Cellulose Nanofiber Capsule Formation Without Organic Solvents

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Solution Overview

Problem

Existing methods for producing cellulose nanofiber capsules using Pickering emulsions require the use of organic solvents, making them unsuitable for applications in biological systems such as cosmetics, medical products, or pharmaceutical compositions.

Innovation Solution

A method involving the formation of a Pickering emulsion by irradiating a mixture of cellulose nanofibers, water, and fluid carbon dioxide with ultrasonic waves in a closed container, without the use of organic solvents, to produce cellulose nanofiber capsules.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional Pickering emulsion methods are used to produce cellulose nanofiber capsules, then capsule production is achieved, but organic solvents must be used which make the capsules unsuitable for biological applications

Engineering Contradiction:

Improvecapsule productionVSAvoidorganic solvent contamination

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The invention extracts and removes the harmful organic solvent component from the emulsion system by replacing it with supercritical carbon dioxide as the gas phase, eliminating toxic residues while maintaining capsule production capability

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the physical state parameters of carbon dioxide from gaseous to supercritical state, enabling it to function as a safe alternative to organic solvents in the Pickering emulsion process, and then returns it to gaseous state for easy removal

Inventive Principle:

Principle #35Parameter changes

2Stability of the object's composition

If hexadecane or triglycerides are used in the oil phase to form Pickering emulsion, then emulsion formation is achieved, but the resulting capsules are harmful to biological systems

Engineering Contradiction:

Improveemulsion stabilityVSAvoidbiological toxicity

Core Design Contradiction:

Stability of the object's compositionVSObject-generated harmful factors

Solution Approach 1:

The invention extracts and removes harmful oil phase components (hexadecane, triglycerides) from the system, replacing the traditional oil-water emulsion with a supercritical carbon dioxide-water system that achieves stability without toxic substances

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention uses supercritical carbon dioxide to create an inert, non-toxic environment that replaces harmful organic oils while maintaining the necessary emulsion stability for capsule formation

Inventive Principle:

Principle #39Inert atmosphere (Inert environment)

3Ease of manufacture

If organic solvents are used to prepare the emulsion phase, then Pickering emulsion formation is achieved, but the capsules cannot be applied to biological systems due to solvent residues

Engineering Contradiction:

Improveemulsion preparationVSAvoidbiological safety

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The invention extracts and eliminates organic solvents from the emulsion preparation process, replacing them with supercritical carbon dioxide which can be completely removed by pressure reduction, ensuring no harmful residues remain

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention discards harmful organic solvents and recovers/uses supercritical carbon dioxide instead, which can be easily discarded by pressure reduction without leaving residues, thereby ensuring biological safety

Inventive Principle:

Principle #34Discarding and recovering

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 method allows for the efficient production of cellulose nanofiber capsules that are safe for biological applications, as they do not contain residual organic solvents, enabling their use in drug delivery systems and other biological systems.

Implementation Method 1

forming a Pickering emulsion by irradiating a mixture containing cellulose nanofibers, water, and fluid carbon dioxide with ultrasonic waves

Methodology Applied

Scientific EffectUltrasonic waves: Ultrasound

Implementation Method 2

irradiating a mixture containing cellulose nanofibers, water, and fluid carbon dioxide with ultrasonic waves

Methodology Applied

Scientific EffectCavitation: Cavitation

Implementation Method 3

emulsions stabilized using solid particles adsorbed on the liquid-liquid interface

Methodology Applied

Scientific EffectAdsorption: Adsorption

Implementation Method 4

forming a Pickering emulsion by irradiating a mixture containing cellulose nanofibers, water, and fluid carbon dioxide

Methodology Applied

Scientific EffectPhase separation: Phase Change

Data Source

PatentUS12465900B2Method for producing cellulose nanofiber capsule

Publication Date: 2025.11.11 FUKUOKA UNIV

AI summary

A method for producing a cellulose nanofiber capsule according to the present invention includes forming a Pickering emulsion by irradiating a mixture containing cellulose nanofibers, water, and fluid carbon dioxide with ultrasonic waves in a closed container; and facilitating encapsulation using cellulose nanofibers from the Pickering emulsion by opening the closed container. The present invention enables encapsulation using the cellulose nanofibers from a Pickering emulsion that does not contain an organic solvent, for example, and is useful in the technical fields of pharmaceutical agents, foods, and cosmetics, for example.