Effect of temperature and filler volume fraction on the creep and recovery behaviour of MWCNT–COOH–reinforced polypropylene films

2020 ◽  
Author(s):  
Vivek Khare ◽  
Sudhir Kamle
Keyword(s):  
Volume Fraction ◽  
Effect Of Temperature ◽  
Creep And Recovery ◽  
Filler Volume Fraction ◽  
Polypropylene Films

scholarly journals Modelling the Molecular Permeation through Mixed-Matrix Membranes Incorporating Tubular Fillers

Membranes ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 58
Author(s):  
Ali Zamani ◽  
F. Handan Tezel ◽  
Jules Thibault
Keyword(s):  
Aspect Ratio ◽  
Relative Permeability ◽  
Polymer Matrix ◽  
Volume Fraction ◽  
Mixed Matrix Membranes ◽  
Analytical Prediction ◽  
Mixed Matrix ◽  
Permeability Ratio ◽  
Filler Volume Fraction ◽  
Matrix Membranes

Membrane-based processes are considered a promising separation method for many chemical and environmental applications such as pervaporation and gas separation. Numerous polymeric membranes have been used for these processes due to their good transport properties, ease of fabrication, and relatively low fabrication cost per unit membrane area. However, these types of membranes are suffering from the trade-off between permeability and selectivity. Mixed-matrix membranes, comprising a filler phase embedded into a polymer matrix, have emerged in an attempt to partly overcome some of the limitations of conventional polymer and inorganic membranes. Among them, membranes incorporating tubular fillers are new nanomaterials having the potential to transcend Robeson’s upper bound. Aligning nanotubes in the host polymer matrix in the permeation direction could lead to a significant improvement in membrane permeability. However, although much effort has been devoted to experimentally evaluating nanotube mixed-matrix membranes, their modelling is mostly based on early theories for mass transport in composite membranes. In this study, the effective permeability of mixed-matrix membranes with tubular fillers was estimated from the steady-state concentration profile within the membrane, calculated by solving the Fick diffusion equation numerically. Using this approach, the effects of various structural parameters, including the tubular filler volume fraction, orientation, length-to-diameter aspect ratio, and permeability ratio were assessed. Enhanced relative permeability was obtained with vertically aligned nanotubes. The relative permeability increased with the filler-polymer permeability ratio, filler volume fraction, and the length-to-diameter aspect ratio. For water-butanol separation, mixed-matrix membranes using polydimethylsiloxane with nanotubes did not lead to performance enhancement in terms of permeability and selectivity. The results were then compared with analytical prediction models such as the Maxwell, Hamilton-Crosser and Kang-Jones-Nair (KJN) models. Overall, this work presents a useful tool for understanding and designing mixed-matrix membranes with tubular fillers.

scholarly journals The Formation Mechanism and Characterization of Al-Si Master Alloys from Sodium Fluosilicate

2019 ◽  
Vol 26 (2) ◽  
pp. 185-191
Author(s):  
Gamal Mohamed Attia MAHRAN ◽  
Abdel-Nasser Mohamed OMRAN ◽  
El-Sayed Sedek ABU SEIF
Keyword(s):  
Reaction Time ◽  
Molten Aluminum ◽  
Volume Fraction ◽  
Eutectic Point ◽  
Effect Of Temperature ◽  
Primary Si ◽  
Master Alloys ◽  
Sodium Fluosilicate ◽  
Mechanism Of The Reaction

A modified Al-Si alloy containing up to 15 wt.% Si has been obtained from the reaction of sodium fluosilicate (Na2SiF6) with molten aluminum. This work attempted to estimate the mechanism of the reaction of Na2SiF6 with molten aluminum to produce Al-Si alloys. The effect of temperature, Na2SiF6/Al Wt ratio and reaction time on the formation of Al-Si alloy were investigated. The thermodynamic data, kinetic and rate of the reaction were studied. The results showed the possibility of the reaction between Na2SiF6 and molten aluminum thermodynamically, and that this reaction might be controlled chemically. The current study aims to optimize the factors that affecting the preparation of a modified Al-Si alloy from a reduction of sodium fluosilicate using molten aluminium. Temperature 950 oC, reaction time 20 – 25 min and Na2SiF6/Al Wt ratio related to the applied Si percentage. The prepared alloys could be modified due to the presence of Na2SiF6 in the used material as a source of sodium in response to modifying the produced Al-Si alloys. The microstructure by using LOM, SEM, and EDX proved that the needle-like silicon converts to fine fibrous. The volume fraction of primary Si reduces and the eutectic point moves to a higher silicon concentration. The modification improves the wear characteristics and increases the tensile and hardness.

scholarly journals Potentialities of a Laser-Induced Breakdown Spectroscopy Technique in the Study of Polymer Composites

2020 ◽  
Vol 74 (6) ◽  
pp. 655-660
Author(s):  
Sebastián Tognana ◽  
Cristian D'Angelo ◽  
Walter Salgueiro ◽  
Susana Montecinos
Keyword(s):  
Polymer Composites ◽  
Potential Application ◽  
Volume Fraction ◽  
Filler Content ◽  
Epoxy Composites ◽  
Laser Induced Breakdown Spectroscopy ◽  
Spectroscopy Technique ◽  
Breakdown Spectroscopy ◽  
Filler Volume Fraction ◽  
Laser Induced Breakdown

A laser-induced breakdown spectroscopy (LIBS) technique was used to evaluate the filler content in particulate epoxy–copper composites. A potential application for a direct and fast measurement of the filler in composites through the LIBS results is suggested using calibrated samples. The methodology used in this work makes possible the incorporation of LIBS as a quantitative technique for the study of particle metal-filled epoxy composites, providing a method to obtain a direct estimation of the filler volume fraction.

MODIFIED GUTH–GOLD EQUATION FOR CARBON BLACK–FILLED RUBBERS

2013 ◽  
Vol 86 (2) ◽  
pp. 218-232 ◽  
Author(s):  
Y. Fukahori ◽  
A. A. Hon ◽  
V. Jha ◽  
J. J. C. Busfield
Keyword(s):  
Carbon Black ◽  
Volume Fraction ◽  
Solid Particles ◽  
Carbon Particles ◽  
Filler Volume Fraction ◽  
Rigid Filler ◽  
Bound Rubber ◽  
Small Volume Fraction ◽  
Filled Rubbers ◽  
Good Agreement

ABSTRACT The modulus increase in rubbers filled with solid particles is investigated in detail here using an approach known widely as the Guth–Gold equation. The Guth–Gold equation for the modulus increase at small strains was reexamined using six different species of carbon black (Printex, super abrasion furnace, intermediate SAF, high abrasion furnace, fine thermal, and medium thermal carbon blacks) together with model experiments using steel rods and carbon nanotubes. The Guth–Gold equation is only applicable to such systems where the mutual interaction between particles is very weak and thus they behave independently of each other. In real carbon black–filled rubbers, however, carbon particles or aggregates are connected to each other to form network structures, which can even conduct electricity when the filler volume fraction exceeds the percolation threshold. In the real systems, the modulus increase due to the rigid filler deviates from the Guth–Gold equation even at a small volume fraction of the filler of 0.05–0.1, the deviation being significantly greater at higher volume fractions. The authors propose a modified Guth–Gold equation for carbon black–filled rubbers by adding a third power of the volume fraction of the blacks to the equation, which shows a good agreement with the experimental modulus increase (G/G0) for six species of carbon black–filled rubbers, where G and G0 are the modulus of the filled and unfilled rubbers, respectively; ϕeff is the effective volume fraction; and S is the Brunauer, Emmett, Teller surface area of the blacks. The modified Guth–Gold equation indicates that the specific surface volume ()3 closely relates to the bound rubber surrounding the carbon particles, and therefore this governs the reinforcing structures and the level of the reinforcement in carbon black–filled rubbers.

scholarly journals The influence of the filler volume fraction on the mechanical behaviour of thermoplastic materials

PAMM ◽  
2004 ◽  
Vol 4 (1) ◽  
pp. 223-224
Author(s):  
Thomas Kletschkowski ◽  
Uwe Schomburg ◽  
Albrecht Betram
Keyword(s):  
Mechanical Behaviour ◽  
Volume Fraction ◽  
Filler Volume Fraction

Improving the Electrical Conductivity of Composites Comprised of Short Conducting Fibers in a Nonconducting Matrix: The Addition of a Nonconducting Particulate Filler

1995 ◽  
Vol 390 ◽  
Author(s):  
Pu-Woei Chen ◽  
D. D. L. Chung
Keyword(s):  
Electrical Conductivity ◽  
Percolation Threshold ◽  
Silica Fume ◽  
Carbon Fibers ◽  
Volume Fraction ◽  
Filler Volume Fraction ◽  
Conducting Filler ◽  
Particulate Filler

ABSTRACTThe addition of a second discontinuous filler (silica fume) that is essentially nonconducting to a composite with a comparably non-conducting matrix (cement) and a conducting discontinuous filler (carbon fibers) was found to increase the electrical conductivity of the composite when the conducting filler volume fraction was less than 3.2%. The maximum conducting filler volume fraction for the second filler to be effective was only 0.5% when the second filler was sand, which was much coarser than silica fume. The improved conductivity due to the presence of the second filler is due to the improved dispersion of the conducting filler. The silica fume addition did not affect the percolation threshold, but the sand addition increased the threshold.

Characterization of Fillers in Vulcanizates According to the Einstein-Guth-Gold Equation

1990 ◽  
Vol 63 (1) ◽  
pp. 32-45 ◽  
Author(s):  
Siegfried Wolff ◽  
Jean-Baptiste Donnet
Keyword(s):  
Surface Activity ◽  
Deformation Temperature ◽  
Volume Fraction ◽  
Crosslinking Density ◽  
High Accuracy ◽  
Effectiveness Factor ◽  
Stress Strain ◽  
Filler Volume Fraction

Abstract 1. Up to now, the application of the Einstein-Guth-Gold equation seemed to be limited to inactive fillers. 2. However, in the form of Equation (6), it describes with high accuracy the moduli of vulcanizates containing active fillers as a function of the filler volume fraction at least up to ϕ=0.22 at uniaxial elongations and for any given value of λ. 3. The effectiveness factor ƒ is independent of crosslinking density, but is dependent on deformation, temperature, and the surface activity of the filler. 4. If ƒ as a function of elongation is known, the respective stress-strain curves of filled networks can be calculated in advance for any given crosslinking density. 5. The interpretation of the effectiveness factor will require further investigations, especially with regard to the influence of the structure and surface activity of the filler.

scholarly journals Performance comparison of selection nanoparticles for insulation of three core belted power cables

2020 ◽  
Vol 10 (3) ◽  
pp. 2779
Author(s):  
Ahmed Thabet ◽  
Youssef Mobarak ◽  
Nourhan Salem ◽  
A. M. El-noby
Keyword(s):  
Electric Field ◽  
Field Distribution ◽  
Electric Field Distribution ◽  
Volume Fraction ◽  
Polymeric Materials ◽  
Performance Comparison ◽  
Effective Dielectric Constant ◽  
Power Cables ◽  
Filler Volume Fraction ◽  
Dielectric Performance

This paper presents an investigation on the enhancement of electrical insulations of power cables materials using a new multi-nanoparticles technique. It has been studied the effect of adding specified types and concentrations of nanoparticles to polymeric materials such as PVC for controlling on electric and dielectric performance. Prediction of effective dielectric constant has been done for the new nanocomposites based on Interphase Power Law (IPL) model. The multi-nanoparticles technique has been succeeded for enhancing electric and dielectric performance of power cables insulation compared with adding individual nanoparticles. Finally, it has been investigated on electric field distribution in the new proposed modern insulations for three-phase core belted power cables. This research has focused on studying development of PVC nanocomposite materials performance with electric field distribution superior to the unfilled matrix, and has stressed particularly the effect of filler volume fraction on the electric field distribution.

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