Electrolytic Eluent Generators with Hydrophilic Surfaces for Voltage Stability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing ion chromatography eluent preparation methods are prone to operator errors and contamination, leading to performance issues such as chromatographic baseline drift and irreproducible retention times, and there is a need to stabilize operating voltages in electrolytic eluent generators to prevent gas bubble adhesion affecting reliability.

Innovation Solution

The use of hydrophilic surface-modified polymers and surfactants in electrolytic eluent generators to minimize gas bubble adhesion, maintaining stable operating voltages and reliable operation, and the incorporation of an electrolyte reservoir, eluent generation chamber, and ion exchange connector to generate high-purity eluents.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If hydrophobic surfaces are used in electrolytic eluent generators, then gas bubbles can form and adhere to surfaces, but this causes operating voltage instability and unreliable operation

Engineering Contradiction:
Improveoperating voltage stabilityVSAvoidgas bubble adhesion
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the surface energy parameter of the electrolyte reservoir and compression block from hydrophobic to hydrophilic. This parameter change prevents gas bubble adhesion by modifying the surface properties, thereby stabilizing operating voltage and ensuring reliable operation for at least 7 days with minimal voltage variation.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If off-line preparation methods are used to prepare eluents, then operator control is possible, but this introduces contamination risks and operator errors

Engineering Contradiction:
Improveeluent purityVSAvoidpreparation complexity
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The electrolytic eluent generator performs self-service by automatically generating high-purity eluents through electrolysis of water. The system eliminates the need for manual off-line preparation, preventing operator errors and contamination while maintaining eluent purity. The device autonomously produces contaminant-free acid or base solutions for chromatographic separations.

Inventive Principle:
Principle #25Self-service

3Loss of energy

If electrolysis is performed without voltage stabilization, then gas bubbles accumulate on surfaces, but this increases heat generation and reduces operational reliability

Engineering Contradiction:
Improveheat generationVSAvoidoperational consistency
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent introduces hydrophilic surface modification as an intermediary between the electrolyte and gas bubbles. This intermediary layer prevents bubble adhesion to surfaces, thereby reducing localized heat generation and maintaining operational consistency. The hydrophilic coating acts as a mediator that eliminates the harmful interaction between gas bubbles and surface materials.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Stabilizes operating voltages within +/- 2.0 V for at least 7 days with minimal voltage variation, reducing heat generation and ensuring reliable operation, thus improving chromatographic performance by preventing gas bubble adhesion and maintaining consistent eluent generation.

Implementation Method 1

electrolytically splitting water at the first electrode to form a hydroxide anion or a hydronium ion in the eluent generation chamber

Methodology Applied
Scientific EffectElectrolysis: Electrolysis

Implementation Method 2

migrating an ion from the electrolyte reservoir through an ion exchange membrane stack to the eluent generation chamber

Methodology Applied
Scientific EffectIon exchange: Ion Exchange

Implementation Method 3

The electrolyte reservoir includes a chamber containing an aqueous electrolyte solution including an electrolyte and a surfactant

Methodology Applied
Scientific EffectSurfactant: Surfactant

Data Source

PatentEP4170342B1Electrolytic eluent generators with stabilized operating voltages
Publication Date: 2025.08.20 DIONEX CORP
  • EP4170342B1 patent drawingFigure 1
  • EP4170342B1 patent drawingFigure 2A
  • EP4170342B1 patent drawingFigure 2B

AI summary

An electrolytic eluent generator comprising an electrolyte reservoir 204 including a chamber containing an aqueous electrolyte solution and a first electrode 208; an eluent generation chamber 202 including a second electrode 206, preferably a perforated cathode; and an ion exchange connector 210. The ion exchange connector 210 including an ion exchange membrane stack and a compression block including a surface-modified polymer having a hydrophilic surface. The compression block disposed between the electrolyte reservoir and the ion exchange membrane stack. The compression block including a plurality of channels.