Preparation and properties of novel cross-linked fluoroalkyl end-capped cooligomeric nanoparticles possessing double decker-type aromatic silsesquioxane segments as core units
Preparation and properties of novel cross-linked fluoroalkyl end-capped cooligomeric nanoparticles possessing double decker-type aromatic silsesquioxane segments as core units
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DOI：
10.1007/s00396-011-2474-0
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发表时间：
2011-06
影响因子：
2.4
通讯作者：
Yuki Goto;Kazuhiro Yoshida;H. Sawada
中科院分区：
文献类型：
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作者：
Yuki Goto;Kazuhiro Yoshida;H. Sawada
通过氟代烷酰基过氧化物与相应的具有双功能乙烯基的芳香族倍半硅氧烷（Ar-SiSQ）和丙烯酰吗啉等共聚单体（Co-M）在温和条件下共聚，制备了以双层型芳香族倍半硅氧烷链段为核心单元的交联氟烷基封端共低聚物[RF-(Ar-SiSQ)x-(Co-M)y-RF] (ACMO)，N,N-二甲基丙烯酰胺(DMAA)和N-(1,1-二甲基-3-氧代丁基)丙烯酰胺(DOBAA)。有趣的是，发现由此获得的这些交联氟化共低聚物形成纳米尺寸控制的纳米颗粒，在包括氟化脂肪族溶剂在内的多种溶剂中具有良好的分散性。与母体芳香族倍半硅氧烷相比，这些氟化低聚纳米粒子被证明具有与芳香族倍半硅氧烷片段的存在相关的红移荧光发射，这表明这些纳米粒子中的每个芳香族部分可以通过芳香族部分之间的π-π堆积有效地相互作用，以提供红移荧光发射。这些氟化纳米颗粒还应用于聚甲基丙烯酸甲酯（PMMA）的表面改性，不仅表现出氟赋予的良好疏油性，而且还表现出与改性PMMA表面纳米颗粒中芳香族倍半硅氧烷链段相关的荧光发射行为。更有趣的是，交联的RF-(Ar-SiSQ)x-(DOBAA)y-RF共低聚物纳米粒子与荧光素相互作用，在甲醇中产生相应的氟化共低聚物粒子/荧光素纳米复合材料。与不具有芳香族倍半硅氧烷链段的氟烷基封端的 DOBAA 低聚物 [RF-(DOBAA)n-RF] 相比，这些氟化荧光素纳米复合材料具有显着增强的光吸收能力 (λmax= 441 nm)。
Cross-linked fluoroalkyl end-capped cooligomers possessing double decker-type aromatic silsesquioxane segments as core units [RF-(Ar-SiSQ)x-(Co-M)y-RF] were prepared under mild conditions by the cooligomerizations of fluoroalkanoyl peroxide with the corresponding aromatic silsesquioxane possessing bifunctional vinyl groups (Ar-SiSQ) and comonomers (Co-M) such as acryloylmorpholine (ACMO),N,N-dimethylacrylamide (DMAA) andN-(1,1-dimethyl-3-oxobutyl)acrylamide (DOBAA). Interestingly, these cross-linked fluorinated cooligomers thus obtained were found to form the nanometer size-controlled nanoparticles with a good dispersibility in a variety of solvents including fluorinated aliphatic solvents. These fluorinated cooligomeric nanoparticles were demonstrated to have red-shifted fluorescent emissions related to the presence of aromatic silsesquioxane segments, compared with that of parent aromatic silsesquioxane, indicating that each aromatic moiety in these nanoparticles can interact effectively with each other through the π–π stacking between the aromatic moieties to afford the red-shifted fluorescent emissions. These fluorinated nanoparticles were also applied to the surface modification of poly(methyl methacrylate) (PMMA) to exhibit not only a good oleophobicity imparted by fluorine but also a fluorescent emission behavior related to aromatic silsesquioxane segments in nanoparticles on the modified PMMA surface. More interestingly, cross-linked RF-(Ar-SiSQ)x-(DOBAA)y-RFcooligomeric nanoparticles interacted with fluorescein to give the corresponding fluorinated cooligomeric particles/fluorescein nanocomposites in methanol. These fluorinated fluorescein nanocomposites were found to afford an extraordinarily enhanced light absorption (λmax= 441 nm), compared with that of fluoroalkyl end-capped DOBAA oligomer [RF-(DOBAA)n-RF] possessing no aromatic silsesquioxane segments.Figure