Research

13 pages, 17915 KiB

Open AccessArticle

Ready-to-Use Recycled Carbon Fibres Decorated with Magnetic Nanoparticles: Functionalization after Recycling Process Using Supercritical Fluid Chemistry

by Sophie Martin, Tatjana Kosanovic Milickovic, Costas A. Charitidis and Sandy Moisan

J. Compos. Sci. 2023, 7(6), 236; https://doi.org/10.3390/jcs7060236 - 06 Jun 2023

Viewed by 993

Abstract

An innovative simultaneous process, using supercritical fluid (SCF) chemistry, was used to recycle uncured prepregs and to functionalize the recovered carbon fibres with Fe₃O₄ magnetic nanoparticles (MNPs), to produce a new type of secondary raw material suitable for composite applications. [...] Read more.

An innovative simultaneous process, using supercritical fluid (SCF) chemistry, was used to recycle uncured prepregs and to functionalize the recovered carbon fibres with Fe₃O₄ magnetic nanoparticles (MNPs), to produce a new type of secondary raw material suitable for composite applications. This specific functionalization allows the fibres to be heated by induction through a hysteresis loss mechanism characteristic for nanoparticle susceptor-embedded systems, for triggered healing properties and a potentially easy route for CF reclamation. Using SCF and hydrothermal conditions for recycling, functionalization of fibres can be performed in the same reactor, resulting in the creation of ready-to-use fibres and limiting the use organic solvent. After cutting the uncured prepreg to the desired length to fit in future applications, supercritical CO₂ extraction is performed to partially remove some components of the uncured prepreg matrix (step 1). Then, the recycled carbon fibres (rCFs), still embedded inside the remaining organic matrix, are brought into contact with reactants for the functionalization step (step 2). Two possibilities were studied: the direct synthesis of MNPs coated with PAA in hydrothermal conditions, and the deposition of already synthesized MNPs assisted by supercritical CO₂-acetone. No CF surface activation is needed thanks to the presence of functional groups due to the remaining matrix. After functionalization, ready-to-use material with homogeneous depositions of MNPs at the surface of rCF is produced, with a strong magnetic behaviour and without observed degradation of the fibres. Full article

(This article belongs to the Special Issue Multifunctional Composite Structures)

► Show Figures

Figure 1

12 pages, 4138 KiB

Open AccessArticle

Inductive Thermal Effect on Thermoplastic Nanocomposites with Magnetic Nanoparticles for Induced-Healing, Bonding and Debonding On-Demand Applications

by Maria Kanidi, Niki Loura, Anna Frengkou, Tatjana Kosanovic Milickovic, Aikaterini-Flora Trompeta and Costas Charitidis

J. Compos. Sci. 2023, 7(2), 74; https://doi.org/10.3390/jcs7020074 - 09 Feb 2023

Cited by 5 | Viewed by 1888

Abstract

In this study, the heating capacity of nanocomposite materials enhanced with magnetic nanoparticles was investigated through induction heating. Thermoplastic (TP) matrices of polypropylene (PP), thermoplastic polyurethane (TPU), polyamide (PA12), and polyetherketoneketone (PEKK) were compounded with 2.5–10 wt.% iron oxide-based magnetic nanoparticles (MNPs) using [...] Read more.

In this study, the heating capacity of nanocomposite materials enhanced with magnetic nanoparticles was investigated through induction heating. Thermoplastic (TP) matrices of polypropylene (PP), thermoplastic polyurethane (TPU), polyamide (PA12), and polyetherketoneketone (PEKK) were compounded with 2.5–10 wt.% iron oxide-based magnetic nanoparticles (MNPs) using a twin-screw extrusion system. Disk-shape specimens were prepared by 3D printing and injection molding. The heating capacity was examined as a function of exposure time, frequency, and power using a radio frequency (RF) generator with a solenoid inductor coil. All nanocomposite materials presented a temperature increase proportional to the MNPs’ concentration as a function of the exposure time in the magnetic field. The nanocomposites with a higher concentration of MNPs presented a rapid increase in temperature, resulting in polymer matrix melting in most of the trials. The operational parameters of the RF generator, such as the input power and the frequency, significantly affect the heating capacity of the specimens, higher input power, and higher frequencies and promote the rapid increase in temperature for all assessed nanocomposites, enabling induced-healing and bonding/debonding on-demand applications. Full article

(This article belongs to the Special Issue Multifunctional Composite Structures)

► Show Figures

Graphical abstract

16 pages, 4552 KiB

Open AccessArticle

Buckling Analysis of Functionally Graded Materials (FGM) Thin Plates with Various Circular Cutout Arrangements

by Adnan Alashkar, Mohamed Elkafrawy, Rami Hawileh and Mohammad AlHamaydeh

J. Compos. Sci. 2022, 6(9), 277; https://doi.org/10.3390/jcs6090277 - 18 Sep 2022

Cited by 11 | Viewed by 1748

Abstract

In this paper, several analyses were conducted to investigate the buckling behavior of Functionally Graded Material (FGM) thin plates with various circular cutout arrangements. The computer model was simulated using the Finite Element (FE) software ABAQUS. The developed model was validated by the [...] Read more.

In this paper, several analyses were conducted to investigate the buckling behavior of Functionally Graded Material (FGM) thin plates with various circular cutout arrangements. The computer model was simulated using the Finite Element (FE) software ABAQUS. The developed model was validated by the authors in previous research. A parametric analysis was employed to investigate the effect of plate thickness and circular cutout diameter on the buckling behavior of the FGM thin plates. The normalized buckling load was also calculated to compare the buckling performance of FGM plates with various dimensions. Moreover, von Mises stress analysis was examined to understand the yield capability of the FGM plates in addition to the buckling modes that show the stress distribution of the critical buckling stress. Hence, this research provides a comprehensive analysis to display the relation between the critical buckling load and the arrangement of the circular cutouts. The results show that the critical buckling load heavily depends on the dimension of the plate and the cutout size. For instance, an increase in the plate thickness and a decrease in the cutout diameter increase the critical buckling load. Moreover, the circular cutout in a horizontal arrangement exhibited the best buckling performance, and as the arrangement shifts to a vertical arrangement, the buckling performance deteriorates. Full article

(This article belongs to the Special Issue Multifunctional Composite Structures)

► Show Figures

Figure 1

18 pages, 4083 KiB

Open AccessArticle

Describing the Material Behavior of Steel and Carbon Fiber Reinforced Composites Using a Combined Damage-Plasticity Approach

by Jan Rehra, Christian Andriß, Sebastian Schmeer and Ulf P. Breuer

J. Compos. Sci. 2022, 6(8), 235; https://doi.org/10.3390/jcs6080235 - 10 Aug 2022

Viewed by 1820

Abstract

Metal fiber hybrids (MFH) exhibit outstanding mechanical properties. They combine the advantages of ductile metallic materials with the well-known advantages of classical glass or carbon fibers in polymer matrices. Previous research has shown that these hybrid material concepts can improve structural integrity and [...] Read more.

Metal fiber hybrids (MFH) exhibit outstanding mechanical properties. They combine the advantages of ductile metallic materials with the well-known advantages of classical glass or carbon fibers in polymer matrices. Previous research has shown that these hybrid material concepts can improve structural integrity and energy absorption while maintaining their excellent weight-specific mechanical properties as well as allowing a wider range of multifunctional applications. In today’s component design process, simulation is a powerful tool for engineers to exploit the full mechanical potential of the material used. However, describing the material behavior including its multifunctional usability in numerically aided design processes of components is currently one of the major challenges for MFH. Against this background, this work focuses on the development and evaluation of a description method for MFH in the finite element analysis (FEA). A steel and carbon fiber reinforced epoxy resin (SCFRP) with hybridization at the laminate level is chosen as the reference material. To describe the behavior of unidirectional steel fiber reinforced plastic (SFRP) layers, a material model combining an orthotropic damage model and a 1D-plasticity model is proposed and implemented as a user-defined subroutine for LS-Dyna. In addition, SCFRP laminates are manufactured, tested under tensile loading, and used to parameterize the material models and to validate the description method for SCFRP. In this study, it is shown that the description method in combination with the newly developed material model is able to describe the complex failure mechanism of SCFRP. In particular, with respect to the material behavior up to the failure of the carbon fibers, a very good mapping accuracy can be achieved. Strain localization effects occur in both numerically predicted and experimentally measured post-failure behavior. Therefore, it could be concluded that the accuracy of the numerical predictions strongly depends on the geometric resolution of the discretization. Full article

(This article belongs to the Special Issue Multifunctional Composite Structures)

► Show Figures

Figure 1

11 pages, 2287 KiB

Open AccessArticle

Gelatin/Cellulose Nanofiber-Based Functional Nanocomposite Film Incorporated with Zinc Oxide Nanoparticles

by Swarup Roy, Deblina Biswas and Jong-Whan Rhim

J. Compos. Sci. 2022, 6(8), 223; https://doi.org/10.3390/jcs6080223 - 04 Aug 2022

Cited by 11 | Viewed by 1994

Abstract

A novel bio-based nanocomposite film was developed using the combination of gelatine and cellulose nanofiber (CNF) as a polymer matrix and zinc oxide nanoparticles (ZnONP) as nanofillers. The nanocomposite film solution was developed using simple solution mixing and film prepared by the following [...] Read more.

A novel bio-based nanocomposite film was developed using the combination of gelatine and cellulose nanofiber (CNF) as a polymer matrix and zinc oxide nanoparticles (ZnONP) as nanofillers. The nanocomposite film solution was developed using simple solution mixing and film prepared by the following casting methods. The fabricated nanocomposite film containing 2 wt% of ZnONP shows excellent UV-light barrier properties (>95%) and high transparency (>75%). The presence of ZnONP also improves the mechanical strength of the film by ~30% compared to pristine gelatin/CNF-based film, while the flexibility and rigidity of the nanocomposite film were also slightly improved. The addition of ZnONP slightly increased (~10%) the hydrophobicity while the water vapor barrier properties remain unaltered. The hydrodynamic properties of the bio-based film were also changed in the presence of ZnONP, moisture content and the swelling ratio slightly enhanced, whereas water solubility was decreased. Moreover, the integration of ZnONP introduced antibacterial activity toward foodborne pathogens. The fabricated bio-based nanocomposite film could be useful in active packaging applications. Full article

(This article belongs to the Special Issue Multifunctional Composite Structures)

► Show Figures

Figure 1

19 pages, 8191 KiB

Open AccessArticle

Effect of Graphene Nanofibers on the Morphological, Structural, Thermal, Phase Transitions and Mechanical Characteristics in Metallocene iPP Based Nanocomposites

by Sandra Novo, Carmen Fonseca, Rosario Benavente, Enrique Blázquez-Blázquez, María L. Cerrada and Ernesto Pérez

J. Compos. Sci. 2022, 6(6), 161; https://doi.org/10.3390/jcs6060161 - 01 Jun 2022

Cited by 2 | Viewed by 1494

Abstract

Several nanocomposites were prepared by extrusion from a commercial metallocene-type isotactic polypropylene (iPP) and different amounts of two types of graphene (G) nanofibers: ones with a high specific surface, named GHS, and the others with a low specific surface, labeled as GLS. The [...] Read more.

Several nanocomposites were prepared by extrusion from a commercial metallocene-type isotactic polypropylene (iPP) and different amounts of two types of graphene (G) nanofibers: ones with a high specific surface, named GHS, and the others with a low specific surface, labeled as GLS. The number of graphene layers was found to be around eight for GLS and about five in the GHS. Scanning electron microscopy (SEM) images of the resultant iPP nanocomposites showed a better homogeneity in the dispersion of the GLS nanofibers within the polymeric matrix compared with the distribution observed for the GHS ones. Crystallinity in the nanocomposites turned out to be dependent upon graphene content and upon thermal treatment applied during film preparation, the effect of the nature of the nanofiber being negligible. Graphene exerted a noticeable nucleating effect in the iPP crystallization. Furthermore, thermal stability was enlarged, shifting to higher temperatures, with increasing nanofiber amount. The mechanical response changed significantly with nanofiber type, along with its content, together with the thermal treatment applied to the nanocomposites. Features of nanofiber surface played a key role in the ultimate properties related to superficial and bulk stiffness. Full article

(This article belongs to the Special Issue Multifunctional Composite Structures)

► Show Figures

Graphical abstract

22 pages, 9204 KiB

Open AccessArticle

Carbon Fiber Reinforced Plastics in Space: Life Cycle Assessment towards Improved Sustainability of Space Vehicles

by Vasiliki Stergiou, Georgios Konstantopoulos and Costas A. Charitidis

J. Compos. Sci. 2022, 6(5), 144; https://doi.org/10.3390/jcs6050144 - 16 May 2022

Cited by 12 | Viewed by 4171

Abstract

Composite materials, specifically carbon fiber reinforced plastics (CFRPs), are used in various applications such as the automotive, aerospace, and renewable energy industries, thus increasing their global production and volume consumption and creating a subsequent increase in CFRP waste. Especially in space applications and [...] Read more.

Composite materials, specifically carbon fiber reinforced plastics (CFRPs), are used in various applications such as the automotive, aerospace, and renewable energy industries, thus increasing their global production and volume consumption and creating a subsequent increase in CFRP waste. Especially in space applications and Vega launcher construction, the use of CFRP components to replace metal envisages significant benefits in the use phase by reducing weight and fuel consumption requirements. The current and future waste management and environmental legislation, considering the actual and impending EU framework on waste management, requires all engineering materials to be properly recovered and recycled from EoL products. In this study, the potential of recycling and the subsequent environmental benefits have been assessed by investigating the EoL of CFRPs through a life cycle assessment (LCA). LCA is a valuable tool for evaluating a composite material’s environmental ecological burdens over its lifetime. Therefore, it is important to the composites industry as a material selection tool when determining the applicability of recycled composites in the design phase. Particularly, the benefits from recycling methods were systematically studied in order to assess the environmental impacts of EoL scenarios, to underline the importance and necessity for the maturity increase in recycling technologies for CFRPs. Full article

(This article belongs to the Special Issue Multifunctional Composite Structures)

► Show Figures

Figure 1

25 pages, 5762 KiB

Open AccessArticle

Fused Filament Fabrication 3D Printing: Quantification of Exposure to Airborne Particles

by Stratos Saliakas, Panagiotis Karayannis, Ioannis Kokkinopoulos, Spyridon Damilos, Eleni Gkartzou, Panagiotis Zouboulis, Anna Karatza and Elias P. Koumoulos

J. Compos. Sci. 2022, 6(5), 119; https://doi.org/10.3390/jcs6050119 - 19 Apr 2022

Cited by 5 | Viewed by 2989

Abstract

Fused Filament Fabrication (FFF) has been established as a widely practiced Additive Manufacturing technique, using various thermoplastic filaments. Carbon fibre (CF) additives enhance mechanical properties of the materials. The main operational hazard of the FFF technique explored in the literature is the emission [...] Read more.

Fused Filament Fabrication (FFF) has been established as a widely practiced Additive Manufacturing technique, using various thermoplastic filaments. Carbon fibre (CF) additives enhance mechanical properties of the materials. The main operational hazard of the FFF technique explored in the literature is the emission of Ultrafine Particles and Volatile Organic Compounds. Exposure data regarding novel materials and larger scale operations is, however, still lacking. In this work, a thorough exposure assessment measurement campaign is presented for a workplace applying FFF 3D printing in various setups (four different commercial devices, including a modified commercial printer) and applying various materials (polylactic acid, thermoplastic polyurethane, copolyamide, polyethylene terephthalate glycol) and CF-reinforced thermoplastics (thermoplastic polyurethane, polylactic acid, polyamide). Portable exposure assessment instruments are employed, based on an established methodology, to study the airborne particle exposure potential of each process setup. The results revealed a distinct exposure profile for each process, necessitating a different safety approach per setup. Crucially, high potential for exposure is detected in processes with two printers working simultaneously. An updated engineering control scheme is applied to control exposures for the modified commercial printer. The establishment of a flexible safety system is vital for workplaces that apply FFF 3D printing. Full article

(This article belongs to the Special Issue Multifunctional Composite Structures)

► Show Figures

Figure 1

12 pages, 2734 KiB

Open AccessArticle

Durability of Shape Memory Polymer Composite Laminates under Thermo-Mechanical Cycling

by Fabrizio Quadrini, Leandro Iorio, Denise Bellisario and Loredana Santo

J. Compos. Sci. 2022, 6(3), 91; https://doi.org/10.3390/jcs6030091 - 15 Mar 2022

Cited by 2 | Viewed by 2214

Abstract

Shape memory polymer composites (SMPCs) have been manufactured by press moulding of carbon fibre-reinforced (CFR) prepregs with SMP interlayers. SMPC laminates have been produced with different numbers of CFR plies (i.e., 2, 4, 6, and 8) and different thicknesses of the SMP interlayers [...] Read more.

Shape memory polymer composites (SMPCs) have been manufactured by press moulding of carbon fibre-reinforced (CFR) prepregs with SMP interlayers. SMPC laminates have been produced with different numbers of CFR plies (i.e., 2, 4, 6, and 8) and different thicknesses of the SMP interlayers (i.e., 100 and 300 µm) for a sum of eight combinations. Co-curing of the prepreg plies and the SMP interlayers has led to an optimal adhesion of structural and functional plies, which has been confirmed by following testing. Single thermo-mechanical cycles at increasing strains (i.e., 0.06%, 0.12%, and 0.18%) and multiple cycling have been performed to test SMPC laminate durability. Delamination and fibre cracking were not observed during testing, and laminates showed a reproducible SM behaviour after 10 consecutive thermo-mechanical cycles. SM properties have been extracted from tests in terms of residual and memory loads as well as shape fixity and shape recovery. These data may be used for comparison of the performances of the different laminates, and as a first base for designing SMPC structures. Thin laminates exhibit lower recovery loads but higher shape fixity than thick ones, but the shape recovery is very high for all the SMPCs, with an average of 98%. Full article

(This article belongs to the Special Issue Multifunctional Composite Structures)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Multifunctional Composite Structures

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Published Papers (9 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI