Filtration Membrane Casting via Statistical Copolymer Solvation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing methods for improving membrane flux, such as grafting and blending, either require lengthy manufacturing steps, lead to loss of selectivity, or are limited to specific membrane types, restricting the use of filtration membranes with dense selective layers.

Innovation Solution

A method involving the preparation of a filtration membrane by dissolving a statistical copolymer in a mixture of a co-solvent and a first organic solvent, coating this solution onto a porous support layer, coagulating to form a thin film composite membrane, and then immersing it in a water bath.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If grafting or blending methods are used to improve membrane flux, then permeability increases, but manufacturing complexity increases and selectivity is lost

Engineering Contradiction:

Improvemembrane fluxVSAvoidmanufacturing steps

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The invention changes the chemical composition parameters of the copolymer (specific ratios of zwitterionic to hydrophobic repeat units) and the solvent system (mixtures of organic solvents and water) to achieve high flux membranes through a straightforward casting process, avoiding complex grafting or blending steps while maintaining selectivity

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention uses composite copolymer materials combining zwitterionic and hydrophobic repeat units in specific ratios, creating a material that inherently provides both high permeability and selectivity without requiring additional processing steps like grafting or blending

Inventive Principle:

Principle #40Composite materials

2Productivity

If grafting or blending methods are used to improve membrane flux, then permeability increases, but selectivity deteriorates

Engineering Contradiction:

Improvemembrane fluxVSAvoidselectivity

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The invention optimizes the compositional parameters of the copolymer (ratio of zwitterionic to hydrophobic units) and the casting conditions to create a dense selective layer that simultaneously achieves high flux and maintains selectivity, avoiding the selectivity loss associated with grafting and blending methods

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If conventional methods are used, then certain membrane types can be produced, but adaptability to dense selective layers is restricted

Engineering Contradiction:

Improvemembrane type rangeVSAvoidprocess simplicity

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The invention develops a universal casting method using statistical copolymers that can produce various types of filtration membranes (microfiltration, ultrafiltration, nanofiltration, reverse osmosis) with dense selective layers through a single standardized process, greatly expanding adaptability while maintaining ease of manufacture

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 method achieves high flux and selectivity in filtration membranes, with permeances of 30 Lm−2h−1bar−1 or higher and effective pore sizes of 0.5 to 5 nm, while maintaining selectivity and not requiring additional processing steps.

Implementation Method 1

providing a copolymer solution by dissolving a statistical copolymer in a mixture of a co-solvent and a first organic solvent

Methodology Applied

Scientific EffectDissolution: Solvation

Implementation Method 2

coating the copolymer solution onto a porous support layer to form a polymeric layer thereon

Methodology Applied

Scientific EffectCoating/Deposition: Deposition (physical)

Implementation Method 3

coagulating the polymeric layer on top of the support layer to form a thin film composite membrane

Methodology Applied

Scientific EffectCoagulation: Coagulation

Implementation Method 4

immersing the thin film composite membrane into a water bath to obtain a filtration membrane

Methodology Applied

Scientific EffectPhase change (water immersion): Phase Change

Data Source

PatentUS12233383B2Fabrication of filtration membranes

Publication Date: 2025.02.25 TRUSTEES OF TUFTS COLLEGE

AI summary

Disclosed is a method of preparing a filtration membrane. The method includes providing a copolymer solution by dissolving a statistical copolymer in a mixture of a co-solvent and a first organic solvent, coating the copolymer solution onto a porous support layer to form a polymeric layer thereon, coagulating the polymeric layer on top of the support layer to form a thin film composite membrane, and immersing the thin film composite membrane into a water bath to obtain a filtration membrane. Also disclosed are a filtration membrane prepared by the method, and a process of filtering a liquid using the filtration membrane thus prepared.