The elaboration of catalytic composite nanofibers (NFs) by electrospinning through a one-pot strategy is described. First, aqueous colloidal suspensions of ruthenium nanoparticles (Ru NPs) formed by reduction of a Ru(III) salt with NaBH₄ and stabilized by poly(cyclodextrin citrate) (PCD) were prepared. Then, poly(vinyl alcohol) (PVA) of different molecular weights was dissolved in the colloidal suspensions that were electrospun. SEM analyses of the resulting nanowebs displayed uniform NFs, whose diameters ranged between 300 and 700 nm and enlarged upon increasing (i) PVA molecular weight, (ii) nanosuspension viscosity, (iii) the amount of NaBH₄ and (iv) the PCD/Ru NP concentration. TEM analysis confirmed that Ru NPs with a mean diameter of around 2 nm were observed at the surface of NFs, embedded in the PVA matrix of NFs. HAADF-STEM and EDS mapping clearly showed that Ru NPs were homogeneously distributed onto and into the matrix of NFs. After their electrospinning, the prepared nanowebs were submitted to a heat post-treatment at 160 °C which was shown to trigger the PVA crystallization. In addition, the physical crosslinking of PVA chains by NaBO₂ resulting from NaBH₄ oxidation in the precursor suspension was also observed. Interestingly, an SEM study evidenced that the thermal post-treatment in combination with the presence of NaBO₂ clearly improved the thermal stability of the synthesized composite nanowebs. Finally, catalytic hydrogenation tests showed the absence of Ru NPs leaching from NFs in the reaction medium, and displayed good conversion of styrene into ethylbenzene.

中文翻译：

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柠檬酸-β-环糊精聚合物稳定含钌纳米颗粒的新型催化复合纳米纤维的合成

描述了通过一锅策略静电纺丝制备催化复合纳米纤维 (NFs)。首先，制备了通过用NaBH ₄还原Ru( III )盐形成并由聚(环糊精柠檬酸盐)(PCD)稳定的钌纳米颗粒(Ru NPs)的水性胶体悬浮液。然后，将不同分子量的聚（乙烯醇）（PVA）溶解在电纺的胶体悬浮液中。所得纳米网的 SEM 分析显示均匀的 NF，其直径范围在 300 和 700 nm 之间，并且随着 (i) PVA 分子量、(ii) 纳米悬浮液粘度、(iii) NaBH _{4的量的增加而增大}(iv) PCD/Ru NP 浓度。TEM 分析证实，在 NFs 表面观察到平均直径约为 2 nm 的 Ru NPs，嵌入在 NFs 的 PVA 基质中。HAADF-STEM 和 EDS 映射清楚地表明，Ru NPs 均匀分布在 NFs 基质上和其中。在它们的静电纺丝之后，制备的纳米网在 160°C 下进行热处理，这被证明可以触发 PVA 结晶。此外，还观察到前体悬浮液中NaBH _{4氧化导致的NaBO 2对PVA链的物理交联。}有趣的是，一项 SEM 研究证明，热后处理与 NaBO _{2的存在相结合}明显改善了合成的复合纳米网的热稳定性。最后，催化加氢测试表明反应介质中不存在从 NFs 中浸出的 Ru NPs，并显示出苯乙烯向乙苯的良好转化。