The structure of trilayer Langmuir-Blodgett (LB) films on oxidized silicon wafers has been investigated using grazing incidence X-ray diffraction at various incidence angles and atomic force microscopy (AFM). These films are formed by two behenic acid (BA) layers and a third monolayer of amphiphilic molecules having different architectures. These molecules have the same polar head and differ from each other by the chain, either saturated or unsaturated hydrogenated or semi-fluorinated. The structure of the first BA monolayer appears as unchanged in all cases, whereas a condensation of the second BA monolayer is evidenced when the third layer is not formed with the saturated hydrogenated chain. We interpret this condensation as resulting from the mismatch between the lattices of the second BA layer and the external monolayer, possibly associated with the formation of a new monolayer-air interface creating line tension effects. Line tension estimation has also been made from the size of the holes observed in the different LB films.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/la401860j | DOI Listing |
J Colloid Interface Sci
January 2023
Department of Physical Chemistry University of Geneva, 30 Quai Ernest-Ansermet, CH-1211 Geneva 4, Switzerland. Electronic address:
Hypothesis: Langmuir-Blodgett (LB) technique allows the deposition of gold nanoparticles and nanoclusters (atomically precise nanoparticles below 2 nm in diameter) onto solid substrates with an unprecedented degree of control and high transfer ratios. Nanoclusters are expected to follow the crinkle folding mechanism, which promotes the formation of trilayers of nanoparticles but kinetically disfavors the formation of the fourth layer.
Experiments: LB films of Au(SCHPh) nanocluster were prepared at a range of surface pressures in the bilayer/trilayer regime and their internal structure was analyzed with X-ray Reflectivity (XRR) and Grazing-Incidence Wide-Angle X-ray Scattering (GIWAXS).
Small
July 2021
Department of Physical Chemistry, University of Geneva, Geneva, 30 Quai Ernest-Ansermet, Geneva 4, CH-1211, Switzerland.
Langmuir-Blodgett technique is utilized to deposit ultrathin films of Au (SC H Ph) nanocluster onto solid surfaces such as mica and silicon. The morphologies of the films transferred at various surface pressures within the mono/bi/trilayer regime are studied by atomic force microscopy (AFM). The time spent on the water surface before the deposition has a decisive effect on the final ordering of nanoclusters within the network and is studied by fast AFM, X-ray reflectivity, and grazing-incidence wide-angle X-ray scattering.
View Article and Find Full Text PDFJ Am Chem Soc
January 2014
Department of Material and Biological Chemistry, Yamagata University, 1-4-12, Kojirakawamachi, Yamagata 990-8560, Japan.
Development of multicolored electrochromic materials is important to realize their applications in electronic devices such as full color electronic paper. One method to increase the number of colors in an electrochromic device is by color mixing. A simple method for color mixing involves two electrochromes deposited at different working electrodes.
View Article and Find Full Text PDFLangmuir
September 2013
Laboratoire de Physicochimie des Polymères et des Interfaces (LPPI, EA 2528), Institut des Matériaux, Université de Cergy-Pontoise, 5 Mail Gay-Lussac Neuville/Oise, 95031 Cergy-Pontoise Cedex, France.
The structure of trilayer Langmuir-Blodgett (LB) films on oxidized silicon wafers has been investigated using grazing incidence X-ray diffraction at various incidence angles and atomic force microscopy (AFM). These films are formed by two behenic acid (BA) layers and a third monolayer of amphiphilic molecules having different architectures. These molecules have the same polar head and differ from each other by the chain, either saturated or unsaturated hydrogenated or semi-fluorinated.
View Article and Find Full Text PDFJ Phys Chem B
May 2012
Cornell High Energy Synchrotron Source, Cornell University, Ithaca, New York 14853, USA.
Hexagonally ordered close-packed monolayers of sterically stabilized FePt nanocrystals were deposited on substrates using the Langmuir-Blodgett technique. Monolayers of nanocrystals were also stacked by sequential Langmuir-Blodgett transfer. The structures of the nanocrystal monolayers and multilayer stacks were examined with scanning electron microscopy (SEM) and grazing-incidence small-angle scattering (GISAXS).
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!