Langmuir−Blodgett Mono- and Multilayers of (Di)alkoxy-Substituted Poly(p-phenylenevinylene) Precursor Polymers. 2. Stability, Transfer, and Multilayer Structure of (Di)alkoxy-Substituted Precursor PPVs

Abstract

The Langmuir monolayer stability and transfer properties of (di)alkoxy-substituted precursor PPVs were studied. All polymers formed stable monolayers, but the packing of the monomeric units in the monolayer depended strongly on the substituents. The less closely packed monolayers can be transferred with the Langmuir-Blodgett technique, while the closely packed monolayers, with strong π-π interaction between the aromatic rings, can only be transferred with the Langmuir-Schaefer technique due to the stiffness of the monolayers. Transmission and grazing incidence reflection FT-IR spectroscopy in combination with IR spectra computer simulations revealed that in many instances the orientation of the precursor at the water interface is largely preserved after transfer of the monolayer. The roughness and the thickness of the multilayers were determined by small-angle X-ray reflection.

Nanotubes of poly(phenylene vinylene) derivative at the air/water interfaceElectronic supplementary information (ESI) available: Detailed experimental procedures and experimental conditions. See http://www.rsc.org/suppdata/cc/b4/b403870c/

“…Since the electronic and optical properties of the polymer films and nanostructures are inherently related to their local structure, it is vitally important to achieve great control of the self-assembly process that takes the polymer from the disordered state in solution into a well-ordered solid state. 6,7 Usually, thin films or fibers of PPV are prepared by soluble precursor routes. 8,9 However, large amounts of solvent and side products have to be removed during this process, which is expected to generate many defects such as bubbles in the final objects and to leave impurities from the solvent.…”

“…Differences among the hysteresis cycles may be attributed to the formation of new aggregating states created by the reorganization of the film after the previous compression and expansion cycles. 6 It is clear that after collapse, a new aggregate of MH-PPV is formed at the air/water interface and the formation process is not reversible. Fig.…”

Controllable Growth of Straight Nanorods and Nanowires in the Langmuir Films of a Bolaamphiphilic PAR Derivative

“…Therefore, both the LB and LS transfer gave the same results. At a higher concentration of the Cu(II) subphase, the film became very rigid and only the LS method was effective, which is similar to some cases of the polymer films 30. In addition, nanowires were only observed at a higher concentration of the Cu(II) ions.…”

Rheological Behavior of Precursor PPV Monolayers

“…This is in accordance with the model of a 2D expanded state of the prec-DBuPPV proposed earlier. 3 Figure 7a depicts isotherms of a prec-DBuPPV monolayer at different temperatures; the different transitions, calculated by MM2 force field minimizations, 2 represented in Figure 7b. The structural changes of prec-DBuPPV that are depicted in this figure were confirmed with IR spectroscopy of this polymer at the air-water interface.…”