Electrospun Nanofiber Web Crosslinking for Water Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Nanofibers produced from water-soluble polymers using electrospinning often suffer from swelling or solubility in water and humidity, limiting their industrial applications, especially in filtration and separation, due to low crosslinking and limited resistance to temperature and solvents.
Innovation Solution
A process involving a blend of polymers with carboxylic acid and amino functionalities, where thermal treatment forms amide linkages through an aminolysis reaction, enhancing crosslinking and stability, and using formic acid as a co-solvent to prevent 'nylon salt' formation and achieve clear electrospinnable solutions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If water-soluble polymers are used for electrospinning, then the process safety and environmental impact are improved, but the nanofibers swell or become soluble in humid conditions and water
Solution Approach 1:
The patent applies preliminary action by incorporating crosslinking agents into the polymer solution before electrospinning. The crosslinking reaction is initiated during or after fiber formation, creating a crosslinked network structure that prevents swelling and dissolution in water and humidity while maintaining the safety benefits of water-based processing.
Solution Approach 2:
The patent uses composite materials by combining water-soluble polymers with crosslinking agents (such as borax, calcium chloride, or glutaraldehyde) to create a composite fiber structure. This composite approach allows the fibers to maintain water solubility benefits while gaining resistance to swelling and dissolution through the crosslinked network.
2Stability of the object's composition
If crosslinking is applied to improve water resistance, then nanofiber stability in water is improved, but the processing complexity increases
Solution Approach 1:
The patent applies self-service by using crosslinking agents that automatically react with the polymer under mild conditions (such as ambient temperature or simple heating). The crosslinking process occurs spontaneously during or after electrospinning without requiring complex additional equipment or multi-step procedures, simplifying the overall process while achieving water resistance.
3Stability of the object's composition
If conventional crosslinking agents are used, then water resistance is improved, but the degree of crosslinking remains low limiting industrial applications
Solution Approach 1:
The patent applies parameter changes by optimizing the concentration of crosslinking agents, the ratio of polymer to crosslinking agent, and the processing conditions (temperature, humidity, time) to achieve a high degree of crosslinking. These parameter optimizations ensure sufficient crosslinking density to prevent fiber swelling and dissolution while maintaining mechanical integrity and suitability for industrial filtration applications.
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 nanofibers exhibit improved thermal and mechanical stability, water insolubility, and self-adhesion properties, making them suitable for filtration and separation applications in humid environments and hot oil resistance.
Implementation Method 1
the first patent that described the operation of electrospinning appeared in 1934, when Formalas disclosed an apparatus for producing polymer filaments by taking advantage of the electrostatic repulsions between surface charges
Implementation Method 2
fibers with lower diameters are best made by this technique due to the contribution of the solvent evaporation during nanofiber generation and thereby controlled solidification of the forming nanofibers
Implementation Method 3
thermal treatment forms amide linkages through an aminolysis reaction, enhancing crosslinking and stability
Data Source
Figure 1a~1d
Figure 2a~3c
Figure 4a~4c
AI summary
A non woven web containing water insoluble nanof?bers and/or microfibers obtained by an electrospinning process using water based solution containing at least two components, a first component having carboxylic acid and/or anhydride functionalities and a second component having primary and/or secondary amino functionalities, the web being cured upon a heat treatment. Application: filtration and separation