Pub Date : 2024-09-30DOI: 10.1016/j.coco.2024.102110
Anodic aluminum oxide-zinc (AAO-Zn) coatings were prepared on aluminum (Al) alloy substrates through anodization and nZnO deposition. Further heat treatment at various temperature is applied to the composite coatings. Among the samples, AZ-250 sample showed lower corrosion current density (1.127 × 10−8 A/cm2) and higher charge-transfer resistance (4.65 × 105 Ω cm2) compared to the AZ-150 and AZ-350 samples. At 250 °C, a greater incorporation of nZnO into the AAO layer facilitated the fusion of ZnO with aluminum oxide, resulting in a denser and more protective coating. The antibacterial research revealed AZ-250 sample achieved a 100 % reduction of S. aureus and 97.9 % of E. coli within 2 h. Even after 40 days of air exposure, the AZ-250 sample maintained high antibacterial effectiveness due to ZnO attachment and sustained Zn2⁺ release from the nanoporous AAO structure. This nanocomposite is suitable for applications in heat exchangers, medical instrument casings, and transport structure.
{"title":"Corrosion resistance and long-term antibacterial performance of ZnO-Al2O3 nanocomposite coatings on aluminum alloy","authors":"","doi":"10.1016/j.coco.2024.102110","DOIUrl":"10.1016/j.coco.2024.102110","url":null,"abstract":"<div><div>Anodic aluminum oxide-zinc (AAO-Zn) coatings were prepared on aluminum (Al) alloy substrates through anodization and nZnO deposition. Further heat treatment at various temperature is applied to the composite coatings. Among the samples, AZ-250 sample showed lower corrosion current density (1.127 × 10<sup>−8</sup> A/cm<sup>2</sup>) and higher charge-transfer resistance (4.65 × 10<sup>5</sup> Ω cm<sup>2</sup>) compared to the AZ-150 and AZ-350 samples. At 250 °C, a greater incorporation of nZnO into the AAO layer facilitated the fusion of ZnO with aluminum oxide, resulting in a denser and more protective coating. The antibacterial research revealed AZ-250 sample achieved a 100 % reduction of <em>S. aureus</em> and 97.9 % of <em>E. coli</em> within 2 h. Even after 40 days of air exposure, the AZ-250 sample maintained high antibacterial effectiveness due to ZnO attachment and sustained Zn<sup>2</sup>⁺ release from the nanoporous AAO structure. This nanocomposite is suitable for applications in heat exchangers, medical instrument casings, and transport structure.</div></div>","PeriodicalId":10533,"journal":{"name":"Composites Communications","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142424788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-09-29DOI: 10.1016/j.coco.2024.102108
In this work, vanillin based inherently flame retardant polyurethane/SiO2 composite foams were designed. Firstly, the vanillin based flame retarding diol (VDP) was synthesized. Then, the KH550 modified nano-SiO2 (KH550-g-SiO2) was prepared as the reinforcement. Subsequently, a series of flame-retardant polyurethane/SiO2 composite foams (PUF-0.5P-xSiO2) were synthesized by tailoring the hard-soft segments and KH550-g-SiO2 contents. The results showed that KH550-g-SiO2 significantly improve the thermal stability of the PUF-0.5P-xSiO2 foams. In addition, the compressive strength of PUF-0.5P-xSiO2 foams was enhanced from 0.18 MPa (PUF-0.5P) to 0.45 MPa (PUF-0.5P-2.0SiO2) under 20 % strain. The flame retardant properties of PUF-0.5P-2.0SiO2 reached UL-94 V-0 grade. Meanwhile, the addition of KH550-g-SiO2 also decreased the thermal conductivity from 0.046 W/m·k to 0.037 W/m·k for PUF-0.5P-2.0SiO2. This work may provide an approach to obtain the biobased lightweight polyurethane foams for the application in packaging and building areas.
{"title":"Preparation of vanillin-based polyurethane/SiO2 nanocomposite foams with excellent flame retardancy and thermal insulation performance","authors":"","doi":"10.1016/j.coco.2024.102108","DOIUrl":"10.1016/j.coco.2024.102108","url":null,"abstract":"<div><div>In this work, vanillin based inherently flame retardant polyurethane/SiO<sub>2</sub> composite foams were designed. Firstly, the vanillin based flame retarding diol (VDP) was synthesized. Then, the KH550 modified nano-SiO<sub>2</sub> (KH550-g-SiO<sub>2</sub>) was prepared as the reinforcement. Subsequently, a series of flame-retardant polyurethane/SiO<sub>2</sub> composite foams (PUF-0.5P-<em>x</em>SiO<sub>2</sub>) were synthesized by tailoring the hard-soft segments and KH550-g-SiO<sub>2</sub> contents. The results showed that KH550-g-SiO<sub>2</sub> significantly improve the thermal stability of the PUF-0.5P-<em>x</em>SiO<sub>2</sub> foams. In addition, the compressive strength of PUF-0.5P-<em>x</em>SiO<sub>2</sub> foams was enhanced from 0.18 MPa (PUF-0.5P) to 0.45 MPa (PUF-0.5P-2.0SiO<sub>2</sub>) under 20 % strain. The flame retardant properties of PUF-0.5P-2.0SiO<sub>2</sub> reached UL-94 V-0 grade. Meanwhile, the addition of KH550-g-SiO<sub>2</sub> also decreased the thermal conductivity from 0.046 W/m·k to 0.037 W/m·k for PUF-0.5P-2.0SiO<sub>2</sub>. This work may provide an approach to obtain the biobased lightweight polyurethane foams for the application in packaging and building areas.</div></div>","PeriodicalId":10533,"journal":{"name":"Composites Communications","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142424726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-09-29DOI: 10.1016/j.coco.2024.102109
In this study, carbon spheres (CS)/g-C3N4 composite materials were fabricated by a hydrothermal method, and the characterizations have confirmed the successful anchoring of CS onto the surface of g-C3N4, constructing enriched nitrogen vacancies during the synthesis process. The photocatalytic CO2 reduction activity of g-C3N4 is enhanced by all of these advantageous factors. The significant enhancement can be attributed to the tight interfacial interaction between CS and g-C3N4, which endows with the photocatalyst a larger specific surface area, higher light utilization efficiency and stronger capability for photoinduced charges separation. Furthermore, the presence of nitrogen vacancies further accelerates the separation and migration efficiency of photogenerated charges, provides additional active sites to promote the adsorption and activation of CO2 molecules, thereby effectively boosting the photocatalytic activity for CO2 reduction. The CO2 conversion rate on CS/g-C3N4 composite materials is higher than that on the reference g-C3N4. The apparent quantum yield (AQY) is also superior to that of the reference g-C3N4 under three different monochromatic light irradiations. The stability of the catalyst was verified through cycling experiments, indicating promising potential practical industrial application. The CO2 reduction mechanism and transformation pathways were elucidated using in-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). The photocatalytic reduction rate constant of Cr(VI) by 50CS/CN is 2.9 times higher than that by CN. This study introduces a facile approach for synthesizing g-C3N4-based photocatalytic materials, providing an interesting strategy to boost photocatalytic activity of g-C3N4 for photocatalytic CO2 and Cr(VI) reduction.
{"title":"Efficient photocatalytic CO2 and Cr(VI) reduction on carbon spheres/g-C3N4 composites with enriched nitrogen vacancies","authors":"","doi":"10.1016/j.coco.2024.102109","DOIUrl":"10.1016/j.coco.2024.102109","url":null,"abstract":"<div><div>In this study, carbon spheres (CS)/g-C<sub>3</sub>N<sub>4</sub> composite materials were fabricated by a hydrothermal method, and the characterizations have confirmed the successful anchoring of CS onto the surface of g-C<sub>3</sub>N<sub>4</sub>, constructing enriched nitrogen vacancies during the synthesis process. The photocatalytic CO<sub>2</sub> reduction activity of g-C<sub>3</sub>N<sub>4</sub> is enhanced by all of these advantageous factors. The significant enhancement can be attributed to the tight interfacial interaction between CS and g-C<sub>3</sub>N<sub>4</sub>, which endows with the photocatalyst a larger specific surface area, higher light utilization efficiency and stronger capability for photoinduced charges separation. Furthermore, the presence of nitrogen vacancies further accelerates the separation and migration efficiency of photogenerated charges, provides additional active sites to promote the adsorption and activation of CO<sub>2</sub> molecules, thereby effectively boosting the photocatalytic activity for CO<sub>2</sub> reduction. The CO<sub>2</sub> conversion rate on CS/g-C<sub>3</sub>N<sub>4</sub> composite materials is higher than that on the reference g-C<sub>3</sub>N<sub>4</sub>. The apparent quantum yield (AQY) is also superior to that of the reference g-C<sub>3</sub>N<sub>4</sub> under three different monochromatic light irradiations. The stability of the catalyst was verified through cycling experiments, indicating promising potential practical industrial application. The CO<sub>2</sub> reduction mechanism and transformation pathways were elucidated using in-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). The photocatalytic reduction rate constant of Cr(VI) by 50CS/CN is 2.9 times higher than that by CN. This study introduces a facile approach for synthesizing g-C<sub>3</sub>N<sub>4</sub>-based photocatalytic materials, providing an interesting strategy to boost photocatalytic activity of g-C<sub>3</sub>N<sub>4</sub> for photocatalytic CO<sub>2</sub> and Cr(VI) reduction.</div></div>","PeriodicalId":10533,"journal":{"name":"Composites Communications","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142424723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-09-28DOI: 10.1016/j.coco.2024.102106
Polybenzoxazine (PBz) aerogels have garnered considerable attention as an innovative and excellent thermal insulation material, celebrated for its lightweight, low thermal conductivity, and outstanding mechanical properties. However, the use of high boiling point toxic solvents in the preparation process requires a cumbersome solvent exchange procedure coupled with insufficient flame-retardant properties, which hinder the potential application of PBz aerogels. Herein, we employed tetraethyl orthosilicate (TEOS) into PBz using an easy, eco-friendly, and cost-less process to achieve hybrid structure polybenzoxazine/silica (PBz/SiO2) aerogels, by thermal catalysis (72 °C) ring-opening polymerization and polycondensation in water-ethanol solvent without any catalysts. The resulting PBz/SiO2 aerogels were characterized with low density (0.181 g/cm3), low thermal conductivity (0.0315 W/(m·K)), excellent flame-retardancy (PHRR value of 32.3 W/g and THR value of 6.3 kJ/g), and superhydrophobicity (the water contact angle up to 155°). Environment-friendly preparation strategy for the PBz/SiO2 aerogels with excellent comprehensive performance, poised to play a pivotal role in energy-saving buildings and fire-resistant applications.
{"title":"Thermal insulating, flame retardant, and superhydrophobic polybenzoxazine/silica aerogels fabricated in water-ethanol solvent using eco-friendly method","authors":"","doi":"10.1016/j.coco.2024.102106","DOIUrl":"10.1016/j.coco.2024.102106","url":null,"abstract":"<div><div>Polybenzoxazine (PBz) aerogels have garnered considerable attention as an innovative and excellent thermal insulation material, celebrated for its lightweight, low thermal conductivity, and outstanding mechanical properties. However, the use of high boiling point toxic solvents in the preparation process requires a cumbersome solvent exchange procedure coupled with insufficient flame-retardant properties, which hinder the potential application of PBz aerogels. Herein, we employed tetraethyl orthosilicate (TEOS) into PBz using an easy, eco-friendly, and cost-less process to achieve hybrid structure polybenzoxazine/silica (PBz/SiO<sub>2</sub>) aerogels, by thermal catalysis (72 °C) ring-opening polymerization and polycondensation in water-ethanol solvent without any catalysts. The resulting PBz/SiO<sub>2</sub> aerogels were characterized with low density (0.181 g/cm<sup>3</sup>), low thermal conductivity (0.0315 W/(m·K)), excellent flame-retardancy (PHRR value of 32.3 W/g and THR value of 6.3 kJ/g), and superhydrophobicity (the water contact angle up to 155°). Environment-friendly preparation strategy for the PBz/SiO<sub>2</sub> aerogels with excellent comprehensive performance, poised to play a pivotal role in energy-saving buildings and fire-resistant applications.</div></div>","PeriodicalId":10533,"journal":{"name":"Composites Communications","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142424789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-09-28DOI: 10.1016/j.coco.2024.102107
The development of innovative therapeutic strategies is highly desired for wound regeneration. In this study, sialic acid substituted chitosan (CS-SA) was reacted with oxidized pullulan (OPL) via Schiff base links to obtain functional CS-SA/OPL hydrogels, into which the polyphenol epigallocatechin gallate (EGCG) was in situ incorporated. The prepared hydrogels exhibited interconnected porous structure and good water absorption ability (over 37 g/g). Furthermore, the CS-SA/OPL hydrogels performed excellent self-healing and adhesive properties. With the incorporation of EGCG, the antibacterial effects against E. coli and S. aureus, as well as antioxidative activity, were significantly improved. In addition, in vitro L-929 cell experiments confirmed that cell viability and cell immigration could be significantly improved with the incorporation of EGCG in CS-SA/OPL hydrogels. Based on the above results, hydrogels possess a promising potential as wound dressings in wound healing applications.
{"title":"Self-healing, adhesive, antibacterial, and biocompatible hydrogel dressings using sialic acid substituted chitosan and oxidized pullulan with incorporation of epigallocatechin gallate","authors":"","doi":"10.1016/j.coco.2024.102107","DOIUrl":"10.1016/j.coco.2024.102107","url":null,"abstract":"<div><div>The development of innovative therapeutic strategies is highly desired for wound regeneration. In this study, sialic acid substituted chitosan (CS-SA) was reacted with oxidized pullulan (OPL) via Schiff base links to obtain functional CS-SA/OPL hydrogels, into which the polyphenol epigallocatechin gallate (EGCG) was <em>in situ</em> incorporated. The prepared hydrogels exhibited interconnected porous structure and good water absorption ability (over 37 g/g). Furthermore, the CS-SA/OPL hydrogels performed excellent self-healing and adhesive properties. With the incorporation of EGCG, the antibacterial effects against <em>E. coli</em> and <em>S. aureus</em>, as well as antioxidative activity, were significantly improved. In addition, <em>in vitro</em> L-929 cell experiments confirmed that cell viability and cell immigration could be significantly improved with the incorporation of EGCG in CS-SA/OPL hydrogels. Based on the above results, hydrogels possess a promising potential as wound dressings in wound healing applications.</div></div>","PeriodicalId":10533,"journal":{"name":"Composites Communications","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142358036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-09-28DOI: 10.1016/j.coco.2024.102100
Developing elastomers that exhibit both high strength and excellent self-healing efficiency has been a longstanding challenge, as enhancing strength typically compromises fracture elongation and self-healing capabilities. In this work, we balance the mechanical strength and self-healing efficiency of waterborne polyurethane (WPU-SS) elastomers by introducing disulfide bonds as dynamic bonds. Disulfide bonds break and reorganize under external forces, inducing microphase separation in the polyurethane system, enhancing tensile strength and toughness, and promoting molecular chain flow to improve self-healing efficiency. The increased hydrogen bonding content further boosts both self-healing efficiency and mechanical strength. As a result, the maximum fracture strength of the WPU-SS elastomer achieves 26.6 MPa with an elongation at break of 664.6 %.and a self-healing efficiency of 83.4 % under mild heating conditions. By modifying liquid metal (LM) with dopamine and compounding it with WPU-SS, WPU-SS/LM composites are obtained. When the volume content of LM was 15 %, the composite exhibits the most significant improvements in mechanical properties and toughness, with a fracture strength of 43 MPa, which is 160 % times of that of WPU-SS. The thermal conductivity of WPU-SS/LM increases proportionally with the LM content, reaching 583.7 % of that of WPU-SS at 25 % LM content. Further, at 10 % LM content, WPU-SS/LM could be physically sintered to achieve permanent electrical conductivity. This enhanced mechanical, thermal, and electrical performance makes WPU-SS/LM composites promising for applications in conductive elastomers and dynamic switches.
{"title":"High-strength, self-healing waterborne polyurethane elastomers with enhanced mechanical, thermal, and electrical properties","authors":"","doi":"10.1016/j.coco.2024.102100","DOIUrl":"10.1016/j.coco.2024.102100","url":null,"abstract":"<div><div>Developing elastomers that exhibit both high strength and excellent self-healing efficiency has been a longstanding challenge, as enhancing strength typically compromises fracture elongation and self-healing capabilities. In this work, we balance the mechanical strength and self-healing efficiency of waterborne polyurethane (WPU-SS) elastomers by introducing disulfide bonds as dynamic bonds. Disulfide bonds break and reorganize under external forces, inducing microphase separation in the polyurethane system, enhancing tensile strength and toughness, and promoting molecular chain flow to improve self-healing efficiency. The increased hydrogen bonding content further boosts both self-healing efficiency and mechanical strength. As a result, the maximum fracture strength of the WPU-SS elastomer achieves 26.6 MPa with an elongation at break of 664.6 %.and a self-healing efficiency of 83.4 % under mild heating conditions. By modifying liquid metal (LM) with dopamine and compounding it with WPU-SS, WPU-SS/LM composites are obtained. When the volume content of LM was 15 %, the composite exhibits the most significant improvements in mechanical properties and toughness, with a fracture strength of 43 MPa, which is 160 % times of that of WPU-SS. The thermal conductivity of WPU-SS/LM increases proportionally with the LM content, reaching 583.7 % of that of WPU-SS at 25 % LM content. Further, at 10 % LM content, WPU-SS/LM could be physically sintered to achieve permanent electrical conductivity. This enhanced mechanical, thermal, and electrical performance makes WPU-SS/LM composites promising for applications in conductive elastomers and dynamic switches.</div></div>","PeriodicalId":10533,"journal":{"name":"Composites Communications","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142424790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-09-28DOI: 10.1016/j.coco.2024.102103
This study investigates the physical, mechanical, and thermal properties of bamboo (BF) and kenaf (KF) fiber-reinforced polylactic acid (PLA) hybrid composites. Three hybrid (30BF-70KF, 50BF-50KF, and 70BF-30KF) and two non-hybrid (BF-PLA and KF-PLA) composites were developed through twin screw extrusion and compression molding techniques. The physical properties (density, void content, crystallinity via XRD, and chemical interactions via FTIR), mechanical properties (tensile, flexural, compressive, impact, and hardness), and thermal properties (Thermogravimetric analysis-TGA and Differential scanning calorimetry-DSC) were thoroughly analyzed. BF reinforcement reduced the composites’ density to 1.1826 g/cm³, while the inclusion of KF increased it to 1.2479 g/cm³. 50:50 blend of bamboo-kenaf reinforcement achieved the lowest void content of 0.27 %. The XRD patterns revealed heightened crystallinity in the BF-PLA composite. FTIR analysis showed stable functional groups, with O–H absorption bands indicative of cellulosic fibers. The BF-PLA non-hybrid composite exhibited the highest tensile strength at 25.95 MPa and compressive strength at 173.15 MPa, with the 30BF-70KF hybrid composite showing notable impact strength. Fractured morphology by FESEM revealed superior fiber-matrix adhesion for BF-PLA composite. TGA demonstrated a variation in thermal degradation temperatures, with the BF30-KF70 composite showing the highest onset of degradation at 484 °C. DSC analysis indicated a reduction in the glass transition temperature (Tg) across all fiber-reinforced samples and revealed significant adjustments in melting and crystallization temperatures. This research highlights the potential of BF-KF/PLA hybrid composites in the development of eco-friendly plastic furniture and consumer products.
{"title":"Physical, mechanical and thermal properties of novel bamboo/kenaf fiber-reinforced polylactic acid (PLA) hybrid composites","authors":"","doi":"10.1016/j.coco.2024.102103","DOIUrl":"10.1016/j.coco.2024.102103","url":null,"abstract":"<div><div>This study investigates the physical, mechanical, and thermal properties of bamboo (BF) and kenaf (KF) fiber-reinforced polylactic acid (PLA) hybrid composites. Three hybrid (30BF-70KF, 50BF-50KF, and 70BF-30KF) and two non-hybrid (BF-PLA and KF-PLA) composites were developed through twin screw extrusion and compression molding techniques. The physical properties (density, void content, crystallinity via XRD, and chemical interactions via FTIR), mechanical properties (tensile, flexural, compressive, impact, and hardness), and thermal properties (Thermogravimetric analysis-TGA and Differential scanning calorimetry-DSC) were thoroughly analyzed. BF reinforcement reduced the composites’ density to 1.1826 g/cm³, while the inclusion of KF increased it to 1.2479 g/cm³. 50:50 blend of bamboo-kenaf reinforcement achieved the lowest void content of 0.27 %. The XRD patterns revealed heightened crystallinity in the BF-PLA composite. FTIR analysis showed stable functional groups, with O–H absorption bands indicative of cellulosic fibers. The BF-PLA non-hybrid composite exhibited the highest tensile strength at 25.95 MPa and compressive strength at 173.15 MPa, with the 30BF-70KF hybrid composite showing notable impact strength. Fractured morphology by FESEM revealed superior fiber-matrix adhesion for BF-PLA composite. TGA demonstrated a variation in thermal degradation temperatures, with the BF30-KF70 composite showing the highest onset of degradation at 484 °C. DSC analysis indicated a reduction in the glass transition temperature (T<sub>g</sub>) across all fiber-reinforced samples and revealed significant adjustments in melting and crystallization temperatures. This research highlights the potential of BF-KF/PLA hybrid composites in the development of eco-friendly plastic furniture and consumer products.</div></div>","PeriodicalId":10533,"journal":{"name":"Composites Communications","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142358037","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-09-25DOI: 10.1016/j.coco.2024.102105
Smart deployable structures are a crucial solution for reducing spacecraft weight and enhancing rocket space utilization. Traditional deployable structures based on composite materials can only achieve either elastic deployment or shape memory deployment, failing to meet multi-condition, high-intelligence requirements. In this work, we developed a tubular hinge with dual-deformation deployability. For rapid deployment needs, the hinge can be deformed at room temperature and achieve quick elastic deployment within 0.3 s at room or low temperatures. For autonomous fixation and slow deployment, the hinge can be fixed at high temperatures and achieve a gentle shape memory deployment within 100 s. More significantly, the hinge exhibits excellent environmental stability, maintaining superior deployable characteristics even after exposure to high and low-temperature environments and long-term folding. This hinge has been used to the deployment of solar panels and solar sails.
{"title":"Smart tubular hinge with multi-environment adaptability for rapid elastic and gentle shape memory deployment","authors":"","doi":"10.1016/j.coco.2024.102105","DOIUrl":"10.1016/j.coco.2024.102105","url":null,"abstract":"<div><div>Smart deployable structures are a crucial solution for reducing spacecraft weight and enhancing rocket space utilization. Traditional deployable structures based on composite materials can only achieve either elastic deployment or shape memory deployment, failing to meet multi-condition, high-intelligence requirements. In this work, we developed a tubular hinge with dual-deformation deployability. For rapid deployment needs, the hinge can be deformed at room temperature and achieve quick elastic deployment within 0.3 s at room or low temperatures. For autonomous fixation and slow deployment, the hinge can be fixed at high temperatures and achieve a gentle shape memory deployment within 100 s. More significantly, the hinge exhibits excellent environmental stability, maintaining superior deployable characteristics even after exposure to high and low-temperature environments and long-term folding. This hinge has been used to the deployment of solar panels and solar sails.</div></div>","PeriodicalId":10533,"journal":{"name":"Composites Communications","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142424724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-09-24DOI: 10.1016/j.coco.2024.102104
The flammability of silicone rubber (SR) significantly limits its broad use in areas that require high flame retardancy. In this study, heptazine-covered Fe2O3, which exhibits effective flame retardancy, was prepared using simple ball milling and heat treatment, which are advantageous for large-scale production. The prepared filler was incorporated into SR. The addition of 7.02 wt% FM filler increased the thermal degradation onset temperature at 5 % weight loss from 492.5 °C for neat SR to 502.7 °C (FM 1:1 composite). Moreover, the peak heat release rate and peak smoke production rate of the FM 1:1 composite significantly decreased by 43.15 % and 68.42 %, respectively, indicating a significant enhancement in the fire safety and smoke suppression of the FM composites. The chemical, morphological, and electronic structures of the FM fillers, pyrolysis gas production, and char residue were thoroughly investigated to reveal the possible flame-retarding mechanisms of the SR composites.
硅橡胶（SR）的易燃性极大地限制了它在要求高阻燃性领域的广泛应用。本研究采用简单的球磨和热处理方法制备了具有有效阻燃性能的七嗪包覆 Fe2O3，这种方法有利于大规模生产。将制备好的填料加入 SR 中。添加 7.02 wt% 的 FM 填料后，在 5% 失重时的热降解起始温度从纯 SR 的 492.5 ℃ 升至 502.7 ℃（FM 1:1 复合材料）。此外，FM 1:1 复合材料的峰值热释放率和峰值烟雾产生率分别显著降低了 43.15 % 和 68.42 %，这表明 FM 复合材料的防火安全性和烟雾抑制能力显著增强。通过对调频填料的化学结构、形态结构和电子结构、热解产气和残炭进行深入研究，揭示了 SR 复合材料可能的阻燃机理。
{"title":"Facile preparation of heptazine-covered Fe2O3 and its synergistic effect on the enhanced flame retardance of silicone rubber composite","authors":"","doi":"10.1016/j.coco.2024.102104","DOIUrl":"10.1016/j.coco.2024.102104","url":null,"abstract":"<div><div>The flammability of silicone rubber (SR) significantly limits its broad use in areas that require high flame retardancy. In this study, heptazine-covered Fe<sub>2</sub>O<sub>3</sub>, which exhibits effective flame retardancy, was prepared using simple ball milling and heat treatment, which are advantageous for large-scale production. The prepared filler was incorporated into SR. The addition of 7.02 wt% FM filler increased the thermal degradation onset temperature at 5 % weight loss from 492.5 °C for neat SR to 502.7 °C (FM 1:1 composite). Moreover, the peak heat release rate and peak smoke production rate of the FM 1:1 composite significantly decreased by 43.15 % and 68.42 %, respectively, indicating a significant enhancement in the fire safety and smoke suppression of the FM composites. The chemical, morphological, and electronic structures of the FM fillers, pyrolysis gas production, and char residue were thoroughly investigated to reveal the possible flame-retarding mechanisms of the SR composites.</div></div>","PeriodicalId":10533,"journal":{"name":"Composites Communications","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142327947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-09-21DOI: 10.1016/j.coco.2024.102090
Two series of thermally conductive poly(vinylidene fluoride) (PVDF) composites were prepared by adding boron nitride (BN) and carbon fiber (CF) of different mass ratios via hot-pressing. The synergistic effects of the dual fillers on the thermal conductivity enhancement were investigated. The morphology, thermal conductivity, crystallinity, thermal stability, mechanical properties, and long-term chemical stability of the PVDF composites were characterized. The results demonstrated a significant synergistic effect between the BN and the CF on enhancing the thermal conductivity of the PVDF-based composites. The maximum thermal conductivity of 1.89 W/(m·K) with an improvement of 1014 % was achieved when 15 wt% BN and 15 wt% CF were added in the PVDF matrix. The synergistic effect resulted in the formation of efficient three-dimensional thermally conductive networks with a synergistic efficiency up to 113 %. The Agari model was employed to illustrate the thermal conduction mechanism, revealing the improved ability of the dual fillers to form conductive pathways. The PVDF composites showed good crystallinity, thermal stability, mechanical strength, and long-term chemical stability. This study highlights the potential of the PVDF/BN/CF composites for applications in membrane heat exchangers and provides significant insights into the design of high-performance thermally conductive polymer composites.
{"title":"Carbon fiber/boron nitride fillers for enhancing through-plane thermal conductivity of poly(vinylidene fluoride): Synergistic effect and mechanism","authors":"","doi":"10.1016/j.coco.2024.102090","DOIUrl":"10.1016/j.coco.2024.102090","url":null,"abstract":"<div><div>Two series of thermally conductive poly(vinylidene fluoride) (PVDF) composites were prepared by adding boron nitride (BN) and carbon fiber (CF) of different mass ratios via hot-pressing. The synergistic effects of the dual fillers on the thermal conductivity enhancement were investigated. The morphology, thermal conductivity, crystallinity, thermal stability, mechanical properties, and long-term chemical stability of the PVDF composites were characterized. The results demonstrated a significant synergistic effect between the BN and the CF on enhancing the thermal conductivity of the PVDF-based composites. The maximum thermal conductivity of 1.89 W/(m·K) with an improvement of 1014 % was achieved when 15 wt% BN and 15 wt% CF were added in the PVDF matrix. The synergistic effect resulted in the formation of efficient three-dimensional thermally conductive networks with a synergistic efficiency up to 113 %. The Agari model was employed to illustrate the thermal conduction mechanism, revealing the improved ability of the dual fillers to form conductive pathways. The PVDF composites showed good crystallinity, thermal stability, mechanical strength, and long-term chemical stability. This study highlights the potential of the PVDF/BN/CF composites for applications in membrane heat exchangers and provides significant insights into the design of high-performance thermally conductive polymer composites.</div></div>","PeriodicalId":10533,"journal":{"name":"Composites Communications","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142318623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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