Tuning the composition of conductive thermoplastics for stiffness switching and electrically activated healing

2019 ◽  
Vol 30 (18-19) ◽  
pp. 2908-2918 ◽  
Author(s):  
Steven I Rich ◽  
Vasudevan Nambeesan ◽  
Rehan Khan ◽  
Carmel Majidi
Keyword(s):  
Passive State ◽  
Filler Concentration ◽  
Large Area ◽  
Thermally Activated ◽  
Wide Range ◽  
Multi Walled Carbon Nanotubes ◽  
Switching Material ◽  
Walled Carbon Nanotubes ◽  
Percolating Network ◽  
Acetylene Carbon

We introduce a class of stiffness-tuning polymer composites and carefully examine the influence of electrical activation and temperature on stiffness for a wide range of use cases. The composites are composed of a polycaprolactone matrix embedded with a percolating network of acetylene carbon black or multi-walled carbon nanotubes. This work builds on previous efforts with thermally activated stiffness-switching composites, which can enable reliable, high-switching-ratio stiffness-switching devices that are stiff in the passive state and are not confined to specific geometries or layouts. Here, we systematically investigate the effects of filler type, filler concentration, and matrix polymer molecular weight on the critical properties of the stiffness-switching material. Using these parameters, we develop a composition selection guide, which we use to construct three different stiffness-switching applications: a highly extensible stiffness-switching tendon, a large area moldable sheet, and an electrically healable mechanical fuse.

scholarly journals A New Method for Dispersing Pristine Carbon Nanotubes Using Regularly Arranged S-Layer Proteins

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1346
Author(s):  
Andreas Breitwieser ◽  
Uwe B. Sleytr ◽  
Dietmar Pum
Keyword(s):  
Carbon Nanotubes ◽  
Covalent Modification ◽  
Silica Layer ◽  
Medical Sciences ◽  
Lysinibacillus Sphaericus ◽  
Wide Range ◽  
Catalytic Sites ◽  
Multi Walled Carbon Nanotubes ◽  
Pristine Mwnts ◽  
Walled Carbon Nanotubes

Homogeneous and stable dispersions of functionalized carbon nanotubes (CNTs) in aqueous solutions are imperative for a wide range of applications, especially in life and medical sciences. Various covalent and non-covalent approaches were published to separate the bundles into individual tubes. In this context, this work demonstrates the non-covalent modification and dispersion of pristine multi-walled carbon nanotubes (MWNTs) using two S-layer proteins, namely, SbpA from Lysinibacillus sphaericus CCM2177 and SbsB from Geobacillus stearothermophilus PV72/p2. Both the S-layer proteins coated the MWNTs completely. Furthermore, it was shown that SbpA can form caps at the ends of MWNTs. Reassembly experiments involving a mixture of both S-layer proteins in the same solution showed that the MWNTs were primarily coated with SbsB, whereas SbpA formed self-assembled layers. The dispersibility of the pristine nanotubes coated with SbpA was determined by zeta potential measurements (−24.4 +/− 0.6 mV, pH = 7). Finally, the SbpA-coated MWNTs were silicified with tetramethoxysilane (TMOS) using a mild biogenic approach. As expected, the thickness of the silica layer could be controlled by the reaction time and was 6.3 +/− 1.25 nm after 5 min and 25.0 +/− 5.9 nm after 15 min. Since S-layer proteins have already demonstrated their capability to bind (bio)molecules in dense packing or to act as catalytic sites in biomineralization processes, the successful coating of pristine MWNTs has great potential in the development of new materials, such as biosensor architectures.

scholarly journals Fabrication and Characterization of Polylactic Acid Electrospun Scaffolds Modified with Multi-Walled Carbon Nanotubes and Hydroxyapatite Nanoparticles

Biomimetics ◽  
2020 ◽  
Vol 5 (3) ◽  
pp. 43
Author(s):  
Athanasios Kotrotsos ◽  
Prokopis Yiallouros ◽  
Vassilis Kostopoulos
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Polylactic Acid ◽  
Physical And Mechanical Properties ◽  
Polymeric Materials ◽  
Cost Effective ◽  
Electrospinning Process ◽  
Wide Range ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

The solution electrospinning process (SEP) is a cost-effective technique in which a wide range of polymeric materials can be electrospun. Electrospun materials can also be easily modified during the solution preparation process (prior SEP). Based on this, the aim of the current work is the fabrication and nanomodification of scaffolds using SEP, and the investigation of their porosity and physical and mechanical properties. In this study, polylactic acid (PLA) was selected for scaffold fabrication, and further modified with multi-walled carbon nanotubes (MWCNTs) and hydroxyapatite (HAP) nanoparticles. After fabrication, porosity calculation and physical and mechanical characterization for all scaffold types were conducted. More precisely, the morphology of the fibers (in terms of fiber diameter), the surface properties (in terms of contact angle) and the mechanical properties under the tensile mode of the fabricated scaffolds have been investigated and further compared against pristine PLA scaffolds (without nanofillers). Finally, the scaffold with the optimal properties was proposed as the candidate material for potential future cell culturing.

scholarly journals Amplitude modulator of Multi-walled Carbon nanotubes/Chitin in the C-band region

2021 ◽  
Vol 2075 (1) ◽  
pp. 012005
Author(s):  
N H Muhamad Apandi ◽  
H Ahmad ◽  
M H Ibrahim ◽  
F Ahmad
Keyword(s):  
Carbon Nanotubes ◽  
Regression Line ◽  
Optical Signal ◽  
Linear Region ◽  
Peak Intensity ◽  
Wide Range ◽  
All Optical ◽  
Multi Walled Carbon Nanotubes ◽  
Amplitude Modulator ◽  
Walled Carbon Nanotubes

Abstract In ultrafast all-optical signal processing, the all-optical method is crucial, and all-fiber technique offers a wide range of applications in optical communications. This study investigated the amplitude modulation using multi-walled carbon nanotubes (MWCNTs) embedded into chitin as saturable absorber (SA). The MWCNTs-chitin SA is fabricate using a liquid phase exfoliation method to reduce complexity and produce an excellent material quality. In this paper, an optical amplitude modulator produced a linear region with a regression line of the peak intensity at pump power range from 17.92 mW to 67.92 mW with modulation efficiency of 0.50 dB/mW.

MWCNTs patterning by thermally enhanced and confined evaporation for transparent and conductive thin film

2018 ◽  
Vol 32 (29) ◽  
pp. 1850360 ◽  
Author(s):  
Xiangmeng Li ◽  
Jinyou Shao ◽  
Xijing Zhu ◽  
Huifen Wei
Keyword(s):  
Thin Film ◽  
Flexible Electronics ◽  
Self Assembly ◽  
Mechanical Performance ◽  
Flexible Substrate ◽  
Adhesive Tape ◽  
Large Area ◽  
Multi Walled Carbon Nanotubes ◽  
Geometric Confinement ◽  
Walled Carbon Nanotubes

Conductive and transparent thin film structures are useful in flexible electronics. In this paper, we report multi-walled carbon nanotubes (MWCNTs) patterning into gradient regular patterns with large area of about several square centimeters on silicon or wafer glass slide via thermally enhanced evaporative self-assembly under wedge-shaped geometric confinement. The morphologies, electrical and optical properties of the MWCNTs thin film were characterized. The findings reveal that the conductance would increase with depositing times, meanwhile the transparency would decrease. The resistance of the grid patterning films of MWCNTs has a nearly linear relation to the transmittance in a relatively large range. The MWCNTs can be easily transferred to flexible substrate such as PET films or an adhesive tape. In comparison, SWCNTs could hardly be deposited into stripes or grid patterns, but the continuous thick films and discontinuous thin films could demonstrate better electrical and mechanical performance.

The role of single- and multi-walled carbon nanotube in breast cancer treatment

2020 ◽  
Vol 11 (10) ◽  
pp. 653-672 ◽  
Author(s):  
Babak Faraji Dizaji ◽  
Amirnezam Farboudi ◽  
Alireza Rahbar ◽  
Mohammadreza Hasani Azarbaijan ◽  
Mohammad Reza Asgary
Keyword(s):  
Breast Cancer ◽  
Cancer Treatment ◽  
Carbon Nanomaterials ◽  
Breast Cancer Diagnosis ◽  
Breast Cancer Treatment ◽  
Wide Range ◽  
Multi Walled Carbon Nanotubes ◽  
Swcnts And Mwcnts ◽  
Walled Carbon Nanotubes

Numerous studies have been conducted to design new strategies for breast cancer treatment. Past studies have shown a wide range of carbon-nanomaterials properties, such as single- and multi-walled carbon nanotubes (SWCNTs and MWCNTs) in breast cancer diagnosis and treatment. In this regard, the current study aims to review the role of both SWCNTs and MWCNTs in breast cancer treatment and diagnosis. For reaching this goal, we reviewed the literature by using various searching engines such as Scopus, PubMed, Google Scholar, Web of Science and MEDLINE. This comprehensive review showed that CNTs could dramatically improve breast cancer treatment and could be used as a novel modality to increase diagnostic accuracy; however, no clinical studies have been conducted based on CNTs. In addition, the literature review demonstrates a lack of enough studies to evaluate the side effects of using CNTs.

BisGMA/EPDM/amine functionalised MWCNTs based nanocomposites

2015 ◽  
Vol 44 (5) ◽  
pp. 266-275 ◽  
Author(s):  
Ankita Pritam Praharaj ◽  
Dibakar Behera ◽  
Tapan Kumar Bastia ◽  
Arun Kumar Rout
Keyword(s):  
Water Absorption ◽  
Low Cost ◽  
Cost Effective ◽  
Point Of View ◽  
Content Type ◽  
Wide Range ◽  
Multi Walled Carbon Nanotubes ◽  
Thermal And Electrical Properties ◽  
Electrical Materials ◽  
Walled Carbon Nanotubes

Purpose – This paper aims to focus on the development and study properties of bisphenol-A glycidyldimethacrylate (BisGMA) and ethylene–propylene–diene monomer (EPDM) blend-based nanocomposites containing amine-functionalised multi-walled carbon nanotubes (MWCNT-NH2) as a compatibiliser. Design/methodology/approach – First, BisGMA was synthesised from epoxy and methacrylic acid followed by the amine functionalisation of MWCNTs. A novel two-roll milling technique was then conducted to prepare nanocomposite specimens with MWCNT-NH2 as compatibiliser. Effect of MWCNT-NH2 content on the mechanical, thermal, electrical, corrosive and water absorption properties of the nanocomposites was investigated and results have been reported. Findings – The results of the present work reveal that MWCNT-NH2 acts as a potential compatibiliser and nanofiller in BisGMA/EPDM blend-based nanocomposites. The authors report here that the nanocomposites exhibit improved mechanical, thermal and electrical properties with increased addition of MWCNT-NH2. Moreover, desirable results are obtained at 5 phr of nanofiller loading beyond which the properties deteriorate due to particle agglomeration. The nanocomposites display negligible corrosion and water absorption characteristics. Thus, the above fabricated nanocomposites with optimum compatibiliser content can serve as low-cost structural, thermal and electrical materials which can also be utilised in corrosive and moist environments. Research limitations/implications – The present investigation has come up with the successful and cost-effective fabrication of BisGMA/EPDM blend-based nanocomposites with optimum nanofiller/compatibiliser (MWCNT-NH2) content that can be used for a wide range of structural, thermal and electrical projects, as it is corrosion and moisture resistant. It is also the most durable from the mechanical point of view. Originality/value – The above nanocomposites have never been designed before.

Dielectrophoretic Assembly of Organized Carbon Nanotubes and Thin Films

2010 ◽  
Author(s):  
Pengfei Li ◽  
Wei Xue
Keyword(s):  
Thin Films ◽  
Carbon Nanotubes ◽  
Nanoelectromechanical Systems ◽  
Experimental Conditions ◽  
Energy Devices ◽  
Nanotube Bundles ◽  
Wide Range ◽  
Multi Walled Carbon Nanotubes ◽  
Controlled Deposition ◽  
Walled Carbon Nanotubes

In this paper, we investigate the dielectrophoretic assembly of organized carbon nanotube (CNT) and CNT thin films. Both single-walled carbon nanotubes (SWNTs) and multi-walled carbon nanotubes (MWNTs) are employed in our experiments. Electrodes with “teeth”-like patterns are fabricated to study the influence of electrode width on CNT deposition and alignment. The entire fabrication process is compatible with optical lithography based techniques. Therefore, the fabrication cost is low and the resulting devices are inexpensive. SWNT and MWNT solutions are prepared with different concentrations. The alignment of SWNT/MWNT thin films and small bundles are achieved under the optimized experimental conditions. The electrical properties of these samples are characterized. The results demonstrate that the controlled deposition of CNT thin films using dielectrophoresis is highly repeatable. The alignment of small nanotube bundles can only be achieved using narrow electrodes and low-concentration solutions. Our investigation shows that it is possible to deposit a controllable amount of CNTs in desirable locations using dielectrophoresis. This research has the potential to enable the development of practical and inexpensive CNT devices that can be used in a wide range of applications: nanoelectronics, nano-bioelectronics, nanoelectromechanical systems (NEMS), and energy devices.

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