NEXAFS studies on the structure of perfluoroalkyl carbonic acid Langmuir Blodgett films

We examined Langmuir Blodgett (LB) films of PFODA (perfluorooctadecanoic ac id) prepared at various surface pressures with NEXAFS (Near Edge X-ray Abso rption Fine Structure) spectroscopy. Experimental results revealed that the sample without the rubbing treatment possesses (1) no anisotropy along the dipping direction with almost vertical alignment to the substrate surface, (2) higher degree of order of the chain for the sample prepared under the higher surface pressure. Moreover, it was found that the rubbing process in duces a uni-directional tilt angle of the chain without changing the magnit ude of the degree of order.