title: Thermal curing of a self-assembled monolayer at the nanoscale.
abstract: On fabrication by contact printing, a nanostructured self-assembled monolayer (SAM) of alkanethiol contains a substantial fraction of unbound molecules that are either inverted among other upright molecules or piled on top of the SAM. The molecular dynamics simulation in the present study demonstrates that thermal annealing cures these defects for a SAM island of octadecanethiol. The SAM island melted partially as a result of heating, so the unbound molecules that had piled on top of the SAM island penetrated down to make contact with the surface, and the inverted molecules flipped to achieve adsorption. With subsequent cooling, the packing of sulfur atoms and alignment of alkyl chains of the SAM island were recovered. The molecular pathways for the adsorption of the unbound molecules were unraveled. The transition state and activation energy, calculated for each pathway in the absence of annealing, showed that these defects are incurable without the help of annealing.
authors.affiliation: Department of Nanoenergy Engineering, Pusan National University, Busan 609-735, South Korea. jkjang@pusan.ac.kr.
authors.forename: Zhengqing
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Nanoenergy Engineering, Pusan National University, Busan 609-735, South Korea. jkjang@pusan.ac.kr.
authors.forename: Hyojeong
authors.initials: H
authors.lastname: Kim
authors.affiliation: Department of Chemistry and Institute of Nano Science and Technology, Hanyang University, Seoul 133-791, South Korea.
authors.forename: Jaegeun
authors.initials: J
authors.lastname: Noh
authors.affiliation: Department of Applied Physics, Kyung Hee University, Yongin 446-701, South Korea.
authors.forename: Yoonho
authors.initials: Y
authors.lastname: Ahn
authors.affiliation: Department of Applied Physics, Kyung Hee University, Yongin 446-701, South Korea.
authors.forename: Jong Yeog
authors.initials: JY
authors.lastname: Son
authors.affiliation: Department of Nanoenergy Engineering, Pusan National University, Busan 609-735, South Korea. jkjang@pusan.ac.kr.
authors.forename: Joonkyung
authors.initials: J
authors.lastname: Jang