Dynamic droplet behavior for analyte localization on phase change liquid infused surfaces.

Area of Science:

• Materials Science
• Surface Chemistry
• Nanotechnology

Background:

• Phase-change liquid-infused surfaces (PC-LIS) offer tunable interfacial properties via oil/wax phase transitions within micro/nanotextures.
• PC-LIS can switch between solid states (pinned droplets) and liquid states (mobile droplets) using thermal control.
• This dynamic switching enhances lubricant durability against abrasion and shearing compared to static LIS.

Purpose of the Study:

• To demonstrate how PC-LIS surface morphology and phase state control drop evaporation dynamics.
• To investigate the impact of PC-LIS on microparticle deposition outcomes.
• To enable new methods for analyte localization for environmental sensing, particularly for dilute contaminants like microplastics.

Main Methods:

• Utilized phase-change liquid-infused surfaces (PC-LIS) with tunable surface morphology and phase states.
• Controlled droplet evaporation dynamics and microparticle deposition by manipulating PC-LIS phase transitions (solid/liquid states).
• Employed model plastic microparticles and real microplastics from bottled water for testing analyte localization capabilities.

Main Results:

• Phase-switching in PC-LIS precisely controls contact angle hysteresis, sliding angle, and droplet evaporation modes.
• PC-LIS significantly reduces deposit footprint, enabling effective analyte localization.
• Demonstrated successful concentration of microplastics using evaporating drops on PC-LIS in the liquid configuration.

Conclusions:

• PC-LIS provides precise control over droplet mobility and deposition footprint, crucial for environmental sensing applications.
• The ability to localize dilute analytes like microplastics using PC-LIS is a significant advancement.
• PC-LIS surfaces can be reverted to a solid state post-analysis, facilitating subsequent detection methods.