scholarly journals The Electrical Conductivity of Fluoroanhydrite Compositions Modified at the Nanoscale Level with Carbon Black

2020 ◽  
Vol 24 (1) ◽  
pp. 706-717
Author(s):  
Grigory Yakovlev ◽  
Grigory Pervushin ◽  
Olga Smirnova ◽  
Ekaterina Begunova ◽  
Zarina Saidova

Abstract The electrical conductivity of fluoroanhydrite compositions modified with different amounts of ultrafine soot was studied. The optimal ratio of additive and binder was determined in terms of both electrical conductivity and compressive strength. The research results have showed that the addition of ultrafine carbon black in the amount of 7 % by the binder mass had a significant influence on the mechanical properties of the composition as well as its electrical conductivity. The strength of the samples with 7 % of ultrafine carbon black decreased up to 23.9 MPa at the age of 14 days whereas the reference sample strength was 40.1 MPa. At the same time the electrical resistance of the modified samples was 99.65 Ω at the age of 14 days whereas the electrical resistance of the reference samples reached 128.1 kΩ. The developed fluoroanhydrite composition was modified at the nanoscale level with carbon black and it can be used as material for the antistatic and grounding conductive flooring.

Author(s):  
Viola Hospodarova ◽  
Nadezda Stevulova ◽  
Vojtech Vaclavik ◽  
Tomas Dvorsky ◽  
Jaroslav Briancin

Nowadays, construction sector is focusing in developing sustainable, green and eco-friendly building materials. Natural fibre is growingly being used in composite materials. This paper provides utilization of cellulose fibres as reinforcing agent into cement composites/plasters. Provided cellulosic fibres coming from various sources as bleached wood pulp and recycled waste paper fibres. Differences between cellulosic fibres are given by their physical characterization, chemical composition and SEM micrographs. Physical and mechanical properties of fibre-cement composites with fibre contents 0.2; 0.3and 0.5% by weight of filler and binder were investigated. Reference sample without fibres was also produced. The aim of this work is to investigate the effects of cellulose fibres on the final properties (density, water absorbability, coefficient of thermal conductivity and compressive strength) of the fibrecement plasters after 28 days of hardening. Testing of plasters with varying amount of cellulose fibres (0.2, 0.3 and 0.5 wt. %) has shown that the resulting physical and mechanical properties depend on the amount, the nature and structure of the used fibres. Linear dependences of compressive strength and thermal conductivity on density for plasters with cellulosic fibres adding were observed.


Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1916 ◽  
Author(s):  
Mauro Giorcelli ◽  
Mattia Bartoli

In this work we focused our attention on an innovative use of food residual biomasses. In particular, we produced biochar from coffee waste and used it as filler in epoxy resin composites with the aim to increase their electrical properties. Electrical conductivity was studied for the biochar and biochar-based composite in function of pressure applied. The results obtained were compared with carbon black and carbon black composites. We demonstrated that, even if the coffee biochar had less conductivity compared with carbon black in powder form, it created composites with better conductivity in comparison with carbon black composites. In addition, composite mechanical properties were tested and they generally improved with respect to neat epoxy resin.


2011 ◽  
Vol 13 ◽  
pp. 27-32 ◽  
Author(s):  
Zdenĕk Jonšta ◽  
Pavel Koštial ◽  
Ivan Ružiak ◽  
Peter Jonšta ◽  
J. Jurčiová ◽  
...  

In the paper we present measurements of transport physical parameters such as thermal conductivity, diffusivity and specific heat capacity and dc electrical conductivity as well as the mechanical values E*, tg δ for rubber compounds filled by different ratio of silica - carbon black fillers. From presented results it is possible to see that proper filler concentration (rubber blend - silica - carbon black) rising all thermal parameters as well as mechanical properties represented by complex Young’s modulus and so, maintains the good mechanical parameters of the blend and finally it also lowers the electrical resistance. All trends are favourable for the improvement of useful rubber blends properties.


2011 ◽  
Vol 324 ◽  
pp. 38-41
Author(s):  
Recep Vatansever ◽  
Harun Mindivan ◽  
E.S. Kayali

In this work, the re-use of aluminum AA6061 chips and fly ash particles by solid-state processes (cryomilling, cold compaction and hot extrusion) is presented. The process was performed in following steps: comminuting of chips, cryomilling of comminuted chips, aluminum powders and fly ash particles, cold pressing-hot extrusion approach without sintering step. Comparative analysis of the recycled composites with fine and coarse granulated chips was focused on mechanical properties and correlated to microstructural features. The density and electrical conductivity of the recycled composites are lower than those of the unreinforced aluminum alloy due to the presence of fly ash particles. Regarding mechanical properties, the recycled composites with coarse granulated chips showed higher hardness and compressive strength than the recycled composites with fine granulated chips, but the compressive strength of the recycled composites with coarse granulated chips decreased with the increase of fly ash content.


Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 313 ◽  
Author(s):  
Xiaoyang Wang ◽  
Hongqiang Ru

Cu–Fe-based friction materials with flake graphite, granulated carbon black, and high-strength graphite as lubricating phase were prepared by the powder metallurgy method. The effects of different types and mass fraction of lubricating phase on the microstructure, mechanical properties, and tribological properties were investigated. The results show that when the mass fraction of granulated carbon black is 5 wt%, it is easy to form a good interface with the matrix, but the interface is prone to pores and cracks when its mass fraction is 10 wt%. The bending strength and compressive strength properties of the composites increased with increasing in the mass fraction of granulated carbon black and reached the maximum of 40 MPa and 70 MPa at 5 wt% granulated carbon black, after which bending strength and compressive strength all decreased. The friction coefficient and the wear loss of the materials initially decreased as the mass fraction of granulated carbon black increased and obtained minimum of 0.436 and 0.145 mm when the mass fraction of granulated carbon black was 5 wt%, then ascended. Compared with the sample with 5 wt% high-strength graphite as lubricating phase, the sample with 5 wt% granulated carbon black as lubricating phase had better sintering performance, mechanical properties, and tribological properties.


Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2102 ◽  
Author(s):  
Chun-Yu Chen ◽  
Szu Ying Huang ◽  
Hung-Yu Wan ◽  
Yi-Ting Chen ◽  
Sheng-Ka Yu ◽  
...  

Electronic textiles (E-textiles) have been an area of intense industrial and academic research for years due to their advanced applications. Thus, the goal of this study was to develop highly conductive silk fibroin electrochromic nanofibers for use in E-textiles. The silk nanofibers were prepared by an electrospinning technique, and the conductive polyaniline (PANI) was added to impart the electrical conductivity and electroactive property to the resultant electrospun silk composite nanofibers. The experimental results showed that tuning the electrospinning procedure could control the morphology of the composite nanofibers, thus altering their mechanical properties and surface wettability. Furthermore, the developed PANI/silk composite fibers possess electroactive and electrochromic properties, such as adjusting the applied voltage. The developed strategy demonstrated the feasibility of incorporating not only electrical functionality but also electroactivity into sustainable silk nanofibers using electrospinning technique.


2017 ◽  
Vol 134 (46) ◽  
pp. 45512 ◽  
Author(s):  
Olga Mysiukiewicz ◽  
Tomasz Sterzyński ◽  
Paweł Ławniczak ◽  
Maria Rogodzińska

2016 ◽  
Vol 722 ◽  
pp. 254-259 ◽  
Author(s):  
Jaroslav Topič ◽  
Jan Trejbal ◽  
Tomáš Plachý ◽  
Zdeněk Prošek

This article deals with utilization of recycled concrete in form of high-speed milled powder into cement based materials. Recycled concrete powder in that form is used as microfiller and cement replacement. This article contains results of mechanical properties of the cement pastes with different amount of recycled concrete powder. The mechanical properties as the compressive strength, flexural strength, dynamic Young's and share moduli are observed during 409 days. According to results can be assumed that recycled concrete powder can be used as microfiller and cement replacement under 30 wt. % of total amount. Especially the results of compressive strength are comparable with reference sample. But there are some abnormalities in long term development of the strength that need to be explained.


2014 ◽  
Vol 7 (1) ◽  
pp. 94-108
Author(s):  
Amer Hameed Majeed ◽  
Mohammed S. Hamza ◽  
Hayder Raheem Kareem

The study covers the effect of nanocarbon black particles (N220) on some important mechanical properties of epoxy reinforced with it [carbon black nanoparticles]. The nanocomposites were prepared with (1 to 10 wt. %) of carbon black nanoparticles using ultrasonic wave bath machine dispersion method. The results had shown that the tensile strength , tensile modulus of elasticity, flexural strength and impact strength are improved by (24.02%,7.93%,17.3% and 6% ) respectively at 2wt % .The compressive strength and hardness are improved by (44.4%, 12%) at 4wt%.


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