Naphthalene Diimide Electrochromic Material for Smart Windows

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Solution Overview

Problem

Existing electrochromic materials struggle to achieve neutral shades like grey and black from a transparent initial state, and forming transmissive-to-black materials is challenging due to difficulties in controlling absorption properties.

Innovation Solution

A naphthalene diimide (NDI) compound of Formula 1, and its salts and solvates, which undergoes a rapid and reversible color change from transparent to black upon electrochemical or photochemical stimulus, suitable for use in smart windows.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If inorganic materials such as transition metal oxides are used as electrochromic materials, then operation effectiveness is improved, but processing and coating methods become energy intensive

Engineering Contradiction:

Improveoperation effectivenessVSAvoidprocessing and coating energy consumption

Core Design Contradiction:

ReliabilityVSUse of energy by stationary object

Solution Approach 1:

The patent replaces inorganic materials requiring energy-intensive metal electrodeposition with organic electrochromic materials that can be applied through solution processing methods, substituting a mechanical/industrial process with a chemical/solution-based process that consumes less energy

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention changes the material state from solid inorganic compounds to soluble organic compounds, enabling processing in solution form rather than requiring high-energy deposition techniques, thus reducing processing energy while maintaining electrochromic functionality

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If polymer films with coloured initial state are used, then neutral shades can be achieved in final state, but the initial transparent state cannot be achieved

Engineering Contradiction:

Improvecolour controlVSAvoidtransparent initial state

Core Design Contradiction:

Manufacturing precisionVSEase of operation

Solution Approach 1:

The patent employs a multi-component system where different polymer components contribute different properties: one component provides the electrochromic coloration capability while another component maintains initial transparency, allowing each component to have optimized local quality for its specific function

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The invention uses composite polymer films combining donor-π-donor polymers with carefully controlled co-polymers, where the composite structure enables both initial transparency and final neutral/black shades by balancing the optical properties of individual components

Inventive Principle:

Principle #40Composite materials

3Manufacturing precision

If metal organic frameworks are used to achieve black colour, then transparent to dark optical transitions are obtained, but design and manufacture become expensive

Engineering Contradiction:

Improveoptical transition controlVSAvoiddesign and manufacture cost

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent replaces expensive metal organic frameworks with organic electrochromic materials that can be synthesized more economically, using readily available organic precursors and standard polymerization techniques, thereby reducing material and manufacturing costs while achieving similar optical transitions

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The invention replicates the successful transparent-to-black optical transition effect of metal organic frameworks using organic polymer materials, copying the functional performance without requiring the complex and expensive metal-organic coordination structures

Inventive Principle:

Principle #26Copying

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 NDI compound achieves a rapid and reversible color change from transparent to black, demonstrating potential for use in smart windows with improved energy efficiency and privacy benefits.

Implementation Method 1

Electrochromic materials change colour when a current is applied. These materials can be used for applications such as smart windows, wherein the transmittance is controlled

Methodology Applied

Scientific EffectElectrochromism: Electrochromism

Implementation Method 2

The compounds of the invention also undergo a colour change upon irradiation with UV light

Methodology Applied

Scientific EffectPhotochromism: Photochromism

Data Source

PatentUS12234408B2Photochromic and electrochromic compounds

Publication Date: 2025.02.25 THE UNIV COURT OF THE UNIV OF GLASGOW

AI summary

Provided are novel naphthalene diimide (NDI) compound of Formula 1. The compounds may exhibit colour change from substantially transparent to substantially black upon electrochemical or photochemical stimulus and may be useful in smart windows.