scholarly journals Energy landscapes and dynamics of glycine on Cu(110)

2017 ◽  
Vol 19 (25) ◽  
pp. 16600-16605 ◽  
Author(s):  
Marco Sacchi ◽  
David J. Wales ◽  
Stephen J. Jenkins
Keyword(s):  
Amino Acids ◽  
Single Crystal ◽  
Long Range ◽  
Self Assembly ◽  
Metal Surfaces ◽  
The Self ◽  
Self Assembled Monolayers ◽  
Energy Landscapes ◽  
Assembly Mechanism ◽  
Assembled Monolayers

Amino acids adsorbed on single-crystal metal surfaces have emerged as prototypical systems for exploring the properties that govern the development of long-range chirality in self-assembled monolayers and supramolecular 2D networks. In this study, we characterise the self-assembly mechanism for glycine on the Cu(110) surface.

scholarly journals STM visualisation of counterions and the effect of charges on self-assembled monolayers of macrocycles

2011 ◽  
Vol 2 ◽  
pp. 674-680 ◽  
Author(s):  
Tibor Kudernac ◽  
Natalia Shabelina ◽  
Wael Mamdouh ◽  
Sigurd Höger ◽  
Steven De Feyter
Keyword(s):  
Self Assembly ◽  
The Self ◽  
Self Assembled Monolayers ◽  
Assembly Process ◽  
Organic Monolayers ◽  
Preferential Adsorption ◽  
Scanning Tunnelling ◽  
Assembled Monolayers ◽  
Tunnelling Microscopy ◽  
Self Assembled

Despite their importance in self-assembly processes, the influence of charged counterions on the geometry of self-assembled organic monolayers and their direct localisation within the monolayers has been given little attention. Recently, various examples of self-assembled monolayers composed of charged molecules on surfaces have been reported, but no effort has been made to prove the presence of counterions within the monolayer. Here we show that visualisation and exact localisation of counterions within self-assembled monolayers can be achieved with scanning tunnelling microscopy (STM). The presence of charges on the studied shape-persistent macrocycles is shown to have a profound effect on the self-assembly process at the liquid–solid interface. Furthermore, preferential adsorption was observed for the uncharged analogue of the macrocycle on a surface.

Preparation of Azobenzenealkanethiols for Self-Assembled Monolayers with Photoswitchable Properties

2010 ◽  
Vol 63 (2) ◽  
pp. 303 ◽  
Author(s):  
Simone Krakert ◽  
Andreas Terfort
Keyword(s):  
Oxygen Atom ◽  
Hybrid Systems ◽  
Self Assembly ◽  
Alkyl Chain ◽  
The Self ◽  
Self Assembled Monolayers ◽  
Assembled Monolayers ◽  
Methylene Groups ◽  
Broad Variety ◽  
Fast Access

A series of azobenzenealkanethiol compounds with the structure p-RC6H4N=NC6H4(CH2)nSH (n = 3, 4) was synthesized using a divergent strategy with the two anilines H2NC6H4(CH2)nSAc as central compounds. This strategy provides fast access to a broad variety of the respective azobenzenethiols without (note!) an oxygen atom in the alkyl chain, thus permitting the self-assembly of these compounds onto gold in a predictable conformation, also taking advantage of the previously found odd–even effect in aromatic–aliphatic hybrid systems. Initial experiments indicate that all of these molecules indeed form dense monolayers, in which the orientation of the azobenzene unit is determined by the number of methylene groups in the aliphatic part of the molecules.

scholarly journals Self-assembly of octadecyltrichlorosilane: Surface structures formed using different protocols of particle lithography

2012 ◽  
Vol 3 ◽  
pp. 114-122 ◽  
Author(s):  
ChaMarra K Saner ◽  
Kathie L Lusker ◽  
Zorabel M LeJeune ◽  
Wilson K Serem ◽  
Jayne C Garno
Keyword(s):  
Self Assembly ◽  
Self Assembled Monolayers ◽  
Contact Printing ◽  
Force Microscopy ◽  
Atomic Force ◽  
Assembly Mechanism ◽  
Assembled Monolayers ◽  
Particle Lithography ◽  
Thickness Measurements

Particle lithography offers generic capabilities for the high-throughput fabrication of nanopatterns from organosilane self-assembled monolayers, which offers the opportunity to study surface-based chemical reactions at the molecular level. Nanopatterns of octadecyltrichlorosilane (OTS) were prepared on surfaces of Si(111) using designed protocols of particle lithography combined with either vapor deposition, immersion, or contact printing. Changing the physical approaches for applying molecules to masked surfaces produced OTS nanostructures with different shapes and heights. Ring nanostructures, nanodots and uncovered pores of OTS were prepared using three protocols, with OTS surface coverage ranging from 10% to 85%. Thickness measurements from AFM cursor profiles were used to evaluate the orientation and density of the OTS nanostructures. Differences in the thickness and morphology of the OTS nanostructures are disclosed based on atomic force microscopy (AFM) images. Images of OTS nanostructures prepared on Si(111) that were generated by the different approaches provide insight into the self-assembly mechanism of OTS, and particularly into the role of water and solvents in hydrolysis and silanation.

Investigation of the non-covalent interactions of molecular self-assembly by scanning tunneling microscopy using the association of aromatic structures in pyrene-4,5,9,10-tetraone and phenanthrene-9,10-dione molecules

RSC Advances ◽  
2015 ◽  
Vol 5 (125) ◽  
pp. 103316-103320 ◽  
Author(s):  
Huiling Zhao ◽  
Shuai Zhang ◽  
Shuang Li ◽  
Xin Song ◽  
Wei Liu ◽  
...  
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Self Assembly ◽  
The Self ◽  
Self Assembled Monolayers ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Aromatic Molecules ◽  
Assembled Monolayers ◽  
Non Covalent Interactions ◽  
Covalent Interactions

The self-assembled monolayers of aromatic molecules (pyrene-4,5,9,10-tetraone and phenanthrene-9,10-dione) were investigated at the liquid/solid (1-phenyloctane/graphite) interface using scanning tunneling microscopy, respectively.

Scrolling up graphene oxide nanosheets assisted by self-assembled monolayers of alkanethiols

Nanoscale ◽  
2017 ◽  
Vol 9 (28) ◽  
pp. 9997-10001 ◽  
Author(s):  
Lin Wang ◽  
Peng Yang ◽  
Yang Liu ◽  
Xiangru Fang ◽  
Xiaotong Shi ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Self Assembly ◽  
The Self ◽  
Self Assembled Monolayers ◽  
Gold Substrate ◽  
Graphene Oxide Nanosheets ◽  
High Quality ◽  
Humidity Sensing ◽  
Assembled Monolayers ◽  
Self Assembled

The fabrication of high-quality nanoscrolls of GO on a gold substrate assisted by the self-assembly of alkanethiol monolayers for humidity sensing.

A BCC Superlattice of Passivated Gold Nanocrystals

1998 ◽  
Vol 4 (S2) ◽  
pp. 716-717
Author(s):  
S.A. Harfenist ◽  
Z.L. Wang ◽  
T.G. Schaaff ◽  
R.L. Whettent
Keyword(s):  
Self Assembly ◽  
Building Blocks ◽  
The Self ◽  
Self Assembled Monolayers ◽  
Nanometer Scale ◽  
Core Diameter ◽  
Ordered Structures ◽  
Gold Nanocrystals ◽  
Transmission Electron ◽  
Assembled Monolayers

A recent development in the study of nanocrystalline materials has been the self-assembly of passivated nanometer scale building blocks into larger, well ordered structures reaching the micron scale. Nanocrystal supercrystals (NCS) have been observed in metallic, semiconductor, and magnetic materials. In most cases the nanocrystals (NXs) are encapsulated in some inert medium that effectively protects the nanocrystal core and its unique electronic and optical properties. Here we describe the self-assembly of gold nanocrystals (∼4.5 nm core diameter), passivated with hexanethiol self-assembled-monolayers into ordered regions exhibiting a body-centered-cubic (bcc) superstructure. Transmission Electron Microscopy (TEM) imaging and Electron Diffraction (ED) experiments were used to characterize the NCSs and their resulting superstructures.A large agglomeration of NCSs can be seen in figure 1. One can clearly see regions of periodicity within the nanocrystal aggregation.

Stochastic Computing via In Operando Modulation of Rectification in Molecular Tunneling Junctions

2020 ◽  
Author(s):  
Xinkai Qiu ◽  
Sylvia Rousseva ◽  
Gang Ye ◽  
Jan C. Hummelen ◽  
Ryan Chiechi
Keyword(s):  
Self Assembly ◽  
Variable Temperature ◽  
Self Assembled Monolayers ◽  
Microfluidic Channels ◽  
Proof Of Concept ◽  
Glycol Ethers ◽  
Stochastic Computing ◽  
Assembled Monolayers ◽  
In Operando ◽  
Tunneling Junctions

This paper describes the reconfiguration of molecular tunneling junctions during operation via the self-assembly of bilayers of glycol ethers. We use well-established functional groups to modulate the magnitude and direction of rectification in assembled tunneling junctions by exposing them to solutions containing different glycol ethers. Variable-temperature measurements establish that rectification occurs by a bias-dependent tunneling-hopping mechanism and that glycol ethers, beside being an unusually efficient tunneling medium, behave identically to alkanes. We fabricated memory bits from crossbar junctions prepared by injecting eutectic Ga-In into microfluidic channels. Two 8-bit registers were able to perform logical AND operations on bit strings encoded into chemical packets as microfluidic droplets that alter the composition of the crossbar junctions through self-assembly to effect memristor-like properties. This proof of concept work demonstrates the potential for fieldable molecular-electronic devices based on tunneling junctions of self-assembled monolayers and bilayers.

Directive Effect of Chain Length in Modulating Peptide Nano-assemblies

2020 ◽  
Vol 27 (9) ◽  
pp. 923-929
Author(s):  
Gaurav Pandey ◽  
Prem Prakash Das ◽  
Vibin Ramakrishnan
Keyword(s):  
Electron Microscopy ◽  
Amino Acids ◽  
Light Scattering ◽  
Chain Length ◽  
Self Assembly ◽  
The Self ◽  
Ionic Charge ◽  
Self Assembling ◽  
Biophysical Techniques

Background: RADA-4 (Ac-RADARADARADARADA-NH2) is the most extensively studied and marketed self-assembling peptide, forming hydrogel, used to create defined threedimensional microenvironments for cell culture applications. Objectives: In this work, we use various biophysical techniques to investigate the length dependency of RADA aggregation and assembly. Methods: We synthesized a series of RADA-N peptides, N ranging from 1 to 4, resulting in four peptides having 4, 8, 12, and 16 amino acids in their sequence. Through a combination of various biophysical methods including thioflavin T fluorescence assay, static right angle light scattering assay, Dynamic Light Scattering (DLS), electron microscopy, CD, and IR spectroscopy, we have examined the role of chain-length on the self-assembly of RADA peptide. Results: Our observations show that the aggregation of ionic, charge-complementary RADA motifcontaining peptides is length-dependent, with N less than 3 are not forming spontaneous selfassemblies. Conclusion: The six biophysical experiments discussed in this paper validate the significance of chain-length on the epitaxial growth of RADA peptide self-assembly.

scholarly journals Lanthanide Homobimetallic Triple-Stranded Helicates: Insight into the Self-Assembly Mechanism

2004 ◽  
Vol 2004 (1) ◽  
pp. 51-62 ◽  
Author(s):  
Mourad Elhabiri ◽  
Josef Hamacek ◽  
Jean-Claude G. Bünzli ◽  
Anne-Marie Albrecht-Gary
Keyword(s):  
Self Assembly ◽  
The Self ◽  
Assembly Mechanism ◽  
Insight Into

Evaluation of the Tunneling Constant for Long Range Electron Transfer in Azobenzene Self-Assembled Monolayers on Gold

Langmuir ◽  
1997 ◽  
Vol 13 (21) ◽  
pp. 5774-5778 ◽  
Author(s):  
H. Z. Yu ◽  
H. B. Shao ◽  
Y. Luo ◽  
H. L. Zhang ◽  
Z. F. Liu
Keyword(s):  
Electron Transfer ◽  
Long Range ◽  
Self Assembled Monolayers ◽  
Assembled Monolayers ◽  
Self Assembled
Sign in / Sign up

Export Citation Format

Share Document