Generalized Synthesis of Highly-Dispersed, Ultrafine Transition Metal Nanoparticles on Silica Spheres for Enhanced Optical Absorption. Qilin Wei, Qilin Wei. Department of Chemistry, Temple University, 1901 North 13th Street, Philadelphia, PA, 19122 USA. Search for more papers by this author.

Abstract Silica micro spheres could be obtained through a semibatch sol–gel process, which was carried out by adding a solution of tetraethyl orthosilicate in ethanol into a mixture batch of KCl, ethanol, NH3•H2O, and water. Compared with other methods the semibatch sol–gel method could produce micro size silica spheres with …

DOI: 10.1016/J.GEOMORPH.2012.09.011 Corpus ID: 33179361; Aeolian microtextures in silica spheres induced in a wind tunnel experiment: Comparison with aeolian quartz @article{Costa2013AeolianMI, title={Aeolian microtextures in silica spheres induced in a wind tunnel experiment: Comparison with aeolian quartz}, author={Pedro J. M. Costa …

Silicon spheres have been the subject of recent investigations in a broad range of fields spanning mechanics 1, biotechnology 2, photonics 3 and green energy 4.A variety of bottom-up 5,6,7 and top ...

This article reports the synthesis of mesoporous silica nano-spheres with radially oriented mesopores using an anionic surfactant as the template. The nano-spheres have pore sizes larger than 3 nm and exhibit high surface area and pore volume. The article also discusses the formation mechanism and the potential applications of …

Fig. 3 shows UV–vis absorption spectra of the SiO 2 @Sn 2+, the SiO 2 @Ag, and the SiO 2 @Au spheres fabricated at different Au concentrations. All the spheres revealed monotonously tailed spectra due to scattering of the silica spheres. The spectrum of the SiO 2 @Sn 2+ was the same as that of the SiO 2 spheres. For the SiO …

Abstract. Spherical and rod-like silica particles were used as cores to deposit shells of silver nanoparticles. Prior silver deposition the siliceous cores were modified with 3-aminopropyltrimetoxysilane to facilitate Ag deposition on the surface of silica particles. The process of Ag deposition was carried out in two consecutive steps: first ...

Recall that for terminal settling, the drag on the sphere is equal to its net weight, which is the weight minus the buoyant force on the sphere. We define the Reynolds number in the same way as before, but with the understanding that it now applies with V = V . A new dimensionless group N = C. D Re 2 is introduced in. terminal D.

Despite their structural complexity and ease of fabrication, only a little is known to date on the thermal conductivity of ensembles of hollow silica spheres. 27–30 Previous studies showed indeed the low thermal conductivity of hollow silica powders in the range from 20 to 33 mW m −1 K −1. However, using the transient hot disk, the ...

A simple one-step procedure is described for the synthesis of spherical mesoporous silica, in which the size of the particles is controlled over a range of diameters from 65 to 740 nm by varying the initial silicate/surfactant concentration under dilute conditions. The particles were characterized using X-ray diffraction, transmission …

The minimum fluidization velocity was thus decreased when conducting the experiment with the binary and ternary biomass-silica sand mixtures. The obtained minimum fluidization velocity range was 0 ...

Silica sand with diameter range of 0.1–0.5 mm was typically used in fluidized bed boiler as inert solid ... The equivalent diameter is the sphere diameter that has equaled volume to the surface area ratio of actual particle. ... This study investigated the minimum fluidization velocities of binary and ternary biomass mixture with silica sand ...

velocities of the actual grain of interest. Some workers [e.g., Gibbs et al., 1971] have proposed reporting settling velocities in terms of a 'sedimentation diameter' where the latter is defined as the diameter of a sphere of the same specific gravity and the same terminal uniform settling velocity as the given particle in

The mechanism by which monodisperse silica spheres precipitate during the base catalyzed hydrolysis of tetraethyl orthosilicate is explored. From a knowledge of the equilibrium solubility of silica in the parent liquor and the change of particle size with time, it is established that nucleation continues for a substantial fraction (gt; 2/3) of the total …

A novel synthesis protocol for fabrication of micron-sized multi-compartmentalized mesoporous silica spheres is developed, which is exemplified by successful synthesis of a family of unprecedented ...

This paper exhibits good example of high well-defined hollow silica spheres by using a low-cost sodium silicate precursor via a facile method. The N2 adsorption isotherm shows that this hollow structure leads to a high Brunauer–Emmett–Teller specific area of ca. 217.755 m2 g−1. Transmission electron microscopy and scanning electron …

Silica spheres and TH-silica spheres were separately added to 1 mL of suspension of bacteria: E. coli or S. aureus (10 7 CFU/mL) and incubated at 37 °C for 12 h and 24 h. The optical density (OD) of the suspension of bacteria incubated with both types of samples was quantified at the wavelength of 595 nm by means of a micro-plate …

Slip flow occurs in colloidal crystals made of 470 nm silica spheres that are chemically modified with hydrocarbon, giving enhanced volume flow rates and a narrower distribution of fluid velocities.

The XRD patterns for the pure carbon spheres, carbon sphere-silica composites and hollow silica spheres are showed in Fig. 5.In curve a, two peaks located at 25.0° and 43.6° were observed, which can be indexed to typical graphitic (0 0 2) and (1 0 0) planes, respectively [32].In curve b, there is one broaden peak located at about 23.6°, …

Abstract. We report, for the first time, a vapor-phase synthesis of nearly monodispersed silica spheres 250–300nm in size through a two-stage hydrolysis of SiCl4. In the first stage, SiCl4 vapor ...

Silica spheres can be synthesized under both acidic and basic conditions. Various templating approaches have been adopted to synthesize the porous materials. Silica spheres provide large specific area and uniformity, and hence, these are used as a catalyst, adsorbent, and host materials. These spheres have large.

mesoporous silica spheres. The synthesis and study of mesoporous silica materials with unique and advantageous properties, such as highly ... particles [25,26], but with reduced longitudinal (LA) and transverse (TA) sound velocities s L and s T, respectively [27-30]. However the elastic modulus and Poisson's ratio for the MSMSPs depend on the ...

Core−shell structured dual-mesoporous silica spheres (DMSS) that possess smaller pores (2.0 nm) in the shell and larger tunable pores (12.8−18.5 nm) in the core have been successfully synthesized by utilizing an amphiphilic block copolymer (polystyrene-b-poly (acrylic acid), PS-b-PAA) and cetyl trimethyl ammonium bromide …

A novel covalent triazine-based framework (CTF)-grafted phenyl-functionalized fibrous silica nanosphere, KCC-1 (named as RS-2) was synthesized via a simple and effective Friedel-Crafts approach. The microporous CTF with fluorene backbone was coupled and grown uniformly on the surface of phenyl-functionalized KCC-1 to …

In this work, we investigate the catalytic properties of silver nanoparticles supported on silica spheres. The technique to support silver particles on silica spheres effectively avoids flocculation of nanosized colloidal metal particles during a catalytic process in the solution, which allows one to carry out the successful catalytic reduction …

The silica gel method involves using a silica gel precursor, such as sodium silicate, and a mineralizer, such as sodium hydroxide, to create a gel-like solution. This solution is then heated and slowly cooled, similar to the Stober method, to form opal-like particles. These particles can be harvested and used to create synthetic opal.

The mesoporous silica spheres were characterized by field emission scanning electron microscopy and Brunauer–Emmett–Teller surface area analysis. Many uniform and mesoporous silica spheres were obtained with a ChCl–1,2-butanediol DES as a reactant. The DES-modified mesoporous silica spheres were used for the adsorption …

FT-IR spectra analysis. The chemical structures of hollow silica spheres and PS/SiO 2 core–shell spheres using TEOS (a, b) and TEOS/VTES (c, d) as silica precursors were characterized by FT-IR as shown in Fig. 2.In the FT-IR spectra of PS/SiO 2 core–shell spheres (b, d), the absorption peaks at 1493, 1451, 754, and 698 cm −1 are …

The monodisperse spherical colloids of hybrid silica were synthesized by using a sol–gel reaction in aqueous solution. In a typical procedure for the preparation of hybrid silica spheres, 3 mL VTES was added in 50 mL H 2 O under vigorous magnetic stirring (300 rpm) for ∼2 h. Then the organic droplets were completely dissolved and a …

For a typical coarse sand with a Powers roundness of 3.5 and a Corey shape factor of 0.7, the settling velocity is about 0.68 that of a sphere of the same D *, with shape and roundness effects contributing about equally to the settling velocity reduction