Patterning phase separation in polymer films with dip-pen nanolithography.

Area of Science:

• Materials Science
• Nanotechnology
• Polymer Science

Background:

• Controlling nanoscale phase separation is crucial for optimizing organic electronic devices.
• Existing methods for patterning polymer films often lack nanoscale precision.

Purpose of the Study:

• To develop a rapid-prototyping method for controlling nanoscale phase separation and pattern formation in conjugated polymer blend films.
• To investigate the use of Dip-Pen Nanolithography (DPN) for nucleating lateral domain formation in polymer blends.

Main Methods:

• Utilized DPN to create patterned alkylthiol monolayers on gold surfaces with feature sizes down to 50 nm.
• Investigated the nucleation of lateral domains in poly-3-hexylthiophene (P3HT) and polystyrene (PS) blends cast from solution onto patterned surfaces.
• Probed phase nucleation at heterogeneous surface sites ranging from 50 to 750 nm.

Main Results:

• Demonstrated successful control over nanoscale phase separation and pattern formation using DPN.
• Achieved polymer features with diameters smaller than 150 nm.
• Showcased the ability to nucleate lateral domain formation at specific surface sites.

Conclusions:

• DPN is an effective rapid-prototyping tool for controlling nanoscale phase separation in polymer films.
• This method allows for the study of polymer film responses to nanoscale surface features.
• The technique holds promise for correlating nanoscale phase separation with optoelectronic processes in organic electronic devices like LEDs and photovoltaics.