Sulfonated Polyphenylene Membrane for Chemical Resistance and Flux

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Solution Overview

Problem

Existing polyphenylene-based membranes lack sufficient chemical resistance, mechanical strength, and water permeability for applications in industrial wastewater treatment and pharmaceutical production, necessitating a balance between these properties.

Innovation Solution

Sulfonate a portion of the polyphenylene-based semipermeable membrane to create a sulfonated layer, controlling its thickness and sulfonation degree to maintain mechanical strength while enhancing water permeability and separation performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If polyamide-based composite hollow fiber membranes are used for seawater desalination, then salt rejection performance is improved, but membrane fouling and chlorine sensitivity worsen

Engineering Contradiction:

Improvesalt rejection performanceVSAvoidmembrane fouling and chlorine sensitivity

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The invention uses polyphenylene sulfone as the base polymer material for the hollow fiber membrane, combining it with specific additives and controlling phase inversion parameters to create a composite structure that achieves both high salt rejection and resistance to fouling and chlorine, eliminating the trade-off present in polyamide-based membranes

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The invention changes the fundamental parameter of base polymer material from polyamide to polyphenylene sulfone, and optimizes additional parameters including additive composition, spinning solution concentration, and phase inversion conditions to achieve simultaneous improvement in salt rejection and resistance to fouling and chlorine

Inventive Principle:

Principle #35Parameter changes

2Productivity

If cross-section non-uniform hollow fiber membranes are used to increase flux, then water permeability is improved, but manufacturing complexity and quality control worsen

Engineering Contradiction:

Improvewater permeabilityVSAvoidmanufacturing complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The invention achieves uniform cross-sectional structure throughout the hollow fiber membrane by controlling the spinning and phase inversion process, ensuring consistent pore distribution and wall thickness, which simplifies manufacturing while maintaining high water permeability through optimized pore structure rather than geometric irregularity

Inventive Principle:

Principle #33Homogeneity

3Productivity

If membrane pore structure is optimized for high flux, then water permeability is improved, but salt rejection performance worsens

Engineering Contradiction:

Improvewater permeabilityVSAvoidsalt rejection performance

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The invention creates different pore structure characteristics in different regions of the membrane: the skin layer has dense, small pores for high salt rejection, while the bulk layer has larger, more connected pores for high water permeability, achieving both requirements simultaneously through spatial variation in pore quality

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The invention uses polyphenylene sulfone's inherent properties combined with controlled phase inversion to create a composite pore structure that simultaneously provides the density needed for salt rejection and the connectivity needed for water permeability, resolving the trade-off between these two performance parameters

Inventive Principle:

Principle #40Composite materials

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 sulfonated polyphenylene-based membranes achieve chemical resistance, improved water permeability, and high ion-rejection rates with balanced mechanical strength, suitable for industrial applications.

Implementation Method 1

a method for producing a polyphenylene-based semipermeable membrane comprising: preparing a polymer solution containing 15 to 25 wt % of polyphenylene sulfone (PPS) as a main polymer material; and performing cross-flow filtration or ultrafiltration using the prepared polymer solution

Methodology Applied

Scientific EffectPhase inversion: Phase Change

Implementation Method 2

cross-flow filtration or ultrafiltration using the prepared polymer solution

Methodology Applied

Scientific EffectPermeation: Permeation

Data Source

PatentEP4129457B1Polyphenylene-based semipermeable membrane and manufacturing method therefor

Publication Date: 2026.04.29 TOYOBO CO LTD

Figure 1(1)~1(5)
Figure 2a~2b
Figure 3~4

AI summary

[Problem] Provided is a semipermeable membrane that achieves chemical resistance (chlorine resistance, acid resistance, alkali resistance), membrane performance, and membrane strength by sulfonating a polyphenylene-based semipermeable membrane base material under specific conditions. [Solution] A polyphenylene-based semipermeable membrane that is composed of a material containing a polyphenylene-based resin, wherein the semipermeable membrane has a first surface of which at least a portion is sulfonated, and wherein, when concentration distribution of elemental sulfur derived from a sulfonic acid group is measured by elemental analysis in a cross section in a thickness direction of the semipermeable membrane, a ratio of a sulfonated layer obtained by the following expression is 50% or less: Ratio of Sulfonated Layer (%) = Sulfonated Layer Thickness / (Sulfonated Layer Thickness + Non-Sulfonated Layer Thickness) × 100.