Dispersion and Functionalization of Nonaqueous Synthesized Zirconia Nanocrystals via Attachment of Silane Coupling Agents

Abstract

Zirconia (ZrO 2) nanocrystals, synthesized from zirconium(IV) isopropoxide isopropanol complex and benzyl alcohol, were dispersed and functionalized in organic solvents using three kinds of bifunctional silane coupling agents (SCAs), 3-glycidoxypropyltrimethoxysilane (GPTMS), 3-aminopropyltriethoxysilane (APTES), and 3-isocyanatopropyltriethoxysilane (IPTES). Completely transparent ZrO 2 dispersions were achieved in tetrahydrofuran (THF) with all three SCAs, in pyridine and toluene with APTES and IPTES, and in N, N-dimethylformamide with IPTES. Dynamic laser scattering (DLS) measurements and high-resolution transmission electron microscopical (HRTEM) observation indicated that the ZrO 2 nanocrystals are dispersed on a primary particle size level. Fourier transform infrared spectroscopy, solid-state (13)C- and (29)Si NMR spectroscopy, and thermogravimetric analysis demonstrated that all three SCAs are chemically attached to the surface of the ZrO 2 nanoparticles, however, in different bonding modes. Except for GPTMS/ZrO 2/THF dispersion and IPTES/ZrO 2/pyridine dispersion, all other transparent dispersions have poor long-term stability. The increasing polarity, due to high amount of APTES attached and high hydrolysis and condensation degree of the bonded APTES, and the aggregation, due to interparticle coupling via the bonded triethoxysilyl group, are the causes of the poor long-term stability for the ZrO 2 dispersions with APTES and IPTES, respectively. Nevertheless, the APTES-functionalized ZrO 2 precipitates can be deagglomerated in water to get a stable and transparent aqueous ZrO 2 dispersion via addition of a little hydrochloric acid.

The effects of adding various ratios of zirconium oxide nanoparticles to poly(methyl methacrylate) on physical and mechanical properties

“…These agents can be adsorbed on nanoparticles for fabricating functionalized silica nanoparticles (18,24). ZrO 2 nanoparticles and APTES attach via the condensation of a trialkoxy group with the hydroxyl group of nano-ZrO 2 (24).…”

“…These agents can be adsorbed on nanoparticles for fabricating functionalized silica nanoparticles (18,24). ZrO 2 nanoparticles and APTES attach via the condensation of a trialkoxy group with the hydroxyl group of nano-ZrO 2 (24). In previous studies, ZrO 2 nanocrystal dispersion was examined with organic dissolvers such as toluene, pyridine, ethane nitrile, acetone, and isopropyl (18,24).…”

“…ZrO 2 nanoparticles and APTES attach via the condensation of a trialkoxy group with the hydroxyl group of nano-ZrO 2 (24). In previous studies, ZrO 2 nanocrystal dispersion was examined with organic dissolvers such as toluene, pyridine, ethane nitrile, acetone, and isopropyl (18,24). Luo et al (24) reported that APTES and IPTES were efficient for the dispersion of ZrO 2 nanocrystals in pyridine and toluene.…”

“…In previous studies, ZrO 2 nanocrystal dispersion was examined with organic dissolvers such as toluene, pyridine, ethane nitrile, acetone, and isopropyl (18,24). Luo et al (24) reported that APTES and IPTES were efficient for the dispersion of ZrO 2 nanocrystals in pyridine and toluene. In the present study, APTES, which is the most commonly applied silane coupling agent, is used to functionalize nano-ZrO 2 with toluene as an organic dissolver.…”

Recent Progress in Nanoparticle Dispersion Using Bead Mill

“…et al, 2002) Silicone (silylating agent) TiO 2 (Ouyang G. et al, 2012) Propyltrimethoxysilane (TMS) ZrO 2 , SiO 2 , BTO (Luo K. et al, 2008;Nomoto H. et al, 2014;Yang X. and Liu Z.-H., 2010) Coupling agent…”