Temperature‐dependent optical dephasing in sol‐gel glasses: Photon echo measurements of rhodamine 101 and quinizarin doped aluminosilica xerogels

1995 ◽  
Vol 103 (22) ◽  
pp. 9880-9883
Author(s):  
Bruce J. Baer ◽  
Eric L. Chronister
1991 ◽  
Author(s):  
Eric L. Chronister ◽  
Drew M. L'Esperance ◽  
John Pelo ◽  
John Middleton ◽  
Robert A. Crowell

Author(s):  
George C. Ruben ◽  
Merrill W. Shafer

Traditionally ceramics have been shaped from powders and densified at temperatures close to their liquid point. New processing methods using various types of sols, gels, and organometallic precursors at low temperature which enable densificatlon at elevated temperatures well below their liquidus, hold the promise of producing ceramics and glasses of controlled and reproducible properties that are highly reliable for electronic, structural, space or medical applications. Ultrastructure processing of silicon alkoxides in acid medium and mixtures of Ludox HS-40 (120Å spheres from DuPont) and Kasil (38% K2O &62% SiO2) in basic medium have been aimed at producing materials with a range of well defined pore sizes (∼20-400Å) to study physical phenomena and materials behavior in well characterized confined geometries. We have studied Pt/C surface replicas of some of these porous sol-gels prepared at temperatures below their glass transition point.


Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 523 ◽  
Author(s):  
Simonas Ramanavičius ◽  
Milda Petrulevičienė ◽  
Jurga Juodkazytė ◽  
Asta Grigucevičienė ◽  
Arūnas Ramanavičius

In this research, the investigation of sensing properties of non-stoichiometric WO3 (WO3−x) film towards some volatile organic compounds (VOC) (namely: Methanol, ethanol, isopropanol, acetone) and ammonia gas are reported. Sensors were tested at several temperatures within the interval ranging from a relatively low temperature of 60 up to 270 °C. Significant variation of selectivity, which depended on the operational temperature of sensor, was observed. Here, the reported WO3/WO3–x-based sensing material opens an avenue for the design of sensors with temperature-dependent sensitivity, which can be applied in the design of new gas- and/or VOC-sensing systems that are dedicated for the determination of particular gas- and/or VOC-based analyte concentration in the mixture of different gases and/or VOCs, using multivariate analysis of variance (MANOVA).


2004 ◽  
Vol 398 (1-3) ◽  
pp. 151-156 ◽  
Author(s):  
M. Feuillade ◽  
C. Croutxé-Barghorn ◽  
L. Mager ◽  
C. Carré ◽  
A. Fort

1984 ◽  
Vol 110 (1) ◽  
pp. 7-13 ◽  
Author(s):  
F.G. Patterson ◽  
William L. Wilson ◽  
H.W.H. Lee ◽  
M.D. Fayer

1998 ◽  
Vol 519 ◽  
Author(s):  
L. Bergogne ◽  
S. Fennouh ◽  
J. Livage ◽  
C. Roux

AbstractBioencapsulation in sol-gel materials has been widely studied during the past decade. Trapped species appear to retain their bioactivity in the porous silica matrix. Small analytes can diffuse through the pores allowing bioreactions to be performed in-situ, inside the sol-gel glass. A wide range of biomolecules and micro-organisms have been encapsulated. The catalytic activity of enzymes is used for the realization of biosensors or bioreactors. Antibody-antigen recognition has been shown to be feasible within sol-gel matrices. Trapped antibodies bind specifically the corresponding haptens and can be used for the detection of traces of chemicals. Even whole cells are now encapsulated without any alteration of their cellular organization. They can be used for the production of chemicals or as antigens for immunoassays.


2004 ◽  
Vol 30 (3) ◽  
pp. 205-214 ◽  
Author(s):  
Massimo Bottini ◽  
Almerinda Di Venere ◽  
Lutz Tautz ◽  
Alessandro Desideri ◽  
Paolo Lugli ◽  
...  

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