Fabrication of Langmuir-Blodgett films of beta-carotene by flow-orientation

Using the Langmuir-Blodgett (LB) method together with the flow-orientation technique which controls the flow of a film material on the subphase, we su ccessfully fabricated a well-ordered film of beta-carotene. The surface pre ssure-area isotherm suggested that beta-carotene in a Langmuir monolayer or iented perpendicular to the water surface. The flow-orientation method enha nced the molecular orientation in the monolayer. X-ray diffraction patterns indicated that the orientation of beta-carotene in the LB films correlates with the number of layers. The films with five and nine layers yielded til t angles of 55 degrees and 40 degrees, respectively. Fourier-transform infr ared spectroscopy revealed that ionone rings of beta-carotene in the LB fil m orient perpendicular to the gold substrate.