Polyamide-Coated Composite Filter Media for Acid-Stable Filtration
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Solution Overview
Problem
Existing filtration technologies struggle to effectively remove ionic contaminants and colloidal particles from liquid materials used in microelectronic device processing, particularly in semiconductor manufacturing, while maintaining high purity and stability in acidic environments.
Innovation Solution
A composite porous filter membrane is developed, comprising a porous hydrophobic polymeric filter media coated with a polyamide polymer that is soluble in formic acid, and further enhanced with a free-radical reaction product of a crosslinker and monomer, providing a semi-continuous coating that enhances non-sieving filtration performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a polyamide coating is applied to increase surface area and dye-binding capacity, then non-sieving filtration performance is improved, but flow rate may be reduced
Solution Approach 1:
The patent applies a polyamide coating specifically to the surface of the porous polymeric filter media, creating a localized functional layer that enhances non-sieving filtration capacity without fundamentally altering the bulk porous structure's flow characteristics. This local modification allows improved contaminant removal while preserving overall flow rate.
Solution Approach 2:
The invention creates a composite filter media combining porous polymeric filter media with a polyamide coating layer. This composite structure integrates the high flow rate characteristics of the porous base material with the enhanced surface area and dye-binding capacity of the polyamide coating, resolving the contradiction between filtration performance and flow rate.
2Reliability
If filter media is used to remove ionic contaminants and colloidal particles, then filtration effectiveness is improved, but stability in acidic environments may be compromised
Solution Approach 1:
The patent selects and modifies polyamide polymer parameters including molecular weight, crystallinity, and chemical structure to enhance acid resistance. By controlling the polyamide coating's physical and chemical parameters, the system achieves both effective filtration of ionic contaminants and stability in acidic environments.
Solution Approach 2:
The patent employs a disposable filter media system where the porous polymeric filter media with polyamide coating is designed for single-use in acidic environments. This approach prioritizes filtration effectiveness in acidic conditions over long-term stability, as the filter is replaced rather than reused, eliminating the need for long-term acid resistance.
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 composite membrane achieves improved non-sieving filtration by increasing surface area and dye-binding capacity, while maintaining high flow rates and stability in acidic conditions, effectively removing ionic contaminants and colloidal particles from liquid materials.
Implementation Method 1
A non-sieving filtration mechanism is a mode of filtration by which a filter membrane retains a suspended particle or dissolved material contained in flow of fluid through the filter membrane in a manner that is not exclusively mechanical, e.g., that includes an electrostatic mechanism by which a particulate or dissolved impurity is electrostatically attracted to and retained at a filter surface
Implementation Method 2
A sieving mechanism is a mode of filtration by which a particle is removed from a flow of liquid by mechanical retention of the particle at a surface of a filter membrane, which acts to mechanically interfere with the movement of the particle and retain the particle within the filter
Implementation Method 3
further enhanced with a free-radical reaction product of a crosslinker and monomer, providing a semi-continuous coating that enhances non-sieving filtration performance
Data Source
AI summary
Provided are certain composite membranes useful for removing various impurities from liquids. In certain aspects, the composite membranes comprise a hydrophobic polymer having a polyamide coated thereon, and in other aspects, such composite membranes having certain acrylic polymers coated thereon. The composite membranes are useful in the removal of various impurities in liquids, such as those encountered in industrial and life sciences processes.