Polymer-Coating Process Uses Pulsed Laser Deposition

A new method of coating polymers that uses a pulsed laser deposition technique has a number of possible applications, including protecting battleship hulls from barnacles.

“Barnacles that attach to naval ships are a huge cost to the Navy. Imagine if you drove a car with a parachute attached; this extra drag force requires more gas,” said Daniel Bubb, an assistant professor of physics at Rutgers University-Camden. He has developed the new method for coating polymers, which are chemical compounds formed from long chains of molecules.

Thanks to a $129,463 National Science Foundation (NSF) grant in its third year, Bubb and his team (including a post-doctoral fellow, undergraduate and graduate students) are refining this new coating process. By employing a pulsed laser deposition technique, a high-power laser is focused onto a target material in a vacuum chamber, creating a plume of vaporized material. The object that is to be coated is placed in the path of the vapor. The researchers then tune the laser to a specific vibrational mode of the polymer to ease the vaporization process and limit photochemical and photothermal damage.

This research will benefit many industries that rely solely on the most commonly used method of spin-coating, a viable technique for certain applications but inefficient for coating devices that are too large or small for its apparatus.

“With spin-coating, it’s difficult to layer and adhesion can be a problem,” said Bubb, whose research also could improve biocompatibility in devices that require coating only on very specific and sensitive areas.

Bubb also has advanced coating polymers that are too thermally sensitive by treating materials with a solvent before using the laser. This aspect of the research is funded through a $35,000 Cottrell College Science Award.

This past summer undergraduate Elijah Brookes and post-baccalaureate student Brian Collins joined Bubb on visits to Vanderbilt University, where the team tested their findings at the W.M. Keck Vanderbilt Free-electron Laser Center.

Bubb’s team establishes preliminary findings on the four lasers housed at Bubb’s lab. Three are solid-state laser systems, while the fourth laser allows the group to tune to specific vibrational bands in materials. The free-electron laser at Vanderbilt provided exceptional power and wavelength range for the team to more definitively pin down their data.

For more information, visit: www.camden.rutgers.edu