scholarly journals Titanium Dioxide Nanofibers and Microparticles Containing Nickel Nanoparticles

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Faheem A. Sheikh ◽  
Javier Macossay ◽  
Muzafar A. Kanjwal ◽  
Abdalla Abdal-hay ◽  
Mudasir A. Tantry ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Production Systems ◽  
Sol Gel ◽  
Titanium Isopropoxide ◽  
Electrospinning Process ◽  
Internal Morphology ◽  
Hydrolysis Of ◽  
Potential Use ◽  
Sem Analyses

The present study reports on the introduction of various nanocatalysts containing nickel (Ni) nanoparticles (NPs) embedded within TiO2 nanofibers and TiO2 microparticles. Typically, a sol-gel consisting of titanium isopropoxide and Ni NPs was prepared to produce TiO2 nanofibers by the electrospinning process. Similarly, TiO2 microparticles containing Ni were prepared using a sol-gel syntheses process. The resultant structures were studied by SEM analyses, which confirmed well-obtained nanofibers and microparticles. Further, the XRD results demonstrated the crystalline feature of both TiO2 and Ni in the obtained composites. Internal morphology of prepared nanofibers and microparticles containing Ni NPs was characterized by TEM, which demonstrated characteristic structures with good dispersion of Ni NPs. In addition, the prepared structures were studied as a model for hydrogen production applications. The catalytic activity of the prepared materials was studied by in situ hydrolysis of NaBH4, which indicated that the nanofibers containing Ni NPs can lead to produce higher amounts of hydrogen when compared to other microparticles, also reported in this paper. Overall, these results confirm the potential use of these materials in hydrogen production systems.

scholarly journals 1D TiO2 Nanostructures Prepared from Seeds Presenting Tailored TiO2 Crystalline Phases and Their Photocatalytic Activity for Escherichia coli in Water

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Julieta Cabrera ◽  
Dwight Acosta ◽  
Alcides López ◽  
Roberto J. Candal ◽  
Claudia Marchi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Photocatalytic Activity ◽  
Bactericidal Activity ◽  
Sol Gel ◽  
Titanium Isopropoxide ◽  
E Coli ◽  
1D Nanostructures ◽  
Sol Gel Synthesis ◽  
Hydrolysis Of ◽  
Tio2 Nanostructures

TiO2 nanotubes were synthesized by alkaline hydrothermal treatment of TiO2 nanoparticles with a controlled proportion of anatase and rutile. Tailoring of TiO2 phases was achieved by adjusting the pH and type of acid used in the hydrolysis of titanium isopropoxide (first step in the sol-gel synthesis). The anatase proportion in the precursor nanoparticles was in the 3–100% range. Tube-like nanostructures were obtained with an anatase percentage of 18 or higher while flake-like shapes were obtained when rutile was dominant in the seed. After annealing at 400°C for 2 h, a fraction of nanotubes was conserved in all the samples but, depending on the anatase/rutile ratio in the starting material, spherical and rod-shaped structures were also observed. The photocatalytic activity of 1D nanostructures was evaluated by measuring the deactivation of E. coli in stirred water in the dark and under UV-A/B irradiation. Results show that in addition to the bactericidal activity of TiO2 under UV-A illumination, under dark conditions, the decrease in bacteria viability is ascribed to mechanical stress due to stirring.

Structurally Composite Membranes of Titanium Oxide and Titanium Phosphorus Oxide for Proton Conduction at Intermediate Temperatures

2002 ◽  
Vol 752 ◽  
Author(s):  
Toshinori Tsuru ◽  
Yasuhito Yagi ◽  
Yosuke Kinoshita ◽  
Tomohisa Yoshioka ◽  
Masashi Asada
Keyword(s):  
Titanium Oxide ◽  
Sol Gel ◽  
Composite Membranes ◽  
Titanium Isopropoxide ◽  
Porous Titanium ◽  
Phosphorus Oxide ◽  
Conductive Membranes ◽  
Electrical Conductivities ◽  
Hydrolysis Of ◽  
Porous Titanium Oxide

ABSTRACTComposite membranes of titanium oxide and phosphorus oxide (TiP) were prepared by the sol-gel method and evaluated for use as proton conductive materials at intermediate temperatures. Titanium phosphorus oxide sol solutions were prepared by the hydrolysis of titanium isopropoxide (TTIP) using hydrochloric acid as a catalyst in isopropanol solutions, and the addition of an appropriate amount of phosphoric acid (H3PO4). A new concept for structurally composite membranes is proposed for proton conductive membranes. A composite membrane, Ti/TiP, where the pores of a porous titanium oxide layer are filled with titanium phosphorus oxide, was found to be effective for high electrical conductivity as well as mechanical strength. Electrical conductivities as high as 0.1 and 0.06 S cm−1 at 100 and 300 °C, respectively, under a partial pressure of water of 50 kPa, was achieved for the Ti/ TiP membranes.

Synthesis of a Silica Material with Surface Macroporous Arrays by a Template Method

2010 ◽  
Vol 129-131 ◽  
pp. 636-639
Author(s):  
Qing Zhong Guo ◽  
Bo Mei ◽  
Ying Wen Xue ◽  
Li Ang Li ◽  
Jiang Yu Wu ◽  
...  
Keyword(s):  
Sol Gel ◽  
Template Method ◽  
Polystyrene Spheres ◽  
Microporous Silica ◽  
Aligned Arrays ◽  
Silica Material ◽  
Internal Structures ◽  
Gel Technique ◽  
Hydrolysis Of

Materials with defined porous structures have drawn considerate attention for decades. Most of these materials display similar porous structure within the entity. Sometimes materials with different surface and internal structures would be appreciated. In the present study, a microporous silica material with surface macroporous arrays was prepared by a sol-gel technique combined with a template method. The sol was prepared via hydrolysis of tetraethoxylsilane by hydrochloric acid. To this sol, monodispersed, hydrophobic polystyrene spheres were added. By ultrasonication, the spheres floated and assembled to regular arrays on the aqueous sol surface. At low temperature, the sol was gradually gelated, which froze the spheres in-situ. By washing with toluene, the polystyrene spheres were dissolved, leaving aligned arrays on the surface of the gel. The macropores can be easily controlled by selecting particles with suitable sizes. The material would find application in catalysis, sensor and adsorption.

Structure and Surface Properties of Anatase TiO2 Thin Film by Sol-Gel Technique

2006 ◽  
Vol 517 ◽  
pp. 165-172 ◽  
Author(s):  
N. Al-Jufairi
Keyword(s):  
Thin Film ◽  
Surface Properties ◽  
Anatase Phase ◽  
Sol Gel ◽  
Film Surface ◽  
Titanium Isopropoxide ◽  
Tio2 Thin Films ◽  
Coating Films ◽  
Gel Technique ◽  
Hydrolysis Of

TiO2 coating films of 50-200nm thickness were prepared by the sol-gel technique using hydrolysis of titanium isopropoxide (TIP) in an attempt to study structure and surface properties of anatase at ambient temperature. The anatase phase is exhibited by the XRD peak at 2θ'=25o with orientation in (101), the crystal parameters of XRD for TiO2 thin films (50-200 nm), were varied depending on the thickness of film and substrate type. An annealing temperature and annealing time had an effect on the film surface quality and exhibit porosity and aggregates in the films. The surface of TiO2 thin film showed cluster particles through SEM and the shrinkage rate on the film increased as a result of heat treatment during annealing process. The film was uniform and homogeneous under AFM investigate. EDS have determined the stochiometric ratio of TiO2 film.

Nmr Imaging of Silica-Silicone Composites

1989 ◽  
Vol 171 ◽  
Author(s):  
Leoncio Garrido ◽  
Jerome L. Ackerman ◽  
James E. Mark
Keyword(s):  
Imaging Techniques ◽  
Spin Echo ◽  
Sol Gel ◽  
Relaxation Times ◽  
Reaction Times ◽  
Silica Glasses ◽  
Spin Lattice ◽  
H Nmr ◽  
Hydrolysis Of

ABSTRACTPolydimethylsiloxane (PDMS) model networks reinforced by in situ precipitated SiO2, and polymer-modified silica glasses were obtained following the usual sol-gel methods. The conditions were chosen to increase the probability of observing inhomogeneities: (i) bulky samples, and (ii) limited reaction times. These composites were characterized by measuring bulk spin-lattice (T1) and spin-spin (T2) relaxation times and using 1H NMR two-dimensional Fourier transform (2DFT) spin echo imaging techniques. The T1 and T2 maps show clear and significant variations of NMR signal intensity throughout the sample due to nonuniform hydrolysis of the tetraethylorthosilicate (TEOS) in the specimens.

Hydrophilic modification of polyvinyl chloride hollow fiber membranes by silica with a weak in situ sol–gel method

RSC Advances ◽  
2015 ◽  
Vol 5 (18) ◽  
pp. 13733-13742 ◽  
Author(s):  
Hai-Peng Xu ◽  
Yan-Hong Yu ◽  
Wan-Zhong Lang ◽  
Xi Yan ◽  
Ya-Jun Guo
Keyword(s):  
Polyvinyl Chloride ◽  
Hollow Fiber ◽  
Sol Gel ◽  
Hollow Fiber Membranes ◽  
Gel Method ◽  
Sol Gel Method ◽  
Hydrophilic Modification ◽  
Fiber Membranes ◽  
Hydrolysis Of

A weak in situ sol–gel method is proposed for the hydrophilic modification of polyvinyl chloride (PVC) hollow fiber membranes by silica, which is generated by the soft hydrolysis of tetraethoxysilane (TEOS) in a deionized water bath.

scholarly journals Synthesis of TiO2/SnO2 core shell nanocomposite via sol-gel method

2012 ◽  
Vol 05 ◽  
pp. 251-256 ◽  
Author(s):  
SORAIA KHOBY-SHENDY ◽  
MOHAMMAD REZA VAEZI ◽  
TORAJ EBADZADEH
Keyword(s):  
Sol Gel ◽  
Titanium Isopropoxide ◽  
Core Shell ◽  
Hydrothermal Processing ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Core ◽  
Transmission Electron ◽  
Diffraction Peaks ◽  
Hydrolysis Of

The particles of TiO 2 core/ SnO 2 shell nanocomposite were prepared by hydrolysis of SnCl 4.5 H 2 O in the presence of titania nanoparticle after drying and calcinations treatments. TiO 2 particle were produced from titanium isopropoxide sol by hydrothermal processing. X-ray diffraction (XRD), Fourier transformed infrared (FTIR), and transmission electron microscopy (TEM) were used to characterize the TiO 2/ SnO 2 core shell nanocomposites. The obtained results from XRD show that the SnO 2 nanoparticles coated on TiO 2 yields diffraction peaks correspond to the crystalline SnO 2 phase. Also, TEM results show that the nanocomposite particles have a spherical morphology and a narrow size distribution. The thickness of SnO 2 shell on the surface of TiO 2 particles were about 8 nm. Moreover, the results obtained from EDX analysis show that the core-shell structured nanocomposites have crystalline structure.

Particle Growth and Development During the In-Situ Precipitation of Silica in a Polymeric Matrix

1990 ◽  
Vol 180 ◽  
Author(s):  
Ping Xu ◽  
Shuhong Wang ◽  
James E. Mark
Keyword(s):  
Sol Gel ◽  
Particle Growth ◽  
Isolation Technique ◽  
Additional Information ◽  
Elastomeric Matrix ◽  
Transmission Electron ◽  
Elastomeric Materials ◽  
Equilibrium Amount ◽  
Hydrolysis Of

ABSTRACTThe hydrolysis of tetraethoxysilane much used in the sol-gel approach to ceramics can be studied in a matrix isolation technique in which the silica thus formed precipitates within a polymeric material. This technique was applied here in the in-situ precipitation of silica particles in an elastomeric matrix of poly(dimethylsiloxane). Transmission electron microscopy and mechanical property measurements were carried out as a function of time over a period of 60 days. The equilibrium amount of silica precipitated was obtained relatively quickly, after approximately one day, but reorganization of the particles continued for several days thereafter. This “aging” process resulted in particles that are better defined and more uniform in size, but their ability to reinforce the elastomeric materials was only marginally increased. Scattering techniques are also being used to obtain additional information on this interesting process.

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