In this study, composites based on thermotropic liquid crystalline polymers (TLCP) and incorporated with hollow glass microspheres (HGM) were prepared via a melt compounding technique facilitated by masterbatch dilution, followed by subsequent shaping through injection molding. The influence of HGM loading (2–10 wt%) on the microstructure, thermal behavior, rheological and mechanical properties, dielectric performance, and hydrophobicity of the composites was comprehensively investigated. Electron microscopy and infrared spectroscopy confirmed uniform dispersion of HGM and strong interfacial hydrogen bonding with the TLCP matrix. X-ray diffraction revealed that HGM disrupts TLCP crystallinity, while differential scanning calorimetry demonstrated a decrease in crystallization and melting temperatures with increasing filler content. Thermogravimetric analysis showed excellent thermal stability, with char yields increasing from 38.2 % for neat TLCP to 48.8 % for TLCP/HGM10. Rheological testing revealed enhanced melt viscosity and viscoelastic moduli, and dynamic mechanical analysis indicated restricted chain mobility and increased glass transition temperatures. Importantly, the dielectric constant (Dk ∼2.43) and loss (Df ∼0.0284) at 2 MHz decreased by approximately 20 % and 59 %, respectively, for TLCP/HGM10 compared to neat TLCP, and these experimental values correlated well with theoretical predictions based on the Maxwell-Garnett model. Water contact angle tests further showed improved surface hydrophobicity, increasing from 77.4° to 88.8° with HGM addition. These results collectively demonstrate that the incorporation of HGM simultaneously enhances the thermal, dielectric, and moisture-resistance characteristics of TLCP composites, making them promising candidates for high-frequency and moisture-resilient electronic applications.
{"title":"Low-dielectric and hydrophobic thermotropic liquid crystalline polyester composites reinforced with hollow glass microspheres for next-generation electronic board materials","authors":"Jun-Hyeop Lee, Ya-Rin Shin, Gyeong-Ig Hwang, Shinwoo Lee, Jongho Moon, Young Gyu Jeong","doi":"10.1016/j.compscitech.2025.111395","DOIUrl":"10.1016/j.compscitech.2025.111395","url":null,"abstract":"<div><div>In this study, composites based on thermotropic liquid crystalline polymers (TLCP) and incorporated with hollow glass microspheres (HGM) were prepared via a melt compounding technique facilitated by masterbatch dilution, followed by subsequent shaping through injection molding. The influence of HGM loading (2–10 wt%) on the microstructure, thermal behavior, rheological and mechanical properties, dielectric performance, and hydrophobicity of the composites was comprehensively investigated. Electron microscopy and infrared spectroscopy confirmed uniform dispersion of HGM and strong interfacial hydrogen bonding with the TLCP matrix. X-ray diffraction revealed that HGM disrupts TLCP crystallinity, while differential scanning calorimetry demonstrated a decrease in crystallization and melting temperatures with increasing filler content. Thermogravimetric analysis showed excellent thermal stability, with char yields increasing from 38.2 % for neat TLCP to 48.8 % for TLCP/HGM10. Rheological testing revealed enhanced melt viscosity and viscoelastic moduli, and dynamic mechanical analysis indicated restricted chain mobility and increased glass transition temperatures. Importantly, the dielectric constant (<em>D</em><sub>k</sub> ∼2.43) and loss (<em>D</em><sub>f</sub> ∼0.0284) at 2 MHz decreased by approximately 20 % and 59 %, respectively, for TLCP/HGM10 compared to neat TLCP, and these experimental values correlated well with theoretical predictions based on the Maxwell-Garnett model. Water contact angle tests further showed improved surface hydrophobicity, increasing from 77.4° to 88.8° with HGM addition. These results collectively demonstrate that the incorporation of HGM simultaneously enhances the thermal, dielectric, and moisture-resistance characteristics of TLCP composites, making them promising candidates for high-frequency and moisture-resilient electronic applications.</div></div>","PeriodicalId":283,"journal":{"name":"Composites Science and Technology","volume":"272 ","pages":"Article 111395"},"PeriodicalIF":9.8,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-24DOI: 10.1016/j.compscitech.2025.111393
Jinlong Wang, Yonggang Shangguan, Qiang Zheng
With the rapid advancement of the highly integrated microelectronics industry, the growing demand for composite materials that offer both high thermal conductivity and effective electromagnetic interference (EMI) shielding to ensure the long-term stability of electronic devices is becoming increasingly significant. However, achieving high through-plane thermal conductivity remains challenging due to the difficulty in establishing continuous thermal conduction pathways through the composite thickness. In this work, polydimethylsiloxane (PDMS) composites with vertically oriented Carbon fiber (CF) structures were successfully fabricated through cast molding and gravity-magnetic field co-induced CF alignment. At 23.5 vol% CF content, the composite exhibits a through-plane thermal conductivity of 12.26 W/(m⋅K), a thermal conductivity enhancement (TCE) of 7500 %, and an electromagnetic interference shielding efficiency (EMI SE) of 27.9 dB. In addition, the influences of CF content on the anisotropic thermal conductivity and EMI shielding properties of the composites were examined. This CF/PDMS composites with vertically aligned CF structures have a broad range of potential applications in thermal management and EMI shielding, such as thermal interface materials in high-power chips, LEDs, 5G RF modules.
{"title":"Thermally conductive and electromagnetic interference shielding polydimethylsiloxane composites with vertically oriented carbon fibers obtained by gravity-magnetic actuation","authors":"Jinlong Wang, Yonggang Shangguan, Qiang Zheng","doi":"10.1016/j.compscitech.2025.111393","DOIUrl":"10.1016/j.compscitech.2025.111393","url":null,"abstract":"<div><div>With the rapid advancement of the highly integrated microelectronics industry, the growing demand for composite materials that offer both high thermal conductivity and effective electromagnetic interference (EMI) shielding to ensure the long-term stability of electronic devices is becoming increasingly significant. However, achieving high through-plane thermal conductivity remains challenging due to the difficulty in establishing continuous thermal conduction pathways through the composite thickness. In this work, polydimethylsiloxane (PDMS) composites with vertically oriented Carbon fiber (CF) structures were successfully fabricated through cast molding and gravity-magnetic field co-induced CF alignment. At 23.5 vol% CF content, the composite exhibits a through-plane thermal conductivity of 12.26 W/(m⋅K), a thermal conductivity enhancement (TCE) of 7500 %, and an electromagnetic interference shielding efficiency (EMI SE) of 27.9 dB. In addition, the influences of CF content on the anisotropic thermal conductivity and EMI shielding properties of the composites were examined. This CF/PDMS composites with vertically aligned CF structures have a broad range of potential applications in thermal management and EMI shielding, such as thermal interface materials in high-power chips, LEDs, 5G RF modules.</div></div>","PeriodicalId":283,"journal":{"name":"Composites Science and Technology","volume":"272 ","pages":"Article 111393"},"PeriodicalIF":9.8,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Polyetherimide (PEI), as a kind of high-temperature dielectrics, still face the issue of current leakage under thermo-electrical coupling fields, leading to a sharp degradation of energy storage performance. In this study, an intrinsic PEI with superior comprehensive properties was synthesized using 4,4'-(4,4′-isopropylidenediphenoxy)bis(phthalic anhydride) (BPADA) and 2,2-bis[4-(4-aminophenoxy)phenyl] propane (BAPP). Through molecular design, an "electron gate" mechanism was introduced via σ-π hyperconjugation effects, effectively suppressing long-range charge delocalization. The resulting intrinsic PEI achieves an energy storage density (Ud) of 1.93 J/cm3 at 150 °C, which is 20.6 % higher than that of commercial Ultem™ PEI film (1.6 J/cm3). Further modification was conducted by doping with three molecular semiconductors: 3,4,9,10-perylenetetracarboxylic diimide (PTCDI), 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTCDA), and 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA). Density Functional Theory (DFT) simulations and Low-Energy Inverse Photoemission Spectroscopy (LEIPS) experiments reveal that all three semiconductors exhibit higher electron affinity than the intrinsic PEI. Additionally, Thermally Stimulated Depolarization Current (TSDC) reveals that the incorporation of molecular semiconductors increases trapped charges and trap energy level compared to intrinsic PEI. Both experimental and simulation results consistently demonstrate that molecular semiconductor doping can enhance energy storage performance by constructing deep trap sites within the PEI matrix. Experimental results demonstrate that at 150 °C, the 0.125 % PTCDI-doped PEI achieves a breakdown strength of 545 MV/m, an Ud of 3.71 J/cm3, and a charge-discharge efficiency (η) of 90.13 % (vs. 436 MV/m, 1.93 J/cm3, and 94.67 % for intrinsic PEI). This research provides an effective strategy for improving the capacitive performance of polymer dielectrics under thermo-electrical coupling conditions.
{"title":"Enhanced dielectric and energy storage performance of polyetherimide doping with molecular semiconductor all-organic composites","authors":"Mingyang Zhang , Likun Zang , Hui Tong , Fuyuan Liu","doi":"10.1016/j.compscitech.2025.111391","DOIUrl":"10.1016/j.compscitech.2025.111391","url":null,"abstract":"<div><div>Polyetherimide (PEI), as a kind of high-temperature dielectrics, still face the issue of current leakage under thermo-electrical coupling fields, leading to a sharp degradation of energy storage performance. In this study, an intrinsic PEI with superior comprehensive properties was synthesized using <strong>4,4'-(4,4′-isopropylidenediphenoxy)bis(phthalic anhydride) (BPADA)</strong> and <strong>2,2-bis[4-(4-aminophenoxy)phenyl] propane (BAPP)</strong>. Through molecular design, an \"electron gate\" mechanism was introduced via <strong>σ-π hyperconjugation effects</strong>, effectively suppressing long-range charge delocalization. The resulting intrinsic PEI achieves an energy storage density (<strong><em>U</em><sub>d</sub></strong>) of <strong>1.93 J/cm<sup>3</sup> at 150 °C</strong>, which is <strong>20.6 % higher</strong> than that of commercial Ultem™ PEI film (1.6 <strong>J/cm<sup>3</sup></strong>). Further modification was conducted by doping with three molecular semiconductors: 3,4,9,10-perylenetetracarboxylic diimide <strong>(PTCDI), 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTCDA), and 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA). Density Functional Theory (DFT)</strong> simulations and <strong>Low-Energy Inverse Photoemission Spectroscopy (LEIPS)</strong> experiments reveal that all three semiconductors exhibit <strong>higher electron affinity</strong> than the intrinsic PEI. Additionally, Thermally Stimulated Depolarization Current (TSDC) reveals that the incorporation of molecular semiconductors increases trapped charges and trap energy level compared to intrinsic PEI. Both experimental and simulation results consistently demonstrate that molecular semiconductor doping can enhance energy storage performance by constructing deep trap sites within the PEI matrix. Experimental results demonstrate that at 150 <strong>°C,</strong> the 0.125 % PTCDI-doped PEI achieves a breakdown strength of 545 MV/m, an <strong><em>U</em><sub>d</sub></strong> of 3.71 J/cm<sup>3</sup>, and a charge-discharge efficiency <strong>(</strong><em>η</em><strong>)</strong> of 90.13 % (vs. 436 MV/m, 1.93 J/cm<sup>3</sup>, and 94.67 % for intrinsic PEI). This research provides an effective strategy for improving the capacitive performance of polymer dielectrics under thermo-electrical coupling conditions.</div></div>","PeriodicalId":283,"journal":{"name":"Composites Science and Technology","volume":"272 ","pages":"Article 111391"},"PeriodicalIF":9.8,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-23DOI: 10.1016/j.compscitech.2025.111392
Guang Yang , Jinze Cui , Kewen Zeng , Yutai Luo , Feng Bao , Jiali Yu , Caizhen Zhu , Jian Xu , Huichao Liu
Chopped ultra-thin carbon fiber tape reinforced polyamide 6 (PA6) composites are considered promising materials for balancing the mechanical properties and ease of processing, particularly due to their in-plane quasi-isotropy, which facilitate structural design and manufacturing in the industry. However, further advancement is hindered by the weak interfacial bonding and modulus mismatch between carbon fiber (CF) and PA6 matrix, as well as high porosity of the CF/PA6 composites. In this work, plasma treatment and mixed COOH-carbon nanotubes (CNTs)/PA6 sizing methods are proposed to enhance the surface roughness (Ra) and surface energy of the CF. Compared to untreated CF, the Ra value and surface energy of the modified CF increased by 45.1 % and 69.7 %, respectively. After 0.6 wt% COOH-CNTs modification, the tensile strength, Young's modulus, and interlaminar shear strength (ILSS) of the composites reach 900.0 MPa, 48.4 GPa, and 62.3 MPa, which are respectively 24.9 %, 19.8 %, and 36.9 % higher than those of the unmodified composites. In particular, the porosity is reduced to 1.22 %, which is 73.3 % lower than that of unmodified composites. Moreover, the [email protected] wt% CNT/PA6 composites exhibit mitigatory modulus gradient across the interphase. This work synergistically enhances the interface adhesion and reduces the porosity of the CF/PA6 composites via a large-scale continuous modification technology.
{"title":"Continuous construction of gradient modulus interphase in CF/PA6 composites with enhanced interfacial properties and reduced porosity","authors":"Guang Yang , Jinze Cui , Kewen Zeng , Yutai Luo , Feng Bao , Jiali Yu , Caizhen Zhu , Jian Xu , Huichao Liu","doi":"10.1016/j.compscitech.2025.111392","DOIUrl":"10.1016/j.compscitech.2025.111392","url":null,"abstract":"<div><div>Chopped ultra-thin carbon fiber tape reinforced polyamide 6 (PA6) composites are considered promising materials for balancing the mechanical properties and ease of processing, particularly due to their in-plane quasi-isotropy, which facilitate structural design and manufacturing in the industry. However, further advancement is hindered by the weak interfacial bonding and modulus mismatch between carbon fiber (CF) and PA6 matrix, as well as high porosity of the CF/PA6 composites. In this work, plasma treatment and mixed COOH-carbon nanotubes (CNTs)/PA6 sizing methods are proposed to enhance the surface roughness (Ra) and surface energy of the CF. Compared to untreated CF, the Ra value and surface energy of the modified CF increased by 45.1 % and 69.7 %, respectively. After 0.6 wt% COOH-CNTs modification, the tensile strength, Young's modulus, and interlaminar shear strength (ILSS) of the composites reach 900.0 MPa, 48.4 GPa, and 62.3 MPa, which are respectively 24.9 %, 19.8 %, and 36.9 % higher than those of the unmodified composites. In particular, the porosity is reduced to 1.22 %, which is 73.3 % lower than that of unmodified composites. Moreover, the <span><span><span>[email protected]</span></span><svg><path></path></svg></span> wt% CNT/PA6 composites exhibit mitigatory modulus gradient across the interphase. This work synergistically enhances the interface adhesion and reduces the porosity of the CF/PA6 composites via a large-scale continuous modification technology.</div></div>","PeriodicalId":283,"journal":{"name":"Composites Science and Technology","volume":"272 ","pages":"Article 111392"},"PeriodicalIF":9.8,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-23DOI: 10.1016/j.compscitech.2025.111390
Wen-yan Wang , Yan-ji Yin , Yuan-chao Jiang , Rui Han , Min Nie
Cellulose nanofibers (CNFs), derived from renewable biomass, offer exceptional mechanical properties, a high aspect ratio, and abundant surface hydroxyl groups, making them highly attractive for polymer composite functionalization. In this study, CNFs are employed as both dispersing and reinforcing agents to address the dual challenges of filler aggregation and poor interfacial adhesion in nylon-based thermally conductive composites. By leveraging their strong hydrogen bonding capability, CNFs not only enable the uniform dispersion of boron nitride (BN) fillers in aqueous systems but also facilitate the construction of robust interfacial networks within the polymer matrix. Using a simple vacuum-assisted filtration and compression molding strategy, we fabricated laminated composites featuring highly aligned BN structures. This unique architecture promotes the formation of efficient thermal pathways, resulting in an in-plane thermal conductivity of 4.5 Wm−1K−1 at 24.5 wt% BN—an 1857 % enhancement over pure nylon. Simultaneously, the CNF-induced interfacial reinforcement leads to excellent mechanical strength and fatigue resistance, with the composite retaining 92 % of its thermal conductivity and 85 % of its tensile strength after 100,000 bending cycles. These findings demonstrate the significant potential of CNF-assisted interfacial engineering for developing high-performance, thermoplastic-based thermal management materials suitable for flexible electronics and other advanced applications.
{"title":"Cellulose nanofibers-enabled interfacial engineering for thermally conductive composites with superior mechanical durability","authors":"Wen-yan Wang , Yan-ji Yin , Yuan-chao Jiang , Rui Han , Min Nie","doi":"10.1016/j.compscitech.2025.111390","DOIUrl":"10.1016/j.compscitech.2025.111390","url":null,"abstract":"<div><div>Cellulose nanofibers (CNFs), derived from renewable biomass, offer exceptional mechanical properties, a high aspect ratio, and abundant surface hydroxyl groups, making them highly attractive for polymer composite functionalization. In this study, CNFs are employed as both dispersing and reinforcing agents to address the dual challenges of filler aggregation and poor interfacial adhesion in nylon-based thermally conductive composites. By leveraging their strong hydrogen bonding capability, CNFs not only enable the uniform dispersion of boron nitride (BN) fillers in aqueous systems but also facilitate the construction of robust interfacial networks within the polymer matrix. Using a simple vacuum-assisted filtration and compression molding strategy, we fabricated laminated composites featuring highly aligned BN structures. This unique architecture promotes the formation of efficient thermal pathways, resulting in an in-plane thermal conductivity of 4.5 Wm<sup>−1</sup>K<sup>−1</sup> at 24.5 wt% BN—an 1857 % enhancement over pure nylon. Simultaneously, the CNF-induced interfacial reinforcement leads to excellent mechanical strength and fatigue resistance, with the composite retaining 92 % of its thermal conductivity and 85 % of its tensile strength after 100,000 bending cycles. These findings demonstrate the significant potential of CNF-assisted interfacial engineering for developing high-performance, thermoplastic-based thermal management materials suitable for flexible electronics and other advanced applications.</div></div>","PeriodicalId":283,"journal":{"name":"Composites Science and Technology","volume":"272 ","pages":"Article 111390"},"PeriodicalIF":9.8,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-19DOI: 10.1016/j.compscitech.2025.111389
Shuai Liu , Qunfu Fan , Sijia Li , Yicang Huang , Yujie Chen , Hezhou Liu
One-dimensional (1D) carbon-based magnetic fibers, characterized by rational multicomponent regulation and refined microstructure design, have emerged as promising candidates for high-performance electromagnetic wave (EMW) absorption. However, conventional 1D absorbers often suffer from densely aggregated and randomly oriented magnetic nanoparticles embedded in carbon matrices, which severely restricts magnetic coupling and consequently compromises magnetic loss capabilities. In this study, 1D necklace-structured nitrogen-doped porous carbon nanofibers embedded with FeCoNi nanoparticles (FeCoNi@NPCNFs) were successfully fabricated through a synergistic combination of hydrothermal synthesis, coaxial electrospinning, and controlled carbonization. By precisely regulating the spatial arrangement of magnetic nanoparticles, we achieved uniform dispersion and enhanced interparticle magnetic interactions within the NPCNFs, resulting in stronger magnetic anisotropy and elevated saturation magnetization. Impressively, the well-designed necklace-like FeCoNi@NPCNFs demonstrated a minimum reflection loss (RLmin) of −52.36 dB at an ultrathin thickness of 1.46 mm, accompanied by a broad effective absorption bandwidth (EAB) of 5.52 GHz (11.70–17.22 GHz) measured at 1.66 mm, which significantly outperformed single-component FeCoNi@CNFs (RLmin = −17.08 dB, EAB = 4.75 GHz). Such excellent EMW absorption performance can be attributed to the multiple magnetic coupling networks, as well as the multiple interface polarization among the biphasic FeCoNi alloys, N-doped carbon species, and the core-shell porous structure. This work proposes a groundbreaking design strategy for high-efficiency, ultra-thin magnetic fibrous EMW absorbers.
{"title":"Necklace-structured FeCoNi@N-doped porous carbon nanofibers with strong magnetic coupling for high-performance microwave absorption","authors":"Shuai Liu , Qunfu Fan , Sijia Li , Yicang Huang , Yujie Chen , Hezhou Liu","doi":"10.1016/j.compscitech.2025.111389","DOIUrl":"10.1016/j.compscitech.2025.111389","url":null,"abstract":"<div><div>One-dimensional (1D) carbon-based magnetic fibers, characterized by rational multicomponent regulation and refined microstructure design, have emerged as promising candidates for high-performance electromagnetic wave (EMW) absorption. However, conventional 1D absorbers often suffer from densely aggregated and randomly oriented magnetic nanoparticles embedded in carbon matrices, which severely restricts magnetic coupling and consequently compromises magnetic loss capabilities. In this study, 1D necklace-structured nitrogen-doped porous carbon nanofibers embedded with FeCoNi nanoparticles (FeCoNi@NPCNFs) were successfully fabricated through a synergistic combination of hydrothermal synthesis, coaxial electrospinning, and controlled carbonization. By precisely regulating the spatial arrangement of magnetic nanoparticles, we achieved uniform dispersion and enhanced interparticle magnetic interactions within the NPCNFs, resulting in stronger magnetic anisotropy and elevated saturation magnetization. Impressively, the well-designed necklace-like FeCoNi@NPCNFs demonstrated a minimum reflection loss (RL<sub>min</sub>) of −52.36 dB at an ultrathin thickness of 1.46 mm, accompanied by a broad effective absorption bandwidth (EAB) of 5.52 GHz (11.70–17.22 GHz) measured at 1.66 mm, which significantly outperformed single-component FeCoNi@CNFs (RL<sub>min</sub> = −17.08 dB, EAB = 4.75 GHz). Such excellent EMW absorption performance can be attributed to the multiple magnetic coupling networks, as well as the multiple interface polarization among the biphasic FeCoNi alloys, N-doped carbon species, and the core-shell porous structure. This work proposes a groundbreaking design strategy for high-efficiency, ultra-thin magnetic fibrous EMW absorbers.</div></div>","PeriodicalId":283,"journal":{"name":"Composites Science and Technology","volume":"272 ","pages":"Article 111389"},"PeriodicalIF":9.8,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-19DOI: 10.1016/j.compscitech.2025.111371
Quentin Maréchal , Mohamed Ichchou , Bruno Berthel , Michelle Salvia , Pascal Fossat , Olivier Bareille , Mohamed Chabchoub
This paper deals with the modeling and sensitivity analysis of spring back for composite made structures. Spring back is a well-known phenomenon connected to the manufacturing of composite parts. It is a multi-physical process involving chemical, thermal, and mechanical issues. The prediction of the spring back is necessary in order to improve the quality of the production while respecting the manufacturing rules and tolerances. This paper specifically addresses a very important question. Indeed when the spring back is connected to a great number of parameters that need to be characterized accordingly, not all of them are of relevance for the prediction. The paper implements a sensitivity analysis process leading to a hierarchy of the needed parameters. Specifically for the composite tested in this paper, it is shown that the cure shrinkage coefficients are the most important parameters that need to be characterized precisely. This conclusion could help make relevant experimental characterization for the final target which is the relevant prediction of the spring back.
{"title":"Composite structures spring back, modeling and sensitivity analysis","authors":"Quentin Maréchal , Mohamed Ichchou , Bruno Berthel , Michelle Salvia , Pascal Fossat , Olivier Bareille , Mohamed Chabchoub","doi":"10.1016/j.compscitech.2025.111371","DOIUrl":"10.1016/j.compscitech.2025.111371","url":null,"abstract":"<div><div>This paper deals with the modeling and sensitivity analysis of spring back for composite made structures. Spring back is a well-known phenomenon connected to the manufacturing of composite parts. It is a multi-physical process involving chemical, thermal, and mechanical issues. The prediction of the spring back is necessary in order to improve the quality of the production while respecting the manufacturing rules and tolerances. This paper specifically addresses a very important question. Indeed when the spring back is connected to a great number of parameters that need to be characterized accordingly, not all of them are of relevance for the prediction. The paper implements a sensitivity analysis process leading to a hierarchy of the needed parameters. Specifically for the composite tested in this paper, it is shown that the cure shrinkage coefficients are the most important parameters that need to be characterized precisely. This conclusion could help make relevant experimental characterization for the final target which is the relevant prediction of the spring back.</div></div>","PeriodicalId":283,"journal":{"name":"Composites Science and Technology","volume":"272 ","pages":"Article 111371"},"PeriodicalIF":9.8,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-18DOI: 10.1016/j.compscitech.2025.111388
Sheng Liu, Bohong Gu, Baozhong Sun
Dielectric breakdown of carbon fiber reinforced polymers is a key factor affecting the lightning protection design of engineering applications. This paper presented a coupled phase field-electrical-thermal model to reveal dielectric breakdown evolution and damage morphology of three-dimensional (3D) braided carbon fiber/epoxy composites. Finite element analysis (FEA) results show that dielectric breakdown occurs in the shortest conductive path along the electrical field direction. The braided yarns outside the shortest path also exhibit a breakdown tendency, which weakens the dielectric breakdown voltage. Testing results verify that dielectric breakdown voltage decreases from 3250 V to 337.5 V as the increasing carbon fiber yarns. Increasing the equivalent length of braided yarn along the loading direction decreases the dielectric breakdown voltage. Furthermore, a similar elliptical damage is observed at the surface braided knot from both the FEA model and the testing results. The verified model finds that both electric potential and current density distributions within the composite undergo abrupt transitions upon complete dielectric breakdown, which further reveals the dielectric breakdown progress.
{"title":"Dielectric breakdown behaviors and high-voltage damages of 3D braided carbon fiber/epoxy resin composites","authors":"Sheng Liu, Bohong Gu, Baozhong Sun","doi":"10.1016/j.compscitech.2025.111388","DOIUrl":"10.1016/j.compscitech.2025.111388","url":null,"abstract":"<div><div>Dielectric breakdown of carbon fiber reinforced polymers is a key factor affecting the lightning protection design of engineering applications. This paper presented a coupled phase field-electrical-thermal model to reveal dielectric breakdown evolution and damage morphology of three-dimensional (3D) braided carbon fiber/epoxy composites. Finite element analysis (FEA) results show that dielectric breakdown occurs in the shortest conductive path along the electrical field direction. The braided yarns outside the shortest path also exhibit a breakdown tendency, which weakens the dielectric breakdown voltage. Testing results verify that dielectric breakdown voltage decreases from 3250 V to 337.5 V as the increasing carbon fiber yarns. Increasing the equivalent length of braided yarn along the loading direction decreases the dielectric breakdown voltage. Furthermore, a similar elliptical damage is observed at the surface braided knot from both the FEA model and the testing results. The verified model finds that both electric potential and current density distributions within the composite undergo abrupt transitions upon complete dielectric breakdown, which further reveals the dielectric breakdown progress.</div></div>","PeriodicalId":283,"journal":{"name":"Composites Science and Technology","volume":"272 ","pages":"Article 111388"},"PeriodicalIF":9.8,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145106933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-16DOI: 10.1016/j.compscitech.2025.111374
Zhiyuan Xu , Ran Tao , Kunal Masania , Sofia Teixeira de Freitas
In this study, a 3D-printed biomimetic overlapping curl structure inspired by spider silk molecular structure, containing sacrificial bonds and hidden lengths, is studied as a toughening mechanism for a bio-based epoxy. Experimental results of the fracture phenomena of the overlapping curl-reinforced bio-based epoxy identify three toughening mechanisms triggered by the overlapping curl: (1) crack re-initiation, (2) overlapping curl bridging, and (3) epoxy ligament. First, the integrated overlapping curl creates a void within the epoxy matrix. As the crack tip reaches the end of this void, the crack re-initiates. Then, as the hidden length of overlapping curl unfolds, it leads to a bridging effect in resisting crack growth. In addition, for the smallest hidden length, an epoxy ligament is formed due to crack branching, significantly improving the energy release rate. The epoxy fracture energy release rate increased by 13 %. The overall modest improvement is attributed to the large plastic dissipation energy of the epoxy and the relatively low overlapping curl load-capacity. However, when expanding the design space numerically, it was shown that as the failure load of the overlapping curl increases, the bridging effect increases progressively. The introduction of the bio-inspired overlapping curl structure into bio-based epoxy proves the concept of a toughening strategy for developing high-performance sustainable composite materials.
{"title":"Bio-inspired overlapping curl structures for toughening bio-based epoxy: A study on the fracture phenomena","authors":"Zhiyuan Xu , Ran Tao , Kunal Masania , Sofia Teixeira de Freitas","doi":"10.1016/j.compscitech.2025.111374","DOIUrl":"10.1016/j.compscitech.2025.111374","url":null,"abstract":"<div><div>In this study, a 3D-printed biomimetic overlapping curl structure inspired by spider silk molecular structure, containing sacrificial bonds and hidden lengths, is studied as a toughening mechanism for a bio-based epoxy. Experimental results of the fracture phenomena of the overlapping curl-reinforced bio-based epoxy identify three toughening mechanisms triggered by the overlapping curl: (1) crack re-initiation, (2) overlapping curl bridging, and (3) epoxy ligament. First, the integrated overlapping curl creates a void within the epoxy matrix. As the crack tip reaches the end of this void, the crack re-initiates. Then, as the hidden length of overlapping curl unfolds, it leads to a bridging effect in resisting crack growth. In addition, for the smallest hidden length, an epoxy ligament is formed due to crack branching, significantly improving the energy release rate. The epoxy fracture energy release rate increased by 13<!--> <!-->%. The overall modest improvement is attributed to the large plastic dissipation energy of the epoxy and the relatively low overlapping curl load-capacity. However, when expanding the design space numerically, it was shown that as the failure load of the overlapping curl increases, the bridging effect increases progressively. The introduction of the bio-inspired overlapping curl structure into bio-based epoxy proves the concept of a toughening strategy for developing high-performance sustainable composite materials.</div></div>","PeriodicalId":283,"journal":{"name":"Composites Science and Technology","volume":"272 ","pages":"Article 111374"},"PeriodicalIF":9.8,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-15DOI: 10.1016/j.compscitech.2025.111387
Angeliki Christoforidou , Abishek Baskar , Entela Kane , Marko Pavlovic
Steel-Reinforced Resin (SRR) is a particulate material originally developed as an injectant for anchoring applications. More recently, it has been proposed as a filler material for cavities embedding mechanical connectors in FRP–steel hybrid bridges. In this context, the compressive behaviour of SRR becomes critical due to the multiaxial stress states and fatigue demands at a joint scale. This paper presents a comprehensive experimental and numerical investigation of SRR under monotonic, incremental cyclic, and fatigue compressive loading in unconfined conditions. A custom triaxial setup is also used to evaluate pressure sensitivity and strength enhancement due to confinement under monotonic loading. In parallel, micromechanical finite element models are developed to simulate the interactions between the resin matrix and the steel balls at the microscale, incorporating interface damage, friction, and cohesive failure. The models reproduce the observed nonlinear behaviour and reveal distinct Poisson's ratio responses in tension and compression, offering deeper insight into the mechanisms governing stiffness degradation, strain softening, and plateau behaviour.
{"title":"Compressive behaviour and micromechanical modelling of steel-reinforced resin under monotonic and cyclic loading","authors":"Angeliki Christoforidou , Abishek Baskar , Entela Kane , Marko Pavlovic","doi":"10.1016/j.compscitech.2025.111387","DOIUrl":"10.1016/j.compscitech.2025.111387","url":null,"abstract":"<div><div>Steel-Reinforced Resin (SRR) is a particulate material originally developed as an injectant for anchoring applications. More recently, it has been proposed as a filler material for cavities embedding mechanical connectors in FRP–steel hybrid bridges. In this context, the compressive behaviour of SRR becomes critical due to the multiaxial stress states and fatigue demands at a joint scale. This paper presents a comprehensive experimental and numerical investigation of SRR under monotonic, incremental cyclic, and fatigue compressive loading in unconfined conditions. A custom triaxial setup is also used to evaluate pressure sensitivity and strength enhancement due to confinement under monotonic loading. In parallel, micromechanical finite element models are developed to simulate the interactions between the resin matrix and the steel balls at the microscale, incorporating interface damage, friction, and cohesive failure. The models reproduce the observed nonlinear behaviour and reveal distinct Poisson's ratio responses in tension and compression, offering deeper insight into the mechanisms governing stiffness degradation, strain softening, and plateau behaviour.</div></div>","PeriodicalId":283,"journal":{"name":"Composites Science and Technology","volume":"272 ","pages":"Article 111387"},"PeriodicalIF":9.8,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145119192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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