Surface Treatments

Surface Treatments for adequate wetting

Emulseo provides easy-to-use hydrophobic surface treatments for microfluidic channel coating to ensure adequate wetting conditions and improved droplet formation in fluorinated oil systems. These treatments form a covalently bound fluorophilic layer on channel surfaces, improving performance, stability, and reproducibility in microfluidic experiments.

The treatments work with Emulseo surfactants and fluorinated oils, supporting consistent droplet-based workflows.

Overview of Surface Treatments

Fluo-ST1

Fluo-ST1 is a hydrophobic surface treatment composed of fluoroalkylsilanes that react with plasma-etched glass and PDMS surfaces. After treatment, a uniform fluorophilic layer is covalently attached to the microfluidic device, resulting in improved droplet stability and performance in fluorinated oil systems.

This coating enhances aqueous droplet formation and stability, and is compatible with Emulseo surfactants and oils.

Benefits:

• Enhanced droplet formation and stability

• Easy-to-use application

• Reproducible microfluidic experiments

General recommendation

For best results, microfluidic channels are filled with the treatment solution, excess is flushed, and the device is typically incubated (e.g. overnight at 65°C in an oven).

Storage and safety notes: 

You can store Fluo-ST1 at room temperature in the supplied vial or in a glass syringe purged with argon for up to six months without loss of performance. Replace the needle before every use. We recommend standard protective equipment (gloves, eye and face protection).

Fluo-ST2

Fluo-ST2 is a versatile surface treatment reagent in a hydrofluoroether solvent. It contains a fluorosilane polymer that covalently bonds to a wide range of surfaces, including glass, PDMS, COC/COP, PMMA, and PC. The resulting thin film has excellent hydrophobic properties, which improves droplet performance and stability in fluorinated oils.

Benefits:

• Broad material compatibility

• Low-viscosity, low-surface-tension coating

• Improves droplet stability in microfluidic systems

Usage:
Apply Fluo-ST2 to cleaned microfluidic channels and allow it to dry into a thin, uniform hydrophobic film.

Fluo-ST3

Fluo-ST3 is a fluorophilic surface treatment consisting of a fluoroalkylsilane dissolved in a perfluorinated polyether solvent. It is a clear, low-viscosity solution with low interfacial tension and is compatible with a wide range of materials including glass, PDMS, COC/COP, PMMA, and PC.

After application, a uniform covalently bound layer forms on channel surfaces, making them both hydrophobic and fluorophilic. This improves droplet formation and stability in fluorinated oils and enhances reproducibility in microfluidic experiments. It is especially suitable for use with Emulseo surfactants and oils.

Benefits:

• Low interfacial tension and easy application

• Broad material compatibility

• Improves reproducibility and stability of microfluidic droplets

Recommended Application:

1. Clean the microfluidic chip with isopropanol

2. Fill channels with Fluo-ST3 and leave for 30 seconds, then flush excess

3. Rinse channels with fluorinated oil

Storage:

Fluo-ST3 can be stored at room temperature for up to one year without performance loss.

Safety Notes:

Standard laboratory safety precautions apply, including protective gloves and eye protection, and inhalation of vapours or mist should be avoided.

Applications of hydrophobic surface treatments:

• Improving flow stability in microchannels
• Suitable for diagnostics and pharmaceutical applications