Naonobu Shimamoto
Hokkaido University
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Naonobu Shimamoto.
Thin Solid Films | 1994
Yuko Hirohata; Naonobu Shimamoto; Tomoaki Hino; T. Yamashima; Katsumasa Yabe
Abstract Numerous silicon nitride films were prepared using different target materials (Si 3 N 4 or Si) and different discharge gases (Ar or N 2 ). In the case with an Si 4 N 4 target and Ar gas pressure (1 Pa), the N-to-Si atomic ratio of the film was stoichiometric, 1.33, even when the substrate temperature was changed considerably. When the As gas pressure was increased from 1 7 Pa, the nitrogen content increased while the deposition rate decreased. In the case with an Si 3 N 4 or Si target and N 2 gas, the nitrogen content increased while the deposition rate decreased with the increase in N 2 pressure. The change in deposition rate due to the pressure was investigated using optical emission spectroscopy. X-ray photoelectron spectroscopy analysis showed that the binding energy is the same if the N-to-Si ratio was in the range from 1.33 to 1.70. It was found by X-ray diffraction analysis that crystallization occured when the substrate temperature was higher than about 1173 K.
Journal of Materials Chemistry B | 2013
Guoqing Wang; Hideyuki Mitomo; Yasutaka Matsuo; Naonobu Shimamoto; Kenichi Niikura; Kuniharu Ijiro
Silver halide (AgX, X = Cl, Br, I)-based materials represent an emerging class of heterogeneous photocatalysts. Despite progress in the synthesis of carrier-separated AgX-based photocatalysts, a number of issues remain unaddressed, including complicated synthesis, unfavorably large size and therefore poor photocatalytic performance of the resultant structures. Here we show the one-step DNA-programmable synthesis of Ag/AgCl nanostructures that takes only approximately 1 min for photocatalytic application. The optimal DNA-encapsulated structures show DNA sequence-specific sizes down to less than 40 nm with a Ag/AgCl composition ratio of 2 : 1, affording a vastly increased surface area and higher photocatalytic activity than any Ag/AgX nanostructures reported previously by over two orders of magnitude. From a physical standpoint, importantly, the plasmonic nanostructured silver in Ag/AgCl accelerates the photocatalytic reaction in terms of fast electron injection to AgCl, leading to enhanced hole-electron separation and high-performance photocatalysis under visible light. To test the effect of DNA encapsulation on the Ag/AgCl nanostructures, both positively and negatively charged organic compounds serve as the model pollutants to assess their photocatalytic selectivity. Our results show that the photodecomposition of the positively charged compounds obeys a first-order rate law, whereas the negatively charged compound is decomposed with zero-order kinetics. This comparison offers a mechanistic insight into reaction kinetics on the DNA-encapsulated photocatalyst. We further find that the DNA-encapsulated Ag/AgCl photocatalysts are robust and can be recycled. To extend the applicability of the Ag/AgCl nanostructures, their use in the efficient photocatalytic inactivation of cancer cells is also demonstrated for the first time, opening up a new avenue to daylight-based theranostics.
Advanced Materials | 2012
Naonobu Shimamoto; Yoshito Tanaka; Hideyuki Mitomo; Ryuzo Kawamura; Kuniharu Ijiro; Keiji Sasaki; Yoshihito Osada
A polymer hydrogel consists of an elastic cross-linked polymer network with water fi lling the interstitial spaces, giving hydrogels viscoelastic properties. [ 1 , 2 ] One specifi c hydrogel characteristic is that the gel swelling state can be modulated through environmental changes, including pH, ionic species, ionic concentration, and temperature, and through physical stimuli such as UV light and electromagnetic fi elds. This enables dynamic control of the gel expansion and contraction, and of the permeation of fl uids or solutes, [ 2 , 3 ] and enables gel applications as stimuli-responsive soft, wet matter, including artifi cial muscles, [ 4 , 5 ]
Shinku | 1993
Naonobu Shimamoto; Yuko Hirohata; Masao Hashiba; Tomoaki Hino; Toshiro Yamashina; Katsumasa Yabe
スパ ッタ法 による化合物薄膜 の作製 には,単 体ターゲ ットを用いる反応性スパ ッタ法 と化合物 ターゲッ トを用 い る方 法 とがあ る.反 応性スパ ッタ法では反応性気体 の 分圧に より膜の組成が大 きく変化す ることは良 く知 られ てい る1).一 方,化 合物 ターゲッ トを用いた方法で も, ターゲ ッ トの選択 スパ ッタ リングや基板上 での反応性な どの点か ら必ず しもターゲ ッ トと同一の膜 が作製 され る とは限 らない. 前 回,Si3N4 化合物 ター ゲッ トを用い て窒化 シ リコン 薄膜 を作製 し,組 成 を調べ た結果 について報告 した 2). Si3N4 ターゲ ッ トの場合 は,析 出速度や基板温度 な どの 作製条件 を変えて も,SiとNの 比は変化 せず ターゲ ッ トと同 じ化学量論組成の Si3N4 膜が作製 された. 本研究では,化 合物 ターゲッ トのスパ ッタ法に加えて, Siタ ー ゲ ッ トを用 い る反応性 スパ ッタ法に よって も, 窒化 シリコン膜の作製 を行 ない,そ の作製条件 による組 成,結 合状態,お よび結晶構造の変化 を調べ比較を行 な った.
Archive | 2010
Kuniharu Ishiro; Ryoichi Kishi; Hideyuki Mitomo; Yoshihito Osada; Ken-Ichi Sano; Naonobu Shimamoto; Daiki Tominaga; 秀之 三友; 健一 佐野; 大輝 富永; 邦治 居城; 良一 岸; 直伸 島本; 義仁 長田
Archive | 2011
Yoshihito Osada; 義仁 長田; Ryuzo Kawamura; 隆三 川村; Kuniharu Ishiro; 邦治 居城; Naonobu Shimamoto; 直伸 島本; Hideyuki Mitomo; 秀之 三友; Naoki Nakamura; 直樹 中村; Takuya Kondo; 拓也 近藤; Manabu Fujine; 学 藤根
Journal of The Surface Finishing Society of Japan | 2013
Hideyuki Mitomo; Naonobu Shimamoto; Kuniharu Ijiro
Meeting Abstracts | 2012
Naonobu Shimamoto; Yoshito Tanaka; Hideyuki Mitomo; Ryuzo Kawamura; Kuniharu Ijiro; Keiji Sasaki; Yoshihito Osada
Advanced Materials | 2012
Naonobu Shimamoto; Yoshito Tanaka; Hideyuki Mitomo; Ryuzo Kawamura; Kuniharu Ijiro; Keiji Sasaki; Yoshihito Osada
Archive | 2010
Kuniharu Ishiro; Ryoichi Kishi; Hideyuki Mitomo; Yoshihito Osada; Ken-Ichi Sano; Naonobu Shimamoto; Daiki Tominaga; 秀之 三友; 健一 佐野; 大輝 富永; 邦治 居城; 良一 岸; 直伸 島本; 義仁 長田
Collaboration
Dive into the Naonobu Shimamoto's collaboration.
National Institute of Advanced Industrial Science and Technology
View shared research outputs