TY - JOUR
T1 - Fabrication of ionic liquid polycrystalline nano thin films and their ion conducting properties accompanied by solid-liquid phase transition
AU - Yoshii, Aya
AU - Maruyama, Shingo
AU - Toyabe, Kaho
AU - Takazawa, Ryoji
AU - Koganezawa, Tomoyuki
AU - Matsumoto, Yuji
N1 - Funding Information:
This work has been partially supported by a Grant-in-Aid for Scientific Research (No. H26886001 ) from the Ministry of Education, Culture, Sports, Science and Technology of Japan , Advanced Technology Institute Research Grants 2014, grants from Iketani Science and Technology Foundation , and Murata Science Foundation . Microbeam GXID experiments were performed at SPring-8 with the approval of the Japan Synchrotron Radiation Research Institute (JASRI) (Proposal No. 2015A1845 , 2016A1672 , 2016B1784 , and 2018A0136 ). The IL [N 1112 ][TFSA] used in this study was provided by courtesy of Koei Chemical Co., Ltd.
Publisher Copyright:
© 2019 Elsevier B.V.
PY - 2019/5/1
Y1 - 2019/5/1
N2 - Ionic liquid, ethyltrimethylammonium bis(trifluoromethylsulfonyl), (IL: [N 1112 ] [TFSA]) that has a melting point of 109 °C, was deposited at room temperature on α-Al 2 O 3 (0001) substrates by continuous-wave infrared laser deposition in a vacuum. No decomposition of IL molecules occurred during the thermal evaporation and the polycrystalline nature of the deposits at RT was found identical to that of the corresponding powder IL. The thin film IL (TF-IL) on a non-treated α-Al 2 O 3 (0001) substrate, with droplet-like shapes in morphology, exhibited almost no ionic conductivity even above the melting point because the IL would not spread over the non-treated substrate. In contrast, the TF-IL, with more dense, granular structures in morphology, deposited on a chemically-modified, wettable α-Al 2 O 3 (0001) substrate, did exhibit a substantial ionic conductivity even at temperatures lower than the melting point, and it was then followed by a drastic increase of the ionic conductivity through its solid-liquid phase transition. The behaviors of the deposited IL growing and melting on the substrate are discussed based on the results of in situ laser microscope and ionic conductivity measurement experiments.
AB - Ionic liquid, ethyltrimethylammonium bis(trifluoromethylsulfonyl), (IL: [N 1112 ] [TFSA]) that has a melting point of 109 °C, was deposited at room temperature on α-Al 2 O 3 (0001) substrates by continuous-wave infrared laser deposition in a vacuum. No decomposition of IL molecules occurred during the thermal evaporation and the polycrystalline nature of the deposits at RT was found identical to that of the corresponding powder IL. The thin film IL (TF-IL) on a non-treated α-Al 2 O 3 (0001) substrate, with droplet-like shapes in morphology, exhibited almost no ionic conductivity even above the melting point because the IL would not spread over the non-treated substrate. In contrast, the TF-IL, with more dense, granular structures in morphology, deposited on a chemically-modified, wettable α-Al 2 O 3 (0001) substrate, did exhibit a substantial ionic conductivity even at temperatures lower than the melting point, and it was then followed by a drastic increase of the ionic conductivity through its solid-liquid phase transition. The behaviors of the deposited IL growing and melting on the substrate are discussed based on the results of in situ laser microscope and ionic conductivity measurement experiments.
KW - Interface
KW - Ionic conductivity
KW - Ionic liquid
KW - Thin solid film
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U2 - 10.1016/j.tsf.2019.03.017
DO - 10.1016/j.tsf.2019.03.017
M3 - Article
AN - SCOPUS:85063586627
SN - 0040-6090
VL - 677
SP - 77
EP - 82
JO - Thin Solid Films
JF - Thin Solid Films
ER -