Editorial

3 pages, 207 KiB

Open AccessEditorial

Carbon-Based Polymer Nanocomposites for High-Performance Applications II

by Ana M. Díez-Pascual

Polymers 2022, 14(5), 870; https://doi.org/10.3390/polym14050870 - 23 Feb 2022

Cited by 4 | Viewed by 1557

In the field of science and technology, carbon-based nanomaterials, such as carbon nanotubes (CNTs), graphene, graphene oxide, graphene quantum dots (GQDs), fullerenes, and so forth, are becoming very attractive for a wide number of applications [...] Full article

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

Research

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17 pages, 4352 KiB

Open AccessArticle

Enhanced Piezoelectric Properties of Poly(Vinylidenefluoride-Co-Trifluoroethylene)/Carbon-Based Nanomaterial Composite Films for Pressure Sensing Applications

by Jia-Wun Li, Chen-Yang Huang, Kuan-Yu Chen, Jian-Xun Chen, Xiao-Yong Hsu, Yan-Feng Chen, Chung-Feng Jeffrey Kuo, Chih-Chia Cheng, Maw-Cherng Suen and Chih-Wei Chiu

Polymers 2020, 12(12), 2999; https://doi.org/10.3390/polym12122999 - 16 Dec 2020

Cited by 18 | Viewed by 2742

Abstract

In this study, heat and polarization treatments were applied to poly(vinylidenefluoride-co-trifluoroethylene (PVDF-TrFE) films to improve their crystallinity and piezoelectric effect. Carbon-based nanomaterials (CBNs) of multiple dimensions (i.e., modified zero-dimensional (0D) carbon black (OCB), one-dimensional (1D) modified carbon nanotubes (CNT–COOH) and two-dimensional (2D) graphene [...] Read more.

In this study, heat and polarization treatments were applied to poly(vinylidenefluoride-co-trifluoroethylene (PVDF-TrFE) films to improve their crystallinity and piezoelectric effect. Carbon-based nanomaterials (CBNs) of multiple dimensions (i.e., modified zero-dimensional (0D) carbon black (OCB), one-dimensional (1D) modified carbon nanotubes (CNT–COOH) and two-dimensional (2D) graphene oxide (GO)) were added to the copolymer to study the effects of different CBN dimensions on the crystallinity and piezoelectric effect of PVDF-TrFE films. Additionally, amphiphilic polymeric dispersants were added to improve the dispersibility of CBNs; the dispersant was synthesized by the amidation, and imidization reactions of styrene-maleic anhydride copolymer (SMAz) and polyoxyalkylene amine (M1000). Polymer solutions with different ratios of CBN to dispersant (z = 10:1, 5:1, 1:1, 1:5, 1:10) were prepared. The enhanced dispersibility enabled the fluorine atoms in the PVDF-TrFE molecular chain to more efficiently form hydrogen bonds with the –COOH group in the CBN, thereby increasing the content of the β crystal phase (the origin of the piezoelectric effect) of the film. Therefore, the resulting film exhibited a higher output voltage on the application side and better sensitivity on the sensing element. The addition of CNT–COOH and polymeric dispersants increased the β-phase content in PVDF-TrFE from 73.6% to 86.4%, which in turn raised the piezoelectric coefficient from 19.8 ± 1.0 to 26.4 ± 1.3 pC/N. The composite film-based pressure sensor also exhibited a high degree of sensitivity, which is expected to have commercial potential in the future. Full article

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

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22 pages, 6936 KiB

Open AccessArticle

Thermal Mechanical Properties of Graphene Nano-Composites with Kevlar-Nomex Copolymer: A Comparison of the Physical and Chemical Interactions

by Jessy Shiju, Fakhreia Al-Sagheer and Zahoor Ahmad

Polymers 2020, 12(11), 2740; https://doi.org/10.3390/polym12112740 - 19 Nov 2020

Cited by 16 | Viewed by 2771

Abstract

This paper reports the preparation of Kevlar-Nomex copolymer nano-composites with exfoliated pristine and functionalized graphene sheets (Grs). The graphene oxide (GrO) platelets were amidized by the reaction of amine-terminated aramid (Ar) with the functional groups present on the GrO surface to prepare the [...] Read more.

This paper reports the preparation of Kevlar-Nomex copolymer nano-composites with exfoliated pristine and functionalized graphene sheets (Grs). The graphene oxide (GrO) platelets were amidized by the reaction of amine-terminated aramid (Ar) with the functional groups present on the GrO surface to prepare the nano-composites films with different loadings of GrO. Chemical changes involved during the oxidation and subsequent amidation were monitored by Raman, FTIR and XP spectroscopic analyses. Morphology of the composite films was studied by atomic force and scanning electron microscopies. Viscoelastic properties of the hybrid films were studied for their glass transition temperature (Tg) and storage modulus by dynamical mechanical thermal analysis (DMTA). A higher shift in glass transition temperature was obtained by chemically binding the aramid copolymer chains on the functionalized Gr sheets. The increase in tensile strength and modulus at various loadings of GrO are compared with the composites using pristine Gr. The effect of interfacial interactions between the matrix chains and the reinforcement on the properties of these hybrids have been explained. Full article

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

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10 pages, 2320 KiB

Open AccessArticle

Preparation and Thermoelectric Properties of Semiconducting Single-Walled Carbon Nanotubes/Regioregular Poly(3-dodecylthiophene) Composite Films

by Mengdi Wang, Qin Yao, Sanyin Qu, Yanling Chen, Hui Li and Lidong Chen

Polymers 2020, 12(11), 2720; https://doi.org/10.3390/polym12112720 - 17 Nov 2020

Cited by 4 | Viewed by 1801

Abstract

Single-walled carbon nanotubes (SWNTs) have been widely used as leading additives for improving the thermoelectric properties of organic materials, due to their unique structure and excellent electronic transport properties. However, the as-synthesized SWNTs are mixtures (mix-SWNT) of semiconducting (sc-SWNT) and metallic (met-SWNT) carbon [...] Read more.

Single-walled carbon nanotubes (SWNTs) have been widely used as leading additives for improving the thermoelectric properties of organic materials, due to their unique structure and excellent electronic transport properties. However, the as-synthesized SWNTs are mixtures (mix-SWNT) of semiconducting (sc-SWNT) and metallic (met-SWNT) carbon nanotubes. The significantly different surface character and transport behavior of sc-SWNT and met-SWNT frequently raise the difficulty of modifying microstructures, and tuning transport properties of SWNTs/organic composites, when using mix-SWNTs as dispersion phase. Herein, we prepared high quality sc-SWNTs/rr-P3DDT composite film by presorting pure sc-SWNT from the raw mix-SWNTs using regioregular poly(3-dodecylthiophene) (rr-P3DDT). Both the smoothness and compactness of sc-SWNTs/rr-P3DDT are great improved, as compared with the mix-SWNTs/rr-P3DDT films, and the sc-SWNTs are well-dispersed and uniformly wrapped by rr-P3DDT with diameter less than 50 nm. The significantly enhanced Seebeck coefficients and power factors are obtained in the sc-SWNT/rr-P3DDT samples. As the result, the maximum power factor of 60 μW/mK² in 50 wt% sc-SWNTs sample is 70% higher than that of mix-SWNTs/P3DDT sample. This work reveals the effectiveness of pure semiconductor SWNTs as fillers to optimize the thermoelectric properties of CNT/polymer nano-composites. Full article

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

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18 pages, 2761 KiB

Open AccessArticle

Effect of MWCNT Surface Functionalisation and Distribution on Compressive Properties of Kenaf and Hybrid Kenaf/Glass Fibres Reinforced Polymer Composites

by Napisah Sapiai, Aidah Jumahat, Mohammad Jawaid and Anish Khan

Polymers 2020, 12(11), 2522; https://doi.org/10.3390/polym12112522 - 29 Oct 2020

Cited by 21 | Viewed by 2265

Abstract

The aim of this study is to evaluate the effect of surface treated multi wall carbon nanotubes (MWCNTs) on compressive properties of the unidirectional (UD) kenaf and hybrid woven glass/UD kenaf fibre reinforced polymer composites. The MWCNTs were first treated using concentrated acid [...] Read more.

The aim of this study is to evaluate the effect of surface treated multi wall carbon nanotubes (MWCNTs) on compressive properties of the unidirectional (UD) kenaf and hybrid woven glass/UD kenaf fibre reinforced polymer composites. The MWCNTs were first treated using concentrated acid (a mix of H₂SO₄ and HNO₃) and silane (three-aminoprophyltriethoxysilane) in order to improve the dispersion within the epoxy matrix using a high shear roll milling technique. In this study, nanomodified epoxies were prepared using 0.5, 0.75 and 1.0 wt % of pristine MWCNT (PCNT), acid treated MWCNT (ACNT) and silane treated MWCNT (SCNT). These nanomodified epoxies were then used for the fabrication of kenaf and hybrid composites using combination of filament winding and resin impregnation. The uniaxial compression test was conducted using a universal testing machine according to the ASTM D3410 standard. The morphology of fractured samples was observed and analysed using scanning electron microscopy (SEM) in order to evaluate the failure behaviour and mechanisms involved during compression. It was found that the addition of treated MWCNT (ACNT and SCNT) improved the compressive properties of kenaf and hybrid composites as compared to those of untreated-MWCNT (PCNT). The addition of 1.0 wt % of SCNT exhibited good compressive properties in both kenaf and hybrid composite systems. The compressive modulus and strength increased by 73.25% and 20.15%, respectively, for composites made of 1.0 wt % SCNT and Kenaf (1.0SCNT/K). For the hybrid composites, the compressive modulus and strength increased by 21.18% and 7.73% for composites made of 1.0 wt % SCNT filled G/K composites (1.0SCNT/G/K). Full article

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

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15 pages, 3448 KiB

Open AccessArticle

A Stimulus-Responsive Polymer Composite Surface with Magnetic Field-Governed Wetting and Photocatalytic Properties

by László Mérai, Ágota Deák, Dániel Sebők, Ákos Kukovecz, Imre Dékány and László Janovák

Polymers 2020, 12(9), 1890; https://doi.org/10.3390/polym12091890 - 21 Aug 2020

Cited by 8 | Viewed by 2582

Abstract

With the increasing demand for liquid manipulation and microfluidic techniques, surfaces with real-time tunable wetting properties are becoming the focus of materials science researches. In this study, we present a simple preparation method for a 0.5–4 µm carbonyl iron (carbonyl Fe) loaded polydimethylsiloxane [...] Read more.

With the increasing demand for liquid manipulation and microfluidic techniques, surfaces with real-time tunable wetting properties are becoming the focus of materials science researches. In this study, we present a simple preparation method for a 0.5–4 µm carbonyl iron (carbonyl Fe) loaded polydimethylsiloxane (PDMS)-based magnetic composite coating with magnetic field-tailored wetting properties. Moreover, the embedded 6.3–16.7 wt.% Ag-TiO₂ plasmonic photocatalyst (d~50 nm) content provides additional visible light photoreactivity to the external stimuli-responsive composite grass surfaces, while the efficiency of this photocatalytic behavior also turned out to be dependent on the external magnetic field. The inclusion of the photocatalyst introduced hierarchical surface roughness to the micro-grass, resulting in the broadening of the achievable contact and sliding angle ranges. The photocatalyst-infused coatings are also capable of catching and releasing water droplets, which alongside their multifunctional (photocatalytic activity and tunable wetting characteristics) nature makes surfaces of this kind the novel sophisticated tools of liquid manipulation. Full article

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

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12 pages, 3254 KiB

Open AccessArticle

Near-Linear Responsive and Wide-Range Pressure and Stretch Sensor Based on Hierarchical Graphene-Based Structures via Solvent-Free Preparation

by Jian Wang, Ryuki Suzuki, Kentaro Ogata, Takuto Nakamura, Aixue Dong and Wei Weng

Polymers 2020, 12(8), 1814; https://doi.org/10.3390/polym12081814 - 13 Aug 2020

Cited by 7 | Viewed by 2809

Abstract

Flexible and wearable electronics have huge potential applications in human motion detection, human–computer interaction, and context identification, which have promoted the rapid development of flexible sensors. So far the sensor manufacturing techniques are complex and require a large number of organic solvents, which [...] Read more.

Flexible and wearable electronics have huge potential applications in human motion detection, human–computer interaction, and context identification, which have promoted the rapid development of flexible sensors. So far the sensor manufacturing techniques are complex and require a large number of organic solvents, which are harmful not only to human health but also to the environment. Here, we propose a facile solvent-free preparation toward a flexible pressure and stretch sensor based on a hierarchical layer of graphene nanoplates. The resulting sensor exhibits many merits, including near-linear response, low strain detection limits to 0.1%, large strain gauge factor up to 36.2, and excellent cyclic stability withstanding more than 1000 cycles. Besides, the sensor has an extraordinary pressure range as large as 700 kPa. Compared to most of the reported graphene-based sensors, this work uses a completely environmental-friendly method that does not contain any organic solvents. Moreover, the sensor can practically realize the delicate detection of human body activity, speech recognition, and handwriting recognition, demonstrating a huge potential for wearable sensors. Full article

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

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15 pages, 6180 KiB

Open AccessArticle

Influence of Reduced Graphene Oxide on the Electropolymerization of 5-Amino-1-naphthol and the Interaction of 1,4-Phenylene Diisothiocyanate with the Poly(5-Amino-1-naphtol)/Reduced Graphene Oxide Composite

by Mihaela Baibarac, Monica Daescu, Marcela Socol, Cristina Bartha, Cătălin Negrila and Szilárd N. Fejer

Polymers 2020, 12(6), 1299; https://doi.org/10.3390/polym12061299 - 05 Jun 2020

Cited by 4 | Viewed by 2653

Abstract

A new composite base on reduced graphene oxide (RGO) and poly(5-amino-1-naphthol) (P5A1N) was synthesized by the electrochemical polymerization of 5-amino-1-naphthol (5A1N) in the presence of HClO₄ and H₄SiW₁₂O₄₀ onto the surface of Au electrode covered with the [...] Read more.

A new composite base on reduced graphene oxide (RGO) and poly(5-amino-1-naphthol) (P5A1N) was synthesized by the electrochemical polymerization of 5-amino-1-naphthol (5A1N) in the presence of HClO₄ and H₄SiW₁₂O₄₀ onto the surface of Au electrode covered with the RGO sheets. The linear dependence of the current densities of the anodic and cathodic peaks with the scan rate of the potential range (0; 0.8) V vs. SCE, reported during electropolymerization of 5A1N, indicates an electron transfer that is controlled by diffusion. A covalent functionalization of the RGO sheets with P5A1N is argued by: (i) the simultaneous disappearance of the IR band at 1584 cm⁻¹ and the appearance of the new IR bands at 812, 976 and 3744 cm⁻¹, and (ii) the appearance of two Raman lines at 738 and 1428 cm⁻¹. An application of the RGO sheets covalently functionalized with P5A1N is demonstrated to support 1,4-phenylene diisothiocyanate (PDITC), a compound used as a cross-linking agent for various biological applications. The chemical adsorption of PDITC onto the RGO sheets covalently functionalized with P5A1N, which involves the appearance of new functional groups of the type thiourea, was proven by Raman scattering and IR spectroscopy. Full article

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

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