Irreversible Thermochromic Cu(I) Coordination Polymer for Thermal History Monitoring

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Solution Overview

Problem

Current thermochromic compounds based on Cu(I) ions cannot determine if a material has exceeded a critical temperature, as their thermochromic properties are reversible, making them unsuitable for thermal monitoring in non-destructive testing.

Innovation Solution

A coordination polymer of Cu(I) ions with a polytopic connector ligand that exhibits an irreversible thermochromic transition when subjected to a temperature exceeding a critical temperature, allowing for the monitoring of thermal experience over time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If reversible thermochromic compounds based on Cu(I) ions are used, then the compounds can monitor instantaneous temperature, but they cannot determine whether a critical temperature has been exceeded over time

Engineering Contradiction:
Improvethermal monitoring capabilityVSAvoidthermal history information
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The invention divides the thermal monitoring function into two distinct components: a reversible thermochromic compound for instantaneous temperature monitoring and an irreversible marker compound for critical temperature detection. This segmentation allows each component to perform its specific function optimally without interference, resolving the contradiction between instantaneous monitoring and thermal history recording.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention introduces a second marker compound with irreversible thermochromic properties that acts as an intermediary to record thermal history. This intermediary compound remains inactive below the critical temperature and activates permanently when the critical temperature is exceeded, thereby preserving thermal history information that the reversible compound alone cannot provide.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of information

If irreversible thermochromic compounds are used to detect critical temperature, then thermal history can be recorded, but the compounds cannot monitor instantaneous temperature variations

Engineering Contradiction:
Improvethermal history informationVSAvoidinstantaneous temperature monitoring
Core Design Contradiction:
Loss of informationVSMeasurement precision

Solution Approach 1:

The invention segments the monitoring system into two specialized compounds: the reversible thermochromic compound handles instantaneous temperature monitoring, while the irreversible marker compound handles critical temperature detection and thermal history recording. This functional segmentation resolves the contradiction by assigning each capability to the appropriate compound type.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention merges the advantages of both reversible and irreversible thermochromic compounds into a single composite monitoring system. By combining these two types of compounds in the same medium, the system simultaneously achieves both instantaneous temperature monitoring and thermal history recording capabilities, eliminating the need to choose one over the other.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of manufacture

If Cu(I) ion complexes are used for luminescence, then low-cost large-scale applications are enabled, but the thermochromism is reversible and cannot track thermal experience

Engineering Contradiction:
Improvelow-cost productionVSAvoidthermal tracking accuracy
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The invention combines low-cost Cu(I) ion-based reversible thermochromic compounds with irreversible marker compounds to create a cost-effective thermal tracking system. This merging maintains the economic advantage of using abundant copper while adding the reliability of irreversible critical temperature detection, thereby resolving the contradiction between cost and reliability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention introduces an irreversible marker compound as an intermediary that works alongside the Cu(I) reversible thermochromic compound. This intermediary provides the missing thermal tracking accuracy by permanently recording when critical temperatures are exceeded, while the Cu(I) compound continues to provide cost-effective luminescence and instantaneous temperature sensing.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Enables the determination of whether a material has exceeded a critical temperature by modifying its luminescence properties irreversibly, providing a means to assess thermal history without decomposition, thus enhancing thermal monitoring capabilities.

Implementation Method 1

Some of the Cu(I) ion complexes also have the particularity of being thermochromic, that is to say that their emission wavelength varies according to the temperature

Methodology Applied
Scientific EffectThermochromism: Thermochromism

Implementation Method 2

The coordination polymer exhibits at least one irreversible thermochromic transition of its luminescence when subjected to a temperature exceeding a critical temperature

Methodology Applied
Scientific EffectPhase change: Phase Change

Data Source

PatentEP3820929B1Coordination polymer of a precursor containing cu(i) ions
Publication Date: 2024.12.04 CENT NAT DE LA RECH SCI (C N R S)
  • EP3820929B1 patent drawingFigure 1
  • EP3820929B1 patent drawingFigure 2
  • EP3820929B1 patent drawingFigure 3

AI summary

The invention relates to a coordination polymer of a precursor containing Cu(I) ions with a polytopic connecting ligand. The precursor is a luminescent complex comprising at least two Cu(I) ions, said two Cu(I) ions of the precursor being interconnected by at least one assembling ligand. The connecting ligand has at least two terminal groups that are independently selected from a nitrogenous aromatic group and a carbonitrile group. The coordination polymer exhibits an irreversible thermochromic transition of its luminescence when it is subjected to a temperature exceeding a critical temperature Tc. The invention also relates to methods for producing said compounds and to corresponding uses.