THE CONFORMATIONAL STATE AND PHASE-TRANSITION OF POLYSILANE IN ARACHIDIC ACID LB FILM MATRIX

Langmuir-Blodgett (LB) films containing a mixture of poly(di-n-hexylsi lane) (PDHS) and arachidic acid were prepared. The surface pressure-ar ea curves indicate that PDHS is positioned between the lipophilic ends of arachidic acid monolayers in the LB films. The Si backbone of PDHS is present in both the trans-zigzag planar and disordered states in t he LB films. The ratio of the two states is dependent on the depositio n number and temperature of the water subphase. The phase transition t emperature (approximately 25 degrees C) in the floating monolayer is r educed compared with that in the cast bulk film (42 degrees C).