Abstract: | Surface fluorination of poly(trimethylsilylpropyne) (PTMSP) membranes by CF4 plasma was studied. The surface fluorination of the membranes was carried out in an atmosphere of CF4 in a capacitively coupled discharge apparatus with external electrodes. Dramatic increase in selectivity (P /P ) was observed. The effect of fluorination conditions such as duration of treatment and discharge power on the permeabilities of the membranes was studied. X-ray photoelectron spectrometric data of modified PTMSP membranes showed a drastic alternation in the surface layer. The P and P /P of the membranes were observed to be dependent on the F/C atomic ratio. At F/C > 1, the P /P value of the membranes could be more than four. © 1993 John Wiley & Sons, Inc. |