Underwater Adhesive Using Dynamic Polymers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional adhesives lose adhesion in water, making them unsuitable for underwater applications, and existing underwater adhesives often require curing steps, are not pressure-sensitive, or are not reusable and recyclable.
Innovation Solution
Dynamic polymers with a hydrophobic backbone and reversible dynamic bonds that provide physical crosslinking through supramolecular interactions and topological entanglements, allowing for high cohesive strength and pressure-sensitive adhesion without solvents or curing, and enabling recycling and reuse.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional adhesives are used, then adhesion strength is achieved in dry conditions, but adhesion is lost in the presence of water
Solution Approach 1:
The patent converts the harmful effect of water into a beneficial feature by using water as the continuous phase in a water-in-oil emulsion system. The hydrophobic domains repel water to maintain adhesive strength, while the hydrophilic domains interact with water to enable underwater application and controlled adhesion reversal through hydration-induced swelling.
Solution Approach 2:
The adhesive comprises a composite emulsion system with hydrophobic polymer domains (for adhesion and water resistance) dispersed in a hydrophilic continuous phase (for water compatibility and controlled reversal). This composite structure combines the benefits of both hydrophobic and hydrophilic properties to achieve underwater adhesion with reversible control.
2Strength
If curable adhesives are used to achieve strong adhesion, then cohesive strength is improved, but application complexity increases due to curing steps
Solution Approach 1:
The adhesive achieves cohesive strength through self-assembly of hydrophobic polymer domains that spontaneously form a percolating network upon contact with water. This self-organizing process eliminates the need for external curing agents, UV light, heat treatment, or complex crosslinking chemistry, providing strong adhesion through simple application and automatic structural organization.
3Strength
If strongly hydrophobic materials are used to remove interfacial water, then adhesion strength is improved, but reusability and recyclability are reduced
Solution Approach 1:
The adhesive employs dynamic, reversible adhesion controlled by water interaction. The hydrophilic continuous phase absorbs water to trigger swelling of the hydrophobic domains, dynamically reversing adhesion. This dynamic control mechanism allows the adhesive to be repeatedly applied and removed without degradation, enabling reusability and recyclability that static hydrophobic adhesives lack.
4Area of stationary object
If pressure-sensitive adhesion is achieved through flow over surface, then contact area is maximized, but cohesive strength may be compromised
Solution Approach 1:
The adhesive is segmented into discrete hydrophobic polymer domains dispersed in a hydrophilic continuous phase. Each hydrophobic domain acts as an independent adhesion unit that can flow and conform to substrate surfaces to maximize contact area, while the collective network of domains provides cohesive strength through their percolating structure. This segmentation allows simultaneous optimization of both adhesion (contact area) and cohesion (strength).
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 solution achieves high underwater adhesive strength, rapid and simple application, reversible adhesion, and recyclability, maintaining performance under both dry and wet conditions, with adhesion strengths comparable to the best reported underwater adhesives and outperforming commercial products.
Implementation Method 1
the hydrophobicity of PFPE enables underwater adhesion by removing interfacial water and preventing water diffusion into the bulk material
Implementation Method 2
dynamic polymers which possess physical crosslinking from both supramolecular interactions and topological entanglements could exhibit high cohesive strength while also readily flowing over a surface
Implementation Method 3
dynamic polymers which possess physical crosslinking from both supramolecular interactions and topological entanglements
Implementation Method 4
embed periodically-placed urethane bonds into a PFPE backbone to create linear dynamic polymers with a nanophase-separated microstructure
Data Source
AI summary
Underwater adhesive are provided that include a hydrophobic polymer backbone having periodically embedded dynamic bonding units, where the underwater adhesive has nanophase separation between a first phase of the hydrophobic polymer backbone and a second phase of the dynamic bonding units. The resulting nanophase-separated morphology has clusters of dynamically bonded groups that are protected from water by a surrounding matrix of hydrophobic polymer backbone. This enables a pressure sensitive underwater adhesive with advantages of: no curing needed, reusable, recyclable, and good adhesion strength.