Functional Composites and Structures最新文献

{"title":"Advanced doping method for highly conductive CNT fibers with enhanced thermal stability","authors":"Minseouk Choi, Young Shik Cho, Kyunbae Lee, Yeonsu Jung, Kyung Tae Park and Taehoon Kim","doi":"10.1088/2631-6331/ad78a2","DOIUrl":"https://doi.org/10.1088/2631-6331/ad78a2","url":null,"abstract":"Due to the inherent limitations of metals, such as their poor performance at high temperatures caused by thermo-oxidation and expansion, carbon nanotube yarns (CNTFs) have emerged as promising alternatives because of their high electrical conductivity and thermal stability. Doping of CNTFs has been widely studied because it significantly increases electrical conductivity through a simple process. Despite these advantages, doped CNTFs are not suitable for extreme environments, especially high temperatures. This is due to the weak interaction between dopants and CNTFs, along with the low thermal stability of the dopants themselves, leading to dopant decomposition and oxidation at high temperatures. Herein, we present doped CNTFs that are covalently functionalized with a nitrogen compound composed of imide and nitro groups, which are renowned for good thermal stability. The electron-withdrawing effect of this nitrogen compound polarizes the CNTFs to a positive charge, inducing p-type doping effects and enhancing electrical conductivity from 2989 to 4008 S cm−1. The strong covalent bonding between the nitrogen compound and CNTFs, along with the thermal stability of the dopants, ensures that the electrical conductivity of our doped CNTFs is maintained even after annealing at 300 °C for 12 h. Our proposed doped CNTFs offer a guideline for expanding the practical applications of doped CNTFs to a wider range of high-temperature environments.","PeriodicalId":12652,"journal":{"name":"Functional Composites and Structures","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142249551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A simplified predictive model for the compression behavior of self-healing microcapsules using an empirical coefficient","authors":"Jaeho Cha and Sungho Yoon","doi":"10.1088/2631-6331/ad7225","DOIUrl":"https://doi.org/10.1088/2631-6331/ad7225","url":null,"abstract":"This study is dedicated to predicting the compression behavior of microcapsules, a key aspect in self-healing applications. Understanding the compression behavior of microcapsules, mainly due to their liquid cores, is a complex task. Equally challenging is the evaluation of the shell properties. We aimed to streamline this prediction process by introducing the empirical coefficient Ccore, which accounts for core influence. We conducted experiments on microcapsules with MUF (Melamine–Urea–Formaldehyde) shells, compressing them between two plates and recording their responses to load and displacement. The empirical coefficient, influenced by capsule size, shell properties, and core volume fraction, was then analyzed in terms of microcapsule size and Young’s modulus. The research results showed that as the diameter of microcapsule and Young’s modulus of the shell increased, the Ccore also increased. This relationship could be represented in a three-dimensional surface. These findings could significantly contribute to estimating shell properties and modeling matrices with dispersed microcapsules.","PeriodicalId":12652,"journal":{"name":"Functional Composites and Structures","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142249553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of multi droplet-based electricity generator system for energy harvesting improvement from a single droplet","authors":"Girak Gwon, Dongik Kam, Sunmin Jang, Moonwoo La, Dongwhi Choi","doi":"10.1088/2631-6331/ad709b","DOIUrl":"https://doi.org/10.1088/2631-6331/ad709b","url":null,"abstract":"Due to high output performance, the droplet-based electricity generator (DEG) is garnering attention as a promising alternative power source for small electronic devices. Accordingly, to utilize the DEG as a power source, the efforts to boost the output have focused on methods to modify material modification and introduce surface structure. However, the behavior feature that the reconfigured droplet falls after the DEG operation leaves room for one more droplet energy harvesting from a single droplet. Here, a multi DEG system (MDEG) constructed with multiple DEG units is proposed to harvest more energy from a single droplet. The continuous movement of a water droplet is realized through the inclined stair structure of the MDEG, resulting in electrical energy generation from a single water droplet as many times as it falls. In particular, 2-step MDEG consisting of two DEG units can have 45% higher performance than a single DEG. Therefore, this study implies a contribution to the development of DEGs by considering the droplet dynamics, which has been overlooked in existing DEG studies.","PeriodicalId":12652,"journal":{"name":"Functional Composites and Structures","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142194645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measurement of the water absorption on hybrid carbon fibre prepreg waste composite and its impact on flexural performance","authors":"Ahmad Ashari Ahmad Shukri, Norlin Nosbi, Mohd Firdaus Omar, Siti Shuhadah Md Saleh, Muhammad Bisyrul Hafi Othman, Norazwana Mohd Najib, Wan Fahmin Faiz Wan Ali","doi":"10.1088/2631-6331/ad6e51","DOIUrl":"https://doi.org/10.1088/2631-6331/ad6e51","url":null,"abstract":"Carbon fibre (CF) prepreg, essential to composites and aircraft, generates waste known as carbon fibre prepreg waste (CFW) due to its limited lifespan. This study investigates recycling CFW through hybridization, milling it into powder and mixing it with epoxy resin and alumina to form hybrid composites. Using Minitab software, optimal compositions were determined from 13 and 20 experimental designs for CFW-EP and CFW-EP-AL, respectively. Results identified 2.5 wt% CFW and 97.5 wt% epoxy resin as optimal for CFW-EP, and 2.5 wt% CFW, 2.5 wt% alumina, and 95 wt% epoxy resin as optimal for CFW-EP-AL. Samples of epoxy resin polymer (EP), carbon prepreg waste reinforced composite (CFW-EP), and carbon prepreg waste reinforced with alumina composite (CFW-EP-AL) were fabricated and tested for moisture absorption and flexural strength, revealing noticeable deterioration over time. These findings highlight the importance of compositional analysis in developing sustainable materials with optimal flexural strength for various applications.","PeriodicalId":12652,"journal":{"name":"Functional Composites and Structures","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142194646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simulation of the tensile behaviour of biaxial knitted fabrics produced based on rib structure using a macro constitutive model","authors":"Mohammad Javad Abghary, Reza Jafari Nedoushan, Hossein Hasani, Woong-Ryeol Yu","doi":"10.1088/2631-6331/ad68c0","DOIUrl":"https://doi.org/10.1088/2631-6331/ad68c0","url":null,"abstract":"This study presents a macro-scale constitutive model to simulate the tensile behaviour of biaxial weft knitted fabrics produced based on a 1 × 1 rib structure. Fabrics were produced using polyester yarns as stitch yarns and nylon yarns as straight yarns in a modern flat knitting machine. Stress–strain curves of 1 × 1 rib structure and corresponding biaxial knitted fabric were measured in three different directions (course, wale and 45 degrees) on a tensile tester. Based on extracted results, a constitutive equation was proposed for macro modelling of biaxial knitted fabrics. The stiffness matrix of the biaxial knitted fabrics was assumed to be a combination of the stiffness matrix of 1 × 1 rib and reinforcement yarns. A UMAT subroutine was provided to implement the constitutive behaviour in Abaqus software. To evaluate the accuracy of the proposed model, fabric tensile behaviour in 22.5° and 67.5° directions were simulated and compared with experimental results. The results showed that the macro model can successfully predict the tensile behaviour of the biaxial weft knitted fabric in different directions.","PeriodicalId":12652,"journal":{"name":"Functional Composites and Structures","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142194647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced compressive strength of graphene strengthened copper (G/Cu) composites","authors":"Deniz Cakir, Omer R Caylan, Erhan Gurpinar, Ogulcan Akgul, H Onat Tugrul, Elif Okay, Eren Atli, Benat Kockar, Goknur Cambaz Buke","doi":"10.1088/2631-6331/ad6954","DOIUrl":"https://doi.org/10.1088/2631-6331/ad6954","url":null,"abstract":"This study explores the compressive mechanical properties of copper composites reinforced with graphene. Graphene was synthesized on copper powders via plasma-enhanced chemical vapor deposition. Multilayer graphene formation has been substantiated by Raman analysis. Graphene-coated copper (G/Cu) powders were then subjected to pressing and sintering to fabricate G/Cu composites. The mechanical properties of G/Cu composites were investigated under compression from room temperature up to 400 °C in air. The results demonstrated a substantial improvement in the mechanical properties of G/Cu composites compared to monolithic copper. Specifically, the yield strength in compression of the G/Cu composite increased by 203% at room temperature and by 190% at 200 °C. At 400 °C, the yield strength enhancement exceeded 370%. Microstructural analysis suggests that the observed enhancements in G/Cu composites can be attributed to reduced porosity, smaller grain size, and inhibited dislocation motion at the increased grain boundary area (due to refined grain size) and graphene-copper interfaces.","PeriodicalId":12652,"journal":{"name":"Functional Composites and Structures","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142194651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Conductive graphene-based coagulated composites for electronic printing applications","authors":"Manoj Aravind Sankar and Prasanna R","doi":"10.1088/2631-6331/ad68bf","DOIUrl":"https://doi.org/10.1088/2631-6331/ad68bf","url":null,"abstract":"Graphene is gaining significance in applications such as sensors, antennas, photonics and spintronics. In particular, it is suitable for printing components and circuits affording the properties of high conductivity alongside flexibility, elasticity and wearability. For this application, graphene is typically customised into a fluidic form—ink or paint. This paper reports a novel, economical, scalable methodology for synthesising electrically conductive graphene-based coagulated composite that could be utilised in the above-mentioned applications. Composites are prepared from graphene powder/ink and screen-printing ink (GP–SPI and GI–SPI, respectively) at different mass ratios, and the optimal composition is identified by brush coating on paper in the form of rectangular strips. As a proof of concept, at optimum mass ratios, the GP–SPI and GI–SPI composites exhibit electrical conductivities ranging 0.068–0.702 mS m−1 and 0.0303–0.1746 μS m−1, in order. The as-prepared conductive composites are then screen-printed onto a square with an area of 1 cm2 on ceramic, FR4, glass, paper, polyester and wood substrates. The coagulated GP–SPI and GI–SPI composites are compatible with all these substrates and yield a conductive coating, demonstrating their suitability in multifaceted applications. Furthermore, the method proposed herein eliminates the need for rare/precious expensive materials, state-of-the art equipment, highly skilled personnel and costs associated with the same, thereby broadening the avenues for low-cost, fluidic graphene-based functional composites.","PeriodicalId":12652,"journal":{"name":"Functional Composites and Structures","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141948019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing the Mechanical properties of CF-Reinforced Epoxy Composites through Chemically Surface Modification of Carbon Fibers via Novel Two-Step Approach by Addition of Epichlorohydrin","authors":"A. Tutunchi, Tara Ghodrati, Arvin Taghizadeh Tabrizi, K. Osouli-Bostanabad","doi":"10.1088/2631-6331/ad6528","DOIUrl":"https://doi.org/10.1088/2631-6331/ad6528","url":null,"abstract":"\u0000 The chemical surface modification was carried out in this study to improve the interface connection between carbon fiber and epoxy matrix to study the mechanical and fracture behavior of CF-reinforced epoxy composites. Finite element analysis was carried out by using ABAQUS software to simulate the variation of the tensile strength (TS), interfacial shear strength (IFSS), and interlaminar shear strength (ILSS). The chemical surface modification was carried out by the chemical oxidation by nitric acid and subsequently, addition of monomer resin of epichlorohydrin in a solution at 80 °C. The Raman Spectroscopy, Fourier Transform Infrared Spectroscopy (FT-IR), and Scanning Electron microscopy (SEM) were carried out to ensure the successful surface modification of CFs. Subsequently, surface-modified CF-reinforced epoxy composites were prepared through the hand lay-up method with the volume fraction of 20 wt.%, and curing was carried out at 80 °C for 4 h. The TS, IFSS, and ILSS values equaled 462.82 MPa, 156 MPa, and 4.1 MPa for modified CF/epoxy composites were achieved, respectively, which are improved remarkably compared to unmodified ones (380, 81, and 2.9 MPa). These improvements are attributed to the successful surface modification of CFs by epichlorohydrin. The surface modification causes the increase in wettability of CFs and the formation of mechanical interlocking and interaction between CFs and epoxy matrix was achieved through uniform and homogenous distribution of epichlorohydrin on the surface of CFs. Fractography was carried out, which indicated the sound and uniform adhesion between CF and epoxy matrix. Achieved results are consistent with simulated results.","PeriodicalId":12652,"journal":{"name":"Functional Composites and Structures","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141825091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electrochemical and structural performances of carbon and glass fiber-reinforced structural supercapacitor composite at elevated temperatures","authors":"Jayani Anurangi, Madhubhashitha Herath, Dona T L Galhena and Jayantha Epaarachchi","doi":"10.1088/2631-6331/ad5e32","DOIUrl":"https://doi.org/10.1088/2631-6331/ad5e32","url":null,"abstract":"The structural supercapacitor can store electrical energy and withstand structural loads while saving substantial weight in many structural applications. This study investigated the development of a structural supercapacitor with a fiber-reinforced polymer composite system and explored the operating temperature’s influence on its performance. The electrochemical and mechanical properties of structural supercapacitors beyond the ambient temperature have not yet been studied; hence, evaluating parameters such as specific capacitance, energy density, cycle life, and structural performance at elevated temperatures are highly desired. We have designed and manufactured single and parallelly connected multilayer structural supercapacitor composites in this research. Carbon fibers were used as a bifunctional component, acting both as a current collector while acting as a mechanical reinforcement. In addition, glass fibers were added as the separator which is also acting as an integral reinforcement. The electrochemical and mechanical behavior of structural supercapacitors at elevated temperatures up to 85 °C were experimentally investigated. The test results revealed that at room temperature, the developed double-cell structural supercapacitor, which demonstrated an area-specific capacitance of 1.16 mF cm−2 and energy density of 0.36 mWh cm−2 at 0.24 mA cm−2, which are comparable to current achievements in structural supercapacitor research. The structural supercapacitor’s tensile, flexural, and compression strengths were measured as 109.5 MPa, 47.0 MPa, and 50.4 MPa, respectively. The specific capacitance and energy density reached 2.58 mF cm−2 and 0.81 mWh cm−2, while tensile, flexural, and compression strengths were reduced to 70.9 MPa, 14.2 MPa, and 8.8 MPa, respectively, at 85 °C. These findings provide new comprehensive knowledge on structural supercapacitor devices suitable for applications operating within a temperature range from ambient conditions to 85 °C.","PeriodicalId":12652,"journal":{"name":"Functional Composites and Structures","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141586737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of solid-state hybrid capacitor using carbon nanotube film as current collector","authors":"Dong Uk Woo, Young Jin Park, Jae Young Cheon, Kyunbae Lee, Yeonsu Jung, Patrick Joohyun Kim and Taehoon Kim","doi":"10.1088/2631-6331/ad5b4b","DOIUrl":"https://doi.org/10.1088/2631-6331/ad5b4b","url":null,"abstract":"Structural energy-storage devices are receiving considerable attention because they can simultaneously store electrical energy and provide structural support, thereby offering high volumetric and gravimetric capacities. Although carbon fiber–based materials have been the most popular choice for current collectors, their conductivity and specific surface area are relatively low; this limits the ability to load other active materials on to the current collector. Carbon nanotube (CNT) fiber is a promising alternative for lightweight structural materials because it has a density of less than 1 g cm−3 as well as high strength and electrical conductivity. In this study, we produced a light, strong, and porous CNT film (CNTF) via direct spinning for use as a current collector. The CNTF exhibited a high specific strength compared with Al foil. We also created an activated carbon–lithium titanium oxide hybrid capacitor with the CNTF current collector, which achieved a capacity similar to that of a capacitor having an Al current collector. Furthermore, a planar pouch cell created using a solid polymer electrolyte achieved a capacity of 74.1 mAh g−1, which is comparable to that of coin cells. Thus, our findings highlight the feasibility of CNTF as a material for current collectors and provide a foundation to develop manufacturing processes for structural batteries.","PeriodicalId":12652,"journal":{"name":"Functional Composites and Structures","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141551986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}