Dual-Control Bi-Stable Color-Changing Microcapsules
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing color-changing leuco dyes require continuous application of voltage and temperature to maintain a certain color state, making them energy-inefficient and environmentally unfriendly, and lack stability in color change.
Innovation Solution
A method to prepare electric and temperature dual-control bi-stable color-changing microcapsules using a specific ratio of leuco dye, electrolyte, and organic solid material, which change color under coordinated voltage and temperature control, with a color change temperature range of −5° C. to +80° C. and a driving voltage of 1-10 V, allowing for stable color retention even after power cutoff.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If continuous voltage and temperature are applied to maintain color state, then color stability is improved, but energy consumption increases and environmental friendliness deteriorates
Solution Approach 1:
The patent applies periodic action by using intermittent voltage pulses instead of continuous voltage application. The microcapsules are stimulated with voltage only when color change is needed, and then maintain that color state without continuous power supply. This periodic stimulation approach reduces energy consumption while maintaining color stability during the required periods.
Solution Approach 2:
The microcapsules exhibit self-service characteristics by maintaining their color state autonomously after initial stimulation. Once the leuco dye molecules are transformed to the colored state through voltage application and heating, they remain in that state without requiring continuous external energy input, effectively serving themselves to maintain color stability.
2Reliability
If continuous voltage and temperature are applied to maintain color state, then color stability is improved, but environmental friendliness deteriorates
Solution Approach 1:
By applying voltage only periodically rather than continuously, the patent reduces the total energy consumption and associated environmental impact. The microcapsules are activated only when color change is required, minimizing unnecessary energy waste and reducing harmful emissions from continuous power consumption.
Solution Approach 2:
The system achieves environmental friendliness through self-service operation where the microcapsules maintain their color state autonomously after initial activation. This eliminates the need for continuous external energy supply, thereby reducing the environmental footprint associated with constant power consumption and heat generation.
3Device complexity
If moncontrol color change elements are used, then device complexity is reduced, but color stability deteriorates
Solution Approach 1:
The patent merges two control mechanisms (electrical field control and thermal control) into a unified dual-control system. The microcapsules contain both leuco dye for electrical control and thermochromic materials for thermal control, allowing the system to achieve bi-stable color states by combining both mechanisms rather than using a single control method.
Solution Approach 2:
The microcapsules utilize composite materials containing leuco dye, color developers, solid solvents, and thermochromic materials in specific combinations. This composite structure enables dual-control functionality where electrical and thermal stimuli work together to achieve stable color states that neither mechanism could achieve alone.
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 microcapsules achieve continuous stable color change under low temperature and power cut conditions, with a driving voltage lower than human body safety voltage, and maintain color stability for up to 5 days, suitable for applications in color-changing textiles and glass.
Implementation Method 1
The color change principle is that: the gain and loss of electrons in the leuco dye is controlled by the on and off of the voltage, so that the structure of the dye changes (the lactone ring is opened and closed), which shows a color change.
Implementation Method 2
Thermochromic dyes are generally mixtures of color-changing leuco dyes, color developers and solid solvents. The solvents determine the color change temperature.
Data Source
AI summary
The disclosure discloses a method of preparing electric and temperature dual-control bi-stable color-changing dyes and microcapsules, belonging to the technical fields of fine chemicals and materials science. According to the disclosure, after an electrolyte, a leuco dye and an organic solid material are mixed according to 1:(2-10):(15-50), a series of electric and temperature dual-control bi-stable color-changing dye compounds having a color change temperature range of −5° C. to +80° C. can be prepared. The dye compounds change color under cooperative control of electricity and temperature, and can be continuously stable at a certain color change state according to different conditions, and finally achieve controllable color change conditions and controllable color change stable states. When being driven by voltage and temperature, the dual-control bi-stable color-changing microcapsules prepared according to the disclosure achieve controllable color change performance and color change stable states, and have the driving voltage being lower than 10 V (much lower than the human body safety voltage 36 V).