Synthesis and Characterization of Ordered Mesoporous Carbon/Silica Hybrid Thin Films

2008 ◽  
Vol 6 (1) ◽  
Author(s):  
Xiaoxian Wang ◽  
Tiehu Li ◽  
Qilang Lin ◽  
Dawei Wang ◽  
Tingkai Zhao
Keyword(s):  
Electron Microscopy ◽  
Pore Size ◽  
Self Assembly ◽  
Sol Gel ◽  
Dip Coating ◽  
Silica Matrix ◽  
Nanocomposite Films ◽  
Evaporation Induced Self Assembly ◽  
Hybrid Thin Films ◽  
Silica Nanocomposite

Carbon/silica nanocomposite films with a hexagonal P6mm structure were fabricated directly by the oxidation and carbonization of surfactant/silica nanocomposite films, which were obtained by a dip-coating technique through a combination of sol-gel and evaporation-induced self-assembly. The as-synthesized nanocomposite films were characterized by scanning electron microscopy, X-ray diffraction, transmission electron microscopy and N2 adsorption-desorption. These analyses reveal that the carbon/silica nanocomposite films, with a narrow pore size distribution of mesopores, have an ordered symmetric structure. The pore sizes of this hybrid film can be controlled within a certain range by changing the carbonization temperature. In addition, the films are composed of a continuous silica matrix and a continuous carbon coating in about 1 nm adhered well to the silica matrix. The formation of carbon coatings from surfactant acts as a framework support to prevent the pore size of the silica matrix from shrinking.

Effect of Pore Size on the Hydrophilicity in Dark of TiO2 Films

2011 ◽  
Vol 130-134 ◽  
pp. 1049-1053
Author(s):  
Qi Wang ◽  
Cheng Pu Lin ◽  
Peng Cui
Keyword(s):  
Contact Angle ◽  
Organic Matter ◽  
Pore Size ◽  
Self Assembly ◽  
Dip Coating ◽  
Molar Ratio ◽  
Water Contact ◽  
Coating Method ◽  
Evaporation Induced Self Assembly ◽  
Dip Coating Method

Mesoporous TiO2 films was prepared by evaporation-induced self-assembly and dip-coating method. And the pore size of the TiO2 films is adjusted by controlling the molar ratio of H2O/TiO2 (H value). Water contact angle was chosen to represent the hydrophilic property, and XRD and AFM were carried out to characterize the films. With the increase of H value, the pore size increased firstly then decreased. And when H is 15, the pore size is the biggest, which hydrophilicity in dark is the best too. With the extention of the non-irridation time, the hydrophilicity is worse. And the reason may be ascribed to the adsorption of organic matter in air.

Meso-Ordered Silica Films Formed by Sugar-Based Surfactants

2002 ◽  
Vol 726 ◽  
Author(s):  
Uraka Lavrenèiè-Štangar ◽  
Michael Puchberger ◽  
Nicola Hüsing
Keyword(s):  
Self Assembly ◽  
Hexagonal Phase ◽  
Sol Gel ◽  
Composite Films ◽  
Dip Coating ◽  
Silica Films ◽  
Alkyl Glycosides ◽  
Packing Parameter ◽  
Evaporation Induced Self Assembly ◽  
Nmr Techniques

AbstractSugar-based amphiphilic molecules are used as templates in the sol-gel processing of thin silica films. The films are prepared relying on solvent evaporation-induced self-assembly during dip-coating in a humidity controlled chamber. Different surfactants, such as the commercially available alkyl glycosides (e.g. n-octyl β-D-glucopyranoside and n-dodecyl β-D-maltopyranoside), are compared with respect to their ability to cooperatively self-assemble in alcoholic silicate solutions. The larger polar headgroup (maltose) decreases the critical packing parameter and thus beneficially influences the formation of a favorable hexagonal phase over the lamellar phase, which is formed with the glucose-based surfactant. The inorganic-organic composite films show a strong influence on the humidity during their synthesis. For nonstructured films, ordering could be achieved by exposing the as-deposited films to a high humidity for several hours. The final material is characterized by X-ray diffraction, nitrogen sorption and solid state NMR techniques.

Evaporation-induced self-assembly of quantum dots-based concentric rings on polymer-based nanocomposite films

Soft Matter ◽  
2016 ◽  
Vol 12 (40) ◽  
pp. 8285-8296 ◽  
Author(s):  
Shaofu Zhang ◽  
Weiling Luan ◽  
Qixin Zhong ◽  
Shaofeng Yin ◽  
Fuqian Yang
Keyword(s):  
Quantum Dots ◽  
Self Assembly ◽  
Nanocomposite Films ◽  
Evaporation Induced Self Assembly

scholarly journals Effect of boron incorporation on the bioactivity, structure, and mechanical properties of ordered mesoporous bioactive glasses

2020 ◽  
Vol 8 (7) ◽  
pp. 1456-1465 ◽  
Author(s):  
Leonie Deilmann ◽  
Oliver Winter ◽  
Bianca Cerrutti ◽  
Henrik Bradtmüller ◽  
Christopher Herzig ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Self Assembly ◽  
Sol Gel ◽  
Bioactive Glasses ◽  
Structure Directing Agent ◽  
Structural Investigations ◽  
Ordered Mesoporous ◽  
Evaporation Induced Self Assembly

B2O3 doped (0.5–15 mol%) ordered mesoporous bioactive glasses were synthesized via sol–gel based evaporation-induced self-assembly using P123 as a structure directing agent and characterized by biokinetic, mechanical and structural investigations.

Monodisperse Mesoporous Microparticles Prepared by Evaporation-Induced Self Assembly Within Aerosols

2003 ◽  
Vol 775 ◽  
Author(s):  
Shailendra Rathod ◽  
G. V. Rama Rao ◽  
Brett Andrzejewski ◽  
Gabriel P. López ◽  
Timothy L. Ward ◽  
...  
Keyword(s):  
Pore Size ◽  
Self Assembly ◽  
Swelling Agent ◽  
Aerosol Generator ◽  
Amphiphilic Molecules ◽  
Brij 58 ◽  
Evaporation Induced Self Assembly ◽  
Uptake Process ◽  
Hexagonally Ordered ◽  
Kinetics Of

AbstractEvaporation induced self assembly (EISA) within microdroplets produced by a vibrating orifice aerosol generator (VOAG) has been used to produce monodisperse mesoporous silica particles. This process exploits the concentration of evaporating droplets to induce the organization of various amphiphilic molecules, effectively partitioning the silica precursor (TEOS) to the hydrophilic regions of the structure. Promotion of silica condensation, followed by removal of the surfactant, provides ordered spherical mesoporous particles. Using the VOAG we have produced highly monodisperse particles in the 5 to 10 μm diameter range. The cationic surfactant CTAB typically leads to hexagonal mesostructure with mean pore size of about 2 nm and specific surface area around 900 m2/g. We have also shown that the pore size in CTABtemplated particles can be increased to 3.8 nm by incorporating trimethylbenzene as a swelling agent. The TMB prefentially locates inside and swells the hydrophobic regions of the surfactant mesostructure. Pore size can also be varied by the choice of amphiphile. Hexagonally ordered particles have been produced using the nonionic surfactant Brij-58 and block copolymer F127. These powders possessed mean pore size 2.8 nm and 6.9 nm, respectively. The uptake of alkyl pyridinium chloride molecules have recently been measured, revealing an uptake capacity that is explained by surface adsorption (as opposed to simple pore infiltration). Kinetics of the uptake process are still be analyzed.

An Undergraduate Laboratory: The Effect of Nanoparticle Self Assembly on the Electrical and Mechanical Properties of Nanocomposites

2006 ◽  
Author(s):  
T. S. Creasy ◽  
J. C. Grunlan ◽  
R. B. Griffin
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Undergraduate Education ◽  
Self Assembly ◽  
Nanocomposite Films ◽  
Polymer Emulsion ◽  
Random Microstructure ◽  
Hands On ◽  
Undergraduate Laboratory ◽  
Scanning Electron

Recent research into the effect of nanoparticle organization on the electrical properties of nanocomposite films was used to create a hands-on laboratory for undergraduate education in nanomanufacturing. Students created two composites using solvent-based solution and polymer emulsion to show that a non-random microstructure can produce the required electrical conductivity with less added nanoparticles. Students evaluated the materials by 4-point probe and scanning electron microscopy.

Ordered mesoporous carbon in solid-phase microextraction for analysis of volatile organic compounds in water samples

2019 ◽  
Vol 11 (29) ◽  
pp. 3741-3749
Author(s):  
Bo Liu ◽  
Yaqiong Hao ◽  
Lixiao Wang ◽  
Mengyun Li ◽  
Hui Jiang
Keyword(s):  
Self Assembly ◽  
Mesoporous Carbon ◽  
Solid Phase ◽  
Dip Coating ◽  
Ordered Mesoporous Carbon ◽  
Ordered Mesoporous ◽  
Volatile Organic ◽  
Coating Method ◽  
Evaporation Induced Self Assembly ◽  
Dip Coating Method

An ordered mesoporous carbon (OMC) film supported on graphite fiber was prepared by a dip-coating method combined with a solvent evaporation induced self-assembly (EISA) strategy.

Fabrication and characterization of mesoporous borosilicate glasses with different boron contents

2007 ◽  
Vol 22 (7) ◽  
pp. 1834-1838 ◽  
Author(s):  
Tongping Xiu ◽  
Qian Liu ◽  
Jiacheng Wang
Keyword(s):  
Boric Acid ◽  
Self Assembly ◽  
Sol Gel ◽  
Sorption Isotherms ◽  
Mesoporous Structure ◽  
Borosilicate Glasses ◽  
Whole Process ◽  
Transmission Electron ◽  
Evaporation Induced Self Assembly ◽  
The Stability

A series of wormhole-like mesoporous borosilicate glasses (MBSGs) with different compositions has been prepared by a combination of surfactant templating, sol-gel methods, and evaporation-induced self-assembly processes. Small-angle x-ray diffraction, high-resolution transmission electron microscopy, and N2 sorption isotherms analysis showed that all the MBSGs prepared possess the mesoporous structure. However, the stability of the mesoporous structure is strongly affected by the boron contents. When boron content was increased, boric acid was found in the final product, and the mesoporous structure was partially degraded. The formation and loss of boric acid through the whole process may account for the partial collapse of the mesostructure.

scholarly journals Surface Modification of LiMn2O4for Lithium Batteries by Nanostructured LiFePO4Phosphate

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
B. Sadeghi ◽  
R. Sarraf-Mamoory ◽  
H. R. Shahverdi
Keyword(s):  
Electron Microscopy ◽  
Sol Gel ◽  
Dip Coating ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrochemical Tests ◽  
Transmission Electron ◽  
Coating Method ◽  
Dip Coating Method ◽  
Spinel Cathode

LiMn2O4spinel cathode materials have been successfully synthesized by solid-state reaction. Surface of these particles was modified by nanostructured LiFePO4via sol gel dip coating method. Synthesized products were characterized by thermally analyzed thermogravimetric and differential thermal analysis (TG/DTA), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDX). The results of electrochemical tests showed that the charge/discharge capacities improved and charge retention of battery enhanced. This improved electrochemical performance is caused by LiFePO4phosphate layer on surfaces of LiMn2O4cathode particles.

The Synthesis of Maghemite and Hematite (γ-Fe2O3, α-Fe2O3) Nanospheres

2007 ◽  
Vol 534-536 ◽  
pp. 157-160 ◽  
Author(s):  
M.A. Dar ◽  
S.G. Ansari ◽  
Rizwan Wahab ◽  
Young Soon Kim ◽  
Hyung Shik Shin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Iron Oxide ◽  
Pore Size ◽  
Field Emission ◽  
Sol Gel ◽  
Oxide Powder ◽  
Transmission Electron ◽  
Scanning Electron

Maghemite and hematite nanospheres were synthesized by using the Sol-gel technique. The structural properties of these nanosphere powders were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM),and pore size distribution.Hematite phase shows crystalline structures.The mean particle size that resulted from BET and XRD analyses were 4.9 nm and 2 nm. The field emission scanning electron microscopy shows iron-oxide powder is composed of nanosized particles, but in nanosized aggregates (agglomeration of particles). It can be seen from transmission electron microscopy that the size of the particles are very small which is in good agreement with the FESEM and the Xray diffraction. TEM and FESEM confirmed that the iron-oxide powder is composed of sizes from 8 nm to 10 nm. The BET and pore size method were employed for specific surface area determination.

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