Laboratoire de Chimie des Polymères Organiques (LCPO), CNRS - ENSCPB - Université de Bordeaux , 16 Avenue Pey-Berland, F-33607 Pessac Cedex, France.
Langmuir. 2011 Dec 6;27(23):14481-8. doi: 10.1021/la2036983. Epub 2011 Nov 7.
The organization process of asymmetric poly(styrene-block-ethylene oxide) (PS-b-PEO) copolymer thin films blended with FePt nanoparticles is studied. In a first step, it is shown that FePt nanoparticles stabilized by oleic acid ligands are distributed within the PS matrix phase, whereas the same particles partially covered with short dopamine-terminated-methoxy poly(ethylene oxide) (mPEO-Dopa) are located at PS/PEO interfaces. The swelling of PS domains, induced by FePt_oleic acid nanoparticles during the solvent annealing process, results in formation of a disordered microstructure in comparison to the well-organized hexagonally close-packed (HCP) cylinder phase formed in the neat PS-b-PEO copolymer. The evolution of the microstructure of PS-b-PEO/FePt_mPEO-Dopa composite has been investigated for different solvent annealing treatments. Under high-humidity conditions during the vapor annealing process, the addition of FePt nanoparticles results in formation of spheres in the film split into terraces. The upper and lower terraces are occupied by spheres organized in an unusual square and HCP phases, respectively. Under low-humidity conditions, undulated PEO cylinders oriented parallel to substrate are formed in the presence of FePt nanoparticles. In this case, we observe that most of the nanoparticles accumulate within the core of topological defects, which induces a low nanoparticle concentration at the PS/PEO interfaces and so stabilizes an intermediate undulated cylinder phase.
研究了具有 FePt 纳米颗粒的不对称聚苯乙烯-嵌段-聚氧化乙烯（PS-b-PEO）共聚物薄膜的组织过程。首先表明，由油酸配体稳定的 FePt 纳米颗粒分布在 PS 基体相中，而部分被短多巴胺末端甲氧基聚（氧化乙烯）（mPEO-Dopa）覆盖的相同颗粒位于 PS/PEO 界面处。在溶剂退火过程中，FePt_油酸纳米颗粒使 PS 畴溶胀，导致形成无序的微观结构，与纯 PS-b-PEO 共聚物中形成的有序六方密堆积（HCP）圆柱相相比。研究了不同溶剂退火处理对 PS-b-PEO/FePt_mPEO-Dopa 复合材料微观结构的演变。在蒸汽退火过程中的高湿度条件下，添加 FePt 纳米颗粒会导致薄膜分裂成梯田中的球体形成。上梯田和下梯田分别由分别以正方形和 HCP 相组织的球体占据。在低湿度条件下，在存在 FePt 纳米颗粒的情况下，平行于基底取向的波纹 PEO 圆柱形成。在这种情况下，我们观察到大多数纳米颗粒积聚在拓扑缺陷的核心内，这导致 PS/PEO 界面处的纳米颗粒浓度较低，从而稳定了中间的波纹圆柱相。
