Editorial

6 pages, 207 KiB

Open AccessEditorial

Carbon-Based Polymer Nanocomposites for High-Performance Applications

by Ana Maria Díez-Pascual

Polymers 2020, 12(4), 872; https://doi.org/10.3390/polym12040872 - 10 Apr 2020

Cited by 27 | Viewed by 3431

Carbon-based nanomaterials such as carbon nanotubes, graphene and its derivatives, nanodiamond, fullerenes, and other nanosized carbon allotropes have recently attracted a lot of attention among the scientific community due to their enormous potential for a wide number of applications arising from their large [...] Read more.

Carbon-based nanomaterials such as carbon nanotubes, graphene and its derivatives, nanodiamond, fullerenes, and other nanosized carbon allotropes have recently attracted a lot of attention among the scientific community due to their enormous potential for a wide number of applications arising from their large specific surface area, high electrical and thermal conductivity, and good mechanical properties [...] Full article

(This article belongs to the Special Issue Carbon-Based Polymer Nanocomposites for High-Performance Applications)

Research

Jump to: Editorial, Review

16 pages, 3715 KiB

Open AccessCommunication

Direct Pre-lithiation of Electropolymerized Carbon Nanotubes for Enhanced Cycling Performance of Flexible Li-Ion Micro-Batteries

by Vinsensia Ade Sugiawati, Florence Vacandio, Neta Yitzhack, Yair Ein-Eli and Thierry Djenizian

Polymers 2020, 12(2), 406; https://doi.org/10.3390/polym12020406 - 11 Feb 2020

Cited by 30 | Viewed by 4795

Abstract

Carbon nanotubes (CNT) are used as anodes for flexible Li-ion micro-batteries. However, one of the major challenges in the growth of flexible micro-batteries with CNT as the anode is their immense capacity loss and a very low initial coulombic efficiency. In this study, [...] Read more.

Carbon nanotubes (CNT) are used as anodes for flexible Li-ion micro-batteries. However, one of the major challenges in the growth of flexible micro-batteries with CNT as the anode is their immense capacity loss and a very low initial coulombic efficiency. In this study, we report the use of a facile direct pre-lithiation to suppress high irreversible capacity of the CNT electrodes in the first cycles. Pre-lithiated polymer-coated CNT anodes displayed good rate capabilities, studied up to 30 C and delivered high capacities of 850 mAh g⁻¹ (313 μAh cm⁻²) at 1 C rate over 50 charge-discharge cycles. Full article

(This article belongs to the Special Issue Carbon-Based Polymer Nanocomposites for High-Performance Applications)

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19 pages, 7113 KiB

Open AccessArticle

Flexible Electrode Based on MWCNT Embedded in a Cross-Linked Acrylamide/Alginate Blend: Conductivity vs. Stretching

by Jake Thibodeau and Anna Ignaszak

Polymers 2020, 12(1), 181; https://doi.org/10.3390/polym12010181 - 09 Jan 2020

Cited by 16 | Viewed by 3740

Abstract

A polyacrylamide-alginate hydrogel electrolyte, blended with Multi-Walled Carbon Nanotubes (MWCNT) as an electronically conductive fraction, allows for the creation of a flexible, durable, and resilient electrode. The MWCNT content is correlated with mechanical characteristics such as stretch modulus, tensile resistance, and electrical conductivity. [...] Read more.

A polyacrylamide-alginate hydrogel electrolyte, blended with Multi-Walled Carbon Nanotubes (MWCNT) as an electronically conductive fraction, allows for the creation of a flexible, durable, and resilient electrode. The MWCNT content is correlated with mechanical characteristics such as stretch modulus, tensile resistance, and electrical conductivity. The mechanical analysis demonstrates tensile strength that is comparable to similar hydrogels reported in the literature, with increasing strength for MWCNT-embedded hydrogels. The impedance spectroscopy reveals that the total resistance of electrodes decreases with increasing MWCNT content upon elongation and that bending and twisting do not obstruct their conductivity. The MWCNT-inserted hydrogels show mixed ionic and electronic conductivities, both within a range of 1–4 × 10⁻² S cm⁻¹ in a steady state. In addition, the thermal stability of these materials increases with incrementing MWCNT content. This observation agrees with long-term charge-discharge cycling that shows enhanced electrochemical durability of the MWCNT-hydrogel hybrid when compared to pure hydrogel electrolyte. The hydrogel-carbon films demonstrate an increased interfacial double-layer current at a high MWCNT content (giving an area-specific capacitance of ~30 mF cm⁻² at 2.79 wt.% of MWCNT), which makes them promising candidates as printable and flexible electrodes for lightweight energy storage applications. The maximum content of MWCNT within the polymer electrolyte was estimated at 2.79 wt.%, giving a very elastic polymer electrode with good electrical characteristics. Full article

(This article belongs to the Special Issue Carbon-Based Polymer Nanocomposites for High-Performance Applications)

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15 pages, 4803 KiB

Open AccessArticle

Electrically Self-Healing Thermoset MWCNTs Composites Based on Diels-Alder and Hydrogen Bonds

by Guilherme Macedo R. Lima, Felipe Orozco, Francesco Picchioni, Ignacio Moreno-Villoslada, Andrea Pucci, Ranjita K. Bose and Rodrigo Araya-Hermosilla

Polymers 2019, 11(11), 1885; https://doi.org/10.3390/polym11111885 - 14 Nov 2019

Cited by 35 | Viewed by 4167

Abstract

In this work, we prepared electrically conductive self-healing nanocomposites. The material consists of multi-walled carbon nanotubes (MWCNT) that are dispersed into thermally reversible crosslinked polyketones. The reversible nature is based on both covalent (Diels-Alder) and non-covalent (hydrogen bonding) interactions. The design allowed for [...] Read more.

In this work, we prepared electrically conductive self-healing nanocomposites. The material consists of multi-walled carbon nanotubes (MWCNT) that are dispersed into thermally reversible crosslinked polyketones. The reversible nature is based on both covalent (Diels-Alder) and non-covalent (hydrogen bonding) interactions. The design allowed for us to tune the thermomechanical properties of the system by changing the fractions of filler, and diene-dienophile and hydroxyl groups. The nanocomposites show up to 1 × 10⁴ S/m electrical conductivity, reaching temperatures between 120 and 150 °C under 20–50 V. The self-healing effect, induced by electricity was qualitatively demonstrated as microcracks were repaired. As pointed out by electron microscopy, samples that were already healed by electricity showed a better dispersion of MWCNT within the polymer. These features point toward prolonging the service life of polymer nanocomposites, improving the product performance, making it effectively stronger and more reliable. Full article

(This article belongs to the Special Issue Carbon-Based Polymer Nanocomposites for High-Performance Applications)

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13 pages, 2725 KiB

Open AccessArticle

Modulating Carrier Type for Enhanced Thermoelectric Performance of Single-Walled Carbon Nanotubes/Polyethyleneimine Composites

by Xiao-Xi Peng, Xuan Qiao, Shuai Luo, Jun-An Yao, Yun-Fei Zhang and Fei-Peng Du

Polymers 2019, 11(8), 1295; https://doi.org/10.3390/polym11081295 - 02 Aug 2019

Cited by 21 | Viewed by 4983

Abstract

Thermoelectric (TE) generators consisting of flexible and lightweight p- and n-type single-walled carbon nanotube (SWCNT)-based composites have potential applications in powering wearable electronics using the temperature difference between the human body and the environment. Tuning the TE properties of SWCNTs, particularly [...] Read more.

Thermoelectric (TE) generators consisting of flexible and lightweight p- and n-type single-walled carbon nanotube (SWCNT)-based composites have potential applications in powering wearable electronics using the temperature difference between the human body and the environment. Tuning the TE properties of SWCNTs, particularly p- versus n-type control, is currently of significant interest. Herein, the TE properties of SWCNT-based flexible films consisting of SWCNTs doped with polyethyleneimine (PEI) were evaluated. The carrier type of the SWCNT/PEI composites was modulated by regulating the proportion of SWCNTs and PEI using simple mixing techniques. The as-prepared SWCNT/PEI composite films were switched from p- to n-type by the addition of a high amount of PEI (>13.0 wt.%). Moreover, interconnected SWCNTs networks were formed due to the excellent SWNT dispersion and film formation. These parameters were improved by the addition of PEI and Nafion, which facilitated effective carrier transport. A TE generator with three thermocouples of p- and n-type SWCNT/PEI flexible composite films delivered an open circuit voltage of 17 mV and a maximum output power of 224 nW at the temperature gradient of 50 K. These promising results showed that the flexible SWCNT/PEI composites have potential applications in wearable and autonomous devices. Full article

(This article belongs to the Special Issue Carbon-Based Polymer Nanocomposites for High-Performance Applications)

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11 pages, 3973 KiB

Open AccessArticle

Facile Fabrication of Conductive Graphene/Polyurethane Foam Composite and Its Application on Flexible Piezo-Resistive Sensors

by Weibing Zhong, Xincheng Ding, Weixin Li, Chengyandan Shen, Ashish Yadav, Yuanli Chen, Mingze Bao, Haiqing Jiang and Dong Wang

Polymers 2019, 11(8), 1289; https://doi.org/10.3390/polym11081289 - 01 Aug 2019

Cited by 44 | Viewed by 5765

Abstract

Flexible pressure sensors have attracted tremendous research interests due to their wide applications in wearable electronics and smart robots. The easy-to-obtain fabrication and stable signal output are meaningful for the practical application of flexible pressure sensors. The graphene/polyurethane foam composites are prepared to [...] Read more.

Flexible pressure sensors have attracted tremendous research interests due to their wide applications in wearable electronics and smart robots. The easy-to-obtain fabrication and stable signal output are meaningful for the practical application of flexible pressure sensors. The graphene/polyurethane foam composites are prepared to develop a convenient method for piezo-resistive devices with simple structure and outstanding sensing performance. Graphene oxide was prepared through the modified Hummers method. Polyurethane foam was kept to soak in the obtained graphene oxide aqueous solution and then dried. After that, reduced graphene oxide/polyurethane composite foam has been fabricated under air phase reduction by hydrazine hydrate vapor. The chemical components and micro morphologies of the prepared samples have been observed by using FT-IR and scanning electron microscopy (SEM). The results predicted that the graphene is tightly adhered to the bare surface of the pores. The pressure sensing performance has been also evaluated by measuring the sensitivity, durability, and response time. The results indicate that the value of sensitivity under the range of 0–6 kPa and 6–25 kPa are 0.17 kPa⁻¹ and 0.005 kPa⁻¹, respectively. Cycling stability test has been performed 30 times under three varying pressures. The signal output just exhibits slight fluctuations, which represents the good cycling stability of the pressure sensor. At the same stage, the response time of loading and unloading of 20 g weight turned out to be about 300 ms. These consequences showed the superiority of graphene/polyurethane composite foam while applied in piezo-resistive devices including wide sensitive pressure range, high sensitivity, outstanding durability, and fast response. Full article

(This article belongs to the Special Issue Carbon-Based Polymer Nanocomposites for High-Performance Applications)

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18 pages, 3187 KiB

Open AccessArticle

Melt-Mixed Thermoplastic Nanocomposite Containing Carbon Nanotubes and Titanium Dioxide for Flame Retardancy Applications

by C. Cabello-Alvarado, P. Reyes-Rodríguez, M. Andrade-Guel, G. Cadenas-Pliego, M. Pérez-Alvarez, V.J. Cruz-Delgado, L. Melo-López, Z.V. Quiñones-Jurado and C.A. Ávila-Orta

Polymers 2019, 11(7), 1204; https://doi.org/10.3390/polym11071204 - 19 Jul 2019

Cited by 24 | Viewed by 4247

Abstract

The study of polymeric nanocomposites is a possible alternative to conventional flame retardants. The aim of the present work is to investigate the effects of carbon-nanotubes (CNT) and TiO₂ nanoparticles (NPs) on the thermo-mechanical, flammability, and electrical properties of polypropylene (PP). In [...] Read more.

The study of polymeric nanocomposites is a possible alternative to conventional flame retardants. The aim of the present work is to investigate the effects of carbon-nanotubes (CNT) and TiO₂ nanoparticles (NPs) on the thermo-mechanical, flammability, and electrical properties of polypropylene (PP). In this work, PP-TiO₂/CNT nanocomposites were obtained with TiO₂/CNT mixtures (ratio 1:2) through the melt extrusion process, with different weight percentage of nanoparticles (1, 5, and 10 wt %). The PP-TiO₂/CNT nanocomposites were characterized by DSC, TGA, MFI, FTIR, XRD, and SEM. It was possible to determine that the thermal stability of the PP increases when increasing the content of NPs. A contrary situation is observed in the degree of crystallinity and thermo-oxidative degradation, which decreased with respect to pure PP. The TiO₂ NPs undergo coalition and increase their size at a lower viscosity of the nanocomposite (1 and 5 wt %). The mechanical properties decreased slightly, however, the Young’s modulus presented an improvement of 10% as well as electrical conductivity, this behavior was noted in nanocomposites of 10 wt % of NPs. Flammability properties were measured with a cone calorimeter, and a reduction in the peak heat release rate was observed in nanocomposites with contents of nanoparticles of 5 and 10 wt % Full article

(This article belongs to the Special Issue Carbon-Based Polymer Nanocomposites for High-Performance Applications)

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20 pages, 4305 KiB

Open AccessArticle

Formation Features of Hybrid Nanocomposites Based on Polydiphenylamine-2-Carboxylic Acid and Single-Walled Carbon Nanotubes

by Sveta Zhiraslanovna Ozkan, Galina Petrovna Karpacheva, Aleksandr Ivanovich Kostev and Galina Nikolaevna Bondarenko

Polymers 2019, 11(7), 1181; https://doi.org/10.3390/polym11071181 - 13 Jul 2019

Cited by 9 | Viewed by 3175

Abstract

Hybrid nanocomposites based on electroactive polydiphenylamine-2-carboxylic acid (PDPAC) and single-walled carbon nanotubes (SWCNTs) were obtained for the first time. Polymer-carbon nanomaterials were synthesized via in situ oxidative polymerization of diphenylamine-2-carboxylic acid (DPAC) in the presence of SWCNTs by two different ways. Hybrid SWCNT/PDPAC [...] Read more.

Hybrid nanocomposites based on electroactive polydiphenylamine-2-carboxylic acid (PDPAC) and single-walled carbon nanotubes (SWCNTs) were obtained for the first time. Polymer-carbon nanomaterials were synthesized via in situ oxidative polymerization of diphenylamine-2-carboxylic acid (DPAC) in the presence of SWCNTs by two different ways. Hybrid SWCNT/PDPAC nanocomposites were prepared both in an acidic medium and in the heterophase system in an alkaline medium. In the heterophase system, the monomer and the SWCNTs are in the organic phase (chloroform) and the oxidant (ammonium persulfate) is in an aqueous solution of ammonium hydroxide. The chemical structure, as well as the electrical and thermal properties of the developed SWCNT/PDPAC nanocomposite materials were investigated. Full article

(This article belongs to the Special Issue Carbon-Based Polymer Nanocomposites for High-Performance Applications)

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19 pages, 3774 KiB

Open AccessArticle

The Effect of Hexamethylene Diisocyanate-Modified Graphene Oxide as a Nanofiller Material on the Properties of Conductive Polyaniline

by José Antonio Luceño Sánchez, Ana Maria Díez-Pascual, Rafael Peña Capilla and Pilar García Díaz

Polymers 2019, 11(6), 1032; https://doi.org/10.3390/polym11061032 - 11 Jun 2019

Cited by 21 | Viewed by 3732

Abstract

Conducting polymers like polyaniline (PANI) have gained a lot of interest due to their outstanding electrical and optoelectronic properties combined with their low cost and easy synthesis. To further exploit the performance of PANI, carbon-based nanomaterials like graphene, graphene oxide (GO) and their [...] Read more.

Conducting polymers like polyaniline (PANI) have gained a lot of interest due to their outstanding electrical and optoelectronic properties combined with their low cost and easy synthesis. To further exploit the performance of PANI, carbon-based nanomaterials like graphene, graphene oxide (GO) and their derivatives can be incorporated in a PANI matrix. In this study, hexamethylene diisocyanate-modified GO (HDI-GO) nanosheets with two different functionalization degrees have been used as nanofillers to develop high-performance PANI/HDI-GO nanocomposites via in situ polymerization of aniline in the presence of HDI-GO followed by ultrasonication and solution casting. The influence of the HDI-GO concentration and functionalization degree on the nanocomposite properties has been examined by scanning electron microscopy (SEM), Raman spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), tensile tests, zeta potential and four-point probe measurements. SEM analysis demonstrated a homogenous dispersion of the HDI-GO nanosheets that were coated by the matrix particles during the in situ polymerization. Raman spectra revealed the existence of very strong PANI-HDI-GO interactions via π-π stacking, H-bonding, and hydrophobic and electrostatic charge-transfer complexes. A steady enhancement in thermal stability and electrical conductivity was found with increasing nanofiller concentration, the improvements being higher with increasing HDI-GO functionalization level. The nanocomposites showed a very good combination of rigidity, strength, ductility and toughness, and the best equilibrium of properties was attained at 5 wt % HDI-GO. The method developed herein opens up a versatile route to prepare multifunctional graphene-based nanocomposites with conductive polymers for a broad range of applications including flexible electronics and organic solar cells. Full article

(This article belongs to the Special Issue Carbon-Based Polymer Nanocomposites for High-Performance Applications)

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10 pages, 2698 KiB

Open AccessEditor’s ChoiceArticle

Direct Writing Supercapacitors Using a Carbon Nanotube/Ag Nanoparticle-Based Ink on Cellulose Acetate Membrane Paper

by Xipeng Guan, Lin Cao, Qin Huang, Debin Kong, Peng Zhang, Huaijun Lin, Wei Li, Zhidan Lin and Hong Yuan

Polymers 2019, 11(6), 973; https://doi.org/10.3390/polym11060973 - 03 Jun 2019

Cited by 23 | Viewed by 3765

Abstract

In this work, we present a cellulose acetate membrane flexible supercapacitor prepared through a direct writing method. A carbon nanotube (CNT) and silver (Ag) nanoparticle were prepared into ink for direct writing. The composite electrode displayed excellent electrochemical and mechanical electrochemical performance. Furthermore, [...] Read more.

In this work, we present a cellulose acetate membrane flexible supercapacitor prepared through a direct writing method. A carbon nanotube (CNT) and silver (Ag) nanoparticle were prepared into ink for direct writing. The composite electrode displayed excellent electrochemical and mechanical electrochemical performance. Furthermore, the CNT-Ag displayed the highest areal capacity of 72.8 F/cm³. The assembled device delivered a high areal capacity (17.68 F/cm³) at a current density of 0.5 mA/cm², a high areal energy (9.08–5.87 mWh/cm³) at a power density of 1.18–0.22 W/cm³, and showed no significant decrease in performance with a bending angle of 180°. The as-fabricated CNT/Ag electrodes exhibited good long-term cycling stability after 1000 time cycles with 75.92% capacitance retention. The direct writing was a simple, cost-effective, fast, and non-contact deposition method. This method has been used in current printed electronic devices and has potential applications in energy storage. Full article

(This article belongs to the Special Issue Carbon-Based Polymer Nanocomposites for High-Performance Applications)

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14 pages, 7558 KiB

Open AccessArticle

Wet-Spinning Assembly of Continuous, Highly Stable Hyaluronic/Multiwalled Carbon Nanotube Hybrid Microfibers

by Ting Zheng, Nuo Xu, Qi Kan, Hongbin Li, Chunrui Lu, Peng Zhang, Xiaodan Li, Dongxing Zhang and Xiaodong Wang

Polymers 2019, 11(5), 867; https://doi.org/10.3390/polym11050867 - 13 May 2019

Cited by 15 | Viewed by 3985

Abstract

Effective multiwalled carbon nanotube (MWCNT) fiber manufacturing methods have received a substantial amount of attention due to the low cost and excellent properties of MWCNTs. Here, we fabricated hybrid microfibers composed of hyaluronic acid (HA) and multiwalled carbon nanotubes (MWCNTs) by a wet-spinning [...] Read more.

Effective multiwalled carbon nanotube (MWCNT) fiber manufacturing methods have received a substantial amount of attention due to the low cost and excellent properties of MWCNTs. Here, we fabricated hybrid microfibers composed of hyaluronic acid (HA) and multiwalled carbon nanotubes (MWCNTs) by a wet-spinning method. HA acts as a biosurfactant and an ionic crosslinker, which improves the dispersion of MWCNTs and helps MWCNT to assemble into microfibers. The effects of HA concentration, dispersion time, injection speed, and MWCNT concentration on the formation, mechanical behavior, and conductivity of the HA/MWCNT hybrid microfibers were comprehensively investigated through SEM, UV-Vis spectroscopy, tensile testing, and conductivity testing. The obtained HA/MWCNT hybrid microfibers presented excellent tensile properties in regard to Young’s modulus (9.04 ± 1.13 GPa) and tensile strength (130.25 ± 10.78 MPa), and excellent flexibility and stability due to the superior mechanical and electrical properties of MWCNTs. This work presents an effective and easy-to-handle preparation method for high-performance MWCNT hybrid microfibers assembly, and the obtained HA/MWCNT hybrid microfibers have promising applications in the fields of energy storage, sensors, micro devices, intelligent materials, and high-performance fiber-reinforced composites. Full article

(This article belongs to the Special Issue Carbon-Based Polymer Nanocomposites for High-Performance Applications)

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16 pages, 11513 KiB

Open AccessArticle

A Combined In-Mold Decoration and Microcellular Injection Molding Method for Preparing Foamed Products with Improved Surface Appearance

by Wei Guo, Qing Yang, Huajie Mao, Zhenghua Meng, Lin Hua and Bo He

Polymers 2019, 11(5), 778; https://doi.org/10.3390/polym11050778 - 01 May 2019

Cited by 26 | Viewed by 6097

Abstract

A combined in-mold decoration and microcellular injection molding (IMD/MIM) method by integrating in-mold decoration injection molding (IMD) with microcellular injection molding (MIM) was proposed in this paper. To verify the effectiveness of the IMD/MIM method, comparisons of in-mold decoration injection molding (IMD), conventional [...] Read more.

A combined in-mold decoration and microcellular injection molding (IMD/MIM) method by integrating in-mold decoration injection molding (IMD) with microcellular injection molding (MIM) was proposed in this paper. To verify the effectiveness of the IMD/MIM method, comparisons of in-mold decoration injection molding (IMD), conventional injection molding (CIM), IMD/MIM and microcellular injection molding (MIM) simulations and experiments were performed. The results show that compared with MIM, the film flattens the bubbles that have not been cooled and turned to the surface, thus improving the surface quality of the parts. The existence of the film results in an asymmetrical temperature distribution along the thickness of the sample, and the higher temperature on the film side leads the cell to move toward it, thus obtaining a cell-offset part. However, the mechanical properties of the IMD/MIM splines are degraded due to the presence of cells, while specific mechanical properties similar to their solid counterparts are maintained. Besides, the existence of the film reduces the heat transfer coefficient of the film side so that the sides of the part are cooled asymmetrically, causing warpage. Full article

(This article belongs to the Special Issue Carbon-Based Polymer Nanocomposites for High-Performance Applications)

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11 pages, 3549 KiB

Open AccessEditor’s ChoiceArticle

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

by Fangfang Wang, Lajun Feng and Man Lu

Polymers 2019, 11(4), 714; https://doi.org/10.3390/polym11040714 - 19 Apr 2019

Cited by 23 | Viewed by 3685

Abstract

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 [...] Read more.

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. Full article

(This article belongs to the Special Issue Carbon-Based Polymer Nanocomposites for High-Performance Applications)

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15 pages, 26755 KiB

Open AccessArticle

Using an Ionic Liquid to Reduce the Electrical Percolation Threshold in Biobased Thermoplastic Polyurethane/Graphene Nanocomposites

by Nora Aranburu, Itziar Otaegi and Gonzalo Guerrica-Echevarria

Polymers 2019, 11(3), 435; https://doi.org/10.3390/polym11030435 - 06 Mar 2019

Cited by 12 | Viewed by 4328

Abstract

Biobased thermoplastic polyurethane (bTPU)/unmodified graphene (GR) nanocomposites (NCs) were obtained by melt-mixing in a lab-scaled conventional twin-screw extruder. Alternatively, GR was also modified with an ionic liquid (GR-IL) using a simple preparation method with the aim of improving the dispersion level. XRD diffractograms [...] Read more.

Biobased thermoplastic polyurethane (bTPU)/unmodified graphene (GR) nanocomposites (NCs) were obtained by melt-mixing in a lab-scaled conventional twin-screw extruder. Alternatively, GR was also modified with an ionic liquid (GR-IL) using a simple preparation method with the aim of improving the dispersion level. XRD diffractograms indicated a minor presence of well-ordered structures in both bTPU/GR and bTPU/GR-IL NCs, which also showed, as observed by TEM, nonuniform dispersion. Electrical conductivity measurements pointed to an improved dispersion level when GR was modified with the IL, because the bTPU/GR-IL NCs showed a significantly lower electrical percolation threshold (1.99 wt%) than the bTPU/GR NCs (3.21 wt%), as well as higher conductivity values. Young’s modulus increased upon the addition of the GR (by 65% with 4 wt%), as did the yield strength, while the ductile nature of the bTPU matrix maintained in all the compositions, with elongation at break values above 200%. This positive effect on the mechanical properties caused by the addition of GR maintained or slightly increased when GR-IL was used, pointing to the success of this method of modifying the nanofiller to obtain bTPU/GR NCs. Full article

(This article belongs to the Special Issue Carbon-Based Polymer Nanocomposites for High-Performance Applications)

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13 pages, 5145 KiB

Open AccessArticle

The Structure and Properties of Polyacrylonitrile Nascent Composite Fibers with Grafted Multi Walled Carbon Nanotubes Prepared by Wet Spinning Method

by Hailong Zhang, Ling Quan, Aijun Gao, Yuping Tong, Fengjun Shi and Lianghua Xu

Polymers 2019, 11(3), 422; https://doi.org/10.3390/polym11030422 - 05 Mar 2019

Cited by 21 | Viewed by 3676

Abstract

Polyacrylonitrile (PAN) grafted amino-functionalized multi walled carbon nanotubes (amino-MWCNTs) were synthesized by in situ polymerization under aqueous solvent. The grafted MWCNT/PAN nascent composite fibers were prepared by the wet spinning method. Fourier transform infrared spectroscopy and Raman spectroscopy indicated that the amino-MWCNTs and [...] Read more.

Polyacrylonitrile (PAN) grafted amino-functionalized multi walled carbon nanotubes (amino-MWCNTs) were synthesized by in situ polymerization under aqueous solvent. The grafted MWCNT/PAN nascent composite fibers were prepared by the wet spinning method. Fourier transform infrared spectroscopy and Raman spectroscopy indicated that the amino-MWCNTs and PAN macromolecular chains had interfacial interactions and formed chemical bonds. The grafting content of the PAN polymer on the amino-MWCNTs was up to 73.2% by thermo gravimetric analysis. The incorporation of the grafted MWCNTs improved the degree of crystallization and crystal size of PAN nascent fibers, and changed the thermal properties during exothermic processing in an air atmosphere. Morphology analysis and testing of mechanical properties showed that the grafted MWCNT/PAN nascent composite fibers with a more uniform diameter distribution and larger diameter had higher tensile strength and tensile modulus than the control PAN nascent fibers. Full article

(This article belongs to the Special Issue Carbon-Based Polymer Nanocomposites for High-Performance Applications)

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Jump to: Editorial, Research

30 pages, 10316 KiB

Open AccessEditor’s ChoiceReview

Carbon-Based Polymer Nanocomposite for High-Performance Energy Storage Applications

by Samarjeet Singh Siwal, Qibo Zhang, Nishu Devi and Vijay Kumar Thakur

Polymers 2020, 12(3), 505; https://doi.org/10.3390/polym12030505 - 26 Feb 2020

Cited by 137 | Viewed by 13115

Abstract

In recent years, numerous discoveries and investigations have been remarked for the development of carbon-based polymer nanocomposites. Carbon-based materials and their composites hold encouraging employment in a broad array of fields, for example, energy storage devices, fuel cells, membranes sensors, actuators, and electromagnetic [...] Read more.

In recent years, numerous discoveries and investigations have been remarked for the development of carbon-based polymer nanocomposites. Carbon-based materials and their composites hold encouraging employment in a broad array of fields, for example, energy storage devices, fuel cells, membranes sensors, actuators, and electromagnetic shielding. Carbon and its derivatives exhibit some remarkable features such as high conductivity, high surface area, excellent chemical endurance, and good mechanical durability. On the other hand, characteristics such as docility, lower price, and high environmental resistance are some of the unique properties of conducting polymers (CPs). To enhance the properties and performance, polymeric electrode materials can be modified suitably by metal oxides and carbon materials resulting in a composite that helps in the collection and accumulation of charges due to large surface area. The carbon-polymer nanocomposites assist in overcoming the difficulties arising in achieving the high performance of polymeric compounds and deliver high-performance composites that can be used in electrochemical energy storage devices. Carbon-based polymer nanocomposites have both advantages and disadvantages, so in this review, attempts are made to understand their synergistic behavior and resulting performance. The three electrochemical energy storage systems and the type of electrode materials used for them have been studied here in this article and some aspects for example morphology, exterior area, temperature, and approaches have been observed to influence the activity of electrochemical methods. This review article evaluates and compiles reported data to present a significant and extensive summary of the state of the art. Full article

(This article belongs to the Special Issue Carbon-Based Polymer Nanocomposites for High-Performance Applications)

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