Three-Dimensional Hexagonal Close-Packed Superlattices of Passivated Ag Nanocrystals

Silver nanocrystals passivated by dodecanethiol self-assembled monolayers were produced using an aerosol technique described in detail elsewhere [1]. Self-assembling passivated nanocrystal-superlattices (NCS's) involve self-organization into monolayers, thin films, and superlattices of size-selected nanoclusters encapsulated in a protective compact coating [2,3,4,5,6,7]. We report the preparation and structure characterization of three-dimensional (3-D) hexagonal close-packed Ag nanocrystal supercrystals from Ag nanocrystals of ˜4.5 nm in diameters. The crystallography of the superlattice and atomic core lattices were determined using transmission electron microscopy (TEM) and high-resolution TEM.SEM was used to image the nanocrystal superlattices formed on an amorphous carbon film of an TEM specimen grid (fig. la). The superlattice films show well shaped, sharply faceted, triangular shaped sheets. Figure lb depicts numerous Ag nanocrystal aggregates uniformly distributed over the imaging region. Inset in this figure is an enlargement of the boxed region at the edge of a supercrystal typifying the ordered nanocrystal packing.

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Transmission electron microscopy of C70 single crystals at room temperature

Journal of Materials Research ◽

10.1557/jmr.1992.2440 ◽

1992 ◽

Vol 7 (9) ◽

pp. 2440-2446 ◽

Cited By ~ 17

Author(s):

Vinayak P. Dravid ◽

Xiwei Lin ◽

Hong Zhang ◽

Shengzhong Liu ◽

Manfred M. Kappes

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Room Temperature ◽

Three Dimensional ◽

Real Space ◽

Acceptable Error ◽

Hexagonal Close Packed ◽

Transmission Electron ◽

High Resolution Tem ◽

Hcp Structure

Transmission electron microscopy (TEM) techniques have been employed to study the room temperature solid state form of chromatographically purified C70. Tilting and electron diffraction experiments in three-dimensional reciprocal space, on samples prepared by crystallization from several different solvents, show that C70 crystallites adopt hexagonal close packed (hcp) structure with a = 1.01 ± 0.05 nm and c = 1.70 ± 0.08 nm. The extinctions and observed reflections conform to the P63/mmc space group. High resolution TEM images reveal the molecular order and periodicity associated with C70 crystallites in real space. The experimental results are in agreement with the preliminary computations of crystal structure within acceptable error limits.

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FCC Superlattice Packing of Faceted Silver Nanocrystals

Microscopy and Microanalysis ◽

10.1017/s1431927600008904 ◽

1997 ◽

Vol 3 (S2) ◽

pp. 403-404

Author(s):

S.A. Harfenist ◽

Z.L. Wang ◽

M.M. Alvarez ◽

I. Vezmar ◽

R.L. Whetten

Keyword(s):

Three Dimensional ◽

Self Assembled Monolayers ◽

Dimensional Model ◽

Three Dimensional Model ◽

Core Diameter ◽

Truncated Octahedron ◽

Assembled Monolayers ◽

High Resolution Tem ◽

Orientational Ordering ◽

Atomic Lattices

The ordering of size selected nanocrystaline particles into large, well ordered supercrystals has been under recent study. Here we describe the ordering of silver nanocrystals, of core diameter ca. 4.5nm, passivated with alkythiolate self-assembled monolayers. The faceted nanocrystals are found to size selectively condense into ordered supercrystals with edge lengths on the order of 0.1 to 0.5 microns. Further, evidence has been found in High Resolution TEM micrographs of packed monolayers of these same nanocrystals implying an orientational ordering of the silver nanocrystals’ atomic lattices within and co-aligning with the supercrystal’s “superlattice”. A three dimensional model using a truncated octahedron for the nanocrystal core morphology is constructed from this evidence into an FCC superlattice which fits the remaining experimental observations.Micrographs of the same region of a nanocrystal Ag supercrystal (NCASX) are shown in figure 1 under differing defocus conditions.

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Three-Dimensional Superlattice Packing of Faceted Silver Nanocrystals

MRS Proceedings ◽

10.1557/proc-457-137 ◽

1996 ◽

Vol 457 ◽

Author(s):

S. A. Harfenist ◽

Z. L. Wang ◽

M. M. Alvarez ◽

I. Vezmar ◽

R. L. Whetten

Keyword(s):

Electron Microscopy ◽

Three Dimensional ◽

Self Assembled Monolayers ◽

Microscopy Imaging ◽

Fundamental Properties ◽

Transmission Electron ◽

Assembled Monolayers ◽

Crystalline Films ◽

Orientational Ordering ◽

First Time

ABSTRACTOrientational ordering of faceted nanocrystals in nanocrystal arrays has been directly observed for the first time, by use of transmission electron microscopy imaging and diffraction to resolve the structure of thin molecular-crystalline films of silver nanocrystals passivated by alkylthiolate self-assembled monolayers. The type of ordering found is determined by the nanocrystals faceted morphology, as mediated by the interactions of surfactant groups tethered to the facets on neighboring nanocrystals. Orientational ordering is crucial for the understanding of the fundamental properties of quantum-dot arrays, as well as for their optimal utilization in optical and electronic applications.

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Synthesis, Self-Assembling and Redox Properties of 2-[(ω-Sulfanylalkyl)amino]-1,4-naphthoquinones

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc20061383 ◽

2006 ◽

Vol 71 (9) ◽

pp. 1383-1391 ◽

Cited By ~ 6

Author(s):

Maryte Kažemekaite ◽

Vilma Railaite ◽

Arunas Bulovas ◽

Zita Talaikyte ◽

Gediminas Niaura ◽

...

Keyword(s):

Reduction Process ◽

Spectroscopic Studies ◽

Self Assembled Monolayers ◽

Raman Spectroscopic ◽

Self Assembling ◽

Electrochemical Parameters ◽

Surface Enhanced ◽

Assembled Monolayers ◽

Surface Enhanced Raman ◽

Group Form

The newly synthesized 1,4-naphthoquinones linked via nitrogen atom to a short chain with terminal sulfanyl group form self-assembled monolayers on gold. The main electrochemical parameters of the monolayers were determined by cyclic voltammetry. Combined voltammetric and in situ Fourier-transform surface-enhanced Raman spectroscopic studies of the Au electrode modified with the title compounds clearly evidence that naphthoquinone group transforms into naphthalenediol during a reduction process.

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Self Assembled Monolayers and Carbon Nanotubes: A Significant Tool’s for Modification of Electrode Surface

Sensor Letters ◽

10.1166/sl.2020.4280 ◽

2020 ◽

Vol 18 (9) ◽

pp. 669-685

Author(s):

Padmaker Pandey ◽

Anamika Pandey ◽

Shruti Singh ◽

Nikhil Kant Shukla

Keyword(s):

Carbon Nanotubes ◽

Volume Ratio ◽

Biological Molecules ◽

Self Assembled Monolayers ◽

Self Assembling ◽

Biological Surfaces ◽

Biological Recognition ◽

Monomolecular Films ◽

Assembled Monolayers ◽

Interfacial Surfaces

A compromising and well-organized model system is needed for investigating the molecular behaviour of biomolecules as many transduction processes and biological recognition occur at biological surfaces. The application of techniques in interfacial surfaces like one molecule thick films has made a feasible and significant tool for modern scientific studies. Self Assembling Monolayers (SAMs) technology is a very useful means for producing monomolecular films of various biological molecules on different substrates. Carbon Nanotubes (CNTs) have length-to-diameter aspect ratio property which provides a large surface-to-volume ratio, making it an intensely capable material for biomolecular attachments. The incorporation of Carbon Nanotubes (CNTs) with biological systems forming functional assemblies has shown an explored area of research. Organo-sulfur mainly alkanethiol (CnH2n+1–SH) molecules get adsorbed onto CNTs. This phenomenon has grabbed a lot of attention because Self Assembling Monolayers (SAMs) of organo-sulfur compound acts as an example system for understanding important chemical, physical or biological processes.

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Initial Electrodeposition Behavior of Amorphous Ni-P Alloys

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.154-155.535 ◽

2010 ◽

Vol 154-155 ◽

pp. 535-539

Author(s):

Xue Tao Yuan ◽

Dong Bai Sun ◽

Zhi Qiang Hua ◽

Lei Wang

Keyword(s):

Amorphous Alloy ◽

Carbon Film ◽

Three Dimensional ◽

Amorphous State ◽

Epitaxial Relationship ◽

Force Microscopy ◽

Transmission Electron ◽

Initial Stage ◽

Crystal Substrate ◽

Structure Of Deposits

The growth morphology and structure of deposits during the initial stages of amorphous Ni-P electrodeposition was studied using atomic force microscopy (AFM), X-ray diffraction (XRD) and transmission electron microscope (TEM). Combined electrochemical and surface analytical measurements showed that the electrocrystallization process follows a three-dimensional instantaneous nucleation and growth mechanism. The structure of the Ni-P deposits progressively changed from polycrystalline to amorphous state with increasing electroplating time. Additional electrodeposition was carried out on amorphous carbon film at potential -650mV (SCE) for 5s in the same bath for plating Ni-P alloy. It was confirmed that the formation of crystal Ni at initial stage of electroplating Ni-P amorphous alloy was not caused by the epitaxial relationship between the crystal Ni and the crystal substrate and there was a nucleation process in the electrodeposition of amorphous alloy.

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Self-Assembled Monolayers Stabilized by Three-Dimensional Networks of Hydrogen Bonds

Journal of the American Chemical Society ◽

10.1021/ja9800277 ◽

1998 ◽

Vol 120 (10) ◽

pp. 2486-2487 ◽

Cited By ~ 50

Author(s):

Robert S. Clegg ◽

Scott M. Reed ◽

James E. Hutchison

Keyword(s):

Hydrogen Bonds ◽

Three Dimensional ◽

Self Assembled Monolayers ◽

Assembled Monolayers ◽

Self Assembled

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Deposition of Nanocrystalline Tin (IV) Oxide Films on Organic Self-Assembled Monolayers

MRS Proceedings ◽

10.1557/proc-576-203 ◽

1999 ◽

Vol 576 ◽

Cited By ~ 4

Author(s):

S. Supothina ◽

M. R. De Guire ◽

T. P. Niesen ◽

J. Bill ◽

F. Aldinger ◽

...

Keyword(s):

Single Crystal Silicon ◽

Self Assembled Monolayers ◽

Crystal Silicon ◽

Deposition Chamber ◽

Transmission Electron ◽

Static Solutions ◽

Assembled Monolayers ◽

Self Assembled ◽

Nanocrystalline Thin Films

ABSTRACTNanocrystalline thin films of tin (IV) oxide (cassiterite) have been deposited from aqueous solutions of tin (IV) chloride and hydrochloric acid at 80°C. Substrates were {100} single-crystal silicon wafers, with and without silanol-anchored, sulfonate-terminated organic self-assembled monolayers (SAMs). Using flowing solutions, films with thicknesses of up to 1 μtm have been grown, whereas the thickness of the films from static solutions is limited to about 80 nm. The films were characterized using transmission electron microscopy and Rutherford backscattering spectroscopy. The role of the flow rate and configuration of the deposition chamber is discussed.

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