A closer look at one of the most promising and versatile amorphous fluoropolymers

Polymer films prepared via spray, dip, and spin coating are commonly used as functional layers and for tuning the surface properties of various materials, from organic electronics and sensorics to medical devices. Still, polymer material property characterization is necessary for developing new applications. One surface analysis technique — time-of-flight secondary ion mass spectrometry (ToF-SIMS) — directs pulsed primary ion beams onto solid samples to extract and separate secondary ions, and generates a mass spectrum that can contain a large numbers of individual signals.

Building on previous studies, Ralf Zimmermann and Mirko Nitschke used ToF-SIMS to provide reference spectra for a grade of the amorphous fluoropolymer Teflon™ AF. The material is characterized by high chemical resistance and thermal stability, and its solubility enables the preparation of durable transparent layers by spray, dip, and spin coating for optoelectronic applications. Because these films enable precise control and movement, Teflon™ AF is the most widely used hydrophobic surface material for electrowetting-on-dielectric, which uses voltage to manipulate liquid droplets.

The researchers used a 30 kilovolt bismuth cluster primary ion beam to measure the spectrometric profile of Teflon™ AF 1601 with positive and negative polarity. In previous studies, they also analyzed interfacial charging of the material in aqueous environments, studied wetting and bio-adhesion at Teflon™ AF-coated structured surfaces, and used it as a basis for plasma-immobilization of (bio)functional surface coatings.

“The features we uncovered can be used by other researchers to identify Teflon™ AF in complex layer architectures like polymeric film-based sensors and micro- and nanofluidic systems,” said Zimmermann. “Reference spectra can be further used to classify materials in recycling processes and for quality control.”

Source: “Time-of-flight secondary ion mass spectrometry reference spectra of polymer coatings: Teflon™ AF 1601 in positive and negative polarity,” by Ralf Zimmermann and Mirko Nitschke, Surface Science Spectra (2026). The article can be accessed at https://doi.org/10.1116/6.0005451 .

This paper is part of the ToF-SIMS of Homogeneous Materials Collection, learn more here .