TY - JOUR
T1 - Self-assembled colloidal crystals from ZrO2 nanoparticles
AU - Woodward, Jonathan D.
AU - Pickel, Joseph M.
AU - Anovitz, Lawrence M.
AU - Heller, William T.
AU - Rondinone, Adam J.
PY - 2006/10/5
Y1 - 2006/10/5
N2 - Ordered three-dimensional (3-D) assemblies of nanocrystalline zirconia were synthesized from aqueous suspensions of ZrO2 nanoparticles without the need for hydrocarbon surfactants or solvents to control colloidal crystal 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 into ordered 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) for further stability. Small-angle X-ray scattering (SAXS) measurements demonstrate that the samples become progressively 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 and residual organics are desorbed, revealing highly controlled interstitial spaces and pores.
AB - Ordered three-dimensional (3-D) assemblies of nanocrystalline zirconia were synthesized from aqueous suspensions of ZrO2 nanoparticles without the need for hydrocarbon surfactants or solvents to control colloidal crystal 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 into ordered 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) for further stability. Small-angle X-ray scattering (SAXS) measurements demonstrate that the samples become progressively 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 and residual organics are desorbed, revealing highly controlled interstitial spaces and pores.
UR - http://www.scopus.com/inward/record.url?scp=33750309042&partnerID=8YFLogxK
U2 - 10.1021/jp062471z
DO - 10.1021/jp062471z
M3 - Article
AN - SCOPUS:33750309042
SN - 1520-6106
VL - 110
SP - 19456
EP - 19460
JO - Journal of Physical Chemistry B
JF - Journal of Physical Chemistry B
IS - 39
ER -