Papers by Keyword: Nano-Filler

Abstract: Dental resin composite cements were prepared with simply mixing method of Part A and Part B. The material components in Part A were composed of Bis-GMA, TEDGMA, 4-META, SiO₂ nanopowders and BPO. The components in Part B were Bis-GMA, TEDGMA, 4-META, SiO₂ nanopowders and 2,2¢-(4-methylphenylimino) diethanol. Before using SiO₂ nano-filler in the formulation of Part A and Part B, it had to be coated with methacryloxypropyltrimethoxysilane (MPS) which served as a silane coupling agent. Therefore, the optimum amount of MPS (1, 1.2, 1.5 and 2%) and SiO₂ nano-filler (20, 27.27 and 33.33 wt%) used to fabricate the composites were investigated. The homogeneous mixture of Part A and Part B at mass fraction of 1:1 was formed into the bar shape with dimension of 25 mm x 2.0 mm x 2.0 mm and then cured under light source for 20 s. Then flexural strength was measured using the universal testing machine. Depth of cure was tested using mould which was perforated in cylindrical shape of 6 mm in depth and of 4 mm in diameter. The result showed that composite with 27.27 wt% of salinized SiO₂ nanopowders by 1.5% of MPS showed the highest flexural strength of 65 MPa and depth of cure of more than 5 mm which were accepted according to ISO 4049. This study could be concluded that using a proper amount of MPS to silanize SiO₂ nanopowders and using an optimum amount of SiO₂ nanopowders significantly improved the flexural strength of dental resin composite cements.

Abstract: The dynamic mechanical properties of the blends of polyacrylic ester and various nano-fillers and the effect of nano-filler on the damping properties of polyacrylic ester damping paint were studied by using dynamic mechanical analysis (DMA) in this paper. The experiment results showed that the glass-transition temperature (Tg), loss factor peak value and effective damping temperature range for the polyacrylic ester damping paint changed correspondingly after blended with various nano-fillers. The damping properties and effective damping temperature range of the polyacrylic ester damping paint would be improved effectively by adding nano-polyacrylic ester rubber filler; the nano-silicon dioxide could enhance the damping properties for the polyacrylic ester damping paint, but the degree of improvement for effective damping temperature range was inferior to nano-polyacrylic ester rubber filler; and the nano-calcium carbonate could also improve the damping properties of the damping paint, but the effective damping temperature range was hardly improved.

Abstract: The solid particle erosion behavior of the body materials used in high-speed moving equipments has attracted widely attention from researchers. In order to enhance the erosion resistance of existing FRP materials and to develop new FRP materials with high strength and excellent erosion resistance, we attempted to use VGCF (vapor-grown carbon fiber) with high strength and high modulus as filler for reinforcing UP resin matrix. In this study, VGCFs were treated by UV ozone treatment for improving the interface adhesion, and the effects of the filler weight content, impact angle and impact velocity upon the erosion wear behavior of UP resin composite materials have been carried out. The mechanical properties of composites materials reinforced by VGCF were also evaluated. The results indicate that it is feasible to improve the erosion resistance and flexural properties of UP resin by VGCF filler simultaneously.

Abstract: This paper highlights a systematic investigation (related to percentage addition of solvents) of finding the appropriate solvent to reduce the viscosity of the structural grade of resin (AV138M) within castable range to effectively disperse the nanofillers (Carbon Nano Powder - CNP and Multi Walled Carbon Nano Tubes - MWCNT). AV138M + HY998/CNP and AV138 + HY998/MWCNT were cast within-process degassing using a vacuum pump of capacity 4 torr. High energy sonic waves (27kHz) were used for dispersion. Morphological studies were undertaken to analyze the uniformity in dispersion of nano fillers. The cured specimens were subjected to: Resistivity measurements using a Resistivity Meter, Glass Transition Temperature (Tg) using a Differential Scanning Calorimetry (DSC) and Tensile properties using UTM. The properties have been determined for the nanocomposites with different wt % of the fillers. It has been found that for 0.6 wt % of filler (CNP / MWCNT), there is an increase in UTS of 10 times for MWCNT compared to CNP; for 1.0 wt % of the fillers, the Tg improved by 10 °C for MWCNT and by 4 °C for CNP when compared with neat resin. Both CNP and MWCNT showed drop in electrical resistivity of the neat resin; a drop to the extent of 10 3 has been achieved with 1 wt % MWCNT and the same was 2 wt % in case of CNP.

Abstract: The paper presents results of investigation of the influence of copper nanoparticles (of mean diameter 66 nm and mass share – 3.5%) on erosive wear of acrylic coatings. It was demonstrated that addition of copper nanoparticles increased the erosive wear resistance of modified coatings in the range from 25% for impact angle of α = 30° to 65% for α = 75° on the average.

Abstract: . Generally rubber products are a typical soft material, and a composite of a nano-filler (typically, carbon black or particulate silica) and a rubber (natural rubber and various synthetics are used). The properties of these soft nano-composites have been well known to depend on the dispersion of the nano-filler in the rubbery matrix. The most powerful tool for the elucidation of it has been transmission electron microscopy (TEM). The microscopic techniques are based on the projection of 3-dimensional (3D) body on a plane (x, y plane), thus the structural information along the thickness (z axis) direction of the sample is difficult to obtain. This paper describes our recent results on the dispersion of carbon black (CB) and particulate silica in natural rubber (NR) matrix observed by TEM combined with electron tomography (3D-TEM) technique, which enabled us to obtain images of 3D nano-structure of the sample. Thus, 3D images of CB and silica in NR matrix are visualized and analyzed in this communication. These results are precious ones for the design of soft nano-composites, and the technique will become an indispensable one in nanotechnology.