Self-Assembled Composite Langmuir Films via Fluorine-Containing Bola-Type Derivative with Metal Ions

The design and preparation of functional bolaamphiphile-based composite films are of key importance for application in a wide variety of fields. This study demonstrates a new approach to constructing composite films by the Langmuir-Blodgett (LB) method using a fluorine-containing bola-type diacid derivative with different metal ions. The bola-type molecule we used could be spread on water surfaces and metal ion subphases to fabricate various nanostructured ultrathin films. The obtained data demonstrated that the employed metal ions, including Ag(I), Cu(II), and Eu(III) ions in subphase solutions, can regulate the organized molecular stacking and form interfacial nanostructures deposited in LB films. It was found that the interfacial coordinating interactions can easily occur between carboxyl groups in a molecular skeleton with metal ions in the formed composite films. The formation of composite films was confirmed by changes in the surface pressure-area isotherms, morphologies, and spectra of the transferred LB films. While various research works have achieved the regulation of functions and nanostructures of sophisticated bola-type compounds, we here demonstrate a simple routine to modulate the nanostructures and organized packing of bola-type compounds composite films by changing the metal ions in subphase solutions.