Development of piezoresistive PDMS/MWCNT foam nanocomposite sensor with ultrahigh flexibility and compressibility

Polymer foam nanocomposites attract great interest in many wide ranges of biomedical and healthcare monitoring applications. In this study, we investigated the effect of porosity and multi-walled carbon nanotube (MWCNT) content on the piezoresistivity, sensitivity, and mechanical properties of Polydimethylsiloxane (PDMS)/MWCNT foam nanocomposite. The foam nanocomposites were fabricated by particulate leaching method and their electrical and mechanical characteristics were investigated using the different porosity levels (60% and 70%) and different conductive nanofiller contents (0.5 wt.% and 1 wt.%). The foam nanocomposites with 0.5 wt.% MWCNT content and 60% porosity possessed higher pressure sensitivity, higher gage factor, and lower electrical hysteresis along with higher mechanical properties. Moreover, fabricated PDMS/MWCNT foam nanocomposite demonstrated high flexibility, high compressibility, and high recoverability in addition to limited mechanical hysteresis (less than 3%) with a large dynamic sensing range. Contrary to the existing foam nanocomposite samples in the literature, PDMS/MWCNT foam nanocomposites withstood higher pressure ranges (3.5–5 MPa) at limited thickness (average 2.3 mm) without experiencing noticeable macroscopic damage.

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Mechanical Properties of Multi-Walled Carbon Nanotube/Waterborne Polyurethane Conductive Coatings Prepared by Electrostatic Spraying

Polymers ◽

10.3390/polym11040714 ◽

2019 ◽

Vol 11 (4) ◽

pp. 714 ◽

Cited By ~ 9

Author(s):

Fangfang Wang ◽

Lajun Feng ◽

Man Lu

Keyword(s):

Mechanical Properties ◽

Electrical Conductivity ◽

Wear Resistance ◽

Carbon Nanotube ◽

Surface Hardness ◽

Waterborne Polyurethane ◽

Conductive Coatings ◽

Mwcnt Content ◽

Electrostatic Spraying ◽

Multi Walled Carbon Nanotube

Electrostatic spraying (ES) was used to prepare multi-walled carbon nanotube (MWCNT)/waterborne polyurethane (WPU) abrasion-proof, conductive coatings to improve the electrical conductivity and mechanical properties of WPU coatings. The dispersity of MWCNTs and the electrical conductivity, surface hardness, and wear resistance of the coating prepared by ES (ESC) were investigated. The ESC was further compared with coatings prepared by brushing (BrC). The results provide a theoretical basis for the preparation and application of conductive WPU coatings with excellent wear resistance. The dispersity of MWCNTs and the surface hardness and wear resistance of ESC were obviously better than those of BrC. With an increase in the MWCNT content, the surface hardness of both ESC and BrC went up. As the MWCNT content increased, the wear resistance of ESC first increased and then decreased, while the wear resistance of BrC decreased. It was evident that ESC with 0.3 wt% MWCNT was fully capable of conducting electricity, but BrC with 0.3 wt% MWCNT failed to conduct electricity. The best wear resistance was achieved for ESC with 0.3 wt% MWCNT. Its wear rate (1.18 × 10−10 cm3/mm N) and friction coefficient (0.28) were the lowest, which were 50.21% and 20.00% lower, respectively, than those of pure WPU ESC.

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Weldability - Behavior of Welded Reinforcement

Revista de Chimie ◽

10.37358/rc.19.10.3469 ◽

2019 ◽

Vol 70 (10) ◽

pp. 3469-3472

Keyword(s):

Mechanical Properties ◽

Chemical Composition ◽

Mechanical Characteristics ◽

Mechanical Performance ◽

Current Work ◽

Carbon Equivalent ◽

Work Process ◽

Ultimate Limit

Weldability involves two aspects: welding behavior of components and safety in operation. The two aspects will be reduced to the mechanical characteristics of the elements and to the chemical composition. In the case of steel reinforcing rebar’s, it is reduces to the percentage of Cech(carbon equivalent) and to the mechanical characteristics: the yielding limit, the ultimate limit, and the elongations which after that represent the ductility class in which the re-bars is framed. The paper will present some types of steel reinforcing rebar’s with its mechanical characteristics and the welding behavior of those elements. In the current work, process-related behavior of welded reinforcement, joint local and global mechanical properties, and their correlation with behavior of normal reinforcement and also the mechanical performance resulted in this type of joints. Keywords: welding behavior, ultimate limit, reinforcing rebar’s

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Composite Material of PDMS with Interchangeable Transmittance: Study of Optical, Mechanical Properties and Wettability

Journal of Composites Science ◽

10.3390/jcs5040110 ◽

2021 ◽

Vol 5 (4) ◽

pp. 110

Author(s):

Flaminio Sales ◽

Andrews Souza ◽

Ronaldo Ariati ◽

Verônica Noronha ◽

Elder Giovanetti ◽

...

Keyword(s):

Mechanical Properties ◽

Experimental Study ◽

Room Temperature ◽

Casting Process ◽

Optical Characteristics ◽

Smart Devices ◽

Superhydrophobic Coating ◽

Gravity Casting ◽

High Flexibility ◽

Physical And Chemical

Polydimethylsiloxane (PDMS) is a polymer that has attracted the attention of researchers due to its unique properties such as transparency, biocompatibility, high flexibility, and physical and chemical stability. In addition, PDMS modification and combination with other materials can expand its range of applications. For instance, the ability to perform superhydrophobic coating allows for the manufacture of lenses. However, many of these processes are complex and expensive. One of the most promising modifications, which consists of the development of an interchangeable coating, capable of changing its optical characteristics according to some stimuli, has been underexplored. Thus, we report an experimental study of the mechanical and optical properties and wettability of pure PDMS and of two PDMS composites with the addition of 1% paraffin or beeswax using a gravity casting process. The composites’ tensile strength and hardness were lower when compared with pure PDMS. However, the contact angle was increased, reaching the highest values when using the paraffin additive. Additionally, these composites have shown interesting results for the spectrophotometry tests, i.e., the material changed its optical characteristics when heated, going from opaque at room temperature to transparent, with transmittance around 75%, at 70 °C. As a result, these materials have great potential for use in smart devices, such as sensors, due to its ability to change its transparency at high temperatures.

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Mechanical properties of SBS block copolymers. II. Effect of structure and selective solvent casting on stress–strain properties and mechanical hysteresis

Journal of Applied Polymer Science ◽

10.1002/app.1979.070230912 ◽

1979 ◽

Vol 23 (9) ◽

pp. 2673-2680 ◽

Cited By ~ 8

Author(s):

Nikos K. Kalfoglou

Keyword(s):

Mechanical Properties ◽

Block Copolymers ◽

Solvent Casting ◽

Selective Solvent ◽

Stress Strain ◽

Mechanical Hysteresis ◽

Effect Of Structure

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Mimicking the Mechanical Properties of Aortic Tissue with Pattern-Embedded 3D Printing for a Realistic Phantom

Materials ◽

10.3390/ma13215042 ◽

2020 ◽

Vol 13 (21) ◽

pp. 5042

Author(s):

Jaeyoung Kwon ◽

Junhyeok Ock ◽

Namkug Kim

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

3D Printing ◽

Mechanical Characteristics ◽

Aortic Wall ◽

Tensile Tests ◽

Human Aorta ◽

Aortic Tissue ◽

Medical Field ◽

Base Materials

3D printing technology has been extensively applied in the medical field, but the ability to replicate tissues that experience significant loads and undergo substantial deformation, such as the aorta, remains elusive. Therefore, this study proposed a method to imitate the mechanical characteristics of the aortic wall by 3D printing embedded patterns and combining two materials with different physical properties. First, we determined the mechanical properties of the selected base materials (Agilus and Dragonskin 30) and pattern materials (VeroCyan and TPU 95A) and performed tensile testing. Three patterns were designed and embedded in printed Agilus–VeroCyan and Dragonskin 30–TPU 95A specimens. Tensile tests were then performed on the printed specimens, and the stress-strain curves were evaluated. The samples with one of the two tested orthotropic patterns exceeded the tensile strength and strain properties of a human aorta. Specifically, a tensile strength of 2.15 ± 0.15 MPa and strain at breaking of 3.18 ± 0.05 mm/mm were measured in the study; the human aorta is considered to have tensile strength and strain at breaking of 2.0–3.0 MPa and 2.0–2.3 mm/mm, respectively. These findings indicate the potential for developing more representative aortic phantoms based on the approach in this study.

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Electromagnetic Interference Shielding and Physical-Mechanical Characteristics of Rubber Composites Filled with Manganese-Zinc Ferrite and Carbon Black

Polymers ◽

10.3390/polym13040616 ◽

2021 ◽

Vol 13 (4) ◽

pp. 616

Author(s):

Ján Kruželák ◽

Andrea Kvasničáková ◽

Klaudia Hložeková ◽

Rastislav Dosoudil ◽

Marek Gořalík ◽

...

Keyword(s):

Mechanical Properties ◽

Carbon Black ◽

Zinc Ferrite ◽

Mechanical Characteristics ◽

Hybrid Composites ◽

Rubber Matrix ◽

Butadiene Rubber ◽

Frequency Range ◽

Manganese Zinc ◽

Manganese Zinc Ferrite

In the present work, composite materials were prepared by incorporation of manganese-zinc ferrite, carbon black and combination of ferrite and carbon black into acrylonitrile-butadiene rubber (NBR). For cross-linking of composites, standard sulfur-based curing system was applied. The main goal was to investigate the influence of the fillers on the physical-mechanical properties of composites. Then, the electromagnetic absorption shielding ability was investigated in the frequency range 1 MHz–3 GHz. The results revealed that composites filled with ferrite provide sufficient absorption shielding performance in the tested frequency range. On the other hand, ferrite behaves as an inactive filler and deteriorates the physical-mechanical characteristics of composites. Carbon black reinforces the rubber matrix and contributes to the improvement of physical-mechanical properties. However, composites filled with carbon black are not able to absorb electromagnetic radiation in the given frequency range. Finally, the combination of carbon black and ferrite resulted in the modification of both physical-mechanical characteristics and absorption shielding ability of hybrid composites.

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Development of Heat Treatment Mode with Quenching in Different Quenching Environments for the Casing Pipe in Order to Obtain the Required Mechanical Properties

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.836.41 ◽

2020 ◽

Vol 836 ◽

pp. 41-45

Author(s):

S.N. Dzhabbarov ◽

E.I. Pryakhin

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Mechanical Characteristics ◽

Oil And Gas ◽

Oil And Gas Industry ◽

Treatment Mode ◽

Gas Industry ◽

Heat Treatment Mode ◽

Optimal Technology ◽

Casing Pipe

Development of an optimal technology of heat treatment for blanks of the casing pipe made of steel 40H (GOST 4543) is used in the oil and gas industry for casing. It is accompanied by quenching in various environments to ensure guaranteed obtainment of the required mechanical characteristics. These characteristics are specified in GOST 632-80 and met in order to improve the properties of the 40H steel.

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Effect of wood particulate size on the mechanical properties of PLA biocomposite

Pigment & Resin Technology ◽

10.1108/prt-12-2019-0117 ◽

2020 ◽

Vol 49 (6) ◽

pp. 465-472

Author(s):

S. Raj Sachin ◽

T. Kandasamy Kannan ◽

Rathanasamy Rajasekar

Keyword(s):

Mechanical Properties ◽

Mechanical Characteristics ◽

Wood Flour ◽

Wood Particle ◽

Poly Lactic Acid ◽

Particle Sizes ◽

Content Type ◽

Particulate Size ◽

Practical Implications

Purpose The purpose of this study is to carry out an investigation of the role of the wood particle size on the mechanical properties of poly lactic acid (PLA)-reinforced neem fiber biocomposite. Design/methodology/approach Composite test specimens were processed by reinforcing neem wood flour (NWF) in two different particle sizes, micro-sized NWF (MNWF) and nano-sized NWF (NNWF) separately into PLA. Composites were extruded at four different fiber loadings (10, 15, 20 and 25 Wt.%) into PLA matrix. The MNWF and NNWF had particle sizes varying from 5 to 15 µm and 10 to 15 nm, respectively. Findings Tensile strength, flexural strength and impact strength of PLA increased with fiber reinforcement for both the MNWF and NNWF cases. The NNWF-reinforced PLA composite at 20 Wt.% fiber loading proved to be the best composite that had outstanding mechanical properties in this research. Practical implications The developed composite can be used as a substitute for conventional plywood for furniture, building infrastructure and interior components for the automobile, aircraft and railway sectors. Originality/value A new biocomposite had been fabricated by using PLA and NWF and had been tested for its mechanical characteristics.

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Mechanical Properties Of Polyaniline / Multi-walled Carbon Nanotube Composite Films

MRS Proceedings ◽

10.1557/proc-791-q10.3 ◽

2003 ◽

Vol 791 ◽

Cited By ~ 4

Author(s):

P. C. Ramamurthy ◽

W. R. Harrell ◽

R. V. Gregory ◽

B. Sadanadan ◽

A. M. Rao

Keyword(s):

Mechanical Properties ◽

Carbon Nanotubes ◽

Carbon Nanotube ◽

Composite Films ◽

Weight Percent ◽

Organic Electronic Devices ◽

Multiwalled Carbon ◽

Multi Walled Carbon Nanotube ◽

Contact Devices ◽

Carbon Nanotube Composite

ABSTRACTHigh molecular weight polyaniline / multi-walled carbon nanotube composite films were fabricated using solution processing. Composite films with various weight percentages of multiwalled carbon nanotubes were fabricated. Physical properties of these composites were analyzed by thermogravimetric analysis, tensile testing, and scanning electron microscopy. These results indicate that the addition of multiwalled nanotubes to polyaniline significantly enhances the mechanical properties of the films. In addition, metal–semiconductor (composite) (MS) contact devices were fabricated, and it was observed that the current level in the films increased with increasing multiwalled nanotube content. Furthermore, it was observed that polyaniline containing one weight percent of carbon nanotubes appears to be the most promising composition for applications in organic electronic devices.

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