pH-dependent water permeability switching and its memory in MoS₂ membranes

Area of Science:

• Materials Science
• Nanotechnology
• Biomimetics

Background:

• Intelligent transport across biological membranes is crucial for cellular functions, characterized by adaptability and memory (hysteresis).
• Creating synthetic membranes with stable hysteretic behavior for molecular transport remains a significant challenge in materials science.

Purpose of the Study:

• To demonstrate memory effects and stimuli-regulated molecular transport using a phase-changing molybdenum disulfide (MoS2) membrane.
• To investigate the pH-dependent hysteretic behavior of water and ion permeation through 1T' MoS2 membranes.

Main Methods:

• Fabrication of phase-changing 1T' MoS2 membranes.
• Characterization of molecular transport properties (water and ion permeation) under varying external pH conditions.
• Analysis of the role of surface charge and exchangeable ions in the observed hysteretic phenomenon.

Main Results:

• The 1T' MoS2 membrane exhibited significant pH-dependent hysteresis in water and ion permeation, with rates switching by orders of magnitude.
• This hysteretic transport behavior was found to be unique to the 1T' phase of MoS2, attributed to its surface charge and ion exchange capabilities.
• Demonstrated potential applications in autonomous wound infection monitoring and pH-responsive nanofiltration.

Conclusions:

• The developed MoS2 membrane displays intelligent, memory-enabled transport properties regulated by external pH.
• This research deepens the understanding of nanoscale water transport mechanisms and offers a new platform for intelligent membrane development.
• The findings pave the way for advanced smart materials in diagnostics and separation technologies.