Results 201 to 210 of about 20,641 (267)

Low-frequency dynamics in silica xerogels

Journal of Physics: Condensed Matter, 1996
Brillouin and Raman experiments have been performed in hydrogenated silica sol - gel and vitreous silica samples made by sol - gel processes (xerogels) and by the melting powder method. The aim of this work has been the study of the low-frequency dynamics of sol - gel systems in comparison with that of amorphous silica.
Fontana, Aldo, E. Moser, F. Rossi, Campostrini, Renzo, Carturan, Giovanni   +4 more
openaire   +2 more sources

Room‐Temperature Phosphorescence and Reversible White Light Switch Based on a Cyclodextrin Polypseudorotaxane Xerogel

Advanced Optical Materials, 2019
The development of metal‐free room‐temperature phosphorescent (RTP) and white‐light‐emitting supramolecular materials is significant for artificial soft materials.
Jingjing Li, Heng Zhang, Yi Zhang, Weilei Zhou, Yu Liu   +4 more
semanticscholar   +1 more source

OPTOGELs: optically active xerogels

SPIE Proceedings, 1992
Using the sol-gel process, we synthesized zirconia/silica matrices doped with different organic dyes (rhodamine 640, ...). These samples were used to perform optical Kerr effect experiments with sequences of ultrashort light pulses (100 fs, 620 nm, 1 (mu) J focused on 50 micrometers diameter) to induce refractive index changes.
Michael Canva, Patrick M. Georges, Alain Brun, Frederic Chaput, Francois Devreux, Jean-Pierre Boilot   +5 more
openaire   +1 more source

Silica xerogels as pharmaceutical drug carriers

Expert Opinion on Drug Delivery, 2009
This review focuses on silica xerogels obtained by the sol-gel method and their application as drug delivery systems. SiO(2) xerogels are potential biomaterials to be used as matrix materials for the extended and controlled release of different kinds of biologically active agents administered by various routes.
David, Quintanar-Guerrero, Adriana, Ganem-Quintanar, María Guadalupe, Nava-Arzaluz, Elizabeth, Piñón-Segundo   +3 more
openaire   +2 more sources

Carbon Xerogels for Effluent Treatment

Journal of Chemical & Engineering Data, 2020
The adsorption process of carbonized xerogels in the form of porous microspheres or monoliths was found to be reversible.
Athulya Pillai, Balasubramanian Kandasubramanian   +1 more
openaire   +1 more source

Similarity of cellulose xerogels of japanese pears in ultrastructure to chitin xerogels chemically prepared

International Journal of Biochemistry, 1978
Abstract 1. 1. Ultrastructure of cellulose (cell wall) xerogels of Japanese pears was compared with that of chitin xerogels chemically prepared, and molecular assemblies of chitin chains to gels was examined by scanning electron microscopy (SEM). 2. 2.
S, Hirano, R, Yamaguchi, N, Matsuda, H, Takeuchi   +3 more
openaire   +2 more sources

Pore Confinement-enhanced Electrochemiluminescence on SnO2 Nanocrystal Xerogel with NO3- as Co-reactant and Its Application in Facile and Sensitive Bioanalysis.

Analytical Chemistry, 2019
Herein, 10-fold electrochemiluminescence (ECL) enhancement from porous SnO2 nanocrystal (SnO2 NC) xerogel (vs. discrete SnO2 NCs) was firstly observed with NO3- as a novel co-reactant. This new booster phenomenon caused by pore characteristic was defined
Yan-Mei Lei, Ying Zhuo, M. Guo, Y. Chai, R. Yuan   +4 more
semanticscholar   +1 more source

Low-Energy Vibration Excess in Silica Xerogels

Physical Review Letters, 1997
Specific heat (1.5-25 K) and Raman scattering (below 100cm −1 in silica xerogels permit one to assess the frequency dependence of the coupling coefficient C(ω)and the low-energy density of states g(ω) Different network connectivity does not change the shape of the quasielastic scattering, but alters the spectral shape of C(ω)The results permit one to ...
FONTANA A, ROSSI F, CARINI, Giuseppe, D'ANGELO, Giovanna, TRIPODO, Gaspare, BARTOLOTTA A.   +5 more
openaire   +4 more sources

CdS semiconductor doped silica xerogels

Materials Science and Engineering: A, 1993
Abstract CdS doped amorphous silica was prepared by the sol-gel method. The CdS concentration in weight varied from 5% to 20%. The samples were characterized by four different and complementary techniques: X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), low frequency inelastic Raman scattering (LOFIRS) and small ...
A. Othmani, C. Bovier, J.C. Plenet, J. Dumas, B. Champagnon, C. Mai   +5 more
openaire   +1 more source

Elastic Properties of Silica Xerogels

Journal of the American Ceramic Society, 1990
To calculate elastic constants, longitudinal and tranverse acoustic wave velocities were measured for silica xerogels as a function of relative humidity (rh). The silica xerogels studied are microporous with open porosity of 53 vol%. The longitudinal wave velocity exhibits a minimum at about 35% rh.
Lisa C. Klein, Bennet Abramoff
openaire   +2 more sources