Multi-layer preparation of phthalocyanine dye and diazonium resin using a self-assembly fabrication method

2006 ◽  
Vol 10 (07) ◽  
pp. 991-995 ◽  
Author(s):  
Young-Min Park ◽  
Byung-Soon Kim ◽  
Young-A Son

By using the electrostatic self-assembly technique, arranged multi-layer thin films composed of diazonium resin as the polycation and phthalocyanine as the anion, were alternately fabricated on a glass slide. The obtained multi-layers were characterized by UV-vis spectroscopy and Atomic Force Microscopy (AFM). The growth of multi-layers formed by the sequential alternative adsorption of diazonium resin and phthalocyanine was observed and determined. The results of UV-vis absorption show that the deposition process is progressive and uniform. In addition, AFM images of the self-assembled multi-layer films reveal that the surface of the films is relatively uniform.

10.26524/jap9 ◽  
2016 ◽  
Vol 1 (2) ◽  
Author(s):  
Jayamurugan P ◽  
Manoharan D ◽  
Ramadevi K ◽  
Upendar Reddy K ◽  
Subba Rao Y V

The nanocolloidal solution has been spin coated on the substrate layer-by-layer, a self-assembly technique has used to form the multilayer thin films. The optical and structural properties of self-assembled multilayer thin films were characterized by UV-visible, photoluminescence, X-ray diffraction and atomic force microscopy


2019 ◽  
Author(s):  
Kevin N. Baumann ◽  
Luca Piantanida ◽  
Javier García-Nafría ◽  
Diana Sobota ◽  
Kislon Voïtchovsky ◽  
...  

The self-assembly of the protein clathrin on biological membranes facilitates essential processes of endocytosis in biological systems and has provided a source of inspiration for materials design by the highly ordered structural appearance. By mimicking the architecture of clathrin self-assemblies to coat liposomes with biomaterials, new classes of hybrid carriers can be derived. Here we present a method for fabricating DNA-coated liposomes by hydrophobically anchoring and subsequently growing a DNA network on the liposome surface which structurally mimics clathrin assemblies. Dynamic light scattering (DLS), ζ-potential and cryo-electron microscopy (cryo-EM) measurements independently demonstrate successful DNA coating. Nanomechanical measurements conducted with atomic force microscopy (AFM) show that the DNA coating enhances the mechanical stability of the liposomes relative to uncoated ones. Furthermore, we provide the possibility to reverse the coating process by triggering the disassembly of the DNA coating through a toehold-mediated displacement reaction. Our results describe a straightforward, versatile, and reversible approach for coating and stabilizing lipid vesicles by an interlaced DNA network. This method has potential for further development towards the ordered arrangement of tailored functionalities on the surfaces of liposomes and for applications as hybrid nanocarrier.


1995 ◽  
Vol 382 ◽  
Author(s):  
Martin Pehnt ◽  
Douglas L. Schulz ◽  
Calvin J. Curtis ◽  
Helio R. Moutinho ◽  
Amy Swartzlander ◽  
...  

ABSTRACTIn this article we report the first nanoparticle-derived route to smooth, dense, phase-pure CdTe thin films. Capped CdTe nanoparticles were prepared by injection of a mixture of Cd(CH3)2, (n-C8H17)3 PTe and (n-C8H17)3P into (n-C8H17)3PO at elevated temperatures. The resultant nanoparticles 32-45 Å in diameter were characterized by x-ray diffraction, UV-Vis spectroscopy, transmission electron microscopy, thermogravimetric analysis and energy dispersive x-ray spectroscopy. CdTe thin film deposition was accomplished by dissolving CdTe nanoparticles in butanol and then spraying the solution onto SnO2-coated glass substrates at variable susceptor temperatures. Smooth and dense CdTe thin films were obtained using growth temperatures approximately 200 °C less than conventional spray pyrolysis approaches. CdTe films were characterized by x-ray diffraction, UV-Vis spectroscopy, atomic force microscopy, and Auger electron spectroscopy. An increase in crystallinity and average grain size as determined by x-ray diffraction was noted as growth temperature was increased from 240 to 300 °C. This temperature dependence of film grain size was further confirmed by atomic force microscopy with no remnant nanocrystalline morphological features detected. UV-Vis characterization of the CdTe thin films revealed a gradual decrease of the band gap (i.e., elimination of nanocrystalline CdTe phase) as the growth temperature was increased with bulk CdTe optical properties observed for films grown at 300 °C.


Author(s):  
Sudheer Neralla ◽  
Sergey Yarmolenko ◽  
Dhananjay Kumar ◽  
Devdas Pai ◽  
Jag Sankar

Alumina is a widely used ceramic material due to its high hardness, wear resistance and dielectric properties. The study of phase transformation and its correlation to the mechanical properties of alumina is essential. In this study, interfacial adhesion properties of alumina thin films are studied using cross-sectional nanoindentation (CSN) technique. Alumina thin films are deposited at 200 and 700 °C, on Si (100) substrates with a weak Silica interface, using pulsed laser deposition (PLD) process. Effect of annealing on the surface morphology of the thin films is studied using atomic force microscopy. Xray diffraction studies revealed that alumina thin films are amorphous in nature at 200 °C and polycrystalline with predominant gamma alumina phase at 700 °C.


2015 ◽  
Vol 1117 ◽  
pp. 139-142 ◽  
Author(s):  
Marius Dobromir ◽  
Radu Paul Apetrei ◽  
A.V. Rogachev ◽  
Dmitry L. Kovalenko ◽  
Dumitru Luca

Amorphous Nb-doped TiO2 thin films were deposited on (100) Si and glass substrates at room temperature by RF magnetron sputtering and a mosaic-type Nb2O5-TiO2 sputtering target. To adjust the amount of the niobium dopant in the film samples, appropriate numbers of Nb2O5 pellets were placed on the circular area of the magnetron target with intensive sputtering. By adjusting the discharge conditions and the number of niobium oxide pellets, films with dopant content varying between 0 and 16.2 at.% were prepared, as demonstrated by X-ray photoelectron spectroscopy data. The X-ray diffraction patterns of the as-deposited samples showed the lack of crystalline ordering in the samples. Surfaces roughness and energy band gap values increase with dopant concentration, as showed by atomic force microscopy and UV-Vis spectroscopy measurements.


2010 ◽  
Vol 65 (2) ◽  
pp. 140-146 ◽  
Author(s):  
Dan Chen ◽  
Jun Peng ◽  
Haijun Pang ◽  
Pengpeng Zhang ◽  
Yuan Chen ◽  
...  

Two kinds of multilayer films based on Keggin polyoxometalates α-[SiW12O40]4−/α- [PMo12O40]3− and methylene blue have been prepared via the layer-by-layer (LBL) self-assembly technique. The multilayer films were characterized by UV/Vis spectra, atomic force microscopy (AFM) and X-ray photoelectron spectra (XPS). The cyclic voltammetry (CV) measurements have demonstrated that the electrochemical properties of POMs are maintained in the LBL films. The antibacterial activity of the LBL films has also been investigated, which shows a distinct antibacterial effect against Escherichia coli.


COSMOS ◽  
2008 ◽  
Vol 04 (02) ◽  
pp. 173-183
Author(s):  
BOON TEE ONG ◽  
PARAYIL KUMARAN AJIKUMAR ◽  
SURESH VALIYAVEETTIL

The present article reviews the self-assembly of oligopeptides to form nanostructures, both in solution and in solid state. The solution structures of the peptides were examined using circular dichroism and dynamic light scattering. The solid state assembly was examined by adsorbing the peptides onto a mica surface and analyzing it using atomic force microscopy. The role of pH and salt concentration on the peptide self-assembly was also examined. Nanostructures within a size range of 3–10 nm were obtained under different conditions.


2012 ◽  
Vol 16 (07n08) ◽  
pp. 977-984 ◽  
Author(s):  
Enno Lorenz ◽  
Christopher Keil ◽  
Derck Schlettwein

Thin films from the monolayer range to the thickness of 40 nm of the perfluorinated copper phthalocyanine (F16PcCu) were prepared by physical vapor deposition on freshly cleaved (001) faces of the alkali halides NaCl , KCl and KBr . The different lattice constants of the substrates provided sufficient difference to trigger the growth of differently ordered phases of F16PcCu . Electron diffraction, Atomic Force Microscopy and UV-vis spectroscopy were used to characterize the structure for F16PcCu monolayers and for films of increasing average film thickness towards bulk films. A square lattice of flat-lying F16PcCu is proposed for the first monolayers. In the bulk films, phases already described for F16PcCu on other substrates were formed, but also a new phase was discovered.


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