Chitosan-Graphene Oxide Membrane Anti-Fouling Filtration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current membrane filtration technologies face challenges such as membrane fouling, low flux, and low hydrophilicity, and are often derived from petroleum-based materials, which are not environmentally sustainable. Additionally, chitosan-graphene oxide nanocomposites have been limited in their application due to weak mechanical properties and solubility issues, and prior reports on graphene oxide membranes are not representative of real-world operations.
Innovation Solution
A scalable chitosan-graphene oxide composite membrane is developed, with up to 25% graphene oxide and 75% chitosan, where graphene oxide flakes are between 80 nm and 105 nm in diameter, and the membrane can be cast into a flat sheet and engineered into a spiral wound module. The process involves mixing graphene oxide with purified water and chitosan in an acid solution, followed by evaporation under reduced pressure to form a stable composite membrane.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If polymeric membranes are used for nanofiltration, then thermal and chemical stability is improved, but membrane fouling and low flux remain challenges
Solution Approach 1:
The patent creates a composite membrane combining chitosan (natural polymer) with graphene oxide (nanomaterial) to achieve both stability and high flux. The graphene oxide nanosheets provide structural integrity and chemical stability while their layered structure creates tortuous pathways that enhance filtration performance and reduce fouling through combined physical sieving and adsorption mechanisms.
Solution Approach 2:
The membrane utilizes a porous structure with controlled pore sizes achieved through the graphene oxide network formation. The porous architecture allows high water flux while the nanoscale pore structure provides effective contaminant rejection. The porosity is optimized to balance permeability with filtration efficiency, preventing membrane fouling through reduced adhesion sites.
2Object-affected harmful factors
If chitosan is used as a membrane material, then hydrophilicity and anti-fouling properties are improved, but weak mechanical properties and solubility issues occur
Solution Approach 1:
The chitosan-graphene oxide composite leverages the strengths of both materials: chitosan provides hydrophilicity and anti-fouling properties through its amino and hydroxyl groups, while graphene oxide contributes mechanical strength and structural stability. The synergistic combination creates a membrane that overcomes the individual limitations of each material.
Solution Approach 2:
Graphene oxide acts as an intermediary reinforcement phase within the chitosan matrix. The nanosheets provide mechanical support and structural framework that prevents chitosan dissolution and enhances tensile strength, while allowing the chitosan to maintain its surface properties for anti-fouling performance.
3Productivity
If graphene oxide is added to polymeric membranes, then hydrophilicity and flux are increased, but manufacturing complexity increases
Solution Approach 1:
The graphene oxide is pre-dispersed in the chitosan solution before membrane fabrication, ensuring uniform distribution throughout the matrix. This preliminary mixing step simplifies the overall manufacturing process by eliminating the need for post-fabrication graphene oxide incorporation, which would be more complex. The pre-formed homogeneous solution facilitates straightforward casting and processing.
Solution Approach 2:
The patent optimizes the concentration of graphene oxide in the casting solution to achieve desired membrane properties without excessive complexity. By controlling parameters such as graphene oxide concentration, solution pH, and casting conditions, the manufacturing process remains manageable while achieving enhanced flux and performance characteristics.
4Strength
If chitosan-graphene oxide nanocomposites are used, then mechanical stability is improved, but application has been limited to small experimental volumes
Solution Approach 1:
The chitosan-graphene oxide composite membrane serves multiple functions simultaneously: filtration, mechanical support, and chemical stability. This multi-functionality allows the same material system to be applied across different scales and configurations, from laboratory experiments to industrial-scale membrane modules, enhancing scaleability while maintaining mechanical stability.
Solution Approach 2:
The membrane can be fabricated in modular formats such as flat sheets that can be assembled into spiral-wound modules or other scalable configurations. This segmentation approach allows the membrane material to be produced at small scales with consistent quality and then assembled into larger systems, bridging the gap between experimental and industrial applications.
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 chitosan-graphene oxide composite membrane demonstrates anti-fouling and antimicrobial properties, with tunable flux and porosity, and effective contaminant rejection, utilizing a biopolymer waste product, and is suitable for pressure-driven water filtration applications.
Implementation Method 1
The process involves mixing graphene oxide with purified water and chitosan in an acid solution, followed by evaporation under reduced pressure to form a stable composite membrane.
Implementation Method 2
The chitosan-graphene oxide composite membrane demonstrates anti-fouling and antimicrobial properties, with tunable flux and porosity, and effective contaminant rejection, utilizing a biopolymer waste product, and is suitable for pressure-driven water filtration applications.
Data Source
AI summary
This invention relates generally to a chitosan-graphene oxide membrane and process of making the same. The nanocomposite membrane can filter water and remove contaminants without fouling like other commercially-available polymer-based water filters. The membrane can be used as a flat sheet filter or can be engineered in a spiral filtration module. The membrane is scalable and tunable for many water contaminants including pharmaceuticals, pesticides, herbicides, and other organic chemicals. The membrane uses chitosan, which is low-cost, renewable biopolymer typically considered to be a waste product and the second most abundant biopolymer on Earth, thus making the membrane an environmentally-friendly product choice.