Consolidated silica glass from nanoparticles

Mayerhöfer, Thomas G.; Shen, Zhijian; Leonova, Ekaterina; Edén, Mattias; Kriltz, Antje; Popp, Jürgen

doi:10.1016/j.jssc.2008.06.011

Cited by 49 publications

(42 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The peaks at 1102 and 472 cm −1 are visible, being related to the asymmetric Si-O-Si stretching vibration and Si-O-Si bending vibration, respectively [28]. These results are also consistent with the XRD.…”

Section: Structural Features Of the Solids By Ftirsupporting

confidence: 85%

“…Further, these results are consistent with the TG analysis. As the contribution of hydroxyl absorption due to physisorbed water is expected to be small, the aforementioned band may be assigned to the hydrogen bonded hydroxyl groups of Si-OH, Al-OH, Zr-OH or Ti-OH [27,28]. This is a good indication of the elimination of the organic precursors to form the nanostructured phases of the oxides mentioned by XRD.…”

Section: Porosity Studiesmentioning

confidence: 99%

See 1 more Smart Citation

Binary Oxides with Defined Hierarchy of Pores in the Esterification of Glycerol

et al. 2016

View full text Add to dashboard Cite

Abstract:Various porous binary oxides with elevated textural properties were obtained in this work. The as-synthesized solids were calcined or modified by reflux and extraction processes. Characterizations through SEM, nitrogen physisorption and TEM techniques demonstrated the formation of porous metal oxide networks over all solids. XRD, thermal analyses and FTIR measurements showed the existence of nanosized rutile TiO 2 , tetragonal ZrO 2 , SiO 2 and γ-Al 2 O 3 phases on the solids. The structure and texture of the as-synthesized SiAl sol-gel derived solid resulted in the formation of well-dispersed nanoparticles on the support. The removal of the organic compounds by ethanol extraction or reflux from SiAl resulted in the presence of structures with defined hierarchy of pores. Among the solids studied, the catalytic results in the esterification of glycerol with acetic acid indicated that best performances were obtained over SiAl sample when submitted to extraction and reflux treatments. This was due to the creation of accessible pores, which facilitated the reaction occurrence at glycerol to acetic acid molar ratio = 1:3 and T = 80 • C for 20 h using 75 mg of catalyst. The solids can be reused three times without complete loss of their catalytic performance.

show abstract

Section: Structural Features Of the Solids By Ftirsupporting

confidence: 85%

Section: Porosity Studiesmentioning

confidence: 99%

Binary Oxides with Defined Hierarchy of Pores in the Esterification of Glycerol

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Protons within inorganic structures devoid of significant internal motions still relax much faster than notoriously slowly relaxing spin-1/2 nuclei in glasses (e.g., 29 Si, 31 P, 13 C, and 89 Y), normally allowing for using 1 H relaxation delays <10 s. Nevertheless, cases do exist where very long pulse delays are required. One example is Si-O 1 H moieties present in very low amounts in vitreous SiO 2 , for which we have encountered T 1 % 190 s, which if using 90°excitation pulses would require 16 min relaxation delays in the signal averaging to ensure a quantitative 1 H NMR spectrum [156].…”

Section: T 1 Relaxation and Pulse Delaysmentioning

confidence: 98%

27Al NMR Studies of Aluminosilicate Glasses

Edén

2015

Annual Reports on NMR Spectroscopy

Self Cite

View full text Add to dashboard Cite

“…Silica gives a strong phonon-polariton signal between about 1050 and 1300 cm −1 . The main oscillator is located at about 1070 cm −1 , which is at the same time the wavenumber of the so-called transversal optical (TO) phonon [85]. The corresponding dip of the 3 nm SiO 2 layer did not appear in proximity to the TO wavenumber, but instead, closer to the longitudinal optical (LO) phonon at about 1250 cm −1 in the range of the Fuchs-Kliewer surface phonon polariton.…”

Section: Linear Nanoantennasmentioning

confidence: 96%

Periodic array-based substrates for surface-enhanced infrared spectroscopy

Mayerhöfer

Popp

2017

Nanophotonics

Self Cite

View full text Add to dashboard Cite

At the beginning of the 1980s, the first reports of surface-enhanced infrared spectroscopy (SEIRS) surfaced. Probably due to signal-enhancement factors of only 10 1 to 10 3 , which are modest compared to those of surface-enhanced Raman spectroscopy (SERS), SEIRS did not reach the same significance up to date. However, taking the compared to Raman scattering much larger crosssections of infrared absorptions and the enhancement factors together, SEIRS reaches about the same sensitivity for molecular species on a surface in terms of the crosssections as SERS and, due to the complementary nature of both techniques, can valuably augment information gained by SERS. For the first 20 years since its discovery, SEIRS relied completely on metal island films, fabricated by either vapor or electrochemical deposition. The resulting films showed a strong variance concerning their structure, which was essentially random. Therefore, the increase in the corresponding signal-enhancement factors of these structures stagnated in the last years. In the very same years, however, the development of periodic array-based substrates helped SEIRS to gather momentum. This development was supported by technological progress concerning electromagnetic field solvers, which help to understand plasmonic properties and allow targeted design. In addition, the strong progress concerning modern fabrication methods allowed to implement these designs into practice. The aim of this contribution is to critically review the development of these engineered surfaces for SEIRS, to compare the different approaches with regard to their performance where possible, and report further gain of knowledge around and in relation to these structures.

show abstract

Consolidated silica glass from nanoparticles

Cited by 49 publications

References 28 publications

Binary Oxides with Defined Hierarchy of Pores in the Esterification of Glycerol

Binary Oxides with Defined Hierarchy of Pores in the Esterification of Glycerol

27Al NMR Studies of Aluminosilicate Glasses

Periodic array-based substrates for surface-enhanced infrared spectroscopy

Contact Info

Product

Resources

About