Studying changes in the electrical resistance of carbon-nanotubes-modified elastomers during their compression, stretching and torsion

2019 ◽  
pp. 128-138
Author(s):  
V. S. Yagubov ◽  
A. V. Shchegolkov ◽  
A. V. Shchegolkov ◽  
N. R. Memetov
Keyword(s):  
Composite Material ◽  
Smart Materials ◽  
Electrical Resistance ◽  
Materials Science ◽  
Measuring System ◽  
Constant Current ◽  
Matrix Composition ◽  
Space Industry ◽  
Different Types ◽  
Elastomer Composites

Developing "smart" materials with improved both structural and functional characteristics is one of the promising areas of materials science. Measuring the electrical resistance of CNTs-modified (various mass contents) polymers and in particular, elastomers during performing several tests (compression, stretching, and torsion) at a constant current is relevant in electrical engineering, mechanical engineering, aviation, and space industry. Changes in the elastomer shape under different types of testing lead to the destruction of macromolecules and the structuring of the material as a whole. Therefore, it is important to study the effect of CNTsbased modifying fillers on the elastomer. When compressing, stretching or twisting the nano-modified elastomer, along with the mutual movement of its macromolecular fragments and aggregates, the modifier particles also move, which generally determines the transport of electrons in the resulting structure and affects the physical and mechanical parameters of the composite material. To conduct studies, elastomers containing different amounts of a CNTs-based modifying filler were prepared. To investigate and elucidate relevant dependencies, a measuring system (MS) was constructed, which makes it possible to determine electrical resistance values of the composite material with different CNTs contents in the polymer matrix composition exposed to various mechanical loads. Basing the research results, it was established that the electrical resistance of the elastomer composites modified with 1.0–2.5 wt.% CNTs decreases when compressing from 0 to 100 N, whereas when the compression force ranges from 100 to 350 N, the electrical resistance remains unchanged. When the elastomer composites modified with 2–2.5 wt.% CNTs were stretched by 30–40 %, the electrical resistance was found to increase from 5·103 to 1.9·107 Ω.

Temperature dependence of TiN/TiAl3/Ti2AlN composite material electric resistivity

2019 ◽  
pp. 36-41
Author(s):  
A. A. Kondakov ◽  
A. V. Karpov ◽  
V. V. Grachev ◽  
A. E. Sytschev
Keyword(s):  
Composite Material ◽  
Electrical Resistance ◽  
Combustion Products ◽  
Specific Electrical Resistance ◽  
Constant Current ◽  
Gaseous Nitrogen ◽  
Full Agreement ◽  
X Ray ◽  
Temperature Range ◽  
Weight Content

The TiN/TiAl3/Ti2AlN composite material was obtained by filtration combustion of the porous TiAl intermetallic samples in gaseous nitrogen. X-ray phase analysis of combustion products provided data to calculate the weight content of each phase as follows: 42 wt.% TiN, 35 wt.% TiAl3, 20 wt.% Ti2AlN and 3 wt.% TiAl. The synthesized composite material containing Ti2AlN МАХ phase features good electrical conductivity of a metallic nature. Specific electrical resistance of the synthesized material was measured by a standard 4-point procedure at constant current in the temperature range 300–1300 K in vacuum 2·10–3 Pa. It was found that specific electrical resistance grows linearly from 0.35 to 1.25 μΩ·m as temperature rises. Subsequent measurements of this indicator at the following heating/cooling cycles demonstrated full agreement of obtained results. This fact indicates that the material has stable electrophysical properties in the investigated temperature range.

A glance on rare earth oxides: importance, reserves, demand, applications, critical uncertainties, global economy, and zeta potential characterization

2020 ◽  
Vol 05 ◽  
Author(s):  
Silas Santos ◽  
Orlando Rodrigues ◽  
Letícia Campos
Keyword(s):  
Rare Earth ◽  
Zeta Potential ◽  
Sample Preparation ◽  
Rare Earths ◽  
Smart Materials ◽  
Global Economy ◽  
Materials Science ◽  
Functional Materials ◽  
Rare Earth Oxides ◽  
Interparticle Forces

Background: Innovation mission in materials science requires new approaches to form functional materials, wherein the concept of its formation begins in nano/micro scale. Rare earth oxides with general form (RE2O3; RE from La to Lu, including Sc and Y) exhibit particular proprieties, being used in a vast field of applications with high technological content since agriculture to astronomy. Despite of their applicability, there is a lack of studies on surface chemistry of rare earth oxides. Zeta potential determination provides key parameters to form smart materials by controlling interparticle forces, as well as their evolution during processing. This paper reports a study on zeta potential with emphasis for rare earth oxide nanoparticles. A brief overview on rare earths, as well as zeta potential, including sample preparation, measurement parameters, and the most common mistakes during this evaluation are reported. Methods: A brief overview on rare earths, including zeta potential, and interparticle forces are presented. A practical study on zeta potential of rare earth oxides - RE2O3 (RE as Y, Dy, Tm, Eu, and Ce) in aqueous media is reported. Moreover, sample preparation, measurement parameters, and common mistakes during this evaluation are discussed. Results: Potential zeta values depend on particle characteristics such as size, shape, density, and surface area. Besides, preparation of samples which involves electrolyte concentration and time for homogenization of suspensions are extremely valuable to get suitable results. Conclusion: Zeta potential evaluation provides key parameters to produce smart materials seeing that interparticle forces can be controlled. Even though zeta potential characterization is mature, investigations on rare earth oxides are very scarce. Therefore, this innovative paper is a valuable contribution on this field.

Adaptive Elastic SMA Elements for Damping Applications

2013 ◽  
Author(s):  
Alexander Czechowicz ◽  
Peter Dültgen ◽  
Sven Langbein
Keyword(s):  
Boundary Conditions ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Smart Materials ◽  
Electrical Resistance ◽  
Thermal Activation ◽  
Hysteretic Behavior ◽  
Damping Function ◽  
Actual Shape ◽  
Elastic Elements

Shape memory alloys (SMA) are smart materials, which have two technical usable effects: While pseudoplastic SMA have the ability to change into a previously imprinted actual shape through the means of thermal activation, pseudoelastic SMA show a reversible mechanical elongation up to 8% at constant temperature. The transformation between the two possible material phases (austenite and martensite) shows a hysteretic behavior. As a result of these properties, SMA can be used as elastic elements with intrinsic damping function. Additionally the electrical resistance changes remarkably during the material deformation. These effects are presented in the publication in combination with potential for applications in different branches at varying boundary conditions. The focus of the presented research is concentrated on the application of elastic elements with adaptive damping function. As a proof for the potential considerations, an application example sums up this presentation.

scholarly journals A Review on a Straight Bevel Gear Made from Composite

2016 ◽  
Vol 5 (3) ◽  
pp. 73 ◽  
Author(s):  
Haidar F. AL-Qrimli ◽  
Karam S. Khalid ◽  
Ahmed M. Abdelrhman ◽  
Roaad K. Mohammed A ◽  
Husam M. Hadi
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Power Transmission ◽  
Bevel Gear ◽  
Robotic Arm ◽  
Straight Bevel Gear ◽  
Different Types ◽  
New Type ◽  
New Form ◽  
Material Composite

The purpose of this work is to present a clear fundamental thought for designing and investigating straight bevel gear made of composite material. Composite materials have the advantage of being light, producing low noises, and extra loading capacities. Due to these properties, it is highly preferable over conventional materials. A comparison between different types of material used in a gear structure will be shown. The outcome shows that a new form of cheap material may be useful for designing a new type of lighter and stiffer gear, designed for robotic arm applications or any power transmission application.

Magnetodynamics and Self-Organization in Strongly Non-Equilibrium Ferrosuspensions

2009 ◽  
Vol 152-153 ◽  
pp. 175-181
Author(s):  
Bronislav Kashevsky ◽  
Sergei Kashevsky ◽  
Igor Prokhorov
Keyword(s):  
Smart Materials ◽  
Materials Science ◽  
Magnetic Hysteresis ◽  
Experimental Studies ◽  
Rotating Magnetic Field ◽  
Self Organization ◽  
Linearly Polarized ◽  
Dilute Suspension ◽  
Soft Particles ◽  
Non Equilibrium

This paper presents computational and experimental studies of two phenomena occurring in magnetic suspensions under strongly non-equilibrium conditions created by high-frequency (in comparison with the inverse characteristic time of the particle mechanical motion) magnetic fields. First is the dynamic magnetic hysteresis in a dilute suspension of highly-coercive particles subjected to linearly polarized fields. Energy absorption by particles is of great interest for cancer treatment, chemical technology, biology and smart materials science. Second is related to polymer composite technologies and represents dissipative self-organization of a system of magnetically soft particles in a drying thin layer of polymer solution set under a rotating magnetic field

Natural Aerobic Degradation of Polylactic Acid (Composites) with Natural Fiber Additives

2018 ◽  
Vol 919 ◽  
pp. 167-174 ◽  
Author(s):  
Jan Prusek ◽  
Martin Boruvka ◽  
Petr Lenfeld
Keyword(s):  
Composite Material ◽  
Polylactic Acid ◽  
Natural Fiber ◽  
Fiber Reinforcement ◽  
Degradation Process ◽  
Composite Sample ◽  
Aerobic Degradation ◽  
Different Types ◽  
Natural Degradation

This paper deals with natural degradation of PLA (polylactic acid) composites with natural fiber reinforcement in non-simulated conditions. Composite material was made of PLA and 6 different types of biodegradable fibers. Fibers made from pulp, wool, bamboo, soya, flax and hemp. All samples had 20% volume of fibers. Three of each composite sample were placed in compost (aerobic surrounding) for 72 weeks. All samples were examined at the beginning every 2 weeks to observe if the degradation process occurred and all samples were examined at the end of 72 weeks period to observe results of degradation of each composite material.

scholarly journals Stimuli-Responsive Graphene Nanohybrids for Biomedical Applications

2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Dinesh K. Patel ◽  
Yu-Ri Seo ◽  
Ki-Taek Lim
Keyword(s):  
Drug Delivery ◽  
Functional Groups ◽  
Hybrid Materials ◽  
Smart Materials ◽  
Biomedical Applications ◽  
Materials Science ◽  
High Surface ◽  
Single Layer ◽  
Stimuli Responsive ◽  
Physiochemical Properties

Stimuli-responsive materials, also known as smart materials, can change their structure and, consequently, original behavior in response to external or internal stimuli. This is due to the change in the interactions between the various functional groups. Graphene, which is a single layer of carbon atoms with a hexagonal morphology and has excellent physiochemical properties with a high surface area, is frequently used in materials science for various applications. Numerous surface functionalizations are possible for the graphene structure with different functional groups, which can be used to alter the properties of native materials. Graphene-based hybrids exhibit significant improvements in their native properties. Since functionalized graphene contains several reactive groups, the behavior of such hybrid materials can be easily tuned by changing the external conditions, which is very useful in biomedical applications. Enhanced cell proliferation and differentiation of stem cells was reported on the surfaces of graphene-based hybrids with negligible cytotoxicity. In addition, pH or light-induced drug delivery with a controlled release rate was observed for such nanohybrids. Besides, notable improvements in antimicrobial activity were observed for nanohybrids, which demonstrated their potential for biomedical applications. This review describes the physiochemical properties of graphene and graphene-based hybrid materials for stimuli-responsive drug delivery, tissue engineering, and antimicrobial applications.

scholarly journals The High Energy Materials Science Beamline (HEMS) at PETRA III

2013 ◽  
Vol 772 ◽  
pp. 57-61 ◽  
Author(s):  
Norbert Schell ◽  
Andrew King ◽  
Felix Beckmann ◽  
Torben Fischer ◽  
Martin Müller ◽  
...  
Keyword(s):  
Smart Materials ◽  
Materials Science ◽  
High Energy ◽  
Test Facility ◽  
Polycrystalline Materials ◽  
Energy Materials ◽  
Friction Stir ◽  
Materials Research ◽  
Set Up

The HEMS beamline at PETRA III has a main energy of 120 keV, is tunable in the range 30-200 keV, and optimized for sub-micrometer focusing with Compound Refractive Lenses. Design, construction, and main funding was the responsibility of the Helmholtz-Zentrum Geesthacht, HZG. Approximately 70 % of the beamtime is dedicated to Materials Research, the rest reserved for “general physics” experiments covered by DESY, Hamburg. The beamline P07 in sector 5 consists of an undulator source optimized for high energies, a white beam optics hutch, an in-house test facility and three independent experimental hutches, plus additional set-up and storage space for long-term experiments. HEMS has partly been operational since summer 2010. First experiments are introduced coming from (a) fundamental research for the investigation of the relation between macroscopic and micro-structural properties of polycrystalline materials, grain-grain-interactions, recrystallisation processes, and the development of new & smart materials or processes; (b) applied research for manufacturing process optimization benefitting from the high flux in combination with ultra-fast detector systems allowing complex and highly dynamic in-situ studies of microstructural transformations, e.g. in-situ friction stir welding; (c) experiments targeting the industrial user community.

Sign in / Sign up

Export Citation Format

Share Document