Fiber-reinforced Nanocomposites Research Articles

Structural integrity of glass fiber reinforced nanocomposites under hydrothermal aging for offshore structure applications

Glass fiber composites are widely used in offshore structures for marine application due to their exceptional strength-to-weight ratio, corrosion resistance, and durability. As offshore structures are exposed to harsh environmental conditions, including saltwater, fluctuating temperatures, and hydrothermal influences, understanding the effects of aging on structural integrity on glass fiber composites becomes very important. In this study glass fiber-reinforced epoxy nanocomposites with 1 % and 2 % nano Al2O3 reinforcement were produced using the vacuum-assisted resin transfer molding. These composites were subjected to a three-month aging process in artificial seawater at a temperature of 70 °C. Mechanical properties were assessed through Tensile and Flexural Tests, while thermal properties were analyzed via TGA, DTA, and DSC analysis. To examine the structural characteristics, Fourier Transform Infrared (FT-IR) spectrophotometry was utilized, and SEM analysis was conducted. Wear properties were evaluated through dry sliding wear tests. Water absorption properties were determined in a precisely controlled seawater bath. The findings reveal that the incorporation of 1 % nano Al2O3 effectively diminishes the water absorption rate, thereby safeguarding the mechanical, thermal, and structural properties within a hydrothermal environment.

High Performance and Reprocessable In Situ Generated Nanofiber Reinforced Composites Based on Liquid Crystal Polyarylate.

Polymers are playing important roles in the rapid development of triboelectric nanogenerators (TENGs); However, most polymers cannot meet the high requirements of thermomechanical performance; Thus, various polymeric composites are developed for triboelectric layer. These composites are hardly recycled since their reinforcements are unevenly distributed after reprocessing, which limits the sustainable development of TENGs. To solve the above challenges, in situ generated nanofiber reinforced composites (NFRCs) based on single-component liquid crystal polyarylate (LCP) are designed and prepared via a one-step polycondensation. Nonlinear naphthalene (NDA) widens the processing window of LCP without destabilizing the liquid crystal phase. The NDA-rich domains act as a matrix while the NDA-poor domains with higher rigidity form oriented nanofibers to achieve self-reinforcement. The resultant NFRCs possess high glass transition temperature (Tg > 220 °C) and storage modulus (E' = 0.1GPa at 350 °C), which are far beyond existing triboelectric polymers, typically Tg < 110 °C and E' < 0.1MPa (flowable) at 350 °C. Furthermore, NFRC-based TENG exhibits superior electrical output performance and retention rate (>90%) after reprocessing; Overall, this work offers a new design principle to prepare self-reinforced composites, which paves a way to explore high performance materials.

Retracted: Effectiveness of Nanosilica on Enhancing the Mechanical and Microstructure Properties of Kenaf/Carbon Fiber-Reinforced Epoxy-Based Nanocomposites

Retracted: Effectiveness of Nanosilica on Enhancing the Mechanical and Microstructure Properties of Kenaf/Carbon Fiber-Reinforced Epoxy-Based Nanocomposites

Effect of hybridization on camphor soot-embedded palmyra fiber-reinforced nylon nanocomposites

In the present study, camphor soot-filled palmyra fiber-reinforced nylon-6 hybrid nanocomposites (CPFNnC) were prepared using a twin-screw extruder with different wt% of CPFNnC (0, 3, 6 or 9 wt%). These composites were characterized to study their thermal, mechanical and rheological properties. Thermogravimetric analysis showed a marginal increase in thermal stability with 6 wt% CPFNnC. Differential scanning calorimetry curves showed a slight increment in the melting point in CPFNnC, while degradation temperature decreased with fiber content. Dynamic mechanical analysis indicated a maximum storage modulus for 6 wt% CPFNnC at 803 MPa compared with fiber-free nylon-6 (696 MPa at 25 °C). Tan δ for 3 wt% CPFNnC showed a better damping effect due to the existence of palmyra fibers. Creep results indicated that CPFNnC containing 6 wt% fibers has a minimum depth impression of 0.124 mm compared with fiber-free nylon with 0.146 mm. Scanning electron microscopy revealed a uniform distribution of modified palmyra fibers in the matrix and brittle fracture was observed in the CPFNnC. Compared with fiber-free nylon-6, the tensile strength, flexural strength and density of the CPFNnC increased with increase in fiber content; however, the impact strength was reduced and a lower melt flow index was found.

Deformation-dependent electrical resistivity of fiber-reinforced nanocomposites: A concentric cylindrical model approach

Fiber-reinforced composites have seen growing demands and widespread use in a variety of fields, including aviation, civil engineering, and the automobile industry. Fiber-reinforced composites must be monitored by nondestructive methods because of their tendency to have complicated and often visually undetectable failure mechanisms. Incorporating self-sensing capabilities into composites through nanofiller modification to leverage the piezoresistive effect is one approach for monitoring these materials. In this method, electrical resistivity is a function of mechanical strains, allowing for intrinsic self-sensing. To date, predictive modeling efforts in this field have mostly concentrated on microscale piezoresistivity. Research on modeling resistivity changes in macroscale fiber–matrix material systems has been limited, and even less research has been conducted to evaluate the impact of continuous fiber reinforcement. To bridge this gap, an analytical model that predicts changes in the resistivity of a material system with nanofiller-modified polymer and continuous fiber reinforcement is proposed. The cornerstone of this strategy is the establishment of an electrical concentric cylindrical model. We begin by defining our domain, which consists of concentric cylinders representing a continuous reinforcing fiber surrounded by a nanofiller-modified matrix. Next, the system is homogenized such that we can predict the change in the axial and transverse resistivity of the concentric cylinders. It is envisaged that the results herein presented will serve as a stepping stone towards the creation of a laminate theory of piezoresistivity.

Pineapple fruit residue-based nanofibre composites: Preparation and characterizations

Abstract Natural fibre composites are widespread for being eco-friendly and having unique properties. This study prepared nanocomposites by water evaporation using cellulose nanofibres (CNFs) as fillers and natural rubber (NR) latex as the matrix. Here, CNFs were extracted from the “pineapple fruit residue,” a waste material in juice industries. These fibre-reinforced nanocomposites were prepared under three different weight/volume percentages (5%, 10%, and 15%) and analysed for their mechanical and thermal properties. Furthermore, the morphology and distribution of CNFs in the NR matrix were examined by scanning electron microscopy and Fourier transform-infrared (FT-IR) analysis. The study found that CNFs were randomly oriented and evenly distributed in the nanocomposite. CNFs were detected by FT-IR spectroscopy in the NR matrix, as indicated by absorption peaks at 1,033 and 1,057 cm−1. Thermogravimetric analysis reveals increased thermal stability with more CNFs. Tensile strength and elastic modulus also increase. Pineapple fruit residue-based CNFs enhance mechanical and thermal properties of NR composites and can be considered an ideal natural reinforcing material.

Carbon Fiber-Reinforced Piezoelectric Nanocomposites: Design, Fabrication and Evaluation for Damage Detection and Energy Harvesting

Carbon Fiber-Reinforced Piezoelectric Nanocomposites: Design, Fabrication and Evaluation for Damage Detection and Energy Harvesting

Anisotropic reinforcement in polymer nanocomposites using dielectric-magnetic difunctional fibers

One-dimensional (1D) functional fibers have been widely used for the property enhancement of polymer nanocomposites. Modulating the orientations of fibers is crucial to maximizing the performances of the nanocomposites. In this work, we report anisotropic polymer nanocomposites enabled by dielectric-magnetic difunctional ceramic fibers, where the magnetic Fe2O3 nanoparticles (FO nps) were confined inside the dielectric ceramic fibers, to produce concurrent strong magnetism and high dielectric/piezoelectric responses. The difunctional fibers can rotate well along the direction of the external magnetic field during the nanocomposite processing, producing notable anisotropic enhancements of polymer nanocomposites. By computing the difference in magnetic and gravitational potential energy versus the internal thermal energy of the fibers that serve the alignment, we determined the optimal content of magnetic FO nps for producing a desirable alignment of fibers, while maintaining the high insulativity of nanocomposites. Finally, the resultant anisotropic polymer nanocomposites with aligned fibers present a maximum 85% enhancement in dielectric constant (ϵr) and 50% enhancement in piezoelectric coefficient (d33), compared to the nanocomposites with random fibers, while maintaining excellent elastic modulus and transmittance. Our work provides an effective strategy for the development of fiber-reinforced polymer nanocomposites with anisotropy and multi-functionality.

Mechanical Interlocking Approaches to the Prediction of Mechanical and Tribological Behavior of Natural Fiber-Reinforced Polymer Hybrid Nanocomposites or Automotive Applications

Polymer matrix composites synthesized with biodegradable natural fiber obtain a predominant structure with specific properties at a low-processing cost. The unique characteristics of polymer matrix composites were magnetized in automotive parts like top roof, panel, and seat frame applications. American Society for Testing and Materials (ASTM) G99 analyzed the wear characteristics of synthesized composites through a pin-on-disc wear tester with an EN32 steel disc. The epoxy hybrid composites have been synthesized via a conventional casting process assisted with a mechanical interlock technique to obtain a predominant structure with specific properties at a low-processing cost. The advanced composite contained different jute weights (50, 25, 50, and 75 g) and coconut coir (50, 70, 45, and 20 g) hybridized with graphite particles. ASTM D2240, D638, and D790 standards evaluated the fabricated composite hardness, tensile, and flexural strength. The Sample 4 hybrid composite found maximum hardness, tensile, and flexural strength of 27.41 ± 0.99 Hv, 51.69 ± 1.01MPa, and 55.94 ± 0.78 MPa, respectively. Sample 4 offered good wear resistance of their volumetric wear rate of 0.043 cm3 on 40 N average load at 0.25 m/s sliding speed. It is increased by 12% compared to Sample 1 at 40 N applied load on 2.5 m/s sliding speed.

Energy harvesting and wireless communication by carbon fiber-reinforced polymer-enhanced piezoelectric nanocomposites

Piezoelectric Internet of Things (IoT) sensors with energy-harvesting capabilities, which can convert mechanical energy into electrical energy, promote battery-less systems. Such sensors can harness the vibration generated by spacecraft and other moving objects, eliminating the need for external power sources or battery replacements, thereby improving the autonomy and reliability of the system. This study investigates the features of a novel piezoelectric vibration energy harvester (PVEH) that comprises a carbon fiber-reinforced polymer (CFRP) electrode. The CFRP electrode provides outstanding electrical conductivity (7190 S/m) and enhances the mechanical characteristics of the energy collector, thereby ensuring a steady electrical energy yield during resonance. The piezoelectric composite consists of potassium sodium niobate (KNN) nanoparticles mixed with epoxy resin. Results show that when the KNN content is about 30 vol%, the piezoelectric properties of d33 and d31 are 15.21 pC/N and − 5.68 pC/N, respectively. Under an applied displacement of 0.05 mm, the CFRP-reinforced PVEH (C-PVEH) provides an impressive output energy volume density of 89.61 μW/cm3, which is capable of lighting LED bulbs with ease. Notably, this technology shows great application potential for powering wireless communication systems, indicating a remarkable advancement in the field of self-powered IoT sensors. This study provides valuable insights into the potential application of this groundbreaking technology.

具有分级界面的纳米纤维增强聚合物复合材料: 用于高温介电储能应用

Flexible polymer nanocomposites reinforced by high-dielectric-constant ceramic nanofillers have shown great potential for dielectric energy storage applications in advanced electronic and electrical systems. However, it remains a challenge to improve their energy density and energy efficiency at high temperatures above 150°C. Here, we report a nanofiber-reinforced polyetherimide nanocomposite employing BN-BaTiO3 heterogeneous nanofibers as fillers, where the BN nanoparticles were embedded inside BaTiO3 nanofibers to create BN/BaTiO3/PEI hierarchical interfaces. The high dielectric constant and the geometric large aspect ratio of the BN-BaTiO3 heterogeneous nanofibers lead to simultaneously increased dielectric constant and breakdown strength of the nanocomposite over a broad temperature range. In particular, the emerging hierarchical BN/BaTiO3/PEI interfaces enable promoted density and energy level of traps for the mobile charges, which further suppresses the conduction loss and improves the breakdown strength under high temperatures, as confirmed by a combination of thermally stimulated depolarization current measurement and phase-field simulation. Finally, the nanocomposite with hierarchical interfaces boosts an ultrahigh energy density of 5.23 J cm−3 with an energy efficiency of > 90% at 150°C, which is the highest energy density reported so far in nanofiber-reinforced polymer nanocomposites and also outperforms most nanocomposites counterparts dispersed with nanoparticles and nanosheets. Our work demonstrates hierarchical interface engineering as an effective strategy to promote the high-temperature energy storage performance of fiber-reinforced polymer nanocomposites, which is of significance for their applications in high-temperature harsh conditions.

Effective elastic properties of nanofiber-reinforced composites with Steigmann-Ogden interface effect

Closed-form bound and exact solutions to the five independent effective elastic constants of nanofiber-reinforced composites with Steigmann-Ogden interface effect are obtained in this work. Four effective elastic constants (ke, ne, le, and pe) have identical bounds and depend only on the stretching stiffness of the interface, while the fifth effective elastic constant (me) has distinct bounds and depends on both the stretching and bending stiffness of the interface. Compared with Maxwell-type approximation formula in the semi-analytical form of Fourier series in the literature, the exact solution to the fifth effective elastic constant (me) is obtained in closed-form by generalized self-consistent method in this work. Both exact solutions are validated to fall inside the bound solutions. Moreover, limit analysis discloses that the bounds of the four effective elastic constants (ke, ne, le, and pe) of pure nanofibers coincide and deviate from the bulk elastic constants of the fiber in the classical case, but the bounds of the fifth effective elastic constant (me) of pure nanofibers are unexpected to be distinct in contrast to the four effective elastic constants (ke, ne, le, and pe) of pure nanofibers or all the effective elastic constants of conventional composites.

Analysis of mechanical properties enhancement on composites of AA7175 by multi walled carbon nano tube (MWCNT)

Developed to meet the demands of appealing contemporary materials, nanocomposites are polyphase materials that include a matrix and nano-reinforcement. The major types of nanocomposites are as follows. They are categorized as fiber-reinforced nanocomposites, laminar nanocomposites, and particulate nanocomposites based on the reinforcing component, whereas they are classed as metal matrix, ceramic matrix, and polymer matrix nanocomposites based on the matrix ingredient. Due to its advantages over polymer and ceramic matrix, metal matrix nanocomposites (MMNCs) are the most common type of nanocomposites employed in industrial applications. To improve the physical, mechanical, thermal, and electrical properties of conventional materials, nanocomposites are often formed by reinforcing nanoscale tubes, fibres, particles, or sheets. To keep up with technological advancements, drive market changes, and bridge technological gaps by revolutionizing the product, innovative nanocomposites must be used in advanced engineering applications. The high-strength, light-weight aluminium alloy matrix nanocomposites (AMNCs) are able to replace traditional materials to a greater extent in cutting-edge applications including the automotive, aircraft, marine, defense, leisure, and electronic industries. In this study deals with the property enhancement analysis by means of the assistance of Multi Walled Carbon nano tube (MWCNT) nano particles encouragement in AA7175 aluminium alloy. The main focus of this investigation on the tensile related mechanical properties such as tensile strength, percentage of elongation and yield strength. The composites were created with the mass fractions of 5.0 wt%, 4.0 wt%, 3.0 wt%, 2.0 wt% and 1.0 wt% of MWCNT with 95.0 wt%, 96.0 wt%, 97.0 wt%, 98.0 wt% and 99.0 wt% of AA7175 aluminium alloy. These composite mechanical properties were compared with the pure AA7175 aluminium alloy. Among the comparison of these composites values 3.0 wt% of MWCNT produce the greater results on the considered composites. The composite sample recorded high Ultimate Tensile Strength of 431.12 MPa, low Percentage of elongation of 9.58% and high Yield strength of 396.63 MPa.

Never-Dried Aramid Nanofibers Dispersed in Organic Solvents for Nanofiber-Reinforced Composites

Aramid nanofibers (ANFs) have received considerable attention due to their high mechanical properties, low density, and ability to be manufactured through upcycling. In response, research on the dispersion of ANFs in organic solvents is essential for adoption in a wider range of applications. In this study, efficient strategies are proposed to overcome the current shortcomings, which are long processing time and small yield, and obtain a never-dried bulk homogeneous ANF dispersion in organic solvents through a series of facile steps, which is expected to assist and broaden applications such as nanofiber-reinforced composites, additives, coatings, and membranes.

Effect of Alumina and Silicon Carbide Nanoparticle-Infused Polymer Matrix on Mechanical Properties of Unidirectional Carbon Fiber-Reinforced Polymer

Unidirectional carbon fiber-reinforced polymer nanocomposites were developed by adding alumina (Al2O3) and silicon carbide (SiC) nanoparticles using ultrasonication and magnetic stirring. The uniform nanoparticle dispersions were examined with a field-emission scanning electron microscope. The nano-phase matrix was then utilized to fabricate the hybrid carbon fiber-reinforced polymer nanocomposites by hand lay-up and compression molding. The weight fractions selected for Al2O3 and SiC nanoparticles were determined based on improvements in mechanical properties. Accordingly, the hybrid nanocomposites were fabricated at weight fractions of 1, 1.5, 1.75, and 2 wt.% for Al2O3. Likewise, the weight fractions selected for SiC were 1, 1.25, 1.5, and 2 wt.%. At 1.75 wt.% Al2O3 nanoparticle loading, the flexural strength modulus improved by 31.76% and 37.08%, respectively. Additionally, the interlaminar shear and impact strength enhanced by 40.95% and 47.51%, respectively. For SiC nanocomposites, improvements in flexural strength (12.79%) and flexural modulus (9.59%) were accomplished at 1.25 wt.% nanoparticle loading. Interlaminar shear strength was enhanced by 34.27%, and maximum impact strength was improved by 30.45%. Effective particle interactions with polymeric chains of epoxy, crack deflection, and crack arresting were the micromechanics accountable for enhancing the mechanical properties of nanocomposites.

Considering Electrospun Nanofibers as a Filler Network in Electrospun Nanofiber-Reinforced Composites to Predict the Tensile Strength and Young's Modulus of Nanocomposites: A Modeling Study.

In this study, a simple approach was described to investigate the theoretical models for electrospun polymer nanofiber-reinforced nanocomposites. For predicting the tensile strength of the electrospun nylon 6 nanofiber-reinforced polyurethane acrylate composites, conventional Pukanszky, Nicolais-Narkis, Halpin-Tsai, and Neilson models were used, while for Young's modulus, Halpin-Tsai, modified Halpin-Tsai, and Hui-Shia models were used. As per the Pukanszky model, composite films showed better interaction since the values of the interaction parameter, B, were more than 3. Similarly, the value of an interfacial parameter, K, was less than 1.21 (K = -5, for the curve fitting) as per the Nicolais-Narkis model, which indicated better interfacial interaction. For composite films, the modified Halpin-Tsai model was revised again by introducing the orientation factor, α, which was 0.333 for the randomly oriented continuous nanofiber-reinforced composites, and the exponential shape factor, ξ = (2l/d)e-avf-b, which showed the best agreement with the experimental Young's modulus results. Based on mentioned remarks, these models would be applicable for estimating the tensile strength and Young's modulus of electrospun nanofiber-reinforced polymer composite films.

Novel Wet Electrospinning Inside a Reactive Pre-Ceramic Gel to Yield Advanced Nanofiber-Reinforced Geopolymer Composites.

Electrospinning is a versatile approach to generate nanofibers in situ. Yet, recently, wet electrospinning has been introduced as a more efficient way to deposit isolated fibers inside bulk materials. In wet electrospinning, a liquid bath is adopted, instead of a solid collector, for fiber collection. However, despite several studies focused on wet electrospinning to yield polymer composites, few studies have investigated wet electrospinning to yield ceramic composites. In this paper, we propose a novel in-situ fabrication approach for nanofiber-reinforced ceramic composites based on an enhanced wet-electrospinning method. Our method uses electrospinning to draw polymer nanofibers directly into a reactive pre-ceramic gel, which is later activated to yield advanced nanofiber-reinforced ceramic composites. We demonstrate our method by investigating wet electrospun Polyacrylonitrile and Poly(ethylene oxide) fiber-reinforced geopolymer composites, with fiber weight fractions in the range 0.1–1.0 wt%. Wet electrospinning preserves the amorphous structure of geopolymer while changing the molecular arrangement. Wet electrospinning leads to an increase in both the fraction of mesopores and the overall porosity of geopolymer composites. The indentation modulus is in the range 6.76–8.90 GPa and the fracture toughness is in the range 0.49–0.76 MPa with a clear stiffening and toughening effect observed for Poly(ethylene oxide)-reinforced geopolymer composites. This work demonstrates the viability of wet electrospinning to fabricate multifunctional nanofiber-reinforced composites.

Effect of Fiber Mixing and Nanoclay on the Mechanical Properties of Biodegradable Natural Fiber-Based Nanocomposites

Combining two types of fibers may aid in improving the fundamental properties of organic fiber-reinforced hybrid polymeric materials. Biomaterials created from raw materials are gaining appeal in the industrial sector due to their high quality, as well as sustainability and environmental considerations. Natural fiber-reinforced hybrid nanocomposites were created in this work using a compression moulding technique with wood particles, hemp fiber, polypropylene, and montmorillonite nanoclay. Following that, the impacts of fiber mixture and vermiculite on mechanical and compostable qualities were studied. Both the coir and the hemp fibers were alkali-treated to minimize their hydrophilic nature before even being employed. Using universal tensile testing equipment, the mechanical characteristics of the prepared composites were investigated and found to be improved following fiber blending and nanoparticle inclusion. The maximum strength was occurred at the combinations like 10 wt. % of wood particle, hemp, nanoclay, and 70% of polypropylene matrix. Scanning electron microscopy showed that nanoclay significantly increased the adherence and interoperability between fiber and the polymer matrices. The good biocompatibility and water absorption capabilities of the nanocomposite were increased by mixing fibers, but nanoparticle additions seemed to have the opposite impact.

Imprinted Glass Fiber-Reinforced Epoxy Nanocomposites Vascular Self-Healing Wind Turbine Blades

Abstract Wind energy is a primary renewable energy source and has been one of the most promising sources of clean, long-term energy. Self-healing is the autonomous ability to recover from failure. Self-healing material systems in wind turbine blades can reduce maintenance, repair, and energy compensation costs. Investigation of the self-healing wind turbine blades is of core interest in this study. This paper initially introduces self-healing properties into vacuum-assisted resin transfer molding molded fiber-reinforced polymer (FRP) nanocomposites and lab preparation for studying the effect of incorporation of carbon nanotubes (CNTs) on the self-healing capabilities using dicyclopentadiene (DCPD) and Grubbs first-generation catalyst. A vascular network was imprinted in a single glass fiber FRP sheet utilizing hexagonal 3D printed templates, infused with DCPD, and later embedded into a multilayer FRP. The effect of adding epoxy resin with 0.3 wt% CNTs to the multilayer FRP was investigated. The samples were tested before and after recovery by performing the three-point bending test. The maximum flexural strengths and percent recovery for the non-healed and healed FRP samples were calculated. Interestingly, the strength of the samples increased at least ten times after the addition of CNTs to the composite, and the percentage of stress recovery was doubled on average.

Recycled (Bio)Plastics and (Bio)Plastic Composites: A Trade Opportunity in a Green Future.

Today’s world is at the point where almost everyone realizes the usefulness of going green. Due to so-called global warming, there is an urgent need to find solutions to help the Earth and move towards a green future. Many worldwide events are focusing on the global technologies in plastics, bioplastic production, the recycling industry, and waste management where the goal is to turn plastic waste into a trade opportunity among the industrialists and manufacturers. The present work aims to review the recycling process via analyzing the recycling of thermoplastic, thermoset polymers, biopolymers, and their complex composite systems, such as fiber-reinforced polymers and nanocomposites. Moreover, it will be highlighted how the frame of the waste management, increasing the materials specificity, cleanliness, and a low level of collected material contamination will increase the potential recycling of plastics and bioplastics-based materials. At the same time, to have a real and approachable trade opportunity in recycling, it needs to implement an integrated single market for secondary raw materials.