Zhou Shuxue, Garnweitner Georg, Niederberger Markus, Antonietti Markus
Department of Colloid Chemistry, Max Planck Institute of Colloids and Interfaces, Research Campus Golm, Potsdam, Germany.
Langmuir. 2007 Aug 28;23(18):9178-87. doi: 10.1021/la700837u. Epub 2007 Jul 31.
The dispersion behavior of crystalline zirconia nanoparticles with a diameter of 3.8 nm, synthesized from zirconium(IV) isopropoxide and benzyl alcohol in tetrahydrofurane (THF), methyl methacrylate (MMA), and styrene (St), was investigated using 3-(trimethoxysilyl)propyl methacrylate (MPS), ethyl 3,4-dihydroxycinnamate (EDHC), allylmalonic acid (AMA), and trimethylolpropane mono allyl ether (TMPMA) as ligating stabilizers containing polymerizable vinyl groups. Analytical ultracentrifugation (AUC) and transmission electron microscopy (TEM) analyses prove that the as-synthesized wet zirconia nanoparticles can be dispersed in THF without any agglomeration when using the appropriate ligand concentrations. Surface-adsorbed water, if intentionally introduced during the washing step, and also air humidity seriously deteriorate their dispersibility. These results suggest that the excellent dispersibility of the zirconia nanoparticles is a direct consequence of the nonaqueous synthesis approach. Fourier transform infrared spectra (FTIR) and thermogravimetric analysis (TGA) illustrate that MPS, EDHC, and AMA are chemically attached but TMPMA is physically attached to the surface of the zirconia nanoparticles. Transparent dispersions of zirconia nanoparticles can also be prepared in MMA with the help of MPS, EHDC, and AMA or in St with MPS and TMPMA, opening a promising pathway for the direct application of zirconia nanoparticles in polymer-based nanocomposites.
以甲基丙烯酸3-(三甲氧基硅基)丙酯(MPS)、3,4-二羟基肉桂酸乙酯(EDHC)、烯丙基丙二酸(AMA)和三羟甲基丙烷单烯丙基醚(TMPMA)作为含可聚合乙烯基的连接稳定剂，研究了由异丙醇锆和苯甲醇在四氢呋喃(THF)、甲基丙烯酸甲酯(MMA)和苯乙烯(St)中合成的直径为3.8 nm的结晶氧化锆纳米颗粒的分散行为。分析超速离心(AUC)和透射电子显微镜(TEM)分析证明，当使用适当的配体浓度时，合成的湿氧化锆纳米颗粒可以在THF中分散而不发生任何团聚。如果在洗涤步骤中有意引入表面吸附的水，以及空气湿度也会严重降低它们的分散性。这些结果表明，氧化锆纳米颗粒的优异分散性是非水合成方法的直接结果。傅里叶变换红外光谱(FTIR)和热重分析(TGA)表明，MPS、EDHC和AMA化学附着在氧化锆纳米颗粒表面，而TMPMA物理附着在其表面。借助MPS、EHDC和AMA也可以在MMA中制备氧化锆纳米颗粒的透明分散体，或者借助MPS和TMPMA在St中制备，这为氧化锆纳米颗粒在聚合物基纳米复合材料中的直接应用开辟了一条有前景的途径。
