to obtain an aqueous gel ink with fixed color
Implementation Method 2
aqueous gel inks with fixed color comprising... gold nanoparticles... the color of the aqueous gel ink by visual observation is the same before application on absorbing support, and after application on absorbing support
Data Source
AI summary
The present invention concerns a process for preparing in situ an aqueous gel ink with fixed color comprising the following steps: (i) preparing a gel-based matrix of aqueous ink comprising reducing agent chosen in the group consisting of citric acid and/or derivatives of citric acid, (ii) adding a solution of gold salts, (iii) adding iron powder, (iv) adding polyvinylpyrrolidone to obtain an aqueous gel ink with fixed color, wherein the steps (ii) and (iii) can be interchanged. The present invention also relates to an aqueous gel ink with fixed color obtained according to the process of the invention, comprising citric acid and derivatives, gold nanoparticles, and iron powder. The invention finally concerns a writing instrument comprising an aqueous gel ink with fixed color according to the invention.