Polyamide Membrane Protective Layer for Dried Storage
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Solution Overview
Problem
Polyamide-based water treatment separation membranes face challenges with durability and salt rejection due to surface damage during manufacturing and storage, and require storage in a wet state to maintain efficiency, which complicates handling and economic feasibility.
Innovation Solution
A polyamide-based water treatment separation membrane is developed with a protective layer formed by polymerizing an amine group-containing compound, an epoxy group-containing compound, and a fluoro-containing compound, along with polyvinyl pyrrolidone, allowing the membrane to be stored and distributed in a dried state while maintaining high salt rejection and permeate flow efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a polyvinyl alcohol-based coating layer is formed on the polyamide active layer to improve durability, then resistance to scratches and damage is improved, but the active surface area decreases causing significant decrease in permeate flow and salt rejection properties
Solution Approach 1:
The patent changes the material parameter from polyvinyl alcohol to polyvinyl pyrrolidone, which fundamentally alters the solubility characteristics. Polyvinyl pyrrolidone can be dissolved in water at room temperature, enabling easy removal without high-temperature treatment, thus resolving the contradiction between providing durability protection and maintaining permeate flow through selective removal
Solution Approach 2:
The patent enables the coating layer to be easily discarded (removed) after serving its protective function during manufacturing and modularization processes. The polyvinyl pyrrolidone coating can be removed by simple water washing at room temperature, allowing recovery of the polyamide active layer's full permeate flow and salt rejection properties without damaging the membrane
2Ease of operation
If the polyamide active layer is dried to enable storage and distribution, then handling and economic feasibility are improved, but pores shrink and moisture content decreases causing significant decrease in salt rejection and permeate flow
Solution Approach 1:
The patent applies a protective coating layer containing polyvinyl pyrrolidone as a preliminary action before drying and storage. This coating acts as a protective barrier that prevents pore shrinkage and maintains moisture content during the drying process, allowing the membrane to be stored in a dried state while preserving salt rejection and permeate flow properties
Solution Approach 2:
The patent creates a composite structure by combining the polyamide active layer with a polyvinyl pyrrolidone coating layer. This composite material approach allows the membrane to simultaneously achieve the benefits of drying for storage and the maintenance of functional properties, as the polyvinyl pyrrolidone coating compensates for the effects of drying on the polyamide layer
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 membrane exhibits enhanced durability, resistance to scratches and fouling, and maintains salt rejection and permeate flow performance even after drying, enabling efficient storage and handling in a dried state without compromising treatment efficiency.
Implementation Method 1
this mPD layer brings in contact with trimesoyl chloride (TMC) by being immersed in a TMC organic solvent or being coated, and is interfacial polymerized to form a polyamide active layer
Implementation Method 2
forming either a single protective layer including a polymer obtained by polymerization an amine group-containing compound, an epoxy group-containing compound and a fluoro-containing compound
Implementation Method 3
a polyamide-based water treatment separation membrane, and the polyamide-based water treatment separation membrane is manufactured using a method in which a fine porous support is formed by forming a polysulfone layer on nonwoven fabric
Implementation Method 4
polyvinyl alcohol is not favorably dissolved in water at room temperature, and in this case, a problem of damaging the polyamide active layer occurs in the coating membrane removal process
Data Source
AI summary
The present invention relates to a water treatment separation membrane having improved durability and including a porous support; a polyamide active layer formed on the porous support; and a protective layer formed on the polyamide active layer and including polyvinyl pyrrolidone, wherein a thickness of the protective layer is 0.5 nm to 1000 nm, and a method for manufacturing the same.