• Bulletin of the Korean Chemical Society
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• v.34 no.12
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• pp.3790-3794
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• 2013

Molecular dynamics simulations were performed to study the structure and stability of a nanoscale self-assembled monolayer (SAM) of alkanethiol on a gold (111) surface. The tilt angle and orientational order of the alkyl chains in the SAM island were examined by systematically varying the size of the island. The chain length dependence of the SAM island was examined by considering alkanethiols containing 12, 16, 20, and 24 carbon atoms. The minimum diameter of SAM islands made from 1-tetracosanethiol, 1-ecosanethiol, 1-hexadecanethiol and 1-dodecanethiol were 2.29, 1.9, 4.7 and 4.76 nm, respectively. These set the ultimate resolution that can be patterned by soft nanolithography. As the length of alkanethiol increases, the SAM islands became more ordered in both orientation and conformation of the alkyl chains.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.10a
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• pp.509-510
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• 2006

• Bulletin of the Korean Chemical Society
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• v.31 no.11
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• pp.3407-3410
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• 2010

• Journal of the Korean Chemical Society
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• v.64 no.6
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• pp.345-349
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• 2020

In the self-assembled monolayer (SAM) of alkanethiol formed on a gold surface, some molecules fail to chemisorb with their terminal alkyl groups physisorbed. The previous molecular dynamics (MD) simulation showed that these defects can be cured by thermal annealing. Herein, we present a simple Ising model of alkanethiol. The Monte Carlo simulation based on the present model reproduced the essential features of the annealing of SAM observed in the MD simulation.

• Bulletin of the Korean Chemical Society
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• v.32 no.1
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• pp.281-285
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• 2011

We investigated the effects of tunneling current on scanning tunneling microscopy (STM) images of 1-octanethiol (OT) and 1-decanethiol (DT) self-assembled monolayers (SAMs). At a low tunneling current, the domain boundaries and ordered alkanethiol molecules were clearly resolved. As the tunneling current was increased at a constant bias voltage, however, the STM images showed disordered structures of the OT and DT SAMs. As the tunneling current was reduced back to low values, the ordered structures of the alkanethiol molecules reappeared. The reversibility of the process suggests that the sulfur head groups did not rearrange under any of the tunneling current conditions. On the basis of our observations, which are inconsistent with the standard model for STM imaging of molecules on metal surfaces, we consider the STM imaging mechanism in terms of a two-region tunneling junction model.

• Bulletin of the Korean Chemical Society
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• v.26 no.3
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• pp.463-466
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• 2005

• Bulletin of the Korean Chemical Society
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• v.34 no.8
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• pp.2245-2246
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• 2013

• Korean Chemical Engineering Research
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• v.46 no.6
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• pp.1069-1074
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• 2008

In this work, we made a study for the 3D SAM formation of octanethiol, decanethiol, and dodecanethiol on copper nanoparticles and we verified stability of the copper particle depending on the ratio of dodecanethiol to copper. The reaction was performed in a one-phase system under nitrogen atmosphere and the thiolated copper particles could be obtained by centrifugation. We could confirm that the nanoparticles consisted of a spherical shape of 3~6 nm from TEM images. FT-IR, XPS and TGA results showed that alkanethiols were chemisorbed via thiol group and the packing density of the alkanethiols on copper surface increased with the alkyl chain lengths. XRD patterns gave us useful information about superlattice formations. Finally, $Cu_2O$ was formed when the molar ratio of dodecanethiol to copper is less than unity and copper nanoparticles formed more compact 3D SAMs when the molar ratio of dodecanethiol to copper was 1.25.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.5
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• pp.104-109
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• 2007

Photochemical patterning of self-assembled mono layers (SAMs) has been performed by diode pumped solid state (DPSS) 3rd harmonic Nd:$YVO_4$ laser with wavelength of 355 nm. SAMs patternings of parallel lines have subsequently been used either to generate compositional chemical patterns or fabricate microstructures by a wet etching. This paper describes a selective etching process with patterned SAMs of alkanetiolate molecules on the surface of gold. SAMs formed by the adsorption of alkanethiols onto gold substrate employs as very thin photoresists. In this paper, the influence of the interaction between the functional group of SAMs and the etching solution is studied with optimal laser irradiation conditions. The results show that hydrophobic functional groups of SAMs are more effective for selective chemical etching than the hydrophilic ones.

• Proceedings of the Optical Society of Korea Conference
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• 2003.07a
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• pp.288-289
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• 2003

금속 박막 위의 알칸티올분자의 흡착에 의한 자기조립단분자막(SAMs)은 접착 방지, 마찰 저하 등의 기능을 가진 코팅층으로서의 응용과 분자 또는 생분자의 미세 구조물 형성을 위한 방법으로 널리 연구되어지고 있다. 이러한 연구 중에서 자기조림단분자막(SAMs)의 매우 얇은 두께(수 nm)의 특성을 활용하여 AFM tip Scratching Lithography 또는 알칸티올 포토패터닝(alkanethiol Photopatterning) 방법을 사용함으로써 microscale의 패턴을 형성하는 연구 결과가 많은 이들의 관심을 받아왔다. (중략)