乙二醇亚相上的钴纳米颗粒朗缪尔-施夫层膜。

Department of Chemistry, Aalto University, P.O.B. 16100, FI-00076 Aalto, Finland.

Langmuir. 2010 Sep 7;26(17):13937-43. doi: 10.1021/la101630q.

The Langmuir-Schaefer (LS) technique was applied to prepare two-dimensional films of tridodecylamine (TDA)-stabilized Co nanoparticles. Ethylene glycol was used as the subphase because the Co nanoparticles spread better on it than on water. Surface pressure-area isotherms provided very little information on the floating films, and Brewster angle microscopy (BAM) was needed to characterize the film formation in situ. In addition to the subphase, various other experimental factors were tested in the LS film preparation, including solvent and presence of free TDA ligands and poly(styrene-b-ethylene oxide) (PS-b-PEO) in the nanoparticle dispersion. LS films deposited from dispersions from which the excess TDA ligands had been removed by washing the Co nanoparticles with 2-propanol consisted of hexagonally organized particles in rafts that were organized in necklace structures. The addition of PS-b-PEO to the deposition dispersion resulted in small nanoparticle rafts evenly distributed over the substrate surface. The best Co-nanoparticle-PS-b-PEO films were obtained with a mass ratio of 20:1 between Co (9 nm) and block copolymer (38 200 g/mol, PEO content 22 mass %). These films were successfully transferred onto Formvar-coated TEM grids and characterized by transmission electron microscopy (TEM) and a superconducting quantum interference device (SQUID) magnetometer. At room temperature the films showed superparamagnetic behavior with a saturation magnetization M(s) of 100 emu/g (Co). Our work indicates that it is possible to obtain thin superparamagnetic LS films of TDA-stabilized Co nanoparticles. This is an important result as the TDA-stabilized Co nanoparticles show a very good resistance to corrosion.

朗缪尔-谢弗（LS）技术被应用于制备三辛基胺（TDA）稳定的 Co 纳米粒子的二维薄膜。乙二醇被用作亚相，因为 Co 纳米粒子在其上的铺展性比在水上更好。表面压-面积等温线几乎没有提供关于浮膜的信息，需要使用布鲁斯特角显微镜（BAM）原位表征膜形成。除了亚相之外，还在 LS 薄膜制备中测试了各种其他实验因素，包括溶剂以及纳米粒子分散体中游离 TDA 配体和聚（苯乙烯-b-环氧乙烷）（PS-b-PEO）的存在。从用 2-丙醇洗涤 Co 纳米粒子去除过量 TDA 配体的分散体中沉积的 LS 膜由在项链结构中组织的筏状六边形组织的颗粒组成。将 PS-b-PEO 添加到沉积分散体中会导致小纳米粒子筏均匀分布在基底表面上。通过透射电子显微镜（TEM）和超导量子干涉仪（SQUID）磁强计对 Co-纳米粒子-PS-b-PEO 薄膜进行了成功的转移和表征，得到的 Co（9nm）和嵌段共聚物（38200g/mol，PEO 含量 22wt%）的质量比为 20:1 的最佳 Co-纳米粒子-PS-b-PEO 薄膜。这些薄膜成功地转移到 Formvar 涂覆的 TEM 网格上，并通过透射电子显微镜（TEM）和超导量子干涉仪（SQUID）磁强计进行了表征。在室温下，这些薄膜表现出超顺磁性，饱和磁化强度 M(s)为 100 emu/g（Co）。我们的工作表明，有可能获得 TDA 稳定的 Co 纳米粒子的薄超顺磁 LS 薄膜。这是一个重要的结果，因为 TDA 稳定的 Co 纳米粒子表现出非常好的抗腐蚀性。