Synthesis, thin-film self-assembly, and pyrolysis of ruthenium-containing polyferrocenylsilane block copolymers
Synthesis, thin-film self-assembly, and pyrolysis of ruthenium-containing polyferrocenylsilane block copolymers
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DOI：
10.1039/c8py00168e
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发表时间：
2018-05
影响因子：
4.6
通讯作者：
Huda Nasser Al-Kharusi;Lipeng Wu;G. Whittell;R. Harniman;I. Manners
中科院分区：
文献类型：
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作者：
Huda Nasser Al-Kharusi;Lipeng Wu;G. Whittell;R. Harniman;I. Manners
含有聚二茂铁基硅烷（PFS）的嵌段共聚物先前已被证明在薄膜或本体相中自组装成富含金属的纳米畴。这种图案化的金属块可以使铁纳米颗粒的阵列的应用在催化碳纳米管生长的制造。在此，我们报告了从聚苯乙烯-嵌段-聚二茂铁基甲基（三甲基甲硅烷基乙炔基）硅烷（PS-b-PFMEt（TMS）S）前体制备含钌的聚二茂铁基硅烷（RuPFMEtS）嵌段共聚物。后者是通过甲基（三甲基甲硅烷基乙炔基）硅[1]二茂铁烷和环戊二烯基封端的聚苯乙烯均聚物的光控开环聚合制备的。通过使用NaOMe进行Si（CH 3）3基团从PFS嵌段上的乙炔基取代基的脱保护。通过与Ru 3（CO）12的反应将Ru 3（CO）9 H团簇引入到嵌段共聚物中以获得PS-b-RuPFMEtS。这提供了两种嵌段共聚物，高度金属化的基于铼的链段，PS265-b-RuPFMEtS 10和PS196-b-RuPFMEtS 31，其含有约10%的钌。10和20质量%的Ru。相分离所得到的嵌段共聚物进行了研究，在散装和薄膜，并被发现产生球形或圆柱形域的RuPFMEtS在PS矩阵，分别。PS265-b-RuPFMEtS 10和PS196-b-RuPFMEtS 31嵌段共聚物在500或800 °C下热解2小时导致形成无定形（约.在500 °C下直径为2 nm）或多晶（约为20 nm）。在800 °C下直径为14 nm）碳质基质中的Fe/Ru纳米颗粒。这些NP复合物是用作非均相加氢催化剂的有前途的候选者。热解的材料，其特征在于通过高分辨率透射电子显微镜，能量色散X-射线光谱，选区电子衍射，扫描电子显微镜和粉末X-射线衍射。
Polyferrocenylsilane (PFS)-containing block copolymers have previously been shown to self-assemble into metal-rich nanodomains in thin films or the bulk phase. This patterning of the metalloblock can enable the fabrication of arrays of Fe nanoparticles for applications in catalytic carbon nanotube growth. Herein, we report the preparation of block copolymers with a ruthenium-containing polyferrocenylsilane (RuPFMEtS) segment from a polystyrene-block-polyferrocenylmethyl(trimethylsilylethynyl)silane (PS-b-PFMEt(TMS)S) precursor. The latter was prepared via the photocontrolled ring-opening polymerisation of methyl(trimethylsilylethynyl)sila[1]ferrocenophane and a cyclopentadienyl-terminated polystyrene homopolymer. Deprotection of the Si(CH3)3 groups from the ethynyl substituents on the PFS block was carried out by using NaOMe. Incorporation of Ru3(CO)9H clusters into the block copolymer was achieved by reaction with Ru3(CO)12 to obtain PS-b-RuPFMEtS. This afforded two block copolymers, highly metallised ruthenium-based segments, PS265-b-RuPFMEtS10 and PS196-b-RuPFMEtS31, containing ca. 10 and 20% Ru by mass, respectively. Phase-separation of the resulting block copolymers was investigated in the bulk and thin films and was found to yield spherical or cylindrical domains of RuPFMEtS in a PS matrix, respectively. Pyrolysis of PS265-b-RuPFMEtS10 and PS196-b-RuPFMEtS31 block copolymers at 500 or 800 °C for 2 h led to the formation of either amorphous (ca. 2 nm in diameter at 500 °C) or polycrystalline (ca. 14 nm in diameter at 800 °C) Fe/Ru nanoparticles in a carbonaceous matrix. These NP composites are promising candidates for use as heterogeneous hydrogenation catalysts. The pyrolysed materials were characterised by high resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy, selected area electron diffraction, scanning electron microscopy and powder X-ray diffraction.