Comparison of dielectric properties of polydimethylsiloxane (PDMS) grafted polyacrylates/nano alumina and nano silica composites

2016 ◽  
Author(s):  
Vrishali V. Murudkar ◽  
Amita A. Gaonkar ◽  
V. D. Deshpande ◽  
S. T. Mhaske
Keyword(s):  
Dielectric Properties ◽  
Nano Silica ◽  
Nano Alumina

scholarly journals Characterization of Polypropylene Modified by Blending Elastomer and Nano-Silica

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1321 ◽  
Author(s):  
Xiaohong Chi ◽  
Lu Cheng ◽  
Wenfeng Liu ◽  
Xiaohong Zhang ◽  
Shengtao Li
Keyword(s):  
Dielectric Properties ◽  
Space Charge ◽  
Power Transmission ◽  
Breakdown Strength ◽  
Tensile Tests ◽  
Mechanical Analysis ◽  
Insulation Material ◽  
Nano Silica ◽  
Scanning Calorimetry ◽  
High Voltage Direct Current

Polypropylene (PP) contains promising application prospects in thermoplastic cables for high voltage direct current (HVDC) power transmission because of its outstanding thermal and dielectric properties. However, the problem of poor toughness and space charge has restricted the application of pure PP in HVDC cables. In this paper, polyolefin elastomer (POE) and nano-silica were blended thoroughly and added into a PP mixture by a melting method. Scanning electron microscopy (SEM) was employed to observe the dispersion of POE and nanoparticles. Thermal properties were characterized by differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). Mechanical properties were evaluated by tensile tests. The elastomeric properties of composites were improved as the dispersed POE could transfer and homogenize external mechanical forces. DC breakdown results showed that the fail strength of composite with 10 phr POE and 1 phr nano-silica was obviously enhanced. The pulsed electro-acoustic (PEA) results showed that the injection and accumulation of space charge was increased by the introduction of POE, while it was restrained by the collective effect caused by nano-silica filling. X-ray diffraction (XRD) spectrograms showed that secondary ordered structures existed in the composites of PP, POE, and nano-silica, and that the ordered structure around the nanoparticles contributed to the enhancement of breakdown strength. The mechanical and dielectric properties were modified synergistically, which made the modified PP a propitious insulation material for HVDC cables.

Influence of nano-silica and nano-alumina in lime-pozzolan and lime-metakaolin binders

2017 ◽  
Vol 4 (7) ◽  
pp. 6908-6922 ◽  
Author(s):  
Maria Stefanidou ◽  
Eirini- Chrysanthi Tsardaka ◽  
Eleni Pavlidou
Keyword(s):  
Nano Silica ◽  
Nano Alumina

scholarly journals Elevated Temperature Effects on the Properties of Self Compacting Mortar Containing Nano Materials and Zircon Sand

2021 ◽  
Author(s):  
Sahaya Ruben ◽  
Raja MA ◽  
SOPHIA M
Keyword(s):  
Elevated Temperatures ◽  
Research Work ◽  
Nano Particles ◽  
Nano Materials ◽  
Nano Silica ◽  
Positive Effects ◽  
Nano Alumina ◽  
Negative Effect ◽  
Combined Action ◽  
Zircon Sand

Abstract The present research work tries to assess the performance of self compacting mortar containing zircon sand as substitute for river aggregate in combination with nano alumina and nano silica as additive for cement. The fresh state results as observed through slump cone and mini V funnel showed positive effects of zircon sand balancing the negative effect of nano particles addition on workability. The mechanical properties, durability and microstructure of the mortar were assessed by conducting experiments at normal temperature and after subjecting to temperatures of 2000C, 4000C, 6000C and 8000C. The results indicate that addition of nano alumina and nano silica contributed towards the mechanical strength enhancement at elevated temperatures in combination with zircon sand which is a very good refractory material. The durability of the self compacting mortar at elevated temperatures enhanced due to the combined action of nano materials and zircon sand which is evident through microstructure analysis.

scholarly journals Effect of Nano-Additives on the Strength and Durability Characteristics of Marl

Minerals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1119
Author(s):  
Mehdi Mirzababaei ◽  
Jafar Karimiazar ◽  
Ebrahim Sharifi Teshnizi ◽  
Reza Arjmandzadeh ◽  
Sayed Hessam Bahmani
Keyword(s):  
Bearing Capacity ◽  
Carbon Dioxide Emissions ◽  
Soil Stabilization ◽  
Nano Silica ◽  
High Carbon ◽  
Volume Changes ◽  
Nano Alumina ◽  
Nano Additives ◽  
Strength And Durability ◽  
High Carbon Dioxide

Low bearing capacity soils may pose serious construction concerns such as reduced bearing capacity and excessive hydro-associated volume changes. Proper soil remediation techniques must be planned and implemented before commencing any construction on low bearing capacity soils. Environmentally friendly soil stabilizers are gradually replacing traditional soil stabilizers with high carbon dioxide emissions such as lime and cement. This study investigated the use of an alternative pozzolanic mix of nano-additives (i.e., nano-silica and nano-alumina) and cement to reduce the usage of cement for achieving competent soil stabilization outcomes. A series of unconfined compressive strength (UCS), direct shear, and durability tests were conducted on marl specimens cured for 1, 7, and 28 days stabilized with nano-additives (0.1~1.5%), 3% cement, and combined 3% cement and nano-additives. The UCS and shear strength of stabilized marl increased with nano-additives up to a threshold nano-additive content of 1% which was further intensified with curing time. Nano-additive treated cemented marl specimens showed long durability under the water, while the cemented marl decomposed early. The microfabric inspection of stabilized marl specimens showed significant growth of calcium silicate hydrate (CSH) products within the micro fabric of nano-silica treated marl with reduced pore-spaces within aggregated particles. The results confirmed that nano-additives can replace cement partially to achieve multi-fold improvement in the strength characteristics of the marl.

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