Methods for obtaining colored or chromic substrates
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Solution Overview
Problem
Existing methods for coloring materials face challenges with dye leaching, particularly in inert materials like PET and PTFE, leading to contamination and toxicity issues, and current techniques are either costly, complex, or limited to specific substrate-dye combinations.
Innovation Solution
A post-fabrication method using gas plasma surface modification to covalently link functionalized coloring agents with radical sensitive or polymerizable groups to the substrate surface, preventing dye leaching and allowing for a wide range of materials and dyes to be used without altering the substrate's fabrication process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If simple staining with organic or aqueous dye solution is used, then the coloring process is straightforward and generally applicable, but significant dye leaching occurs when contacted with liquid
Solution Approach 1:
The patent applies preliminary action by treating the substrate surface with plasma before applying the dye. This pre-treatment creates reactive groups on the substrate surface that enable covalent bonding with the dye molecules, preventing leaching while maintaining process simplicity. The plasma treatment is performed as a separate preparatory step that modifies the substrate surface properties before the actual coloring operation.
2Stability of the object's composition
If dye doping is used to add dye before or during fabrication, then the dye is distributed homogenously in the bulk material, but dye leaching still occurs particularly when the substrate contacts solvents
Solution Approach 1:
The plasma treatment is applied as a preliminary step before dye application, creating covalent bonding sites on the substrate surface. This ensures that when dye is applied subsequently (whether by staining or doping), it forms strong covalent bonds that prevent leaching while maintaining homogeneous distribution if doping is used.
Solution Approach 2:
The patent changes the chemical state of the substrate surface through plasma treatment, transforming inert surfaces into reactive surfaces with functional groups. This parameter change in surface chemistry enables covalent bonding without affecting the bulk material properties or the homogeneous distribution of dye achieved through doping.
3Loss of substance
If fixating agents are added to immobilize dye, then dye leaching is reduced significantly, but the method is restricted to charged dyes and does not completely prevent leaching
Solution Approach 1:
The patent replaces the electrostatic interaction mechanism of fixating agents with a covalent bonding mechanism through plasma treatment. Covalent bonds are non-specific and can form with any dye molecule that has appropriate functional groups, eliminating the restriction to charged dyes while achieving complete leaching prevention.
Solution Approach 2:
The plasma treatment changes the bonding parameter from weak electrostatic interactions to strong covalent bonds. This fundamental change in interaction strength and type enables universal applicability to various dye types while completely preventing leaching, unlike fixating agents that only work for charged dyes.
4Loss of substance
If covalent linkage through copolymerization is used to immobilize dye, then dye leaching is completely eliminated, but the process requires complex synthesis and optimization for each polymer blend
Solution Approach 1:
The patent extracts the complex copolymerization synthesis step and replaces it with a simpler plasma treatment process. The plasma treatment achieves covalent bonding without requiring the dye to be synthesized as a monomer or copolymer, eliminating the need for complex synthesis and optimization for each polymer-dye combination while maintaining complete leaching prevention.
Solution Approach 2:
The patent substitutes the complex chemical synthesis process (copolymerization) with a physical-chemical plasma treatment process. The plasma provides the necessary activation and bonding conditions without requiring the dye to undergo complex synthesis reactions, dramatically simplifying the overall process while achieving the same covalent immobilization result.
5Loss of substance
If specific surface functionalities are incorporated to enable covalent linkage, then dye immobilization is achieved, but the approach is restricted to reactive surfaces and requires precursor incorporation during fabrication
Solution Approach 1:
The plasma treatment serves as a preliminary action that creates the necessary surface functionalities in-situ, eliminating the need to incorporate precursor compounds during substrate fabrication. This makes the process applicable to any substrate material without requiring modifications to the substrate manufacturing process.
Solution Approach 2:
The plasma treatment changes the surface chemical parameters of the substrate, creating reactive functional groups on the surface. This parameter change enables covalent bonding capability without altering the bulk substrate composition or requiring precursor incorporation during fabrication, making the process universally applicable to various substrate materials.
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 method effectively immobilizes dyes on the substrate surface, reducing leaching, allowing for a broad applicability across various materials and dyes, with minimal dye usage and short treatment times, while maintaining the substrate's properties and enabling continuous processing.
Implementation Method 1
subjecting the substrate and colorant to radical species from a plasma generated by an atmospheric plasma apparatus
Implementation Method 2
form covalent bonds between the functionalized coloring agent and the substrate
Data Source
AI summary
The present invention provides a post-fabrication modification approach for the fabrication of colored and chromic materials and sensors using plasma surface modification to covalently bind the coloring agent to the substrate, thus avoiding leaching of the dye. Advantageously, in said methods, said coloring agent is a dye or pigment linked to a radical sensitive functional group, such as an alkenyl or alkynyl functional group, and is applied to the substrate prior to the gas plasma treatment. The methods envisaged herein are generic in nature, which allow the covalent immobilization of various dyes on different materials. The covalently coated materials after plasma surface modification, particularly the covalently coated chromic materials and sensors, can be used in many different applications, such as protective textile and wound dressing applications.