NEGATIVE FIELD-ION MICROSCOPY OF THE INITIAL-STAGES OF POLYMERIZATIONOF TETRACYANOETHYLENE

The initial stages of polymerization of tetracyanoethylene (TCNE) on a field cathode metal tip were investigated by negative field ion micro scopy (NFIM). Field electron emission into the TCNE gas, leading to th e formation of a deposit on the tip surface, was found to be a prerequ isite for the growth of the polymer layer by anionic polymerization. I n the first step after electron emission anionic polymerization of TCN E to long linear polymer chains occurs at low and even zero field stre ngths. The transition to the polymer structure which leads to the appe arance of bright rings in the ion images is caused by a longer exposur e of the polymer layer to NFI conditions, i.e., by anionic polymerizat ion of TCNE molecules absorbed in the layer which changes the elastic properties of the layer.