Limits...
Morphology and photoluminescence study of titania nanoparticles.

Memesa M, Lenz S, Emmerling SG, Nett S, Perlich J, Müller-Buschbaum P, Gutmann JS - Colloid Polym Sci (2011)

Bottom Line: The sol-gel components-hydrochloric acid, titanium tetraisopropoxide, and triblock copolymer-are varied to investigate their effect on the resulting titania morphology.The interplay among the sol-gel components via our triblock copolymer results in different sized titania nanoparticles with higher packing densities.Smaller sized titania particles, (∼13-20 nm in diameter) in the range of exciton diffusion length, are formed by 2% by weight polymer and show good crystallinity with less surface defects and high oxygen vacancies.

View Article: PubMed Central - PubMed

ABSTRACT
Titania nanoparticles are prepared by sol-gel chemistry with a poly(ethylene oxide) methyl ether methacrylate-block-poly(dimethylsiloxane)-block-poly(ethylene oxide) methyl ether methacrylate triblock copolymer acting as the templating agent. The sol-gel components-hydrochloric acid, titanium tetraisopropoxide, and triblock copolymer-are varied to investigate their effect on the resulting titania morphology. An increased titania precursor or polymer content yields smaller primary titania structures. Microbeam grazing incidence small-angle X-ray scattering measurements, which are analyzed with a unified fit model, reveal information about the titania structure sizes. These small structures could not be observed via the used microscopy techniques. The interplay among the sol-gel components via our triblock copolymer results in different sized titania nanoparticles with higher packing densities. Smaller sized titania particles, (∼13-20 nm in diameter) in the range of exciton diffusion length, are formed by 2% by weight polymer and show good crystallinity with less surface defects and high oxygen vacancies.

No MeSH data available.


XRD diffractograms of as-prepared (a), heated at 450 °C (b), and heated at 1,000 °C (c) 1%HCl samples (standard sol–gel). Typical anatase titania peaks [6] are shown at the bottom
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3102206&req=5

Fig5: XRD diffractograms of as-prepared (a), heated at 450 °C (b), and heated at 1,000 °C (c) 1%HCl samples (standard sol–gel). Typical anatase titania peaks [6] are shown at the bottom

Mentions: The structural stability of the titania structures upon elevated annealing temperature is observed by SEM imaging in correlation with GISAXS experiments. However, the crystallinity of the particles changed from amorphous to anatase and moreover to rutile, as observed from the X-ray diffraction (XRD) experiment (Fig. 5) after samples were prepared and heated to 450 and 1,000 °C. Typical anatase titania peaks [6] are also depicted in Fig. 5 beneath the XRD curves. An as-prepared sample (Fig. 5a) is amorphous and showed no peak. After heating at 450 °C, typical anatase titania peaks were observed (Fig. 5b). Further increase in heating temperature to 1,000 °C resulted in additional rutile phase, as indicated by additional XRD peaks (Fig. 5c). For application in semiconducting material requiring devices, anatase titania is needed. Heating temperature of 450 °C is less costly and destructive to the substrate than treatment at 1,000 °C. Moreover, rutile phase which will act as an impurity among anatase particles was observed after heating to 1,000 °C.Fig. 5


Morphology and photoluminescence study of titania nanoparticles.

Memesa M, Lenz S, Emmerling SG, Nett S, Perlich J, Müller-Buschbaum P, Gutmann JS - Colloid Polym Sci (2011)

XRD diffractograms of as-prepared (a), heated at 450 °C (b), and heated at 1,000 °C (c) 1%HCl samples (standard sol–gel). Typical anatase titania peaks [6] are shown at the bottom
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3102206&req=5

Fig5: XRD diffractograms of as-prepared (a), heated at 450 °C (b), and heated at 1,000 °C (c) 1%HCl samples (standard sol–gel). Typical anatase titania peaks [6] are shown at the bottom
Mentions: The structural stability of the titania structures upon elevated annealing temperature is observed by SEM imaging in correlation with GISAXS experiments. However, the crystallinity of the particles changed from amorphous to anatase and moreover to rutile, as observed from the X-ray diffraction (XRD) experiment (Fig. 5) after samples were prepared and heated to 450 and 1,000 °C. Typical anatase titania peaks [6] are also depicted in Fig. 5 beneath the XRD curves. An as-prepared sample (Fig. 5a) is amorphous and showed no peak. After heating at 450 °C, typical anatase titania peaks were observed (Fig. 5b). Further increase in heating temperature to 1,000 °C resulted in additional rutile phase, as indicated by additional XRD peaks (Fig. 5c). For application in semiconducting material requiring devices, anatase titania is needed. Heating temperature of 450 °C is less costly and destructive to the substrate than treatment at 1,000 °C. Moreover, rutile phase which will act as an impurity among anatase particles was observed after heating to 1,000 °C.Fig. 5

Bottom Line: The sol-gel components-hydrochloric acid, titanium tetraisopropoxide, and triblock copolymer-are varied to investigate their effect on the resulting titania morphology.The interplay among the sol-gel components via our triblock copolymer results in different sized titania nanoparticles with higher packing densities.Smaller sized titania particles, (∼13-20 nm in diameter) in the range of exciton diffusion length, are formed by 2% by weight polymer and show good crystallinity with less surface defects and high oxygen vacancies.

View Article: PubMed Central - PubMed

ABSTRACT
Titania nanoparticles are prepared by sol-gel chemistry with a poly(ethylene oxide) methyl ether methacrylate-block-poly(dimethylsiloxane)-block-poly(ethylene oxide) methyl ether methacrylate triblock copolymer acting as the templating agent. The sol-gel components-hydrochloric acid, titanium tetraisopropoxide, and triblock copolymer-are varied to investigate their effect on the resulting titania morphology. An increased titania precursor or polymer content yields smaller primary titania structures. Microbeam grazing incidence small-angle X-ray scattering measurements, which are analyzed with a unified fit model, reveal information about the titania structure sizes. These small structures could not be observed via the used microscopy techniques. The interplay among the sol-gel components via our triblock copolymer results in different sized titania nanoparticles with higher packing densities. Smaller sized titania particles, (∼13-20 nm in diameter) in the range of exciton diffusion length, are formed by 2% by weight polymer and show good crystallinity with less surface defects and high oxygen vacancies.

No MeSH data available.