Pub Date : 2024-07-31DOI: 10.3389/fmats.2024.1428912
Imran Khan, Asma Alshehri, Pi-Chung Wang, Ibrahim A. Hameed
Introduction: The emergence of electromagnetic wave pollution as a new form of pollution in human society is attributed to the advancements in communication technology and the electronic information business. In addition to harming priceless electronic equipment, these electromagnetic radiation and interference issues brought on by electrical and electronic devices have a major negative influence on human productivity and wellbeing. The secret to getting rid of electromagnetic radiation interference (EMI) and improving performance is electromagnetic shielding technology. Metamaterial absorber is a type of metamaterial that absorb EMI radiation. The benefits of metamaterial absorbers include their lightweight, simple construction, and excellent absorptivity.Methods: This paper proposes a novel metamaterial absorber for EMI radiation absorption. It consists of dielectric layers, metamaterial shielding layer and transmission line. The reflection of radiation is reduced by miniaturization of metamaterials.Results and Discussion: Simulation results show that the proposed design has better performance as compared to existing methods. The operating frequency range is from 23.1 to 28.3 GHz. The values of S21 with and without shielding are −5 dB and −0.05 dB, and the shielding effectiveness is 10.10 dB and a maximum of 12.63 dB.
{"title":"Design and performance evaluation of a compact radiation absorber for 5G applications","authors":"Imran Khan, Asma Alshehri, Pi-Chung Wang, Ibrahim A. Hameed","doi":"10.3389/fmats.2024.1428912","DOIUrl":"https://doi.org/10.3389/fmats.2024.1428912","url":null,"abstract":"Introduction: The emergence of electromagnetic wave pollution as a new form of pollution in human society is attributed to the advancements in communication technology and the electronic information business. In addition to harming priceless electronic equipment, these electromagnetic radiation and interference issues brought on by electrical and electronic devices have a major negative influence on human productivity and wellbeing. The secret to getting rid of electromagnetic radiation interference (EMI) and improving performance is electromagnetic shielding technology. Metamaterial absorber is a type of metamaterial that absorb EMI radiation. The benefits of metamaterial absorbers include their lightweight, simple construction, and excellent absorptivity.Methods: This paper proposes a novel metamaterial absorber for EMI radiation absorption. It consists of dielectric layers, metamaterial shielding layer and transmission line. The reflection of radiation is reduced by miniaturization of metamaterials.Results and Discussion: Simulation results show that the proposed design has better performance as compared to existing methods. The operating frequency range is from 23.1 to 28.3 GHz. The values of S<jats:sub>21</jats:sub> with and without shielding are −5 dB and −0.05 dB, and the shielding effectiveness is 10.10 dB and a maximum of 12.63 dB.","PeriodicalId":12524,"journal":{"name":"Frontiers in Materials","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141866986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-07-31DOI: 10.3389/fmats.2024.1354560
Tahani M. Almeleebia, Mokhtar Jasim Naser, Shakir Mahmood Saeed, Majeed M. Abid, Usama S. Altimari, Murtadha Laftah Shaghnab, Fadhil A. Rasen, Ahmed Alawadi, Irfan Ahmad, Ali Alsalamy
In this study, Co3O4 nanoparticles were used as nanocatalyst for two different series of nitrogen-containing heterocyclic compounds, including pyrrole (Pyo) derivatives and pyrano [2, 3-c]pyrazole (Pya[2, 3-c]Pyz) derivatives. In the synthesis of derivatives, using 15 mol% and 10 mol% of the catalyst for Pyo derivatives and Pya[2, 3-c]Pyz derivatives, respectively, an efficiency between 83% and 96%, were observed. In addition, novel derivatives of Pyo and Pya[2,3-c]Pyz were synthesized and their structures were confirmed. In general, the advantages of using cobalt nanoparticles compared to previous reports include the synthesis of new derivatives, lower temperature used in the synthesis of derivatives, shorter synthesis time and high efficiency. The biological properties of the synthesized products, such as antibacterial, antifungal, and antioxidant properties, were tested and investigated. In antibacterial and antifungal tests, IZD, MIC, MBC, and MFC were measured and reported. In antioxidant activity, IC50 was calculated and reported. High reusability, green and environmentally friendly, synthesis of new derivatives and synthesis of products with higher efficiency and shorter time were the important benefits of using cobalt nanoparticles as a catalyst. In antioxidant tests, the IC50 for synthesized Pyo derivatives and Pya[2, 3-c] Pyz derivatives were between 12.2 and 13.71 μg/mL, and 16.18–17.75 μg/mL, respectively. In antimicrobial testes, the MIC for synthesized Pyo derivatives and Pya[2, 3-c]Pyz derivatives were between 2 and 4,096 μg/mL, and 2–2048 μg/mL, respectively. The results showed that the antioxidant property of Pyo derivatives were more than Pya[2, 3-c] Pyz derivatives, but the antimicrobial effect of Pya[2,3-c] Pyz derivatives were more than Pyo derivatives. The antioxidant results proved that the activity of Pyo derivatives and Pya[2, 3-c] Pyz derivatives does not depend on the substitutions of the derivatives and is close to each other. Therefore, based on this, a proposed mechanism for stability of DPPH by Pyo derivatives and Pya[2, 3-c] Pyz derivatives were suggested. Finally, based on the more stable resonance structures of Pyo derivatives, compared to Pya[2, 3-c] Pyz derivatives, its high antioxidant property was justified. Pya[2, 3-c] Pyz derivatives has two heterocyclic rings connected together pyrano and pyrazole, but Pyo derivatives has only one heterocyclic ring (pyrrole). So high antimicrobial property of Pya[2, 3-c] Pyz derivatives compared to Pyo derivatives can be attributed to having two bioactive heterocyclic rings.
{"title":"Multi-component synthesis and invitro biological assessment of novel pyrrole derivatives and pyrano[2,3-c]pyrazole derivatives using Co3O4 nanoparticles as recyclable nanocatalyst","authors":"Tahani M. Almeleebia, Mokhtar Jasim Naser, Shakir Mahmood Saeed, Majeed M. Abid, Usama S. Altimari, Murtadha Laftah Shaghnab, Fadhil A. Rasen, Ahmed Alawadi, Irfan Ahmad, Ali Alsalamy","doi":"10.3389/fmats.2024.1354560","DOIUrl":"https://doi.org/10.3389/fmats.2024.1354560","url":null,"abstract":"In this study, Co<jats:sub>3</jats:sub>O<jats:sub>4</jats:sub> nanoparticles were used as nanocatalyst for two different series of nitrogen-containing heterocyclic compounds, including pyrrole (Pyo) derivatives and pyrano [2, 3-c]pyrazole (Pya[2, 3-c]Pyz) derivatives. In the synthesis of derivatives, using 15 mol% and 10 mol% of the catalyst for Pyo derivatives and Pya[2, 3-c]Pyz derivatives, respectively, an efficiency between 83% and 96%, were observed. In addition, novel derivatives of Pyo and Pya[2,3-c]Pyz were synthesized and their structures were confirmed. In general, the advantages of using cobalt nanoparticles compared to previous reports include the synthesis of new derivatives, lower temperature used in the synthesis of derivatives, shorter synthesis time and high efficiency. The biological properties of the synthesized products, such as antibacterial, antifungal, and antioxidant properties, were tested and investigated. In antibacterial and antifungal tests, IZD, MIC, MBC, and MFC were measured and reported. In antioxidant activity, IC<jats:sub>50</jats:sub> was calculated and reported. High reusability, green and environmentally friendly, synthesis of new derivatives and synthesis of products with higher efficiency and shorter time were the important benefits of using cobalt nanoparticles as a catalyst. In antioxidant tests, the IC<jats:sub>50</jats:sub> for synthesized Pyo derivatives and Pya[2, 3-c] Pyz derivatives were between 12.2 and 13.71 μg/mL, and 16.18–17.75 μg/mL, respectively. In antimicrobial testes, the MIC for synthesized Pyo derivatives and Pya[2, 3-c]Pyz derivatives were between 2 and 4,096 μg/mL, and 2–2048 μg/mL, respectively. The results showed that the antioxidant property of Pyo derivatives were more than Pya[2, 3-c] Pyz derivatives, but the antimicrobial effect of Pya[2,3-c] Pyz derivatives were more than Pyo derivatives. The antioxidant results proved that the activity of Pyo derivatives and Pya[2, 3-c] Pyz derivatives does not depend on the substitutions of the derivatives and is close to each other. Therefore, based on this, a proposed mechanism for stability of DPPH by Pyo derivatives and Pya[2, 3-c] Pyz derivatives were suggested. Finally, based on the more stable resonance structures of Pyo derivatives, compared to Pya[2, 3-c] Pyz derivatives, its high antioxidant property was justified. Pya[2, 3-c] Pyz derivatives has two heterocyclic rings connected together pyrano and pyrazole, but Pyo derivatives has only one heterocyclic ring (pyrrole). So high antimicrobial property of Pya[2, 3-c] Pyz derivatives compared to Pyo derivatives can be attributed to having two bioactive heterocyclic rings.","PeriodicalId":12524,"journal":{"name":"Frontiers in Materials","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141866988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-07-31DOI: 10.3389/fmats.2024.1365896
Deyong Wang, Guoxun Li, Lingang Jiang, Huaizhi Zhang, Jie Zhang, Xiaowei Si
The dynamic modulus of asphalt mixture is an important factor in the design of asphalt pavement, and many scholars have proposed different models for estimating the dynamic modulus of asphalt mixture, but there are almost no studies on the prediction of the dynamic modulus of semi-flexible materials. In order to analyze and estimate the dynamic modulus of semi-flexible materials, we set up a high-performance cementitious paste (HPCP) semi-flexible material and a reference group Stone Mastic Asphalt (SMA-16) under multiple conditions, first measured its dynamic modulus in the laboratory, and analyzed the dynamic modulus characteristics of the material, and then used the equation the estimation equation proposed by Witczak et al. (Witczak1-37A) as a benchmark to introduce a new parameter, grouting mass ratio (Pb) to develop a Witczak-G prediction model to compare and validate the predicted dynamic modulus with the measured values. The results show that compared with SMA-16, HPCP semi-flexible material exhibits higher dynamic modulus and lower phase angle, and its temperature sensitivity and deformation resistance are significantly better than those of SMA-16. Under the influence of porosity and Pb factor, the dynamic modulus is positively correlated with both factors, and the phase angle increases first and then decreases, showing strong elastic properties. In this paper, we propose a dynamic modulus prediction model based on viscosity and Pb, Witczak-G, which predicts the highest coefficient of determination (R2) of the predicted dynamic modulus as high as 0.99 after initial fitting and validation, which indicates that the Witczak-G model is suitable for predicting the dynamic modulus of semi-flexible materials injected with HPCP.
{"title":"Dynamic modulus characteristics and prediction model of semi-flexible materials filled with high-performance cement paste","authors":"Deyong Wang, Guoxun Li, Lingang Jiang, Huaizhi Zhang, Jie Zhang, Xiaowei Si","doi":"10.3389/fmats.2024.1365896","DOIUrl":"https://doi.org/10.3389/fmats.2024.1365896","url":null,"abstract":"The dynamic modulus of asphalt mixture is an important factor in the design of asphalt pavement, and many scholars have proposed different models for estimating the dynamic modulus of asphalt mixture, but there are almost no studies on the prediction of the dynamic modulus of semi-flexible materials. In order to analyze and estimate the dynamic modulus of semi-flexible materials, we set up a high-performance cementitious paste (HPCP) semi-flexible material and a reference group Stone Mastic Asphalt (SMA-16) under multiple conditions, first measured its dynamic modulus in the laboratory, and analyzed the dynamic modulus characteristics of the material, and then used the equation the estimation equation proposed by Witczak et al. (Witczak1-37A) as a benchmark to introduce a new parameter, grouting mass ratio (Pb) to develop a Witczak-G prediction model to compare and validate the predicted dynamic modulus with the measured values. The results show that compared with SMA-16, HPCP semi-flexible material exhibits higher dynamic modulus and lower phase angle, and its temperature sensitivity and deformation resistance are significantly better than those of SMA-16. Under the influence of porosity and Pb factor, the dynamic modulus is positively correlated with both factors, and the phase angle increases first and then decreases, showing strong elastic properties. In this paper, we propose a dynamic modulus prediction model based on viscosity and Pb, Witczak-G, which predicts the highest coefficient of determination (R2) of the predicted dynamic modulus as high as 0.99 after initial fitting and validation, which indicates that the Witczak-G model is suitable for predicting the dynamic modulus of semi-flexible materials injected with HPCP.","PeriodicalId":12524,"journal":{"name":"Frontiers in Materials","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141866987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Neat high-temperature vulcanized silicone rubber (HTV SR) showed bad hydrophobicity due to the existence of a large number of inorganic reinforcing fillers on its surface, which affected its security application in outdoor insulation systems. In this work, hydrophobic silane chains were grafted onto the surface of inorganic particles on the skin layer of HTV SR by a one-step coupling modification to improve its hydrophobicity. The effects of coupling agent types and coupling reaction conditions on the hydrophobicity of HTV SR were investigated. It was determined that the perfluorooctane trichlorosilicon with a large number of low surface energy fluorine atoms was the preferred coupling agent. The contact angle of HTV SR was increased by 15.70% when the optimal coupling reaction conditions were determined to be a reaction temperature of 60°C, a reaction time of 4 h, and an amount of coupling agent of 0.5%. The study found that both etching reaction and grafting reaction occurred during the whole coupling modification process, which led to the disappearance or decrease of a lot of holes on the HTV SR surface. After the fluorination coupling reaction, the surface of HTV SR became smooth and dense that led to the decrease of water absorption. The result of Fourier-transform infrared spectroscopy analysis showed the formation of C-F bond in HTV SR after fluorination modification, and the energetic dispersive spectroscopy analysis showed that the fluorine content on the surface of the fluorinated HTV SR increased significantly. Moreover, the stability analysis showed that the fluorinated HTV SR still had a good thermal stability and mechanical property stability.
纯净的高温硫化硅橡胶（HTV SR）由于表面存在大量无机增强填料，因此憎水性较差，影响了其在室外隔热系统中的安全应用。在这项工作中，通过一步偶联改性将疏水性硅烷链接枝到 HTV SR 表皮层的无机颗粒表面，以改善其疏水性。研究了偶联剂类型和偶联反应条件对 HTV SR 疏水性的影响。结果表明，具有大量低表面能氟原子的全氟辛烷三氯氢硅是首选的偶联剂。当最佳偶联反应条件确定为反应温度为 60°C、反应时间为 4 小时、偶联剂用量为 0.5%时，HTV SR 的接触角增加了 15.70%。研究发现，在整个偶联改性过程中，既发生了蚀刻反应，又发生了接枝反应，使 HTV SR 表面的孔洞大量消失或减少。氟化偶联反应后，HTV SR 表面变得光滑致密，从而降低了吸水性。傅立叶变换红外光谱分析结果表明，氟化改性后 HTV SR 中形成了 C-F 键，而能谱色散分析表明，氟化 HTV SR 表面的氟含量显著增加。此外，稳定性分析表明，氟化 HTV SR 仍具有良好的热稳定性和机械性能稳定性。
{"title":"Preparation and mechanism research on hydrophobic coupling modification of HTV silicone rubber","authors":"Qiang Li, Mingdong Lei, Ziyou Li, Qiang Gan, Yong Sun, Xiaoxing Wei","doi":"10.3389/fmats.2024.1405274","DOIUrl":"https://doi.org/10.3389/fmats.2024.1405274","url":null,"abstract":"Neat high-temperature vulcanized silicone rubber (HTV SR) showed bad hydrophobicity due to the existence of a large number of inorganic reinforcing fillers on its surface, which affected its security application in outdoor insulation systems. In this work, hydrophobic silane chains were grafted onto the surface of inorganic particles on the skin layer of HTV SR by a one-step coupling modification to improve its hydrophobicity. The effects of coupling agent types and coupling reaction conditions on the hydrophobicity of HTV SR were investigated. It was determined that the perfluorooctane trichlorosilicon with a large number of low surface energy fluorine atoms was the preferred coupling agent. The contact angle of HTV SR was increased by 15.70% when the optimal coupling reaction conditions were determined to be a reaction temperature of 60°C, a reaction time of 4 h, and an amount of coupling agent of 0.5%. The study found that both etching reaction and grafting reaction occurred during the whole coupling modification process, which led to the disappearance or decrease of a lot of holes on the HTV SR surface. After the fluorination coupling reaction, the surface of HTV SR became smooth and dense that led to the decrease of water absorption. The result of Fourier-transform infrared spectroscopy analysis showed the formation of C-F bond in HTV SR after fluorination modification, and the energetic dispersive spectroscopy analysis showed that the fluorine content on the surface of the fluorinated HTV SR increased significantly. Moreover, the stability analysis showed that the fluorinated HTV SR still had a good thermal stability and mechanical property stability.","PeriodicalId":12524,"journal":{"name":"Frontiers in Materials","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141866989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-07-30DOI: 10.3389/fmats.2024.1438660
Chenyang Niu, Dongwen Li, Yujia Zhang, Yunkai Wang, Shangbo Ning, Gang Zhao, Zhihui Ye, Yu Kong, Donghong Yang
Clear aligner therapy is a rapidly developing orthodontic treatment. 3D-printing technology, which enables the creation of complex geometric structures with high precision, has been used in dentistry. This article aims to summarize the various aspects of 3D-printing clear aligners and give an outlook on their future development. The traditional thermoforming technology is introduced and the principle and application of 3D-printed clear aligners and materials are introduced, as well as the application prospects of 3D-printed clear aligners. According to PRISMA statement, the relevant literature of 3D-printing clear aligner was searched in PubMed, Web of Science, Embase and other databases. We searched the related words in the MESH database and then carried out advanced searches. We read systematic review and conference papers to find the articles related to the subject and manually added and excluded articles by reading the title and abstract. The production of clear aligners combines computer-aided 3D analysis, personalized design and digital molding technology. The thickness and edges of the 3D-printed clear aligner can be digitally controlled, which allows appliance more efficiently fitted. Presently, the array of clear resins suitable for 3D-printing include photo polymeric clear methacrylate-based resin (Dental LT) (Form Labs, Somerville, Mass), aliphatic vinyl ester-polyurethane polymer (Tera Harz TC-85) (Graphy, Seoul, South Korea). They all have good biocompatibility. But no such material is currently approved on the market. Developing biocompatible resins and further improving the material’s mechanical properties will be critical for the combination of 3D-printing and clear aligners. However, the literature on 3D-printed clear aligners is limited and lacks clinical application. Further in vivo and in vitro tests, as well as additional exploration in conjunction with corresponding cytological tests, are required for the research on available materials and machinery for 3D-printing clear aligners.
透明矫治器疗法是一种发展迅速的正畸治疗方法。三维打印技术可以高精度地创建复杂的几何结构，目前已被应用于牙科领域。本文旨在总结3D打印透明矫治器的各个方面，并对其未来发展进行展望。在介绍传统热成型技术的基础上，介绍了3D打印透明矫治器的原理、应用和材料，以及3D打印透明矫治器的应用前景。根据PRISMA声明，在PubMed、Web of Science、Embase等数据库中检索了3D打印透明对齐器的相关文献。我们在 MESH 数据库中检索了相关词，然后进行了高级检索。我们阅读了系统综述和会议论文，找到了与主题相关的文章，并通过阅读标题和摘要手动添加和排除了文章。透明矫治器的生产结合了计算机辅助三维分析、个性化设计和数字成型技术。三维打印透明矫治器的厚度和边缘可以通过数字控制，从而使矫治器更有效地安装。目前，适合三维打印的透明树脂包括光聚合物甲基丙烯酸酯基透明树脂（Dental LT）（Form Labs, Somerville, Mass）、脂肪族乙烯基酯-聚氨酯聚合物（Tera Harz TC-85）（Graphy, Seoul, South Korea）。它们都具有良好的生物相容性。但目前市场上还没有此类材料获得批准。开发生物相容性树脂并进一步提高材料的机械性能，对于 3D 打印和透明对齐器的结合至关重要。然而，有关3D打印透明矫治器的文献资料非常有限，而且缺乏临床应用。需要进一步进行体内和体外测试，并结合相应的细胞学测试进行更多探索，以研究用于三维打印透明对齐器的可用材料和机械。
{"title":"Prospects for 3D-printing of clear aligners—a narrative review","authors":"Chenyang Niu, Dongwen Li, Yujia Zhang, Yunkai Wang, Shangbo Ning, Gang Zhao, Zhihui Ye, Yu Kong, Donghong Yang","doi":"10.3389/fmats.2024.1438660","DOIUrl":"https://doi.org/10.3389/fmats.2024.1438660","url":null,"abstract":"Clear aligner therapy is a rapidly developing orthodontic treatment. 3D-printing technology, which enables the creation of complex geometric structures with high precision, has been used in dentistry. This article aims to summarize the various aspects of 3D-printing clear aligners and give an outlook on their future development. The traditional thermoforming technology is introduced and the principle and application of 3D-printed clear aligners and materials are introduced, as well as the application prospects of 3D-printed clear aligners. According to PRISMA statement, the relevant literature of 3D-printing clear aligner was searched in PubMed, Web of Science, Embase and other databases. We searched the related words in the MESH database and then carried out advanced searches. We read systematic review and conference papers to find the articles related to the subject and manually added and excluded articles by reading the title and abstract. The production of clear aligners combines computer-aided 3D analysis, personalized design and digital molding technology. The thickness and edges of the 3D-printed clear aligner can be digitally controlled, which allows appliance more efficiently fitted. Presently, the array of clear resins suitable for 3D-printing include photo polymeric clear methacrylate-based resin (Dental LT) (Form Labs, Somerville, Mass), aliphatic vinyl ester-polyurethane polymer (Tera Harz TC-85) (Graphy, Seoul, South Korea). They all have good biocompatibility. But no such material is currently approved on the market. Developing biocompatible resins and further improving the material’s mechanical properties will be critical for the combination of 3D-printing and clear aligners. However, the literature on 3D-printed clear aligners is limited and lacks clinical application. Further <jats:italic>in vivo</jats:italic> and <jats:italic>in vitro</jats:italic> tests, as well as additional exploration in conjunction with corresponding cytological tests, are required for the research on available materials and machinery for 3D-printing clear aligners.","PeriodicalId":12524,"journal":{"name":"Frontiers in Materials","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141866991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-07-30DOI: 10.3389/fmats.2024.1420014
Awen Bruneau, François Mahé, Christophe Binetruy, Sébastien Comas-Cardona, Charlotte Landry, Nelly Durand
A numerical model of packing applied to rigid objects is presented. It aims at describing a random stack of polymer composite chips in order to model the packing step of an existing recycling technique. The geometric properties of the stack play a major role in the mechanical properties of the recycled products. Short, simple and effective geometric descriptors of the stack are proposed. Their ability to differentiate random stacks is illustrated with an example. Then, a validation is proposed based on experimental data obtained from a bench specially designed for this work. The tests consist in the free fall of square chips. Finally, the developed model is compared to other models (free fall and packing of fibers) in order to enforce its relevance in the simulation of packing of rigid objects.
{"title":"Packing simulation and analysis applied to a thermoplastic composite recycling process","authors":"Awen Bruneau, François Mahé, Christophe Binetruy, Sébastien Comas-Cardona, Charlotte Landry, Nelly Durand","doi":"10.3389/fmats.2024.1420014","DOIUrl":"https://doi.org/10.3389/fmats.2024.1420014","url":null,"abstract":"A numerical model of packing applied to rigid objects is presented. It aims at describing a random stack of polymer composite chips in order to model the packing step of an existing recycling technique. The geometric properties of the stack play a major role in the mechanical properties of the recycled products. Short, simple and effective geometric descriptors of the stack are proposed. Their ability to differentiate random stacks is illustrated with an example. Then, a validation is proposed based on experimental data obtained from a bench specially designed for this work. The tests consist in the free fall of square chips. Finally, the developed model is compared to other models (free fall and packing of fibers) in order to enforce its relevance in the simulation of packing of rigid objects.","PeriodicalId":12524,"journal":{"name":"Frontiers in Materials","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-07-30DOI: 10.3389/fmats.2024.1397937
Daniel Wyn Müller, Ben Josten, Sebastian Wältermann, Christoph Pauly, Sebastian Slawik, Kristina Brix, Ralf Kautenburger, Frank Mücklich
Introduction: Topographic surface patterning in the micro- and nanometer scale has evolved into a well applied approach in surface functionalization following biomimetic blueprints from nature. Depending on the production process an additional impact of process-related substrate modification has to be considered in functional surface optimization. This is especially true in case of antimicrobial applications of Cu surfaces where a modification of the substrate properties might impact bactericidal efficiency.Methods: In this regard, the effect of ultrashort pulsed direct laser interference patterning on the microstructure of pure Cu and resulting antimicrobial properties was investigated alongside line-like patterning in the scale of single bacterial cells.Results and Discussion: The process-induced microstructure modification was shown to play an important role in corrosion processes on Cu surfaces in saline environment, whereas the superficial microstructure impacts both corrosive interaction and ion emission. Surprisingly, antimicrobial efficiency is not predominantly following deviating trends in Cu ion release rates but rather depends on surface topography and wettability, which was shown to be impacted by the substrate microstructure state, as well. This highlights the need of an in-depth understanding on how different surface properties are simultaneously modulated during laser processing and how their interaction has to be designed to acquire an effective surface optimization e.g., to agitate active antimicrobial surface functionalization.
{"title":"Microstructure versus topography: the impact of crystallographic substrate modification during ultrashort pulsed direct laser interference patterning on the antibacterial properties of Cu","authors":"Daniel Wyn Müller, Ben Josten, Sebastian Wältermann, Christoph Pauly, Sebastian Slawik, Kristina Brix, Ralf Kautenburger, Frank Mücklich","doi":"10.3389/fmats.2024.1397937","DOIUrl":"https://doi.org/10.3389/fmats.2024.1397937","url":null,"abstract":"Introduction: Topographic surface patterning in the micro- and nanometer scale has evolved into a well applied approach in surface functionalization following biomimetic blueprints from nature. Depending on the production process an additional impact of process-related substrate modification has to be considered in functional surface optimization. This is especially true in case of antimicrobial applications of Cu surfaces where a modification of the substrate properties might impact bactericidal efficiency.Methods: In this regard, the effect of ultrashort pulsed direct laser interference patterning on the microstructure of pure Cu and resulting antimicrobial properties was investigated alongside line-like patterning in the scale of single bacterial cells.Results and Discussion: The process-induced microstructure modification was shown to play an important role in corrosion processes on Cu surfaces in saline environment, whereas the superficial microstructure impacts both corrosive interaction and ion emission. Surprisingly, antimicrobial efficiency is not predominantly following deviating trends in Cu ion release rates but rather depends on surface topography and wettability, which was shown to be impacted by the substrate microstructure state, as well. This highlights the need of an in-depth understanding on how different surface properties are simultaneously modulated during laser processing and how their interaction has to be designed to acquire an effective surface optimization e.g., to agitate active antimicrobial surface functionalization.","PeriodicalId":12524,"journal":{"name":"Frontiers in Materials","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141866990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Developing eco-friendly polymeric plasticizers with excellent migration resistance is one of the research hotspots in the polyvinyl chloride (PVC) industry. A low-molecular-weight biobased polyester rubber (LMW-BPR) was synthesized from five biobased polyester monomers in a 100-L reactor and evaluated as a potential eco-friendly polymeric plasticizer for PVC. The obtained LMW-BPR is an amorphous polyester material with a low glass transition temperature of −48°C and a molecular weight of 22 kg/mol, which is lower than that of existing polyester rubber but higher than those of most polyester plasticizer commodities. Plasticized PVC composites with a total plasticizer content of 50 phr were prepared by using the mixture of LMW-BPR and di-isononyl cyclohexane-1,2-dicarboxylate (DINCH, an eco-friendly monomeric plasticizer commodity) as the plasticizer. The migration resistance test showed that the migration loss of plasticizer in plasticized PVC composite decreased significantly with the increase of LMW-BPR content. When the content of LMW-BPR reaches 30 phr, the plasticized PVC composites are almost nonmigratory. In addition, compared with PVC composite plasticized by pure DINCH, co-plasticized PVC composites containing LMW-BPR exhibit higher tensile strength and thermal stability, and their flexibility, low-temperature resistance and biocompatibility are also maintained at a similar level to the former. Overall, LMW-BPR is an effective eco-friendly polymeric plasticizer for PVC and also sustainable and scalable, thus it is worthy of wide application.
{"title":"Synthesis and performance evaluation of low-molecular-weight biobased polyester rubber as a novel eco-friendly polymeric plasticizer for polyvinyl chloride","authors":"Qinan Zhang, Jiahui Sun, Zehao Yao, Xuejia Ding, Zhao Wang, Liqun Zhang","doi":"10.3389/fmats.2024.1406469","DOIUrl":"https://doi.org/10.3389/fmats.2024.1406469","url":null,"abstract":"Developing eco-friendly polymeric plasticizers with excellent migration resistance is one of the research hotspots in the polyvinyl chloride (PVC) industry. A low-molecular-weight biobased polyester rubber (LMW-BPR) was synthesized from five biobased polyester monomers in a 100-L reactor and evaluated as a potential eco-friendly polymeric plasticizer for PVC. The obtained LMW-BPR is an amorphous polyester material with a low glass transition temperature of −48°C and a molecular weight of 22 kg/mol, which is lower than that of existing polyester rubber but higher than those of most polyester plasticizer commodities. Plasticized PVC composites with a total plasticizer content of 50 phr were prepared by using the mixture of LMW-BPR and di-isononyl cyclohexane-1,2-dicarboxylate (DINCH, an eco-friendly monomeric plasticizer commodity) as the plasticizer. The migration resistance test showed that the migration loss of plasticizer in plasticized PVC composite decreased significantly with the increase of LMW-BPR content. When the content of LMW-BPR reaches 30 phr, the plasticized PVC composites are almost nonmigratory. In addition, compared with PVC composite plasticized by pure DINCH, co-plasticized PVC composites containing LMW-BPR exhibit higher tensile strength and thermal stability, and their flexibility, low-temperature resistance and biocompatibility are also maintained at a similar level to the former. Overall, LMW-BPR is an effective eco-friendly polymeric plasticizer for PVC and also sustainable and scalable, thus it is worthy of wide application.","PeriodicalId":12524,"journal":{"name":"Frontiers in Materials","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141866994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-07-26DOI: 10.3389/fmats.2024.1443259
Guowen Song, Marta Oliveira, Bryan Ormond
{"title":"Editorial: Challenges and emerging issues on firefighter’s toxic chemical exposure: smoke chemicals, contaminated PPE, and off-gassing","authors":"Guowen Song, Marta Oliveira, Bryan Ormond","doi":"10.3389/fmats.2024.1443259","DOIUrl":"https://doi.org/10.3389/fmats.2024.1443259","url":null,"abstract":"","PeriodicalId":12524,"journal":{"name":"Frontiers in Materials","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141799925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-07-25DOI: 10.3389/fmats.2024.1443089
Muhammad Iftikhar Faraz
Vinyl ester/flax (VE/flax) bio-composites were made after incorporating hybrid concentrations (0, 3, and 6% by weight (wt)) of halloysite nanotubes (HNT), magnesium hydroxide (MHO) and chitosan infused ammonium polyphosphate (CAP) particles. The purpose of incorporation of these particles was to improve the fire-retardant (FR) properties of the VE/flax composite; however, its effect on mechanical properties was also evaluated. To reduce the number of experiments (from 27 to 9), Taguchi design of experiment was employed during composite fabrication phase. Initially, the burning time and burning rate of all the composites were calculated using a horizontal burning test while tensile properties were determined using a tensile test. To predict an optimum composition, a signal to noise (S/N) ratio analysis of the burning time and tensile strength was conducted as “larger is better” criteria. The combination of 6% MGO and 3% CAP was predicted to be an optimum hybrid filler for enhanced fire retardancy, while VE/flax composite with no filler proved to have the highest tensile strength. HNT was found to be the least effective filler for both tensile and fire-retardant properties. The predicted composition was then fabricated and validated through experimental characterizations. The fire-retardant properties of the optimized composite were additionally assessed using a limiting oxygen index (LOI) test and thermal stability was evaluated using a thermogravimetric analysis (TGA). The burning time of the optimized composite was found to be delayed by 46.5% of that of VE/flax composite, while its thermal degradation was 11.23% lower than VE/flax composite.
{"title":"Optimizing the synergistic effect of organic and inorganic fillers on fire-retardant and mechanical properties of vinyl ester/flax bio-composites","authors":"Muhammad Iftikhar Faraz","doi":"10.3389/fmats.2024.1443089","DOIUrl":"https://doi.org/10.3389/fmats.2024.1443089","url":null,"abstract":"Vinyl ester/flax (VE/flax) bio-composites were made after incorporating hybrid concentrations (0, 3, and 6% by weight (wt)) of halloysite nanotubes (HNT), magnesium hydroxide (MHO) and chitosan infused ammonium polyphosphate (CAP) particles. The purpose of incorporation of these particles was to improve the fire-retardant (FR) properties of the VE/flax composite; however, its effect on mechanical properties was also evaluated. To reduce the number of experiments (from 27 to 9), Taguchi design of experiment was employed during composite fabrication phase. Initially, the burning time and burning rate of all the composites were calculated using a horizontal burning test while tensile properties were determined using a tensile test. To predict an optimum composition, a signal to noise (S/N) ratio analysis of the burning time and tensile strength was conducted as “larger is better” criteria. The combination of 6% MGO and 3% CAP was predicted to be an optimum hybrid filler for enhanced fire retardancy, while VE/flax composite with no filler proved to have the highest tensile strength. HNT was found to be the least effective filler for both tensile and fire-retardant properties. The predicted composition was then fabricated and validated through experimental characterizations. The fire-retardant properties of the optimized composite were additionally assessed using a limiting oxygen index (LOI) test and thermal stability was evaluated using a thermogravimetric analysis (TGA). The burning time of the optimized composite was found to be delayed by 46.5% of that of VE/flax composite, while its thermal degradation was 11.23% lower than VE/flax composite.","PeriodicalId":12524,"journal":{"name":"Frontiers in Materials","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141777165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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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