Self-Organizing Fiberlike Nanostructures and Wrapping-Up Processes in Langmuir−Blodgett Films

Abstract

Fiberlike supramolecular structures, almost monodisperse in diameter (14 ± 2 nm), were obtained in quercetin-3-O-palmitate (QP) Langmuir−Blodgett monolayers transferred on solid substrates by working at a relatively high subphase temperature (37 °C) and surface pressure (30 mN/m). The formation of QP fiberlike structures of similar diameter was also reached by exploiting phase separation processes occurring in mixed monolayers of dimyristoylphosphatidylcholine and QP at 10 °C. In the mixed films, the nanoscopic fibers were observed to curve and wrap up, leading to novel spirallike domains. The wrapping-up process was observed to be enhanced either by lowering the barrier compression speed at the air/water interface or by heating the solid support at the air/solid interface. The above phenomena were observed by scanning probe microscopy of the transferred monolayers. By employment of different operative modes including tapping, phase, friction, and the dynamic attractive regime, important insights on the phase separation as well as the mechanical properties of the nanostructures were found.

New Lipophilic Piceatannol Derivatives Exhibiting Antioxidant Activity Prepared by Aromatic Hydroxylation with 2-Iodoxybenzoic Acid (IBX)

“…In this way amphiphilic phenolic compounds that are able to distribute between the aqueous phase and the lipophilic phase and interact with an emulsifier at the interface were obtained. Recently, it has been reported that these compounds are potentially interesting for possible applications in nanotechnology [ 30 ]. To the best of our knowledge, lipophilic piceatannol derivatives have not been reported in the literature and no chemical or enzymatic synthetic procedures are described.…”

Exploring the Interplay Between Ligand Derivatisation and Cation Type in the Assembly of Hybrid Polyoxometalate Mn‐Andersons

“…Moreover, the longer the organic ligands the larger the distance between fibers and the larger the limit area in the Langmuir isotherms, which suggests that the organic tails act as spacers between aligned POM clusters. The small height of the architectures suggests that the organic ligands are aligned almost parallel to the substrate plane, hence these structures are not likely to be molecular dimensional mismatch‐induced ripple phases at surfaces 13. The nature of the nano‐scale periodicity and the random orientation of the anisotropic domains strongly indicate that they are also not the result of the LB transfer 14…”

The complexation mode of metal ions with Langmuir monolayers of nitrogen-containing flavonoid glycoside-based surfactants derived from rutin

“…The negative pair binging energy ( E (pa) ) for both RuCn-RuCn and metal-RuCn interaction indicated that a spontaneous attractive interaction occurred not only in metal-RuCn complexes, but also in the RuCn. This result indicates that it is possible for RuCn to self-assemble into nanoscale or mesoscale aggregates, just like a fiberlike structure of quercetin-3-O-palmitate (XY plane, ripple shape in Z-axis direction) with short periodicity [23].…”