Self-Assembled Colloidal Crystals from ZrO2 Nanoparticles
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- 作者：Jonathan D. Woodward ; Joseph M. Pickel ; Lawrence M. Anovitz ; William T. Heller ; Adam J. Rondinone
- 刊名：Journal of Physical Chemistry B
- 出版年：2006
- 出版时间：October 5, 2006
- 年：2006
- 卷：110
- 期：39
- 页码：19456 - 19460
- 全文大小：191K
- 年卷期：v.110,no.39(October 5, 2006)
- ISSN：1520-5207
文摘
Ordered three-dimensional (3-D) assemblies of nanocrystalline zirconia were synthesized from aqueoussuspensions of ZrO2 nanoparticles without the need for hydrocarbon surfactants or solvents to control colloidalcrystal growth. Nanoparticles were suspended in mild acid and subsequently titrated from low to neutral pH.The solubility was reduced as the surfaces were neutralized, promoting assembly of the nanoparticles intoordered monoliths. TEM measurements indicated the formation of three-dimensional, hexagonal faceted,micrometer-sized colloidal crystals composed of 4 nm diameter ZrO2 nanoparticles. Lacking organic surfactants,the colloidal crystals were exceptionally robust and were sintered at high temperatures (300-500 
C) forfurther stability. Small-angle X-ray scattering (SAXS) measurements demonstrate that the samples becomeprogressively more amorphous above 350 C, although some ordered domains of nanoparticles persist.Additionally, the heat treatment dramatically increases the surface area of the colloidal crystals as water andresidual organics are desorbed, revealing highly controlled interstitial spaces and pores.
C) forfurther stability. Small-angle X-ray scattering (SAXS) measurements demonstrate that the samples becomeprogressively more amorphous above 350 C, although some ordered domains of nanoparticles persist.Additionally, the heat treatment dramatically increases the surface area of the colloidal crystals as water andresidual organics are desorbed, revealing highly controlled interstitial spaces and pores.