Eutectic Ionic Liquid Mixture Dissolves Cellulose

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Solution Overview

Problem

Current methods for dissolving cellulose using ionic liquids require high temperatures and are not scalable or safe for industrial applications, leading to potential degradation and hazards such as explosions.

Innovation Solution

A mixture of imidazolium ionic liquids with chloride or acetate anions, forming a eutectic system, is used to dissolve cellulose at temperatures below the melting point of the pure ionic liquids, avoiding hazardous conditions and enabling scalable and efficient cellulose dissolution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional ionic liquids are used to dissolve cellulose, then dissolution can be achieved, but high temperatures (70-100°C or higher) are required which lead to degradation and safety hazards

Engineering Contradiction:

Improvesafety and stability of dissolution processVSAvoiddissolution temperature

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The invention changes the chemical composition parameters of the ionic liquid system by combining multiple ionic liquids in specific ratios to create a new solvent system with superior dissolution capability at lower temperatures, thereby resolving the contradiction between safe operation and effective dissolution

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention uses a composite ionic liquid system comprising multiple ionic liquids (e.g., imidazolium-based and pyridinium-based ionic liquids) combined in specific weight ratios to achieve synergistic effects that enable cellulose dissolution at lower temperatures with improved safety and stability

Inventive Principle:

Principle #40Composite materials

2Productivity

If statistical mixtures of ionic liquids are used to dissolve cellulose, then higher cellulose dissolution (up to 35wt%) is achieved, but microwave heating is required which is not scalable for industrial processes

Engineering Contradiction:

Improvecellulose dissolution efficiencyVSAvoidscalability of dissolution process

Core Design Contradiction:

ProductivityVSEase of manufacture

Solution Approach 1:

The invention optimizes the composition parameters of the ionic liquid mixture and adjusts the temperature parameter to achieve high cellulose dissolution efficiency through conventional heating methods, eliminating the need for microwave heating and enabling industrial scalability

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention creates a specifically formulated ionic liquid mixture with optimized local composition (specific cation-anion combinations and weight ratios) that provides enhanced dissolution capability at specific temperature ranges suitable for industrial processes

Inventive Principle:

Principle #3Local quality

3Reliability

If pure ionic liquids are used to dissolve cellulose, then dissolution occurs above the melting point, but the process is hazardous and not suitable for industrial application

Engineering Contradiction:

Improvesuitability for industrial applicationVSAvoidoperating temperature above melting point

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The invention develops a composite ionic liquid system that combines multiple ionic liquids to create a new solvent with a lowered effective operating temperature range, enabling safe and reliable cellulose dissolution suitable for industrial applications

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The invention modifies the physical and chemical parameters of the ionic liquid system through composition optimization, achieving cellulose dissolution at temperatures below the melting points of individual components, thereby improving industrial suitability

Inventive Principle:

Principle #35Parameter changes

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 eutectic mixture effectively dissolves cellulose up to 10 times more than single ionic liquids, achieving high yields under mild conditions, suitable for industrial use, and preserving the characteristics of ionic liquids like negligible vapor pressure, allowing for the production of cellulosic materials like sheets and foils.

Implementation Method 1

Cellulose is difficult to dissolve due to the strong network of hydrogen bonds between and within its polymeric chains

Methodology Applied

Scientific EffectHydrogen bonding:

Implementation Method 2

the mixture of the invention has a eutectic behaviour

Methodology Applied

Scientific EffectEutectic behavior:

Implementation Method 3

which prohibits solvation by conventional solvents

Methodology Applied

Scientific EffectSolvation: Solvation

Data Source

PatentEP3480246B1Mixtures of salts for dissolving cellulose

Publication Date: 2021.04.14 UNIVERSITY OF SANTIAGO DE COMPOSTELA

Figure 1

AI summary

Mixtures of salts to dissolve cellulose. The present invention refers to a composition based in a eutectic mixture of imidazolium salts and natural biopolymers, in particular cellulose, its manufacturing process and method of use to obtain foils or films. The composition is based in a eutectic mixture of imidazolium salts with 0.1 to 50wt% of biomass.