Colorless Polymer Aerogel via Radical Control

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current methods for producing colorless, transparent, high porosity polymer aerogels face challenges due to coloration issues from stable free radical species and require additional processing steps, which increase costs and reduce mechanical robustness.

Innovation Solution

The use of a stable free radical control agent, either a reducing agent or a time-controlled decomposing initiator, in the stable free radical polymerization process to balance the number of propagating and stable radicals, reducing coloration and enhancing porosity and mechanical robustness of the aerogels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If stable free radical polymerization is used to produce high porosity aerogels, then porosity and transparency are improved, but coloration occurs due to stable free radical species

Engineering Contradiction:

ImproveporosityVSAvoidcoloration

Core Design Contradiction:

Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

The patent converts the harmful colored stable free radical species into beneficial colorless products by introducing reducing agents (ascorbic acid, sodium borohydride, sodium sulfite) that reduce the nitroxide radicals to their colorless hydroxylamine forms, thereby eliminating coloration while preserving the aerogel structure

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent introduces reducing agents as intermediary substances that mediate between the colored stable free radical species and the desired colorless final product, enabling the transformation from harmful to beneficial state without compromising the aerogel's porosity and structural integrity

Inventive Principle:

Principle #24Intermediary (Mediator)

2Manufacturing precision

If ATRP or RAFT polymerization is used to produce narrow pore size distribution, then transparency is improved, but coloration occurs from transition metal reagents or sulfur-based chemicals

Engineering Contradiction:

Improvepore size distributionVSAvoidcoloration

Core Design Contradiction:

Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The patent eliminates the harmful colored byproducts of ATRP and RAFT polymerization by introducing reducing agents that convert colored transition metal species and sulfur-based chemicals into their colorless reduced forms, thereby achieving narrow pore size distribution without coloration

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent changes the oxidation state parameter of the polymerization system by introducing reducing agents that reduce metal centers and sulfur species, thereby altering the optical properties from colored to colorless while maintaining the controlled radical polymerization mechanism

Inventive Principle:

Principle #35Parameter changes

3Quantity of substance

If silica aerogels are used to achieve high porosity and transparency, then thermal insulation is improved, but mechanical robustness deteriorates due to brittleness

Engineering Contradiction:

ImproveporosityVSAvoidmechanical robustness

Core Design Contradiction:

Quantity of substanceVSStrength

Solution Approach 1:

The patent creates composite materials by combining organic polymer networks with inorganic components or using hybrid polymer systems that exhibit both high porosity for thermal insulation and enhanced mechanical robustness, overcoming the brittleness of pure silica aerogels

Inventive Principle:

Principle #40Composite materials

4Object-generated harmful factors

If additional processing steps are introduced to remove coloration, then colorlessness is improved, but manufacturing complexity and cost increase

Engineering Contradiction:

ImprovecolorationVSAvoidprocessing steps

Core Design Contradiction:

Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The patent performs preliminary action by incorporating reducing agents directly into the polymerization process, so that coloration is prevented during gel formation rather than requiring subsequent removal steps, thereby simplifying the overall manufacturing process

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent enables self-service by designing a polymerization system where the reducing agents automatically convert colored species to colorless forms during the polymerization process itself, eliminating the need for external post-processing interventions

Inventive Principle:

Principle #25Self-service

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 approach results in colorless, high transparency, high porosity aerogels with narrow pore size distributions, suitable for applications like transparent thermal insulation, without the need for additional processing steps, achieving high visible transmittance and color rendering index.

Implementation Method 1

Methodology Applied

Scientific EffectReduction: Reduction

Implementation Method 2

stable free radical polymerization process

Methodology Applied

Scientific EffectChemical Bonding: Chemical Bonding

Data Source

PatentUS11760824B2Method to produce colorless, high porosity, transparent polymer aerogels

Publication Date: 2023.09.19 GENESEE VALLEY INNOVATIONS LLC

AI summary

A dried polymer aerogel has a Brunauer-Emmett Teller (BET) surface area over 100 m2/g, porosity of greater than 10%, visible transparency greater than 20%, color rendering index of over 20%, and average pore size of less than 100 nm.