Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 38 for “"fumed silica"”.
-
Gelation Kinetics of Fumed Silica-Alcohol Suspensions
Aggregation and gelation kinetics of fumed silica were investigated by altering the solvent-surface interactions. Native and surface-modified (hydrophobic) fumed silica particles were dispersed in short-chain linear alcohols. Based on the kinetics of aggregation and gelation, it is shown that the …
-
Novel Shear-Thinning of Aged PDMS/Fumed Silica Admixtures and Properties of Related Silicone Elastomers
Fumed silica filler has long been used to structurally reinforce silicone elastomers. Unfortunately, the combination of as little as a few weight percent of untreated fumed silica nanoparticles [uFSN] with a siloxane polymer, such as PDMS, forms a difficult to process waxy solid admixture that even …
-
Geometrical and electronic structure of metal oxide nanoparticles on silica and alumina
… nanoparticles, which were tethered to fumed silica and alumina to provide surrogates for fly ash. We collected XANES and EXAFS data, which are useful for characterizing disordered mixtures where the metal is a minor component. The effect of particle size on structural properties was …
-
Viscoelastic and fracture behaviour of polyolefin based nanocomposites
… the role played by different kinds of amorphous silica (SiO2) micro and nanoparticles on the viscoelastic and fracture behaviour of LLDPE based composites, prepared through a melt compounding process. Different typologies of silica filler have been considered : hydrophilic and hydrophobic fumed …
-
Intumescent formulations incorporating melamine phosphate
… additives were tested, two successful ones being fumed silica and a solvent, isopropanol. The low percentages fumed silica used was incorporated into the sample and the viscosity and fire test results compared with a `standard sample'. An expanding graphite incorporated into a standard sample made …
-
Fundamental Importance of Fillers, Cure Condition, and Crosslink Density on Model Epoxy Properties
The influence of silane treated amorphous fumed silica fillers on properties of the cured epoxy was examined in the first part of the study. Silica particles were treated with 3- aminopropyldiethoxymethylsilane (APDS) and 3-aminopropyltriethoxysilane (APTS) coupling agents. The filler and coupling …
-
Development of novel indicators
… developed, using Reichardt's dye adsorbed onto fumed silica to identify and measure the concentration of various solvent vapours. The fumed silica films are shown to be faster in response than polymer systems and have been shown to distinguish between different solvent vapours, but do not do so …
-
The Effect of Composition on the Linear and Nonlinear Mechanical Properties of Particulate Filled Elastomers
… mechanical behavior was investigated on fumed silica filled Poly(dimethylsiloxane) rubber. For the first time, necking was observed for a lightly cross-linked poly(dimethylsiloxane) elastomer filled with 30 phr (parts per hundred rubber) or more of high surface area (≥300 m<sup>2</sup>/g) …
-
Study of the rheological properties of nomex fibrids
Paints and caulks typically contain (spherical) fumed silica particulates as viscosity enhancers. A similar viscosity enhancement can be achieved by using aramid fibrids. Aramid fibrids are believed to form microstructures in suspensions because of the "space-filling" nature of their shapes and …
-
Handling Characteristics and Colloidal Stability of an Orthodontic Sealant Containing Microcapsules
… in the continuous phase, glass loading, and fumed silica loading to show their effect on flow and stability. Low stress monomers and a low viscosity monomer was utilized in the formulations. Results demonstrated that glass loading had an effect on flow and the low viscosity monomer had an …
-
An investigation on thermal performance characteristics of hollow-core vacuum insulated panels
… of high performance insulating materials such as fumed silica VIPs.This thesis aims to develop and evaluate the performance of a conceptual prototype of hollow-core VIPs. Initial simulations of a simplied model were used to evaluate desirable values for main parameters such as emissivity and panel …
-
Flexural Strength and Fracture Toughness of Flowable Composites Containing Low Stress Monomers and Microcapsules
… phase, the amount of glass loaded, the amount of fumed silica loaded, and the inclusion of low viscosity monomers. The study confirms that these variables affect the flexural strength and fracture toughness of the formulations and suggest that there is potential for developing a low stress, BPA …
-
Adhesion of Orthodontic Cements Formulated with Microencapsulated Remineralizing Agents
… phase, the glass loading level, and the fumed silica loading level. The monomers used in the formulations were bisGMA and TEGMA in different ratios. In these formulations, the microcapsules were loaded between 5-10 w/w% (2-7 w/w% of aqueous fluoride solution, 2 w/w% of aqueous calcium …
-
Experiments and Design Considerations toward a Novel Continuous Flow Aluminum Fuel Reactor for Underwater Vehicles
… higher shear rate mixer and double the amount of fumed silica were needed to produce a homogenous non-clumping aluminum slurry. Lastly, pumping experiments, unfortunately, showed that in its current state, the fuel cannot be reliably pumped due to the settling of the aluminum inside the piping. …
-
NOVEL SOFT SURFACES WITH INTERESTING SURFACE AND BULK MORPHOLOGY
… disappearance and reappearance of untreated fumed silica nanoparticles at the PDMS near surface and their correlation with the volume fraction of siliceous phase have been studied. This research with PDMS nanocomposites has led to the development of an alternative route for improving …
-
Flexural Strength of a Pit and Fissure Sealant Containing Microcapsules
… a range of 4:1 through 1:1. Barium boroaluminosilicate glass was loaded over a range of 3-60 w/w%, fumed silica was loaded over a range of 0.1-3.0 w/w%. The potential number of formulations exploring these variables is substantial. Therefore, a range of formulations was tested that explored …
-
Effects of silica nanoparticle surface treatment and average diameter on the physical and mechanical properties of poly(dimethylsiloxane)-silica nanocomposites
… of this thesis was to quantify the effects of silica nanoparticle surface treatments and average silica nanoparticle diameter on various macroscopic properties of poly(dimethylsiloxane)-silica nanocomposites, specifically stiffness, wettability, and permeability to organic solvents. …
-
Colloidal Stability, Rheology, and Flexural Strength of Antiviral 3D Printable Colloids
… research is to determine the effect of mixing fumed silica (FS) and 5 different antiviral fillers (5 and 10 w/w%) on colloidal stability, viscosity, and flexural strength. Methods: Colloids consisting of five different antiviral fillers [BIOSAFE Glass and 4 different ion-releasing zeolites (Ag …
-
The development and characterization of aluminum fueled power systems and a liquid aluminum fuel
… by mass into a mixture of mineral oil and fumed silica. This newly developed liquid fuel can be pumped easily, stay in suspension for months, and retains full levels of reaction completion. Finally, a joint hydrogen-steam IC engine concept was presented and analyzed. This engine utilizes …
Page 1 of 2