Nanoparticle-Loaded Cellulose Dispersion for Stable Paper Coatings

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Nanoparticle dispersions are unstable, prone to aggregation, and hazardous due to dusting and skin absorption, posing handling challenges during paper and board production.

Innovation Solution

A process involving mechanical disintegration of pre-treated cellulose fibers and nanoparticles in a pressure homogenizer to produce a stable dispersion where nanoparticles are absorbed onto or into microfibrillated cellulose, reducing free nanoparticles and enhancing dispersion stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If nanoparticles are added to dispersions or slurries, then the reactive properties are improved, but the dispersion stability deteriorates and nanoparticles form aggregates

Engineering Contradiction:
Improvereactive propertiesVSAvoiddispersion stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent uses microfibrillated cellulose as an intermediary substance that absorbs nanoparticles, preventing direct nanoparticle-nanoparticle contact that leads to aggregation. The cellulose acts as a mediator maintaining nanoparticle dispersion stability while preserving reactivity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention creates a composite material system where nanoparticles are integrated with microfibrillated cellulose matrix. This composite structure combines the reactive properties of nanoparticles with the stabilizing properties of cellulose, resolving the contradiction between reactivity and stability.

Inventive Principle:
Principle #40Composite materials

2Reliability

If nanoparticles are used in dispersions, then functional properties are enhanced, but dusting problems increase and handling becomes hazardous

Engineering Contradiction:
Improvefunctional propertiesVSAvoiddusting and skin absorption
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

Microfibrillated cellulose serves as a protective intermediary that binds nanoparticles, preventing them from becoming airborne as dust or being absorbed through skin. The cellulose matrix encapsulates nanoparticles, eliminating harmful effects while preserving functional properties.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The microfibrillated cellulose forms a flexible matrix or shell around nanoparticles, creating a physical barrier that prevents dusting and skin contact. This thin film structure maintains nanoparticle functionality while protecting against harmful exposure.

Inventive Principle:
Principle #30Flexible shells and thin films

3Stability of the object's composition

If pre-treated cellulose fibers are mechanically disintegrated, then dispersion stability is improved, but energy consumption increases

Engineering Contradiction:
Improvedispersion stabilityVSAvoidenergy consumption
Core Design Contradiction:
Stability of the object's compositionVSUse of energy by moving object

Solution Approach 1:

The patent applies pre-treatment to cellulose fibers before mechanical disintegration, preparing the fibers in advance to require less energy-intensive processing. This preliminary chemical or enzymatic treatment weakens fiber bonds, making subsequent mechanical disintegration more energy-efficient while achieving the desired microfibrillation for stability.

Inventive Principle:
Principle #10Preliminary action

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 process results in a stable, less hazardous dispersion with reduced dusting and improved handling, enabling efficient transportation and safer use in various applications.

Implementation Method 1

treating the slurry by mechanical disintegration so that a dispersion comprising microfibrillated cellulose is formed in which the nanoparticles are being absorbed to the surface of the microfibrillated cellulose

Methodology Applied
Scientific EffectAdsorption: Adsorption

Data Source

PatentEP2771387B2Process for producing a dispersion comprising nanoparticles and a dispersion produced according to the process
Publication Date: 2025.12.03 STORA ENSO OYJ

AI summary

The present invention relates to a process for producing a dispersion comprising microfibrillated cellulose and nanoparticles wherein the process comprises the steps; providing a slurry comprising pre-treated cellulose fibers, adding nanoparticles to the slurry and treating the slurry by mechanical disintegration so that a dispersion comprising microfibrillated cellulose is formed in which the nanoparticles are being absorbed to the surface of the microfibrillated cellulose and/or being absorbed into the microfibrillated cellulose. The invention further relates to a dispersion produced according to the process, a paper or board product being coated with a coating comprising said dispersion and a paper or board product being produced from said dispersion as well as a composite comprising said dispersion.