Monolayer Fibers on Solid Surfaces Made of a Quinone Sulfonate

Abstract

2-Octadecylquinone-5-sulfonic acid (1) formed orthogonal molecular monolayers on the Langmuir trough, which were reduced to long-lived anions with dithionite added to the subphase. After the smooth films were transferred to different substrates, quantitative rearrangement to long fibers of flat-lying molecules was observed. The fibers formed typical disclinations known from liquid-crystalline compounds. Addition of a -tetraethyl--tetrapyridinyl-porphyrin (2) mixed monolayer, containing flat-lying as well as uprightstanding porphyrin domains, led to selective fluorescence quenching. Only the flat-lying porphyrins (λmax ) 645 nm) were reached by the quinone fibers; the upright-standing porphyrins (λmax ) 660 nm) continued to fluoresce.

Langmuir–Blodgett Assembly of One-Dimensional Nanostructures

“…The surface pressure p follows a p ± A (area) curve, Figure 2, that is commonly observed during the LB compression of amphiphilic surfactants or surfactant capped nanoclusters on the water surface. [12] Superstructure formation from these anisotropic nanoparticles, however, displays much more complex behavior than the spherical particles, as have been demonstrated in our experiments with BaCrO 4 , BaWO 4 , Au nanorods, and Mo 3 Se À 3 nanowires. Superstructure formation is highly dependent on the aspect ratio of the nanorods and the collective interactions among these individual units.…”

“…Figure 1 schemati cally shows the experimental apparatus. The surface pressure π follows a π – A (area) curve, Figure 2, that is commonly observed during the LB compression of amphiphilic surfactants or surfactant capped nanoclusters on the water surface 12. Superstructure formation from these anisotropic nanoparticles, however, displays much more complex behavior than the spherical particles, as have been demonstrated in our experiments with BaCrO 4 , BaWO 4 , Au nanorods, and Mo 3 Se$\rm{_{3}^{-}}$ nanowires.…”

Langmuir–Blodgett assembly of bent-shaped rigid amphiphiles into spiral rings

“…23 The overall nematic-like arrangements are frequently disrupted by disclinations, which results in the spiral morphology. 24,25 It is noticed that this type of morphology seldom occurs in nanorod systems, presumably because it is energetically unfavorable. 26 However, in our system the spiral rings composed of organic molecular nanorods are stable in a range of surface pressure (p < 5 mN m À1 ).…”

Starre Lipidmembranen und Nanometerlücken – Motive zur Gestaltung molekularer Landschaften

“…Auf Wasser bildet das Amphiphil eine stabile Monoschicht; beim Versuch, daraus LB‐Schichten auf Glimmer zu übertragen, geht die Monoschicht in ein Geflecht micellarer Fasern über, die so wohlgeordnet nebeneinander liegen, dass sie sich mit AFM lateral auflösen lassen (Abbildung 12). 50 Auch hier wird die Faserbildung wahrscheinlich durch eine starke Wechselwirkung des Substrats mit der chinoiden Kopfgruppe hervorgerufen. Nur führt sie diesmal nicht zur Zerstörung der Krümmung, sondern zu ihrer Bildung.…”