Purine Pyrimidine Polyamide Membrane Salt Rejection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current polyamide-based water-treatment membranes face challenges in achieving high salt rejection without compromising flux, as they often rely on amine compounds that form unstable bonds with TMC, leading to suboptimal performance.
Innovation Solution
Incorporating purine-based and pyrimidine-based compounds, such as uracil and guanine, into the interfacial polymerization composition to form stable covalent bonds with TMC, enhancing the membrane's salt rejection and flow rate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional amine compounds are used in interfacial polymerization, then the membrane can be manufactured with standard process, but the bond stability with TMC is insufficient leading to lower salt rejection
Solution Approach 1:
The invention changes the chemical parameters of the amine compound by introducing purine and pyrimidine ring structures with specific nitrogen positions. These structural modifications enable formation of stable covalent bonds with TMC through the exocyclic amino group and ring nitrogen, resolving the bond stability issue while maintaining salt rejection performance
Solution Approach 2:
The invention creates a composite polyamide structure by incorporating purine and pyrimidine-based compounds into the polymer matrix. This composite approach combines the beneficial properties of the heterocyclic rings (stable bonding, salt rejection) with the polyamide framework, achieving both high salt rejection and bond stability
2Reliability
If the polyamide active layer is formed to achieve high salt rejection, then salt rejection improves, but the flux may be compromised
Solution Approach 1:
The invention introduces functional groups with specific local properties (exocyclic amino groups, ring nitrogen) at strategic positions within the polyamide chain. These localized functional groups provide stable bonding sites and contribute to salt rejection without uniformly compromising the membrane's permeability, thus maintaining flux while achieving high salt rejection
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 use of these compounds significantly improves salt rejection to 99.5% or greater while maintaining a stable flux, outperforming membranes without these additives.
Implementation Method 1
forming a polyamide active layer on a microporous support by interfacial polymerizing the composition for interfacial polymerizing polyamide and an acyl halide compound
Implementation Method 2
when applying an external pressure higher than an osmotic pressure, the solvent moves toward the solution with a low solute concentration, and this phenomenon is referred to as reverse osmosis
Data Source
AI summary
Provided is a composition for interfacial polymerizing polyamide including an amine compound; and one or more types of compounds selected from among a purine-based compound and a pyrimidine-based compound of Chemical Formula 1:wherein, in Chemical Formula 1:X is N or NH;Y is O or OH;Z is O, OH or NH2;R1 and R2 are each hydrogen or a substituted or unsubstituted alkyl group; and is a single bond or a double bond,and a method for manufacturing a water-treatment membrane and a water-treatment membrane using the same.