Surface-Initiated Hydrophilic Polymer Coating Without Substrate Degradation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for modifying substrate surfaces with superhydrophilic polymers face challenges such as the use of aggressive solvents that degrade common polymers, high polymerization rates of (meth)acrylamide monomers, and hydrolysis issues in aqueous media, making it difficult to achieve thin, effective coatings for medical devices.
Innovation Solution
A method involving surface activation through flame, plasma discharge, or chemical etching to create reactive functional groups, followed by bonding a radical polymerization initiator, and applying a controlled radical polymerization process in an aqueous medium with (meth)acrylamide monomers to form a polymeric coating layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If controlled radical polymerization (ATRP) is used to modify substrate surfaces with superhydrophilic polymers, then polymer architecture can be controlled, but the process requires aggressive solvents that cause degradation of common polymers and corrosion of metal substrates
Solution Approach 1:
The patent changes the chemical parameters of the polymerization process by using redox-initiated polymerization instead of ATRP, allowing the reaction to proceed in water without requiring aggressive organic solvents. This parameter change eliminates substrate degradation while maintaining controlled polymer formation
Solution Approach 2:
The patent introduces redox initiators as intermediaries that enable polymerization in aqueous media. These initiators act as mediators between the water-based environment and the polymerization reaction, allowing controlled radical polymerization without requiring copper-based catalysts or aggressive solvents that would harm the substrate
2Ease of operation
If ATRP initiators are used in aqueous medium for surface polymerization, then polymerization can occur in water, but the initiators rapidly hydrolyze and lose their ability to control polymerization
Solution Approach 1:
The patent changes the chemical parameters by selecting redox initiators with stability profiles suited for aqueous environments. These initiators maintain their functionality in water without rapid hydrolysis, enabling reliable controlled polymerization in aqueous medium
Solution Approach 2:
The patent uses redox initiators that are consumed in the initiation step and do not require long-term stability in aqueous media like ATRP catalysts. These initiators perform their function rapidly and are replaced, avoiding the hydrolysis problem of persistent ATRP initiators
3Manufacturing precision
If (meth)acrylamide monomers are polymerized via ATRP, then superhydrophilic coating can be achieved, but the exceptionally high polymerization rate makes control difficult
Solution Approach 1:
The patent employs periodic or controlled redox reactions to manage the polymerization rate. By using redox initiators that can be activated and deactivated in a controlled manner, the exceptionally high polymerization rate of (meth)acrylamide monomers is regulated, allowing precise coating formation without runaway reactions
4Ease of manufacture
If aggressive chemical attack methods are used to create functional groups on polymer surfaces for initiator binding, then initiator attachment can be achieved, but common polymers are rapidly degraded
Solution Approach 1:
The patent enables the polymer surface to self-generate the necessary functional groups through mild oxidation in aqueous redox environments, eliminating the need for aggressive chemical attacks. The surface serves itself by forming hydroxyl or carboxyl groups under gentle conditions that do not degrade the polymer substrate
Solution Approach 2:
The patent changes the chemical environment from aggressive organic solvents to mild aqueous redox conditions. This parameter change allows functional group formation and initiator binding without compromising polymer substrate integrity
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
Results in a durable, superhydrophilic coating with low water contact angles, suitable for various substrates, including medical devices, providing anti-fouling and lubricious properties.
Implementation Method 1
modifying the substrate via flame, corona discharge, argon plasma discharge or chemical etching to generate reactive functional groups on the substrate
Implementation Method 2
modifying the substrate via flame, corona discharge, argon plasma discharge or chemical etching to generate reactive functional groups on the substrate
Implementation Method 3
modifying the substrate via flame, corona discharge, argon plasma discharge or chemical etching to generate reactive functional groups on the substrate
Implementation Method 4
allowing the polymerization initiator to be chemically bonded to the surface by reaction of the polymerization initiator with the reactive functional groups on the substrate
Implementation Method 5
forming a polymeric coating layer on the surface via a controlled radical polymerization (CRP) process
Implementation Method 6
Results in a durable, superhydrophilic coating with low water contact angles
Data Source
AI summary
Methods for applying a polymeric coating to a substrate are provided comprising:(a) generating reactive functional groups on the polymeric substrate;(b) contacting the substrate with a radical polymerization initiator;(c) allowing the polymerization initiator to be chemically bonded to the substrate by reaction of the polymerization initiator with the reactive functional groups on the substrate;(d) contacting the polymerization initiator that is chemically bonded to the substrate with a monomer composition comprising a free-radical polymerizable monomer having at least one hydrophilic functional group;(e) forming a polymeric coating layer on the substrate via a radical polymerization process; and optionally(f) subjecting the polymeric coating layer on the substrate to conditions to effect curing of reactive functional groups on the polymers of the polymeric coating layer. The monomer composition may comprise at least 10 percent by weight of a (meth)acrylamide monomer having at least one ionic functional group.