Spherical Cellulose Fine Particles Dispersion Stability
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Solution Overview
Problem
Current methods for producing cellulose fine particles with small particle diameters and high average polymerization degrees are limited, resulting in non-uniform sizes, low mechanical strength, and aggregation issues, which hinder their use in applications requiring high sphericity and dispersion stability, especially in liquid and organic solvent environments.
Innovation Solution
The development of spherical cellulose fine particles with average diameters ranging from 9 to 400 nm and average polymerization degrees between 150 to 3,000, achieved through a process involving cuprammonium solutions, coagulation, and regeneration, which enhances mechanical strength and dispersion stability without the need for surfactants.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If polystyrene fine particles are used to achieve small particle diameter and high sphericity, then particle shape and size uniformity are improved, but hydrophobicity causes poor dispersion stability in water and aggregation
Solution Approach 1:
The invention changes the material parameter from hydrophobic polystyrene to hydrophilic cellulose, fundamentally altering the surface properties and interaction with water. This parameter change resolves the contradiction by providing both high sphericity and inherent hydrophilicity for stable dispersion without aggregation
Solution Approach 2:
The invention replaces expensive polystyrene with cellulose, a natural, abundant, and biodegradable material. This substitution achieves the same functional goals (small particle size, high sphericity) while eliminating the hydrophobicity problem through the inherent properties of cellulose
2Length of moving object
If polystyrene fine particles are used to achieve small particle diameter, then particle size is reduced, but mechanical strength becomes insufficient due to low melting point and high solubility
Solution Approach 1:
The invention replaces polystyrene with cellulose, a natural polymer with superior thermal stability and mechanical strength. Cellulose particles maintain their structural integrity at high temperatures and resist dissolution in organic solvents, resolving the mechanical strength deficiency while preserving small particle diameter
3Stability of the object's composition
If surfactant is added to enhance hydrophilicity of polystyrene particles, then dispersion stability is improved, but nonspecific adsorption occurs causing measurement error
Solution Approach 1:
The invention extracts and eliminates the surfactant component from the system by using inherently hydrophilic cellulose particles. This removal of the surfactant resolves the nonspecific adsorption problem while maintaining dispersion stability through the natural hydrophilic properties of cellulose
Solution Approach 2:
The cellulose particles self-provide the hydrophilic surface properties needed for stable dispersion without requiring external surfactants. This self-service approach eliminates the harmful side effects of surfactant addition while achieving the desired dispersion stability
4Area of moving object
If fine particles are microparticulated to achieve small particle diameter, then specific surface area is increased, but mechanical strength and uniformity become difficult to maintain
Solution Approach 1:
The invention changes the material parameters (using cellulose with appropriate molecular weight and degree of polymerization) to enable the production of monodisperse fine particles. This parameter change allows achieving small particle diameter with high uniformity and maintained mechanical strength, overcoming the limitations of conventional microparticulation methods
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 resulting cellulose fine particles exhibit high mechanical strength, uniform particle size distribution, and excellent dispersion stability in various liquids, including organic solvents, allowing for their use in diverse applications without additional stabilizers and maintaining stability over time.
Implementation Method 1
cellulose is dissolved in a cuprammonium solution
Implementation Method 2
subsequently re-precipitating it using a precipitant
Implementation Method 3
cellulose fine particles having a number average particle diameter of 400 nm or less and a volume average particle diameter of 1,000 nm or less can be successfully obtained
Data Source
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AI summary
An object of the present invention is to provide cellulose fine particles having a small particle diameter and a high average polymerization degree, and a liquid dispersion or a solid dispersion thereof. The inventive cellulose fine particles have an average particle diameter of 9 to 400 nm and an average polymerization degree (DP) of cellulose of 150 to 3,000.