Fiber Loading Research Articles

Influence of NaHCO3 treated kenaf/nettle fiber on mechanical and sliding wear performance of epoxy composites

This investigation addresses the experimental research on the mechanical and sliding wear behavior of kenaf/nettle-epoxy composites. The mechanical properties like tensile strength, flexural strength, and hardness in this investigation were found to be greatly affected by the kenaf/nettle fiber content. The variation of reinforcement (keanf/nettle) from 0 wt% to 12 wt% was used for fabricating the composites. Moreover, up-to 8 wt% of fiber loading, tensile strength-153.20 MPa (61.75 %) and flexural strength- 68.57 MPa (55.24 %) are increased as compared to neat epoxy composites, whereas higher hardness (63.42 Hv) is achieved at 12 wt% of fiber loading. Sliding wear tests are conducted at different normal loads (10-40N) and reveal that higher wear resistance is achieved at 12 wt% at 30N of fiber loading, which is 4.0033/N-m × 10-8. From this investigation, it can be clearly shown that plant fiber (kenaf/nettle) could be innovative feasible alternative to renewable, eco-friendly, and light weight fiber reinforced composites with moderate mechanical and wear properties.

On the bending behavior of hybrid fiber–metal laminates (HFMLs) based on aluminum and glass/Kevlar fibers reinforced epoxy

In this work, the mechanical behaviors under flexural loading of fiber–metal laminates (FMLs) comprised of an aluminum alloy reinforced with glass fibers (GFs) and Kevlar fibers (KFs) embedded in an epoxy composite are experimentally investigated. For this purpose, non-FMLs, FMLs, and hybrid FMLs (HFMLs) are tested and their results are compared in terms of the flexural strength and modulus, strain to failure, toughness, interlaminar shear strength (ILSS), and specific properties. Results show that the incorporation of GFs on the compression side and KFs on the tensile side improves the bending properties of the HFMLs compared to the KF-based FMLs, which enhances the laminates’ resistance to bending loads. The HFMLs exhibit improvements of 24%, and 5% in flexural strength and modulus, respectively, compared to the KF-based FMLs. Moreover, hybridization significantly improves strain to failure by up to 115% compared to the GF-based FMLs. Additionally, the ILSS analysis reveals improved values in FMLs compared to non-FML samples, when GF-based FMLs demonstrate higher ILSS than KF-based ones, which can be attributed to GFs’ stiffness and high-quality bonding with the aluminum sheets. HFMLs attain a 19% improvement in ILSS compared to the KF-based FMLs. The failure mechanism depends on the intrinsic features of the studied fibers, while the studied FMLs display better damage tolerance. In this context, the HFMLs present enhanced toughness, delamination resistance, and the ability to prevent crack propagation, positioning them as promising candidates for lightweight structural applications where a balance between strength, stiffness, and toughness is required.

Fabrication and Characterization of Baobab Pod (Adansoniadigitata) FiberReinforced Polyester Resin Composite

Baobab pod fibres were obtained from Sabo market in Zaria and sliced longitudinally, screened out from the baobab fruit, washed with water, dried under sun for fabrication and characterization. The fiber was extracted and treated with 5% NaOH solution. Important samples were fabricated with different fiber loading of 10wt%-30wt%. The samples were moulded using Hand Lay-up method followed by pressing and post cured at 60oC for 3 hours. The result showed tensile strength decreases as the loading of fiber increased from 20 wt% to 30 wt%. It was also observed that baobab composite has the highest tensile strength of 18.85 MPa at 20 wt% and least (16.45 MPa) at 15 wt%. The result also revealed the elongation at break increased from 20 wt% to 25 wt%. At 25wt% it has a maximum value (18.4%) elongation at break; at 30wt%. It was also observed that the density increased with increase in the fiber loading from 15wt% to 30wt% (1.23g/cm3 - 2g/cm3) respectively. At 15wt% shows a maximum water take-up of 6.53% while from 20 wt% to 30 wt%, Flexural strength increased from 10 wt% to 15 wt% (23.98MPa - 46.3Mpa). However, the bending stress decreases on increasing the fiber loading from 20-30 wt% (30.2 Mpa – 25.2 Mpa). The elastic nature of the composite generally increases with increased in fiber loading. This study, however recommend hybridization of baobab pod fiber with other natural fiber to investigate the mechanical and physical property of the hybrid composite for better result.

MECHANICAL PERFORMANCE AND WATER ABSORPTION OF COCONUT FIBER/POLYETHYLENE WASTE BIOCOMPOSITE PREPARED VIA A CHEMICAL-FREE APPROACH

Plastic wastes have caused serious environmental issues worldwide, and thus viable solutions for their replacement are now urgently needed. This work aimed to develop biocomposite materials based on polyethylene (PE) wastes as matrix reinforced with coconut fiber, without any additional chemical treatments, using extrusion and compression molding. The effects of polymer matrix type (high-density and low-density PE (HDPE and LDPE)) and fiber loading (5-15 wt%) on the mechanical properties and long-term water absorption behaviour of the materials were evaluated. Tensile strength results showed the optimum performance at 5 wt% fiber – of 16.6 MPa for the HDPE matrix and 7.3 MPa for the LDPE matrix, but flexural and impact strengths reduced with the fiber loading. An increasing trend of water absorption capacity was noted as a function of filler loading and of the water temperature during immersion, with a weight gain of up to 5%, following the trend: cold water > room temperature tap water > hot water. From the results, HDPE based biocomposites had better mechanical performance and lower water absorption capacity, compared with LDPE based biocomposites.

EFFECT OF VARIOUS CHEMICAL TREATMENTS ON PHYSICOCHEMICAL AND THERMAL PROPERTIES OF ERYTHRINA VARIEGATA FIBERS: APPLICATION IN EPOXY COMPOSITES

Recently, there has been an increasing trend in utilizing lignocellulosic fiber reinforced composites in structural applications within the construction and automobile industries, replacing conventional materials based on metals and their derivatives. In the present study, Erythrina variegata fibers (EVFs) were subjected to a number of chemical treatments individually (alkalization, benzoyl peroxide, potassium permanganate, and stearic acid treatments). The effects of these chemical treatments on the EVFs were examined through chemical composition analysis, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). This comprehensive analysis aimed to assess the suitability of the chemically treated EVFs for use as reinforcement in thermoset polymer matrix composites. The alkali treated fibers (AEVFs) were found as optimum and were then used as reinforcement in epoxy adhesives. Different fiber loadings (0, 5, 10, 15, 20, and 25 wt%) were incorporated into the epoxy matrix to investigate their effects on the properties of the composites. Therefore, the tensile strength, flexural strength, impact strength, and thermal stability of the prepared composites were evaluated under controlled laboratory conditions. The findings collectively suggested that the epoxy composites reinforced with 20 wt% of AEVFs exhibited promising characteristics for lightweight structural applications.

Optimization, Sodium Hydroxide and Plantain Fibres: Mechanical Properties of Unsaturated Polyester Composites for Transtibial Prosthetic Socket

Low mechanical behaviors of natural fibres in the reinforcement of polymer composites have remain an issue of concern. This study is aimed at investigating the effect of NaOH treatment on the mechanical properties of plantain fiber for the transtibial prosthetic sockets made of polyester resin. Plantain fiber was extracted from the plantain bast using water retting techniques. The fibres were modified using alkaline treatment method of 5 – 25% for variable time of 30 to 150 minutes. It was optimized using 3-level Factorial design (3-LCD) of response surface methodology based on tensile properties of treated fibres. The polyester composites of plantain and glass fibers were prepared using hand-layup techniques. Instron Universal testing machine-3369 model was used to determine the tensile and impact properties of fibers and polyester composites. Rockwell hardness tester-RBHT/S-39 model was used to determine the hardness property. The optimum process conditions of 5 % NaOH for 119 minutes improved plantain fiber tensile strength, modulus, strain, energy, and extension by improved by 102.03, 208.07, 9.70, 210.52 and 205.73 %, respectively. The ultimate tensile strength and modulus was obtained at 10 and 12.5% fiber loading. The hardness and impact strength of NaOH modified unsaturated polyester composites was marginally more than 3.51 and 10.69% of glass fiber reinforced unsaturated composites, respectively, at 12.5% fiber loading. FTIR analysis revealed the improvement in mechanical properties. Thus, NaOH modified plantain fiber unsaturated polyester composites serves as a better alternative for making transtibial prosthetic socket.

A short banana fiber—PLA filament for 3D printing: Development and characterization

AbstractThis study aims to develop a 3D printable composite filament using short banana fiber and polylactic acid (PLA). The filament was acquired through a single screw extruder, employing various blending techniques. Various fiber loadings were examined, impacting PLA's mechanical, thermal, and printability properties. The results revealed altered mechanical characteristics, with reduced tensile and flexural properties compared with pure PLA. However, these values are at an acceptable level for non‐structural applications. Compared with previous works, the filament developed in the present work is found out to be second strongest among the cellulose fiber‐reinforced PLA filaments. 3D printing with the composite filament encountered no significant issues. A modified mixing method improved mechanical characteristics, although 3D‐printed samples showed deteriorated mechanical characteristics due to poor interfacial bonding. This research introduces an environmentally viable strategy for advancing 3D printing technology by integrating banana fibers into PLA filament. The proposed strategy can be effectively utilized in making cellulose/PLA filaments for 3D printing applications. This innovative approach preserves PLA's natural biodegradability while carefully managing the integration of banana fibers and their potential effects on mechanical properties.Highlights Fiber loading influences mechanical, with minimal impact on thermal properties. Solution casting improved fiber/matrix bonding and filler homogeneity. Plasticizing effect reduces the tensile strength. Modified mixing resulted in even filament diameter and improved tensile properties.

Influence of multi-walled carbon nanotubes on thermal behaviour and mechanical properties of pineapple leaf fibre-based natural rubber composites

Replacing synthetic fibres with natural fibres as reinforcement fillers in natural rubber (NR) tends to yield eco-friendly bio-composites. This study investigated the tensile and hardness properties, and the thermal behaviour of pineapple leaf fibre (PALF)-reinforced NR composites with and without the addition of multi-walled carbon nanotubes (MWCNT). The fibre content was varied at 0, 10, 20, and 30 parts per hundred rubber (phr) and the MWCNT content was fixed at 10 phr. The surface morphology of the tensile-fractured specimens was examined using scanning electron microscopy (SEM) to identify the rubber-matrix adhesion and tear mechanisms of the fibres in the NR matrix. The results revealed that including the PALF and MWCNT allowed the NR composites to exhibit excellent stretching stress at low elongations. Additionally, the composites displayed enhanced stiffness, further increasing the hardness of the composite, ranging from 46.8 to 62.8 Shore A. However, PALF reduces the thermal stability of the composite, where the initial degradation temperature increases. From the thermogravimetric analysis, the residues remaining in the NR composites ranged from 6 to 13% at various fibre loadings. Therefore, this study provides valuable insights into the tensile and hardness properties and the thermal behaviour of PALF-reinforced NR composites to improve end-use properties.

Impact of Molding Temperature, Fiber Loading and Chemical Modifications on the Physicomechanical, and Microstructural Morphology Properties of Woven Kenaf Fiber/PLA Composites for Non-Structural Applications

ABSTRACT These days, green composites are getting a lot of attention for their biodegradability, sustainability, and affordability. This study applies polylactic acid as the matrix and untreated and surface-treated kenaf fibers as reinforcement to fabricate kenaf-reinforced PLA-based composites. Kenaf fibers are exposed to three different chemical treatments (sodium hydroxide, potassium permanganate, and potassium dichromate) and investigate the effect of surface modifications on the mechanical properties of kenaf/PLA composites. The surface modified fibers were characterized by FTIR Spectroscopy. The consequences of processing variables such as fiber volume percent ranging from 25% to 50% and molding temperature range of 160°C to 180°C were also examined on the mechanical characteristics of developed composites and are validated using SEM analysis. Surface modifications result in improved tensile and flexural characteristics of developed treated kenaf/PLA composites. Alkali treated woven kenaf fiber composites with greater matrix adhesion have optimum tensile and flexural strength of 72.81 MPa and 94.45 MPa respectively. The present study revealed that composites (fabricated at 170°C molding temperature) have maximal tensile and flexural strength at 35% fiber volume fraction.

Impact of molybdenum disulfide diffused coir fiber on the physical, mechanical, thermal, and vibrational characteristics of polyester composites

AbstractThis research focuses on comparing the properties of molybdenum disulfide (MoS2) diffused coir fiber polyester composites (MCF‐PCs) with neat coir fiber polyester composites (NCF‐PCs) and exploring its applications in various industrial sectors such as automotive, construction and manufacturing, where mechanical strength and fire resistance are critical factors. The study aims to investigate the physical, mechanical, thermal degradation, fire performance, and vibration properties of these composites. Compression molding was used to develop composites with different coir fiber loadings (10%, 20%, and 30% by weight). MoS2 nanoparticles diffused on the fiber surface significantly improved mechanical characteristics, thermal stability, and fiber‐matrix compatibility. The findings indicate better crystallinity and physical properties in MCF‐PCs compared to NCF‐PCs. Morphological observations confirmed improved fiber‐matrix compatibility in MoS2‐diffused fiber composites with polyester. The MCF‐PC with 20% loading exhibited the highest tensile (28 ± 1.24 MPa), flexural (50 ± 0.50 MPa), and impact (15 ± 1.01 kJ/m2) strength. The flame retardancy of the composites was evaluated using a horizontal combustion test apparatus. In addition, MCF‐PCs exhibited better flame retardancy as evidenced by lower flame propagation velocity (9 ± 0.20 mm/min) and increased ignition time (13 ± 0.29 Sec). The MCF‐PC with 20% loading shows maximum natural frequencies of 77 ± 4.1 Hz.Highlights This study investigated MoS2‐diffused coir fiber‐reinforced polyester composites. Fiber‐matrix adhesion can be improved with modified fiber‐reinforced composites. The MoS2 diffusion on fibers improved the physical and mechanical properties of polyester composites. The MoS2 diffusion on fibers enhanced the thermal and vibrational characteristics of polyester composites. MoS2‐diffused natural fiber composites offer considerable research potential.

Feasibility of incorporating leaf date palm fibers in geopolymer composites made from mining waste

This study explores the potential of developing novel high performance geopolymer composite (GPC) materials utilizing mining waste (MW) as an aluminosilicate precursor for the geopolymer matrix and reinforcing it with leaf date palm fibers (LDPFs). Specifically, we examined the effects of incorporating varying amounts of LDPF fibers on the mechanical, physical, and morphological properties of the formulated GPC. The explored range of the incorporated fibers was from 0% to 4% (wt/wt). Mechanical properties were evaluated using modulus of rupture (MOR) and modulus of elasticity (MOE), while physical properties were assessed through water absorption (WA) and thickness swelling (TS). Additionally, X-ray diffraction (XRD), FTIR spectroscopy, scanning electron microscopy (SEM), and energy dispersive X-ray (EDX) were employed to visualize matrix phases and analyze the composition, elucidate changes in the structure, and examine the interfacial failure morphology, respectively. The results revealed that the MOR and MOE nearly doubled in the formulation reinforced with 2% (wt/wt) LDPF fibers compared to the geopolymer matrix, confirming the efficacy of these fibers as reinforcing element enhancing the strength and stiffness of the geopolymer matrix. The physical properties exhibited an increase with higher fiber loading, though they remained lower compared to those of other composites found in literature, confirming the suitability of LDPF fibers for geopolymer composite formulations. The structural and morphological analyses of the geopolymer composites indicated an acceptable degree of geopolymerisation and the fibers displayed good interfacial bonding with the geopolymer matrix, respectively. The research findings suggest that leaf date palm fibers are well-suited for reinforcing geopolymer matrix derived from mining waste, presenting a cost-effective option for construction materials.

Utilisation of human hair wastage from local saloons as reinforcement for improving the mechanical properties of zucchini fibre reinforced polypropylene biocomposite

ABSTRACT Solid waste management is an urgent issue in the current day and age, with the utilisation of refuse materials being essential to reduce environmental contamination. The usage of sustainable and biodegradable biocomposites from these wastages is becoming more widespread in research. This work incorporated human hair from local saloon to strengthen the mechanical performance of the zucchini fibre reinforced polypropylene biocomposite. Zucchini fibre was first reinforced in the polypropylene matrix through hot-pressing with various fibre loading levels (5,10,15, and 20 wt%). Subsequent to this, hybrid bio-composites were produced by merging human hair and zucchini fibre in the polypropylene matrix, with a ratio of 1:1. Measuring the mechanical properties such as tensile, flexural and impact of each composite revealed that hybrid bio-composites reinforced with both human hair and zucchini fibre outperformed those reinforced only with zucchini fibre in terms of mechanical properties at each fibre loading level. Scrutiny of SEM analysis revealed that the hybrid biocomposite reinforced with human hair and zucchini fibre had a better fibre distribution, thereby justifying the improved mechanical properties. The 10% fibre loaded hybrid biocomposite attained the optimal mechanical properties among all samples, showcasing an 11.35% increase in tensile strength compared to pure polypropylene. All these qualities make this composite ideal for use in automobile interiors.

Effect of fiber orientation on mechanical properties of betel nut (areca palm) stem fiber reinforced laminated polyester composites

ABSTRACT This study explored the effect of fibre orientation on the mechanical properties of Betel Nut (Areca palm) stem fibres (BNSF)-reinforced laminated polyester composites. Composites are fabricated by hand lay-up method with 15% (vol.) fibre loading and 0°/90°/0° and −45°/0°/45° orientations. The mechanical properties of composites are determined by testing as per ASTM standards and revealed that composite strengths vary significantly with fibre orientation. The tensile, flexural, and impact strengths of the composite are found 58.19 MPa, 153.96 MPa, and 25.68 kJ/m2, respectively, for the 0°/90°/0° fibre orientation, which are higher than the composite of −45°/0°/45° fibre orientation. Furthermore, strengths are found greater than the betel nut husk and leaf, bamboo, coir, banana, and jute fibres-reinforced polymer composites. The bonding between fibres and matrix, voids, micro-cracks, etc. are investigated by optical microscopy of a tensile-fractured specimen. This study revealed that BNSF would be a novel and potential natural fibre for reinforcing polymer composites. Its strength can be enhanced by choosing suitable numbers of fibre laminations and orientations. Since areca palm trees grow extended, moderate-sized composite boards/panels can be produced from BNSF to replace synthetic fibres-based ones. It will help reduce environmental pollution as a green composite.

Analysis of the Effects of Fiber Loading on the Mechanical Behavior of Jute Reinforced Thermoplastic Composites

Natural fiber-reinforced composites are becoming a growing trend because of their affordability, sustainability, abundant natural source, and minimal environmental effect. It has also shown to be an effective replacement of synthetic fiber, particularly in the transportation and construction sectors as ceiling, paneling, partition etc. In this study the jute fiber (Hessian Cloth) reinforced (10% to 50% fiber content by weight) Polypropylene (PP) and Polyethylene (PE) composite were made by compression molding technique to understand the effect of fiber loading on mechanical properties of two different thermoplastic composite materials. For jute fabric-reinforced thermoplastic composites, it was discovered that with 30 % fiber loading with PP and PE yielded the best results. It was found that the mechanical properties of the composites enhanced significantly with 30 % fiber content with PP and PE thermoplastic matrixes in contrast to 10% and 20% fiber content composites. However, increasing the fiber content over 30%, dramatically decrease the mechanical properties of the composite samples. The relationship between Tensile Strength (TS), Bending Strength (BS), Impact Strength (IS) and Tensile Modulus (TM), Bending Modulus (BM) was examined, along with water resistance properties for both composites. Additionally, the jute-reinforced polypropylene (PP) composite showed superior mechanical capabilities compared to the jute-polyethylene (PE) composite. This suggests that it could be a suitable replacement for the toy manufacturing, home or garden furniture, automotive and interior construction industries in the future.

Effect of kenaf fibre loading on thermal and dynamic mechanical properties of bio epoxy composites

Effect of kenaf fibre loading on thermal and dynamic mechanical properties of bio epoxy composites

Degradation characteristics of the pineapple leaf fibre reinforced green composite developed by injection moulding under different environmental conditions

The present study examines the mechanical and morphological characteristics of a green composite reinforced with pineapple leaf fiber (PLF) under different environmental conditions. PLF underwent chemical treatment at optimal conditions, using a 1% w/v sodium carbonate solution for 6 hours, to produce an environmentally friendly pineapple leaf fiber (PLF)/polylactic acid (PLA)-based composite via injection molding. The optimal injection settings of 165℃ (melting temperature), 50 mm/sec (injection speed), and 110 bars (injection pressure) to produce the PLF/PLA composite. The PLF/PLA composite was developed with a fiber loading of 20% and a length of 3 mm. The produced PLF/PLA composites were then exposed to a variety of environmental conditions, including water, soil, refrigeration, and room temperature. The impact of these diverse conditions on the mechanical properties (tensile, flexural, compression, and shear) was scientifically observed for four-week. Additionally, the morphology of the fractured specimens was assessed using a scanning electron microscope (SEM). The contact angle measurement was conducted to assess the hydrophilic characteristics of the PLF/PLA green composite. There has been a lack of comprehensive research on the effects of different environmental conditions on the mechanical, wettability, and morphological properties of green composites derived from PLF/PLA. Thus, in this study, emphasis is given for investigating the effect of various environmental conditions on the mechanical properties of PLF/PLA injection-molded green composite. The composite material demonstrated the highest water absorption and swelling thickness at 6.45% and 5.51%, respectively, in comparison to the dry PLF/PLA samples. The green composite of PLF/PLA demonstrated excellent mechanical performance under ambient conditions compared to other environmental conditions. The PLF/PLA composite displayed a peak contact angle of 83.26° when subjected to soil burial conditions. On the contrary, the initial samples of the PLF/PLA composite displayed the minimum contact angle of 56.72°.

INVESTIGATION OF MECHANICAL AND PHYSICAL PROPERTIES OF DATE PALM STEM FIBRE REINFORCED EPOXY COMPOSITES

The growing demand for sustainable materials, particularly date palm stem fibre (DPSF), has garnered attention in the area of engineering applications due to its advantageous traits. Its composites offer distinctive characteristics such as satisfactory mechanical properties, low density and a cost-effective production. This study examines the mechanical characteristics of epoxy (LY-556) composites reinforced with DPSF. A range of composite configurations with different compositions and fibre loadings were meticulously crafted, using a hand lay-up technique. The research meticulously examines DPSF and epoxy composites with loadings of (10, 15, 20, and 25) w/%, comprehensively characterizing their flexural, tensile, impact and water-absorption behaviours. Across the varied compositions, the characteristics of flexural strength, tensile strength, impact strength and water absorption are thoroughly analysed. The conclusive findings underscore optimal enhancements in the flexural, tensile and impact strengths achieved with the DPSF loading of 20 %. This empirical understanding bears significance for designing natural fibre reinforced composites with superior mechanical attributes, reaffirming DPSF’s potential as a valuable reinforcement in modern engineering applications.

Microstructure and Mechanical Properties of Carbon Fiber Phenolic MatrixComposites containing Carbon Nanotubes and Silicon Carbide

A novel class of hybrid composites was prepared containing carbon fibers along with carbon nanotubes and silicon carbide particles in phenolic resin for improved mechanical performance. The loading of carbon fibers was ~60 wt% while carbon nanotubes and silicon carbide particles were reinforced in the fractions of 0.1 wt% and 5 wt%, respectively. Individually reinforced composites containing 0.1 wt% carbon nanotubes and 5 wt% silicon carbide particles were also manufactured for comparison with hybrid composites. Microstructural and mechanical property characterization was performed using electron microscopy and mechanical testing, respectively. Uniform dispersion of nanometer-scale carbon nanotubes and micrometer-scale silicon carbide particles was observed under microscopy. The pooled effect of carbon nanotubes and silicon carbide particles significantly increased the tensile, compressive, and flexural performance of composites while carbon nanotubes offered greater weight fraction value improvement than silicon carbide particles.

Theoretical study of the effect of orientations and fibre volume on the thermal insulation capability of reinforced polymer composites

Abstract In industry, synthetic fibre reinforcements are popular due to their cost-effectiveness and lightweight nature. However, the non-reusability and non-degradability have raised environmental concerns and prompted scientists to explore more environmentally friendly alternatives. Natural fibres are being investigated as potential replacements to address these issues and promote sustainability. This study investigated the effect of fibre loading and orientation on the heat conductivity of polymer resins using a finite element-based numerical model developed in our previous research. The numerical analysis was conducted in ANSYS® modelling and simulation using glass and sisal fibres in combination with three distinct matrix materials (epoxy, polyester, and vinyl ester). Different orientations (parallel, perpendicular, 45°, and normal) and volume of fibre fractions (20–35%) were used for the analysis. The properties of the materials were incorporated into the ANSYS Engineering database, and the composite model was divided into five segments to analyse the heat transfer. The thermal boundary condition was implemented by keeping one side of the cylinder at 120°C. The results showed that the thermal conductivity of the composites decreased as the volume fraction of natural fibres increased. Epoxy-based composites exhibited better insulation performance than polyester and vinyl ester-based composites. This study demonstrated the potential of using natural fibres to improve the thermal insulation properties of composites.

Hollow-core fiber loading of nanoparticles into ultra-high vacuum

Many experiments in the field of optical levitation with nanoparticles today are limited by the available technologies for particle loading. Here, we introduce a particle loading method that solves the main challenges, namely deterministic positioning of the particles and clean delivery at ultra-high vacuum levels as required for quantum experiments. We demonstrate the efficient loading, positioning, and repositioning of nanoparticles in the range of 100–755 nm diameter into different lattice sites of a standing wave optical trap, as well as direct loading of 143–365 nm diameter particles into ultra-high vacuum, down to an unprecedented pressure below 10−9 mbar. Our method relies on the transport of nanoparticles within a hollow-core photonic crystal fiber using an optical conveyor belt, which can be precisely positioned with respect to the target trap. Our work opens the path for increasing nanoparticle numbers in the study of multiparticle dynamics and high turn-around times for exploiting the quantum regime of levitated solids in ultra-high vacuum.