Electric-Field-Induced Molecular Orientation for Structural Control of Langmuir and Langmuir-Blodgett Films

Abstract

Controlling the structure of Langmuir and Langmuir-Blodgett (LB) films is essential for tailoring their physical and functional properties. In this paper, we introduce the electric-field-induced molecular orientation (EFIMO) method as a novel and versatile approach to modulate the molecular organization within these films. The method was validated using Sudan III molecules, which typically exhibit strong aggregation behavior. Application of the EFIMO technique enabled control over the film structure, as evidenced by changes in molecular aggregation, wettability, and both macroscopic and microscopic surface morphologies. This proof of concept demonstrates the potential of EFIMO for improving the quality of LB films—especially those formed from non-amphiphilic molecules such as polymers—and for enabling the development of advanced materials for applications in gas sensors, solar cells, and biofunctional coatings.

Keywords: molecular orientation in subphase, saturation polarization, Langmuir trough, wetting contact angle.