Reactive Polyfluoroalkyl Siloxane Oligomers for Durable Coatings
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Solution Overview
Problem
Current technologies for imparting hydrophobic and oleophobic properties to surfaces are labor-intensive, costly, and lack durability, especially when exposed to corrosive environments, as they often require pre-roughening of surfaces and lack covalent bonding of hydrophobic agents, leading to property degradation over time.
Innovation Solution
Development of reactive poly(fluoroalkyl-functional siloxane) oligomers with reactive SiX groups, derived from fluoroalkyl-functional silanes, which form durable films through partial hydrolysis and condensation, providing excellent hydrophobic and oleophobic properties and chemical resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If surfaces are pre-roughened by functionalization with nanoparticles, etching or electrochemical etching to achieve superamphiphobic properties, then hydrophobic and oleophobic properties are improved, but the process becomes labor intensive and requires costly ingredients and equipment
Solution Approach 1:
The patent applies preliminary action by incorporating reactive SiX groups into the fluoroalkyl-functional silane oligomers before application. These pre-installed reactive groups automatically form covalent bonds with the surface upon contact, eliminating the need for preliminary surface roughening steps while ensuring durable hydrophobic and oleophobic properties
Solution Approach 2:
The patent extracts and removes the complex pre-roughening steps (nanoparticle functionalization, acid etching, base etching, electrochemical etching) from the process, retaining only the essential coating application step. The reactive oligomers self-adhere to smooth surfaces through covalent bonding, making the complex preparatory steps unnecessary
2Reliability
If fluoroalkyl-functional silanes are hydrolyzed in excess water and solvent to prepare linear low molecular weight oligomers, then hydrophobic properties are achieved, but the linear structure lacks branching and is not facile in forming crosslinked three dimensional films
Solution Approach 1:
The patent applies local quality by creating branched oligomer structures with multiple reactive SiX groups distributed throughout the molecule. This branched architecture provides multiple local bonding sites that enable crosslinking in specific regions while maintaining the overall hydrophobic fluoroalkyl functionality, resulting in both hydrophobicity and crosslinked film formation
Solution Approach 2:
The patent creates composite structures by combining fluoroalkyl functional groups (providing hydrophobicity) with reactive SiX groups (enabling crosslinking) within the same oligomer molecule. This composite molecular structure integrates both hydrophobic properties and crosslinking capability, forming durable three-dimensional films
3Area of stationary object
If tetra-alkoxysilane is used to provide silanol rich surface through hydrolysis, then surface coverage is improved, but silanols are hydrophilic and increase surface energy, decreasing hydrophobic and oleophobic properties
Solution Approach 1:
The patent applies local quality by incorporating fluoroalkyl functional groups at specific locations on the silane oligomer structure. These fluoroalkyl groups are positioned to orient toward the external environment, providing hydrophobic and oleophobic properties at the surface interface, while the silane backbone provides surface coverage and adhesion
Solution Approach 2:
The patent changes the chemical composition parameters by using fluoroalkyl-functional silanes instead of conventional tetra-alkoxysilanes. The fluoroalkyl groups fundamentally alter the surface energy characteristics, making the surface hydrophobic and oleophobic even when silanol groups are present for surface bonding
4Ease of operation
If emulsions contain surface wetting agents and surfactants to improve coating application, then coating processability is improved, but hydrophobic properties decrease and silylation of the surface is inhibited
Solution Approach 1:
The patent uses the reactive SiX groups as intermediaries between the coating and the surface. These reactive groups mediate the bonding process by forming covalent bonds with surface hydroxyl groups, eliminating the need for surfactants and wetting agents that would otherwise compromise hydrophobic properties
5Ease of manufacture
If oligomeric silsesquioxanes are spin coated onto inert surfaces to impart hydrophobic and oleophobic properties, then coating simplicity is improved, but lack of covalent bonding results in loss of properties upon aging especially in corrosive environments
Solution Approach 1:
The patent applies preliminary action by pre-equipping the oligomers with reactive SiX groups that automatically form covalent bonds with the surface upon contact. This preliminary inclusion of bonding capability ensures durability from the outset without complicating the coating application process
Solution Approach 2:
The patent extracts and removes the need for complex surface pre-treatment steps while retaining durability through the reactive oligomers. The simple spin-coating process is maintained, but the coating material itself is enhanced with reactive groups that provide covalent bonding and long-term stability in corrosive environments
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 reactive poly(fluoroalkyl-functional siloxane) oligomers create durable, chemically resistant coatings that maintain hydrophobic and oleophobic properties even after exposure to corrosive environments, offering improved surface treatment compared to existing methods.
Implementation Method 1
partial or complete hydrolysis and condensation of fluoroalkyl-functional silanes
Implementation Method 2
partial or complete hydrolysis and condensation of fluoroalkyl-functional silanes
Implementation Method 3
impart hydrophobic and oleophobic properties to provide a water and oil repellant or water and oil resistant surface
Implementation Method 4
Fluoroalkyl functional compounds, when deposited onto surfaces, impart low surface energy properties
Data Source
AI summary
Reactive poly(fluoroalkyl-functional siloxane) oligomers, method of making the same, and compositions comprising the same are shown and described herein. The reactive poly(fluoroalkyl-functional siloxane) oligomers are is derived from a hydrolysable fluoroalkyl-functional silanes. Coating compositions comprising reactive poly(fluoroalkyl-functional siloxane) oligomer(s) may be used to form a coating or a film on a substrate and impart hydrophobic and/or oleophobic properties. The reactive poly(fluoroalkyl-functional siloxane) oligomer are more hydrophobic and oleophobic and show better chemical resistance than the hydrolysable fluoroalkyl-functional silane.