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The Development and Characterization of Zirconia-Silica Sand Nanoparticles Composites  [PDF]
Tahir Ahmad, Othman Mamat
World Journal of Nano Science and Engineering (WJNSE) , 2011, DOI: 10.4236/wjnse.2011.11002
Abstract: The present study aims to develop zirconia-Silica sand nanoparticles composites through powder processing route and to study the physical properties, mechanical properties and microstructure of the composites. Zirconia based silica sand nanoparticles composite with 5, 10, 15 and 20 wt.% were developed through powder processing technique and sintered at 1500 ℃ for two hours. A decreasing trend of green density however an improvement in sintered density was observed. Also the addition of silica sand nanoparticles with 20 wt.% increased the hardness up to 12.45 GPa and microstructures indicated the diffusion mechanism of silica sand nanoparticles into pore sites of the composites.
The Impact Compression Behaviors of Silica Nanoparticles—Epoxy Composites  [PDF]
Pibo Ma, Gaoming Jiang, Yanyan Li, Wenxin Zhong
Journal of Textile Science and Technology (JTST) , 2015, DOI: 10.4236/jtst.2015.11001
Abstract: The compressive properties of epoxy with different silica nanoparticles (SiO2 nanoparticles) contents at quasi-static and high strain rates loading were investigated via experiment. This article evaluates the compressive failure behaviors and modes at different SiO2 nanoparticles contents and different strain rates. The results indicated that the stress strain curves were sensitive to strain rate, and the compressive failure stress of composites with various SiO2 nanoparticles contents increased with the strain rates, and it increased along with SiO2 nanoparticles contents and then declined. The compressive failure stress and the compressive failure modes of the composites were apparently different from the change of SiO2 nanoparticles contents.
Mechanical Properties and Fracture Mechanism of Epoxy Resin Improved by Adding Silica Nanoparticles

TANG Long-cheng,ZHANG Hui,ZHANG Hui,ZHANG Zhong,WU Xiao-ping,

实验力学 , 2011,
Abstract: This work focuses on the effect of highly-dispersed silica nanoparticles on toughening/reinforcing high-performance epoxy resin. It is found that the mechanical properties of epoxy nanocomposites are significantly improved with adding the silica nanoparticles. Experimental results show that the elastic modulus, the tensile strength and the fracture toughness (GIC) of epoxy resin added 14wt% silica are enhanced about 21%, 17% and 49%, respectively. Scanning electron microscope observation revealed that the presence of nanoparticles may induce resin matrix plastic deformation such as shear banding and cavity growth. Theoretical analysis further demonstrates that the matrix plastic deformation, including plastic shear banding and void growth, should be the main mechanism of fracture toughness increasing of high-performance epoxy resin improved by adding silica nanoparticles.
Effect of Silica Content on the Dielectric Properties of Epoxy/Crystalline Silica Composites  [cached]
Jae-Jun Park?
Transactions on Electrical and Electronic Materials , 2012,
Abstract: Crystalline silica was synthesized by annealing amorphous silica at 1,300℃ or 1,400℃ for various times, and thecrystallinity was estimated by X-ray diffraction (XRD) analysis. In order to prepare a low dielectric material, epoxy/crystalline silica composites were prepared, and the effect of silica content on the dielectric properties was studiedunder various functions of frequency and ambient temperature. The dielectric constant decreased with increasingcrystalline silica content in the epoxy composites, and it also decreased with increasing frequency. At 120 Hz, the valueof 5 wt% silica decreased by 0.25 compared to that of 40 wt% silica, and at 23 kHz, the value of 5 wt% silica decreasedby 0.23 compared to that of 40 wt% silica. The value increased with increasing ambient temperature.
Thermo-mechanical and Light Transmittance of Silica Diffusant Filled Epoxy Composites
Lim Wei Chin,Huong Ling Hung,Chow Wen Shyang
Journal of Physical Science , 2010,
Abstract: Epoxy ternary blends (DCN) were prepared by mixing diglycidyl ether bisphenol A (DGEBA), cycloaliphatic epoxy, and novolac epoxy. The silica diffusants were prepared by the addition of spherical silica (SS) into epoxy blends. The thermal properties of the epoxy composites were characterised using a thermo-mechanical analyser (TMA), a differential scanning calorimeter (DSC), and a dynamic mechanical analyser (DMA). It was found that the storage modulus of the epoxy was increased in the presence of SS diffusants. However, the coefficient of thermal expansion (CTE) and the glass transition temperature (Tg) of the epoxy ternary blends was reduced by the addition of SS diffusants, which was because the expansion of the epoxy matrix was constrained in the presence of silica fillers. The UV/Vis spectroscopy results demonstrated that the percentage of transmittance of epoxy was decreased by the incorporation of the silica diffusant.
Effect of Silica Particle Size on the Mechanical Properties in an Epoxy/Silica Composite for HV Insulation
Jae-Jun Park
Transactions on Electrical and Electronic Materials , 2012,
Abstract: In order to develop a high voltage insulation material, epoxy/micro-silica composites (EMC) and epoxy/micro-silica/nano-silica composites (EMNC) with three different particle sizes in μm and one particle size in nm were preparedand their tensile and flexural tests were carried out and the data was estimated by Weibull statistical analysis. Thetensile strength of the neat epoxy was 82.8 MPa and those of the EMCs were larger than that of the neat epoxy, andthey were much more advanced by the addition of 10 nm sized nano-silica to the EMCs. Flexural strength showed thesame tendency of the tensile strength. As the micro-particle size decreased, tensile and flexural strength increased.
Synergetic role of nanoparticles and micro-scale short carbon fibers on the mechanical profiles of epoxy resin
eXPRESS Polymer Letters , 2011, DOI: 10.3144/expresspolymlett.2011.85
Abstract: It was demonstrated in our previous work that the combined carbon nanofibers (CNFs) and microsized short carbon fibers (SCFs) in epoxy (EP) leads to significant improvements in the mechanical properties of the matrix. In this work, the effect of nano-SiO2 particles, having an extremely different aspect ratio from CNFs, on the tensile property and fracture toughness of SCFs-filled EP was studied. It was revealed that the combined use of SCFs and silica nanoparticles exerts a synergetic effect on the mechanical and fracture properties of EP. Application of SCFs and the nanoparticles is an effective way to greatly enhance the modulus, strength and fracture toughness of the EP simultaneously. The synergetic role of the multiscale fillers was explained by prominent changes in the stress state near the microsized fillers and the plastic zone ahead of the crack tip. The synergetic role of multiscale fillers is expected to open up new opportunities to formulate highperformance EP composites.
Effect of Silica Nanoparticles on the Curing Kinetics of Epoxy Vinyl Ester Resin  [cached]
Aghili A.,Arabli V.
Proceedings of the International Conference Nanomaterials : Applications and Properties , 2013,
Abstract: A nanocomposite was synthesized using silica nanoparticles (SN) and Epoxy Vinyl Ester Resin (VE671). Nanoparticles were dispersed in the mixture by ultrasonic equipment to prevent the agglomeration. Transmission electron microscopy (TEM) was used to investigate the dispersion of the silica nanoparticles in the mixture. Non-isothermal differential scanning calorimetry (DSC) technique was used to study the cure kinetics of VE671 resin with and without adding silica nanoparticles. The activation energy (Ea) was determined by using Kissinger and Ozawa equations. The Ea values of curing for VE671 / 4% SN system showed a decrease with respect to the neat resin. It means that there is a catalytic effect of silica nanoparticles in the cure reaction. A dynamic kinetic model was obtained to predict the degree of cure and cure rate of resin. The results showed a good agreement between the model and the experimental data for different heating rates. The char yields increased with the addition of 4% of SN to the epoxy resin and improved the polymer flame retardancy and thermal resistance at high temperatures.
H. Zuhailawati,P. Samayamutthirian,C.H. Mohd Haizu
Journal of Physical Science , 2007,
Abstract: The fabrication and testing of aluminium-silica particulate composites (Al-SiO2) have been prepared by using powder metallurgy method. Two grades of silica particulates were used, i.e. silica sand and commercial silica. Silica content in the composite was 0, 10, 20, 30 and 40 vol. %. Mixing of Al-SiO2 was performed using planetary mill for 2 hours with ball to powder weight ratio of 10:1. Powder compaction was conducted at 200 MPa pressure and sintering was performed under flowing argon gas for 5 hours at 600oC. Results showed that Vickers hardness and modulus of rupture of Al-SiO2 composite increased with the increasing of silica content phase up to 30 vol. % and finally drop when 40 vol. % of silica was incorporated. Aluminium matrix composites reinforced with silica sand showed that the mechanical properties were slightly better than composites reinforced with commercial silica, which is beneficial in reducing the material cost.
Controversial effects of fumed silica on the curing and thermomechanical properties of epoxy composites
eXPRESS Polymer Letters , 2010, DOI: 10.3144/expresspolymlett.2010.48
Abstract: The effect of fumed silica on the curing of a trimethylolpropane epoxy resin was investigated by thermal analysis methods like Differential Scanning Calorimetry (DSC), and Dynamic Mechanical Analysis (DMA). The fumed silica used here is a by-product of the silicon and ferrosilicon industry, consisting of micro and nanosized particles. Both the curing reaction and the properties of the obtained composites were affected by the filler content. Different trends were observed for filler contents above and below the 30 wt%. Up to 30 wt%, the behaviour can be explained as a predominantly agglomeration effect. For 30 wt% and higher filler contents, single particles seem to play a more important role.
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