Structure and Molecular Motion of Polystirene Adsorbed on porous silica by the Spin label method

自旋标记法吸附在多孔二氧化硅上的聚苯乙烯的结构和分子运动

• 批准号: 06651048
• 负责人: SHIMADA Shigetaka
• 金额: $ 1.22万
• 依托单位: Nagoya Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06651048/
• 关键词: Monodisperse Polystirene; Porous Silica; Adsorption; Interaction with Silica; Graft Copolymerization; Poly (ethylene oxide); Molecular Motion; Electron Spin Resonance

Spin-label method is used to study structure and molecular motion of polystirene (PS) chains having molecular weights, Mw=3X10^3,9.6X10^4, and 3.8X10^5, adsorbed in a pore of porous silica and the silica suface grafted with poly (ethylene oxide) (PEO).(1)The adsorption rate and the amount of the adsorbed PS depend on the grafting ratio lower than 2%.(2)The molecular interaction between PS and silica and the molecular motion of PS chain depend on its molecular weight. The adsorped PS having Mw=3X10^3 strongly interacts with silica, whereas PS having Mw=9.6X10^4 and 3.8X10^5 moves rapidly as "tail or loop segment" at a short adsorption decreases its mobility with increasing adsorption time, and change to "train segment".(3)Molecular mobility of the grafted PEO chain is higher than the adsoroed PS chain, having Mw=3.8X10^5. This fact suggests that the PS chains spread out the grafted chains and adsrbed on the silica surface as "train segments", whereas PEO chains protrude as "tail segmens". It was also found that the molecular structure of the chains change with adsorption time. Their structure of PEO and PS depend on molecular weight of PS and grafting ratio of PEO.

用自旋标记法研究了相对分子质量分别为3×10~(-4)、9.6×10~(^4)和3.8×10~(-5)的聚苯乙烯(PS)链在多孔二氧化硅和表面接枝聚氧乙烯(PEO)表面上的吸附结构和分子运动.(1)接枝率小于2%时，PS的吸附速率和吸附量依赖于接枝率.(2)PS与二氧化硅之间的分子相互作用和PS链的分子运动依赖于其相对分子质量.分子量为3×10~(^3)的PS与白炭黑有较强的相互作用，而分子量为9.6×10~(-4)和3.8×10~(^5)的PS在短时间内以“尾段或环段”形式快速移动，随着吸附时间的延长，其迁移率降低，并转变为“链段”.(3)接枝的PEO链的分子迁移率高于吸附的PS链，分子量为3.8×10~(^5)，这表明PS链以“链段”形式铺展在二氧化硅表面，而PEO链则以“尾段”的形式突出.研究还发现，链的分子结构随吸附时间的变化而变化。PEO和PS的结构与PS的相对分子质量和PEO的接枝率有关。

项目成果

嶋田繁隆: "高分子材料の分析・フィルムの分析" 高藻一弘(技術情報協会), 30 (1994)

Shigetaka Shimada：“高分子材料的分析和薄膜分析”Kazuhiro Takamo（技术信息协会），30（1994）

S.Shimada: "Molecular Motion of Chain End Peroxy Radicals of Polyethylene Molecules Tethered on a Fresh Surface of Poly (tetrafluoroethylene)" Macromolecules. 29. 973-977 (1996)

S.Shimada：“束缚在聚（四氟乙烯）新鲜表面上的聚乙烯分子链端过氧自由基的分子运动”大分子。

M.Sakaguchi: "molecular Motion of Polyethylene Chain-End Redicals Tetherad on the Surtace of Poly (tetrafluoroethyleme) in Vacuo at Extremely Low Temperatures" Macromolecules. 28. 8450-8452 (1995)

M.Sakaguchi：“极低温度下真空中聚四氟乙烯表面上聚乙烯链末端红色系链的分子运动”大分子。

Shigetaka Shimada: Polymer Structure -Magnetic Rresonance Method-. Kyouritu Shuppann, 493-507 (1995)

Shigetaka Shimada：聚合物结构-磁共振法-。

Shigetaka Shimada: Charecterization of Polymeric Marerials・Charecterization of Polymer Film. Cijyutu Jyouhou Kyoukai, 199-228 (1994)

Shigetaka Shimada：聚合物材料的表征·聚合物薄膜的表征，199-228（1994）。