scholarly journals A Simple Incorporation Route of Tris(8-hydroxyquinoline)aluminum(III) into Transparent Mesoporous Silica Films and Their Photofunctions

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Motohiro Tagaya ◽  
Kenji Shinozaki ◽  
Yuri Maruko
Keyword(s):  
Mesoporous Silica ◽  
Pore Size ◽  
Optical Devices ◽  
The State ◽  
Molecular Aggregation ◽  
Photoluminescence Spectra ◽  
Silica Films ◽  
Adsorbed Amount ◽  
Yellow Color ◽  
Mesoporous Film

The molecular aggregation states of tris(8-hydroxyquinoline)aluminum(III) (Alq) adsorbed in the transparent mesoporous silica (MPS) films with the different pore sizes (3.0 and 5.4 nm) were successfully clarified. The Alq molecules were easily incorporated into the films from the solution without the segregation on the surfaces. The adsorbed amount of Alq was controlled by changing the added amount in the initial solution to resultantly give the transparent and yellow-color films. The photoluminescence spectra significantly revealed that the state of Alq molecules in the mesopore varied depending on the adsorbed amount of Alq as well as the pore size, suggesting the characteristic mobility of the adsorbed Alq molecules in the mesopores as compared with that at the bulk or solution state. Therefore, the guest-guest interactions between Alq molecules as well as the host-guest interactions between Alq and mesopore were elucidated. This finding by the use of the mesoporous film hosts will be utilized for including luminescence species and be applicable for optical devices.

scholarly journals Effects of morphology and pore size of mesoporous silicas on the efficiency of an immobilized enzyme

RSC Advances ◽  
2021 ◽  
Vol 11 (17) ◽  
pp. 10010-10017
Author(s):  
Ping-Chung Kuo ◽  
Zhi-Xun Lin ◽  
Tzi-Yi Wu ◽  
Chun-Han Hsu ◽  
Hong-Ping Lin ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Mesoporous Silica ◽  
Pore Size ◽  
Immobilized Enzyme ◽  
Mesoporous Silicas ◽  
High Loading ◽  
Loading Capacity ◽  
Silica Films

Mesoporous silica films were used as supports with high loading capacity and enzyme activity.

scholarly journals Pore Size-Dependent Structure of Confined Water in Mesoporous Silica Films from Water Adsorption/Desorption Using ATR–FTIR Spectroscopy

Langmuir ◽  
2019 ◽  
Vol 35 (37) ◽  
pp. 11986-11994 ◽  
Author(s):  
Bettina Baumgartner ◽  
Jakob Hayden ◽  
Jérôme Loizillon ◽  
Sophia Steinbacher ◽  
David Grosso ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Ftir Spectroscopy ◽  
Pore Size ◽  
Water Adsorption ◽  
Confined Water ◽  
Silica Films ◽  
Size Dependent ◽  
Adsorption Desorption

Controlling Thermal Conductivity in Mesoporous Silica Films Using Pore Size and Nanoscale Architecture

2020 ◽  
Vol 11 (9) ◽  
pp. 3731-3737 ◽  
Author(s):  
Yan Yan ◽  
Man Li ◽  
Sophia King ◽  
Tiphaine Galy ◽  
Michal Marszewski ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Mesoporous Silica ◽  
Pore Size ◽  
Silica Films

Ortho-Positronium Reemission Yield and Energy in Surfactant-Templated Mesoporous Silica Films

2008 ◽  
Vol 607 ◽  
pp. 30-33 ◽  
Author(s):  
Laszlo Lizkay ◽  
C. Corbel ◽  
P. Perez ◽  
P. Desgardin ◽  
Marie France Barthe ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Pore Size ◽  
Positron Annihilation ◽  
Time Of Flight ◽  
Positron Beam ◽  
High Porosity ◽  
Silica Layer ◽  
Silica Films ◽  
Gamma Energy ◽  
Positron Energy

Positron annihilation gamma energy distribution, lifetime spectroscopy and time-of-flight method were used to study surfactant-templated mesoporous silica films deposited on glass. The lifetime depth profiling was correlated to Doppler broadening and 3γ annihilation fraction measurements to determine the annihilation characteristics inside the films. A set of consistent fingerprints for positronium annihilation, o-Ps reemission into vacuum, and pore size was directly determined. The lifetime measurements were performed in reflection mode with a specially designed lifetime spectrometer mounted on a slow positron beam system. The intensity of the 142 ns vacuum lifetime component was recorded as a function of the energy of the positron beam. In a film with high porosity a reemission efficiency of as high as 40 % was found at low positron energy. Positron lifetime in samples capped by a thin silica layer was used to determine the pore size. The energy of the reemitted o-Ps fraction was measured by a time-of-flight detector, mounted on the same system, allowing determination of both o-Ps re-emission efficiency and energy in the same sample. We demonstrate the potential of the simultaneous use of different positron annihilation techniques in the study of thin porous films.

Polyaniline nanowire arrays generated through oriented mesoporous silica films: effect of pore size and spectroelectrochemical response

2021 ◽  
Author(s):  
Wahid Ullah ◽  
Gregoire Herzog ◽  
neus vila ◽  
Alain Walcarius
Keyword(s):  
Mesoporous Silica ◽  
Pore Size ◽  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Self Assembly ◽  
Cationic Surfactants ◽  
Nanowire Arrays ◽  
Silica Films ◽  
Oxide Electrodes ◽  
Vertically Aligned

Indium-tin oxide electrodes modified with vertically aligned silica nanochannel membrane have been produced by electrochemically assisted self-assembly of cationic surfactants (cetyl- or octadecyl-trimethylammonium bromide) and concomitant polycondensation of the silica...

Microstructural Analysis of Disordered and Ordered Mesoporous Silica Films

1998 ◽  
Vol 4 (S2) ◽  
pp. 726-727
Author(s):  
C. A. Drewien ◽  
Y. Lu ◽  
C. J. Brinker ◽  
R. Ganguli ◽  
M. T. Anderson
Keyword(s):  
Mesoporous Silica ◽  
Pore Size ◽  
Size Structure ◽  
Sol Gel ◽  
Microstructural Analysis ◽  
Dip Coating ◽  
Inorganic Membranes ◽  
Cross Sectional ◽  
Silica Films ◽  
Plan View

Processing can be controlled to produce a family of mesoporous silica films with either disordered, lamellar, hexagonal, or cubic pore distributions[l]. These films, formed by surfactant-templated synthesis and exhibiting a unimodal pore size, promise potential use as inorganic membranes, catalysts, and optically-based sensors[l,2]. The mesoporous films can be formed from initially homogeneous silica sols by a continuous, surfactant-templated process, which relies upon solvent evaporation during the sol-gel dip-coating process. Films of 100-500 nm thick are formed within seconds in a continuous coating operation. The microstructure of the films is dependent upon the cationic surfactant concentration CTAB (CH3(CH2)15N+(CH3)3Br-) and the dip-coating rate. Several films, processed under differing conditions, were investigated by TEM to characterize pore size, structure, and orientation.Figures 1 a & b show the plan view and cross-sectional microstructure of a 2-d hexagonal mesoporous silica film deposited on silicon; the sample was calcined at 400 °C for 3 hours in air. The images were obtained on a Philips CM30 TEM, operated at 300 kV.

scholarly journals Open Porosity and Pore Size Distribution of Mesoporous Silica Films Investigated by Positron Annihilation Lifetime Spectroscopy and Ellipsometric Porosimetry

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3371
Author(s):  
Bangyun Xiong ◽  
Jingjing Li ◽  
Chunqing He ◽  
Jiale Lai ◽  
Xiangjia Liu ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Positron Annihilation ◽  
Open Porosity ◽  
Positron Annihilation Lifetime Spectroscopy ◽  
Silica Films ◽  
Ellipsometric Porosimetry ◽  
Positron Annihilation Lifetime

Tunable mesoporous silica films were prepared though a sol-gel process directed by the self-assembly of various triblock copolymers. Positron annihilation γ-ray energy spectroscopy and positron annihilation lifetime spectroscopy (PALS) based on intense pulsed slow positron beams as well as ellipsometric porosimetry (EP) combined with heptane adsorption were utilized to characterize the open porosity/interconnectivity and pore size distribution for the prepared films. The consistency between the open porosities was examined by the variations of orthopositronium (o-Ps) 3γ annihilation fractions and the total adsorbed volumes of heptane. The average pore sizes deduced by PALS from the longest-lived o-Ps lifetimes are in good agreement with those by EP on the basis of the Barrett–Joyner–Halenda model, as indicated by a well fitted line of slope k = 1. The results indicate that the EP combined with heptane adsorption is a useful method with high sensitivity for calibrating the mesopore size in highly interconnected mesoporous films, whereas PALS is a novel, complementary tool for characterizing both closed and open pores in them.

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