Preparation of multilayered Langmuir-Blodgett films of a short chain perfluorinated carboxylic acid.

We report the first successful preparation of Langmuir-Blodgett (LB) films of henecosafluoroundecanoic acid, C(10)F(21) COOH, one of the perfluorinated carboxylic acids which have previously been inaccessible to LB technique for assembly of monolayers. Films of up to 50 monolayers of this compound were readily prepared at 20C by means of a subphase having 5 x 10(-5) M of aluminum ions and a ph of 5.8. Examination of the films by x-ray and capacitance measurements show the layered structure to be highly organized with smooth interlayer surface and with each layer having the same uniform thickness of about 16.1angstroms.