Upconverting Liquid-Filled Polymers for Oxygen Protection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing upconverting materials face challenges in achieving high mechanical stability, transparency, and efficient upconversion efficiency due to phase segregation and oxygen quenching, particularly in solid-state forms, which limits their application in energy conversion and bioimaging.

Innovation Solution

Development of optically upconverting liquid-filled polymeric materials with a phase-separated morphology, where a hydrophobic liquid phase dissolves upconverting chromophores and is housed within a hydrophilic, cross-linked polymer matrix, providing mechanical stability and protection from oxygen, allowing for high upconversion efficiency under ambient conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If upconverting materials are prepared in solid-state forms, then mechanical stability is improved, but upconversion efficiency deteriorates due to phase segregation and oxygen quenching

Engineering Contradiction:
Improvemechanical stabilityVSAvoidupconversion efficiency
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The material is segmented into distinct liquid and solid phases through phase-separated morphology. The liquid phase domains (containing chromophores) are dispersed within the solid polymer matrix, allowing each phase to fulfill its specific function: liquid phase maintains high upconversion efficiency while solid matrix provides mechanical stability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention creates a composite material system combining liquid crystalline phases with solid polymer matrices. This composite structure integrates the advantages of both phases: the liquid phase enables efficient triplet-triplet annihilation upconversion while the solid matrix provides mechanical support and oxygen barrier properties.

Inventive Principle:
Principle #40Composite materials

2Reliability

If conventional solutions are used for upconversion, then upconversion efficiency is improved, but mechanical stability deteriorates

Engineering Contradiction:
Improveupconversion efficiencyVSAvoidmechanical stability
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The liquid phase containing chromophores is encapsulated within the solid polymer matrix structure, creating a flexible composite system. The liquid-filled domains are confined within the solid matrix framework, preserving the liquid-phase photophysical properties while gaining mechanical stability from the solid structure.

Inventive Principle:
Principle #30Flexible shells and thin films

3Reliability

If liquid phase is used to dissolve chromophores, then upconversion efficiency is improved, but protection from oxygen deteriorates

Engineering Contradiction:
Improveupconversion efficiencyVSAvoidoxygen quenching
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The solid polymer matrix acts as an intermediary barrier between the liquid phase containing chromophores and the external oxygen environment. This intermediate solid layer protects the oxygen-sensitive liquid phase from oxygen quenching while allowing the liquid phase to maintain its superior upconversion efficiency.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The solid polymer matrix creates an oxygen-barrier environment around the liquid phase domains, effectively isolating the chromophores from external oxygen. This inert protective environment prevents oxygen quenching of triplet excited states, enabling efficient upconversion even in ambient conditions.

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

4Manufacturing precision

If phase-separated morphology is created, then transparency is improved, but oxygen diffusion increases

Engineering Contradiction:
ImprovetransparencyVSAvoidoxygen diffusion
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The material exhibits local quality differentiation where the solid polymer matrix provides oxygen barrier properties while the liquid phase domains maintain optical transparency. The phase-separated structure creates local regions with different functional properties: transparent liquid domains for light transmission and solid matrix regions for oxygen protection.

Inventive Principle:
Principle #3Local quality

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 materials exhibit high transparency, mechanical stability, and efficient upconversion efficiency, maintaining properties similar to oxygen-free solutions while being suitable for various applications, including energy conversion and bioimaging, with a one-step production process.

Implementation Method 1

a substantially liquid phase that serves to dissolve upconverting chromophores

Methodology Applied
Scientific EffectDissolution: Solvation

Implementation Method 2

offers some protection from oxygen... providing mechanical stability and protection from oxygen

Methodology Applied
Scientific EffectDiffusion barrier: Diffusion Barrier

Implementation Method 3

the domains formed by the two phases are so small that light scattering is largely suppressed, which renders the upconverting liquid-filled polymeric materials largely transparent

Methodology Applied
Scientific EffectLight scattering: Scattering

Implementation Method 4

Light upconversion (UC) is a process capable of transforming low-energy radiation into blue-shifted light by combining the energy of two or multiple photons

Methodology Applied
Scientific EffectUpconversion:

Implementation Method 5

UC by means of triplet-triplet annihilation (TTA) relies on organic and/or organometallic dyes

Methodology Applied
Scientific EffectTriplet-triplet annihilation:

Implementation Method 6

an optionally cross-linked polymer matrix that retains or houses the liquid phase

Methodology Applied
Scientific EffectCross-linking: Chemical Bonding

Data Source

PatentEP3383969B1Optically upconverting liquid-filled polymeric materials
Publication Date: 2020.02.05 ADOLPHE MERKLE INSTITUTE UNIVERSITY OF FRIBOURG
  • EP3383969B1 patent drawingFigure 1
  • EP3383969B1 patent drawingFigure 2
  • EP3383969B1 patent drawingFigure 3a~4c

AI summary

Optically upconverting liquid-filled polymeric materials that are made by curing a curable composition. The materials include a substantially liquid phase that serves to dissolve upconverting chromophores, optionally surfactants and an optionally cross-linked polymer matrix that retains or houses the liquid phase, provides mechanical stability, and offers some protection from oxygen. The optically upconverting liquid-filled polymeric materials have a phase-separated morphology. In preferred embodiments, the domains formed by the two phases are so small that light scattering is largely suppressed, which renders the upconverting liquid-filled polymeric materials largely transparent. The liquid phase provides a high mobility of the dissolved chromophores and the photophysical properties, such as the high upconversion quantum efficiency and the low excitation intensity threshold required to achieve upconverison, are thus more reminiscent of conventional or oxygen-free solutions than polymeric solids. These photophysical properties can be achieved by preparing the polymers under oxygen-free or, in preferred embodiments, under ambient conditions. The design principle introduced here to create upconverting liquid-filled polymeric materials is versatile and general; the liquid phase, the surfactants, the polymer matrix, and the upconverting chromophores can all readily be varied. Importantly, the optically upconverting liquid-filled polymeric materials can be prepared in a one-step process, which makes them preferable over other liquid-containing polymers that enable upconversion.