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宮崎 司*; 宮田 登*; 吉田 鉄生*; 有馬 寛*; 津村 佳弘*; 鳥飼 直也*; 青木 裕之; 山本 勝宏*; 金谷 利治*; 川口 大輔*; et al.
Langmuir, 36(13), p.3415 - 3424, 2020/04
被引用回数:14 パーセンタイル:60.48(Chemistry, Multidisciplinary)We investigated in detail the structures in the poly(vinyl alcohol) (PVA) adsorption layers on a Si substrate, which remained on the substrate after immersing the relatively thick 30 - 50 nm films in hot water, by neutron reflectometry under humid conditions. For the PVA with a degree of saponification exceeding 98 mol %, the adsorption layer exhibits a three-layered structure in the thickness direction. The bottom layer is considered to be the so-called inner adsorption layer that is not fully swollen with water vapor. This may be because the polymer chains in the inner adsorption layer are strongly constrained onto the substrate, which inhibits water vapor penetration. The polymer chains in this layer have many contact points to the substrate via the hydrogen bonding between the hydroxyl groups in the polymer chain and the silanol groups on the surface of the Si substrate and consequently exhibit extremely slow dynamics. Therefore, it is inferred that the bottom layer is fully amorphous. Furthermore, we consider the middle layer to be somewhat amorphous because parts of the molecular chains are pinned below the interface between the middle and bottom layers. The molecular chains in the top layer become more mobile and ordered, owing to the large distance from the strongly constrained bottom layer; therefore, they exhibit a much lower degree of swelling compared to the middle amorphous layer. Meanwhile, for the PVA with a much lower degree of saponification, the adsorption layer structure consists of the two-layers. The bottom layer forms the inner adsorption layer that moderately swells with water vapor because the polymer chains have few contact points to the substrate. The molecular chains in the middle layer, therefore, are somewhat crystallizable because of this weak constraint.
柏倉 潤*; 久保 篤彦*; 出田 博和*; 鈴木 寿之*; 大内 公一*; 吉田 利司*
PNC TJ9124 96-008, 103 Pages, 1996/03
大型炉蒸気発生器(SG)で生じうる水リークをより現実的に評価し、適切な設計基準水リーク(DBL)を設定することが高速炉の合理的な設計推進の観点から急務となっている。DBLに影響を及ぼす要因の1つとして伝熱管の高温ラプチャ型破損が考えられるが、この破損挙動はナトリウム-水反応時のリークジェットによる管外の熱伝達率に大きく依存する。従って、高温ラプチャの支配因子の1つであるリークジェットによる熱的挙動を明らかにするため、ナトリウム-水反応試験を行い管外熱伝達率を試験的に測定する必要がある。本報告書は、このナトリウム-水反応時の管外熱伝達率測定試験を行うために、試験装置の設計を行ったものである。なお、設計する装置は、動燃事業団所有の高速炉安全性第1試験室に設置するものとする。