Date Approved


Date Posted


Degree Type

Open Access Thesis

Degree Name

Master of Science (MS)

Department or School

Engineering Technology

Committee Member

Erik Lokensgard, PhD. Chair

Committee Member

Mary L. Brake, PhD.

Committee Member

Pamela Speelman, PhD.


A radio frequency plasma (13.56 MHz) was used to modify the surface of a poly (ethylene terepthalate) (PET) sample. The plasma was generated in a pure oxygen process atmosphere at pressures of 100 mTorr, and 2.0 Torr at output powers of 250 Watts and 500 Watts.

Optical emission spectroscopy (OES) was used to characterize the plasma/sample interaction. Spectra were measured from 250 nm to 900 nm during each of the processing sessions.

The spectra showed changes depending upon the pressure of the plasma. Molecules of OH and atomic oxygen were observed at low pressures (100 mTorr), whereas CO and atomic hydrogen were observed at high pressures (2.0 Torr).

The sessile drop method was used to determine the relative change in the wettability of the sample surface along a continuum from hydrophobic to hydrophilic.

The measured angles were compared to the initial readings (Figure 18) and showed a decrease of 40-50% in contact angle after treatment.

There was an observable change in the PET samples after processing; in particular, the surface was visibly degraded.