Nanocellulose Gas-Barrier Composition with Crosslinking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing gas-barrier materials made from nanocellulose suffer from degradation in humidity due to aggregation and gelling under acidic conditions, leading to inferior coatability and gas-barrier properties, and non-crosslinked products exhibit poor gas-barrier performance compared to crosslinked ones.
Innovation Solution
A gas-barrier composition comprising nanocellulose with sulfuric acid, sulfo, or phosphoric acid groups and a reactive crosslinking agent, such as citric acid, along with a polyvalent cationic resin, forming a dense crosslinked film that maintains excellent gas-barrier properties even in humid conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If nanocellulose with carboxyl groups is used as coating agent, then gas-barrier properties are improved, but film strength degrades in high-humidity atmosphere
Solution Approach 1:
The patent changes the chemical parameters of nanocellulose by introducing sulfuric acid groups and sulfo groups instead of using only carboxyl groups. This chemical modification allows the material to maintain gas-barrier properties while improving film strength in high-humidity conditions through enhanced crosslinking capability and reduced aggregation
Solution Approach 2:
The patent creates a composite system by combining modified nanocellulose with crosslinking agents (such as polyvinyl alcohol and borax) to form a crosslinked network structure. This composite approach maintains the gas-barrier properties of nanocellulose while adding the strength and humidity resistance provided by the crosslinked matrix
2Reliability
If crosslinking agent is added to nanocellulose to prevent degradation in humidity, then gas-barrier properties are maintained, but coatability degrades due to aggregation and gelling
Solution Approach 1:
The patent performs preliminary chemical modification of nanocellulose to introduce sulfuric acid groups and sulfo groups before adding the crosslinking agent. This preliminary action enhances the crosslinking efficiency and controls the timing of crosslinking reactions, preventing premature aggregation and gelling that would degrade coatability
Solution Approach 2:
The patent optimizes the concentration parameters of both the modified nanocellulose and the crosslinking agent to achieve the right balance between forming sufficient crosslinks for gas-barrier properties and maintaining low enough viscosity for good coatability. The controlled parameter range prevents excessive aggregation while ensuring adequate crosslinking
3Reliability
If carboxyl group content is limited to maintain gas-barrier properties, then barrier performance is improved, but aggregation occurs under acidic conditions with high crosslinking efficiency
Solution Approach 1:
The patent changes the type of functional groups on nanocellulose from carboxyl groups to sulfuric acid groups and sulfo groups. These alternative groups provide similar gas-barrier properties but with different chemical characteristics that reduce aggregation tendency under acidic crosslinking conditions while maintaining high crosslinking efficiency
Solution Approach 2:
The patent uses the modified functional groups (sulfuric acid groups and sulfo groups) as intermediaries that mediate between the need for gas-barrier properties and the need for dispersion stability. These groups enable controlled crosslinking while preventing unwanted aggregation during the coating process
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 composition achieves stable dispersion and formation of a dense crosslinked film, enhancing gas-barrier properties and coatability while preventing aggregation, resulting in superior performance compared to non-crosslinked materials.
Implementation Method 1
a reactive crosslinking agent... forming a dense crosslinked film
Implementation Method 2
nanocellulose containing at least one of a sulfuric acid group, a sulfo group, or a phosphoric acid group... stable dispersion
Data Source
AI summary
A gas-barrier composition including nanocellulose containing at least one of a sulfuric acid group, a sulfo group, or a phosphoric acid group; and a reactive crosslinking agent.