Fractal Self-Assembly of Single-Stranded DNA on Hydrophobic Self-Assembled Monolayers

2012 ◽  
Vol 116 (38) ◽  
pp. 11594-11599 ◽  
Author(s):  
Chunyan Xing ◽  
Haiyan Qiao ◽  
Yongjun Li ◽  
Xi Ke ◽  
Zhe Zhang ◽  
...  
MRS Bulletin ◽  
1999 ◽  
Vol 24 (8) ◽  
pp. 31-35 ◽  
Author(s):  
S. Mantl ◽  
Q.T. Zhao ◽  
B. Kabius

Most microfabrication techniques employ masks to transfer the desired microstructure onto a wafer using ultraviolet light, x-rays, electrons, or ions for the projection of the structures. Generally, photoresist processing and etching follow to form the final structures. In all cases, the facilities necessary to perform these processes grow increasingly more complex as the feature size of the structures diminishes, and these processes face their practical or economic limits at dimensions of about 50 nm. Thus alternative approaches are under investigation, including different self-assembly techniques. They require no costly facilities and no masks with nanometer structures, and they promise high throughput, since the patterning is directly achieved by a physical or chemical process. Self-assembled monolayers of long-chain organic molecules are the most widely studied examples, where chemisorption and spontaneous self-ordering of the molecules are observed on appropriate substrates. Another interesting example is island-ordering, laterally or in a vertical direction, during epitaxial growth. The lattice-mismatched islands tend to nucleate preferentially on top of each other when separated by a thin spacer layer, due to the associated strain field. Another approach is the use of specific stressor layers on the surface to obtain alignment of buried precipitates along the stressor lines. However, the main challenges of all self-assembly techniques are precise control of the dimensions of the structures and reproducibility.


2011 ◽  
Vol 2 ◽  
pp. 674-680 ◽  
Author(s):  
Tibor Kudernac ◽  
Natalia Shabelina ◽  
Wael Mamdouh ◽  
Sigurd Höger ◽  
Steven De Feyter

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.


2017 ◽  
Vol 204 ◽  
pp. 191-213 ◽  
Author(s):  
A. Della Pia ◽  
D. Luo ◽  
R. Blackwell ◽  
G. Costantini ◽  
N. Martsinovich

Self-assembly of three related molecules – terephthalic acid and its hydroxylated analogues – at liquid/solid interfaces (graphite/heptanoic acid and graphite/1-phenyloctane) has been studied using a combination of scanning tunnelling microscopy and molecular mechanics and molecular dynamics calculations. Brickwork-like patterns typical for terephthalic acid self-assembly have been observed for all three molecules. However, several differences became apparent: (i) formation or lack of adsorbed monolayers (self-assembled monolayers formed in all systems, with one notable exception of terephthalic acid at the graphite/1-phenyloctane interface where no adsorption was observed), (ii) the size of adsorbate islands (large islands at the interface with heptanoic acid and smaller ones at the interface with 1-phenyloctane), and (iii) polymorphism of the hydroxylated terephthalic acids’ monolayers, dependent on the molecular structure and/or solvent. To rationalise this behaviour, molecular mechanics and molecular dynamics calculations have been performed, to analyse the three key aspects of the energetics of self-assembly: intermolecular, substrate–adsorbate and solvent–solute interactions. These energetic characteristics of self-assembly were brought together in a Born–Haber cycle, to obtain the overall energy effects of formation of self-assembled monolayers at these liquid/solid interfaces.


2016 ◽  
Vol 7 (2) ◽  
pp. 1422-1429 ◽  
Author(s):  
Jason C. Applegate ◽  
Monisola K. Okeowo ◽  
Nathan R. Erickson ◽  
Brad M. Neal ◽  
Cindy L. Berrie ◽  
...  

Azulene is a convenient platform for accessing heterobimetallic complexes and self-assembled monolayers of a π-linker with asymmetric junctions.


RSC Advances ◽  
2016 ◽  
Vol 6 (85) ◽  
pp. 81726-81730
Author(s):  
Xiao-Ping Liu ◽  
Ke Deng ◽  
Qian Wei ◽  
Ming-hui Liang ◽  
Zhan-Jun Zhang ◽  
...  

Scanning tunneling microscopy images of trithia-9-crown-3 and octathia-24-crown-8 self-assembled monolayers (SAMs) reveal completely different SAM structures for the two kinds of thiacrown molecules at liquid n-tetradecane/Au(111) interface.


2007 ◽  
Vol 990 ◽  
Author(s):  
Xiaofang Ang ◽  
Li Cheong Chin ◽  
Guo Ge Zhang ◽  
Jun Wei ◽  
Zhong Chen ◽  
...  

ABSTRACTElevated bonding temperature for interconnection deteriorates the reliability of both the device and the interconnect; hence the imperative for developing low temperature bonding methods. This study investigates the feasibility of using self-assembled monolayers (SAMs) to assist direct gold-gold bonding. This involves a simple molecular self-assembly process whereby a monolayer of alkyl chains with a sulfur end group is attached to the gold surface prior to thermocompression bonding. Using this method, we have achieved gold to gold bonding at a bonding temperature below 100°C, a significant reduction compared to the conventional bonding temperatures of above 150 °C. We attribute this temperature reduction to two properties of SAMs - (1) surface passivation of the Au surface that precludes adsorption of surface contaminants, and (2) The easy displacement of SAMs through thermal desorption just before bonding occurs. This SAMs-assisted bonding mechanism is supported by X-ray photoelectron spectroscopy (XPS) and surface plasmon resonance (SPR) results.


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