Rare-earth/inorganic/organic polymeric hybrid materials: molecular assembly, regular microstructure and photoluminescence.
Rare-earth/inorganic/organic polymeric hybrid materials: molecular assembly, regular microstructure and photoluminescence.
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DOI：
10.1021/jp073531j
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发表时间：
2007-10
期刊：
影响因子：
--
通讯作者：
B. Yan;Xiaofei Qiao
中科院分区：
文献类型：
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作者：
B. Yan;Xiaofei Qiao
2-通过羟基烟酸（HNA）的羟基与3-（三乙氧基硅基）丙基异氰酸酯（特匹克）的异氰酸酯基之间的氢转移亲核加成反应，将HNA与特匹克接枝，得到分子前体HNA-Si。然后，以HNA-Si为桥分子，通过共水解和共缩聚过程，既能与稀土离子（HNA-Si-RE）配位，又能与正硅酸乙酯（TEOS）形成无机Si-O网络，构建了化学键合的稀土/无机高分子杂化材料（A）。在此基础上，通过引入三种不同的有机高分子链，组装了三种新型的稀土/无机/有机高分子杂化材料（B-D）。首先，将甲基丙烯酸（MAA）[或摩尔比为1：1的甲基丙烯酸和丙烯酰胺（ALM）]与作为引发剂的过氧化苯甲酰（BPO）混合，以形成聚（甲基丙烯酸）（PMAA）[或聚（甲基丙烯酸和丙烯酰胺）（PMAALM）]，然后在HNA-Si-RE组装之前将PMAA或PMAALM加入到前体HNA-Si中，得到杂化材料HNA-Si-RE-PMAA（B）和HNA-Si-RE-PMAALM（C）。其次，在HNA-Si-RE配合物中加入聚乙烯吡咯烷酮（PVP），通过羰基与稀土离子配位，得到杂化HNA-Si-RE-PVP（D）。所有这些杂化材料都表现出均匀、规则和有序的微观结构和形态，表明无机网络和有机链的自组装发生。这些材料的光致发光性能的测量表明，三元稀土/无机/有机聚合物杂化物呈现更强的发光强度，更长的寿命，和更高的发光量子效率比二元稀土/无机聚合物杂化物，表明有机聚合物链的引入是一个整体的混合系统的发光的好处。
2-Hydroxynicotinic acid (HNA) was grafted by 3-(triethoxysilyl)propyl isocyanate (TEPIC) to achieve the molecular precursor HNA-Si through the hydrogen-transfer nucleophilic addition reaction between the hydroxyl group of HNA and the isocyanate group of TEPIC. Then, a chemically bonded rare-earth/inorganic polymeric hybrid material (A) was constructed using HNA-Si as a bridge molecule that can both coordinate to rare-earth ions (HNA-Si-RE) and form an inorganic Si-O network with tetraethoxysilane (TEOS) after cohydrolysis and copolycondensation processes. Further, three types of novel rare-earth/inorganic/organic polymeric hybrids (B-D) were assembled by the introduction of three different organic polymeric chains into the above system. First, methacrylic acid (MAA) [or methacrylic acid and acrylamide (ALM) in the molar ratio of 1:1] was mixed to polymerize (or copolymerize) with benzoyl peroxide (BPO) as the initiator to form poly(methacrylic acid) (PMAA) [or poly(methacrylic and acrylamide) (PMAALM)], and then PMAA or PMAALM was added to the precursor HNA-Si before the assembly of HNA-Si-RE, resulting in the hybrid materials HNA-Si-RE-PMAA (B) and HNA-Si-RE-PMAALM (C). Second, poly(vinylpyrrolidone) (PVP) was added to coordinate to the rare-earth ions by the carbonyl group in the complex HNA-Si-RE, to achieve the hybrid HNA-Si-RE-PVP (D). All of these hybrid materials exhibit homogeneous, regular, and ordered microstructures and morphologies, suggesting the occurrence of self-assembly of the inorganic network and organic chain. Measurements of the photoluminescent properties of these materials show that the ternary rare-earth/inorganic/organic polymeric hybrids present stronger luminescent intensities, longer lifetimes, and higher luminescent quantum efficiencies than the binary rare-earth/inorganic polymeric hybrids, indicating that the introduction of the organic polymer chain is a benefit for the luminescence of the overall hybrid system.