PULSED PLASMA POLYMERIZATION OF BENZALDEHYDE FOR RETENTION OF THE ALDEHYDE FUNCTIONAL-GROUP

Pulsed plasma polymerization of benzaldehyde is used to produce thin f ilms containing aldehyde functional groups. The effects of pulse peak power, pulse-on time, duty cycle, and monomer pressure on film composi tion, especially aldehyde functional groups, and surface polarity are examined. Film properties are determined using Fourier transform infra red (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), conta ct angle measurements, and scanning electron microscopy (SEM). Analysi s using these techniques shows retention of the aromatic structure occ urs with the longest off times and smallest duty cycles while retentio n of the aldehyde group occurs only under plasma conditions that resul t in fragmentation of the aromatic ring, higher peak pulse power, and a relatively large duty cycle (20%).