scholarly journals Composite Materials for Passive Antiradar Camouflage

2019 ◽  
Vol 57 (2) ◽  
pp. 15-22
Author(s):  
Cristiana Epure ◽  
Teodora Zecheru ◽  
Gabriel Epure ◽  
Claudiu Lazaroaie ◽  
Ovidiu Iorga ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Composite Materials ◽  
Composite Structure ◽  
Experimental Device ◽  
Active Charcoal ◽  
Powder Materials ◽  
Frequency Range ◽  
Polymeric Matrices ◽  
Aluminum Trioxide ◽  
Polymeric Structures

In this study, a new solution for the development of an antiradar camouflage by overlaying several mono-pigment polymeric structures in a composite structure is provided. In this respect, powder materials with antiradar properties (carbon nanotubes, graphite, active charcoal, aluminum trioxide) were embedded in polymeric matrices. The performances of the developed products were tested using an experimental device for the measurement of electromagnetic efficiency within the frequency range from 1 to 18 GHz.

scholarly journals Влияние методов формирования полимерных композитных материалов с углеродными нанотрубками на механизмы электропроводности

2021 ◽  
Vol 91 (3) ◽  
pp. 475
Author(s):  
Ф.Ф. Комаров ◽  
И.Д. Парфимович ◽  
А.Г. Ткачев ◽  
А.В. Щегольков ◽  
О.В. Мильчанин ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Composite Materials ◽  
Treatment Method ◽  
Filler Concentration ◽  
Electric Transport ◽  
Frequency Range ◽  
Nanostructured Polymer ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

The influence of the method of formation of nanostructured polymer composites filled with carbon nanotubes to their electrophysical properties was carried out. The influence of the «size effect» of multi-walled carbon nanotubes, functionalization method, and ultrasonic treatment method on the electrical conductivity of composite materials in the frequency range 50 Hz - 5 MHz and the temperature range 15 - 375 K has been established. The presence of various mechanisms of electric transport in composite materials that affect the final value of electrical conductivity is established. The best results of electrophysical parameters are observed with a combination of non-covalent functionalization of nanotubes and high-power ultrasonic exposure. This method allows us to achieve a conductivity value of composite materials of 0.01 S/cm in the studied frequency range at a filler concentration of 0.5 wt.%.

The conductivity in Composite Materials Based on Oriented Carbon Nanotubes

2021 ◽  
Vol 76 (1) ◽  
pp. 29-35
Author(s):  
E. A. Vorobyeva ◽  
A. P. Evseev ◽  
V. L. Petrov ◽  
A. A. Shemukhin ◽  
N. G. Chechenin
Keyword(s):  
Carbon Nanotubes ◽  
Composite Materials

scholarly journals Electromagnetic Interference Shielding Efficiency in the Range 8.2-12.4 GHz of Polymer Composites with Dispersed Carbon Nanoparticles

2011 ◽  
Vol 14 (1) ◽  
pp. 55 ◽  
Author(s):  
Anna V. Gubarevich ◽  
Kazuki Komoriya ◽  
Osamu Odawara
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Black ◽  
Polymer Composites ◽  
Electromagnetic Interference ◽  
Carbon Nanoparticles ◽  
Hot Press ◽  
Frequency Range ◽  
Electromagnetic Interference Shielding ◽  
X Band ◽  
Graphite Nanoparticles

In the present work, electromagnetic interference shielding properties of polymer composites with dispersed cup-stacked carbon nanotubes, graphite nanoparticles and carbon black were investigated. The polymer composites with carbon nanoparticles content from 1 to 5 w% were successfully prepared by the coagulation method, and composite sheets with thickness from 0.25 to 0.77 mm were formed by the hot press technique. The electromagnetic interference shielding efficiency measured in the frequency range of 8.2~12.4 GHz (X-band) of cup-stacked carbon nanotubes/polymer composite was considerably higher than that of carbon black and graphite nanoparticles polymer composites at the same contents of carbon nanoparticles, and contribution of absorption to the shielding efficiency was found to be higher than that of reflection.

scholarly journals The development of an advanced composite structure using evolutionary design methods

2009 ◽  
Author(s):  
◽  
David Van Wyk
Keyword(s):  
Composite Materials ◽  
Composite Structure ◽  
Composite Structures ◽  
Empirical Method ◽  
Optimum Shape ◽  
Evolutionary Design ◽  
Structural Optimisation ◽  
Design For Manufacture ◽  
Advanced Composite ◽  
Evolutionary Optimisation

The development of an evolutionary optimisation method and its application to the design of an advanced composite structure is discussed in this study. Composite materials are increasingly being used in various fields, and so optimisation of such structures would be advantageous. From among the various methods available, one particular method, known as Evolutionary Structural Optimisation (ESO), is shown here. ESO is an empirical method, based on the concept of removing and adding material from a structure, in order to create an optimum shape. The objective of the research is to create an ESO method, utilising MSC.Patran/Nastran, to optimise composite structures. The creation of the ESO algorithm is shown, and the results of the development of the ESO algorithm are presented. A tailfin of an aircraft was used as an application example. The aim was to reduce weight and create an optimised design for manufacture. The criterion for the analyses undertaken was stress based. Two models of the tailfin are used to demonstrate the effectiveness of the developed ESO algorithm. The results of this research are presented in the study.

The influence of functionalization time of carbon nanotube on the mechanical properties of the epoxy composites

2017 ◽  
Vol 51 (12) ◽  
pp. 1693-1701 ◽  
Author(s):  
EA Zakharychev ◽  
EN Razov ◽  
Yu D Semchikov ◽  
NS Zakharycheva ◽  
MA Kabina
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Carbon Nanotube ◽  
Composite Materials ◽  
Polymer Composites ◽  
Epoxy Composites ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

This paper investigates the structure, length, and percentage of functional groups of multi-walled carbon nanotubes (CNT) depending on the time taken for functionalization in HNO3 and H2SO4 mixture. The carbon nanotube content and influence of functionalization time on mechanical properties of polymer composite materials based on epoxy matrix are studied. The extreme dependencies of mechanical properties of carbon nanotube functionalization time of polymer composites were established. The rise in tensile strength of obtained composites reaches 102% and elastic modulus reaches 227% as compared to that of unfilled polymer. The composites exhibited best mechanical properties by including carbon nanotube with 0.5 h functionalization time.

Fabrication and electrochemical characterization of super-capacitor based on three-dimensional composite structure of graphene and a vertical array of carbon nanotubes

2018 ◽  
Vol 52 (22) ◽  
pp. 3039-3044 ◽  
Author(s):  
Daniel Choi ◽  
Eui-Hyeok Yang ◽  
Waqas Gill ◽  
Aaron Berndt ◽  
Jung-Rae Park ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Vapor Deposition ◽  
Composite Structure ◽  
Graphene Layer ◽  
Three Dimensional ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Silicon Substrates ◽  
Vertical Array ◽  
Pressure Chemical

We have demonstrated a three-dimensional composite structure of graphene and carbon nanotubes as electrodes for super-capacitors. The goal of this study is to fabricate and test the vertically grown carbon nanotubes on the graphene layer acting as a spacer to avoid self-aggregation of the graphene layers while realizing high active surface area for high energy density, specific capacitance, and power density. A vertical array of carbon nanotubes on silicon substrates was grown by a low-pressure chemical vapor deposition process using anodized aluminum oxide nanoporous template fabricated on silicon substrates. Subsequently, a graphene layer was grown by another low-pressure chemical vapor deposition process on top of a vertical array of carbon nanotubes. The Raman spectra confirmed the successful growth of carbon nanotubes followed by the growth of high-quality graphene. The average measured capacitance of the three-dimensional composite structure of graphene-carbon nanotube was 780 µFcm−2 at 100 mVs−1.

Mechanisms of Electrical Conductivity in Carbon Nanotubes and Graphene

2018 ◽  
pp. 2673-2684 ◽  
Author(s):  
Rafael Vargas-Bernal
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Composite Materials ◽  
Hybrid Materials ◽  
Carbon Nanomaterials ◽  
Electronics Industry ◽  
Future Generations ◽  
Science And Engineering ◽  
The World ◽  
Technological Impact

There is enormous interest in carbon nanomaterials, due to their exceptional physical properties, from the perspective of science and engineering of materials applied to the electronics industry. Until now, significant progress has been made towards understanding the mechanisms of electrical conductivity of carbon nanotubes and graphene. However, scientists around the world even today continue studying these mechanisms, for exploiting them fully in different electronic applications with a high technological impact. This article discusses the mechanisms of electrical conductivity of both nanomaterials, analyzes the present implications, and projects its importance for future generations of electronic devices. In particular, it is important to note that different mechanisms may be identified when these nanomaterials are used individually, when they are incorporated as fillers in composite materials or hybrid materials, or even when they are doped or functionalized. Finally, other electrical variables with important role in electrical conductivity of these materials are also explored.

Sign in / Sign up

Export Citation Format

Share Document