MAX phases are considered to be promising microwave absorbing materials in fifth-generation (5G) communications, but their high electrical conductivity causes impedance mismatching, weakening their ability to absorb microwaves. Here, we present a universal preoxidation strategy to improve the impedance matching and the microwave absorption performance of a Ti3AlC2 MAX phase absorbing material. The microwave absorption properties of Ti3AlC2 particles were enhanced after preoxidation at temperatures of 500–700 °C for only 30 min in air, as compared with unoxidized Ti3AlC2 particles. More interestingly, the 600 °C-preoxidized Ti3AlC2 material reached a minimum reflection loss (RLmin) value of −50.56 dB at 8.87 GHz, superior to −12.36 dB at 12.82 GHz for the original Ti3AlC2 material. The preoxidized Ti3AlC2 particles were covered by a thin oxidation layer comprising both amorphous TiO2 (a-TiO2) and rutile TiO2 (R-TiO2). The oxidation layer endows the preoxidized Ti3AlC2 particles with good impedance matching, and a large number of nano-interfaces of a-TiO2/R-TiO2 and micro-interfaces of a-TiO2/Ti3AlC2 also contribute to the dielectric loss mechanism, thus improving its microwave absorption ability. This work provides a practical strategy for the fundamental study and the optimal design of MAX microwave absorbing materials.
MAX 相被认为是第五代（5G）通信中前景广阔的微波吸收材料，但其高导电性会导致阻抗失配，削弱其吸收微波的能力。在此，我们提出了一种通用预氧化策略，以改善 Ti3AlC2 MAX 相吸收材料的阻抗匹配和微波吸收性能。与未氧化的 Ti3AlC2 粒子相比，Ti3AlC2 粒子在 500-700 °C 的温度下于空气中预氧化仅 30 分钟后，其微波吸收性能就得到了增强。更有趣的是，经 600 °C 预氧化的 Ti3AlC2 材料在 8.87 GHz 时的最小反射损耗（RLmin）值为 -50.56 dB，优于原始 Ti3AlC2 材料在 12.82 GHz 时的 -12.36 dB。预氧化的 Ti3AlC2 颗粒被一层薄薄的氧化层覆盖，这层氧化层包括无定形二氧化钛（a-TiO2）和金红石型二氧化钛（R-TiO2）。氧化层赋予了预氧化 Ti3AlC2 颗粒良好的阻抗匹配性，大量的 a-TiO2/R-TiO2 纳米界面和 a-TiO2/Ti3AlC2 微界面也有助于介电损耗机制，从而提高了其微波吸收能力。这项工作为 MAX 微波吸收材料的基础研究和优化设计提供了实用策略。
{"title":"Enhanced microwave absorption properties of Ti3AlC2 particles modified by a facile preoxidation strategy","authors":"Xiachen Fan, Shibo Li, Weiwei Zhang, Xuejin Zhang, Junji Mou","doi":"10.1016/j.mtnano.2024.100539","DOIUrl":"10.1016/j.mtnano.2024.100539","url":null,"abstract":"<div><div>MAX phases are considered to be promising microwave absorbing materials in fifth-generation (5G) communications, but their high electrical conductivity causes impedance mismatching, weakening their ability to absorb microwaves. Here, we present a universal preoxidation strategy to improve the impedance matching and the microwave absorption performance of a Ti<sub>3</sub>AlC<sub>2</sub> MAX phase absorbing material. The microwave absorption properties of Ti<sub>3</sub>AlC<sub>2</sub> particles were enhanced after preoxidation at temperatures of 500–700 °C for only 30 min in air, as compared with unoxidized Ti<sub>3</sub>AlC<sub>2</sub> particles. More interestingly, the 600 °C-preoxidized Ti<sub>3</sub>AlC<sub>2</sub> material reached a minimum reflection loss (RL<sub>min</sub>) value of −50.56 dB at 8.87 GHz, superior to −12.36 dB at 12.82 GHz for the original Ti<sub>3</sub>AlC<sub>2</sub> material. The preoxidized Ti<sub>3</sub>AlC<sub>2</sub> particles were covered by a thin oxidation layer comprising both amorphous TiO<sub>2</sub> (a-TiO<sub>2</sub>) and rutile TiO<sub>2</sub> (R-TiO<sub>2</sub>). The oxidation layer endows the preoxidized Ti<sub>3</sub>AlC<sub>2</sub> particles with good impedance matching, and a large number of nano-interfaces of a-TiO<sub>2</sub>/R-TiO<sub>2</sub> and micro-interfaces of a-TiO<sub>2</sub>/Ti<sub>3</sub>AlC<sub>2</sub> also contribute to the dielectric loss mechanism, thus improving its microwave absorption ability. This work provides a practical strategy for the fundamental study and the optimal design of MAX microwave absorbing materials.</div></div>","PeriodicalId":48517,"journal":{"name":"Materials Today Nano","volume":"28 ","pages":"Article 100539"},"PeriodicalIF":8.2,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663711","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}
Poly aryletherketone chemically modified multi-walled carbon nanotubes/poly etheretherketone (PAEK-m-CNTs/PEEK) electromagnetic interference (EMI) shielding foams were fabricated using supercritical carbon dioxide (Sc-CO2) foaming technique saturated near-melting point (Tm). The percolation thresholds for conductivity and EMI shielding of PAEK-m-CNTs/PEEK foams were both significantly reduced by the presence of the porous structure, reaching to 0.0457 vol% and 0.123 vol%, respectively. These reductions were observed to be 87.72 % and 75.20 % of those of PAEK-m-CNTs/PEEK composites. This could be attributed to the heterogeneous nucleation of PAEK-m-CNTs, which are uniformly dispersed in PEEK, in addition to the Sc-CO2 foaming technique saturated near Tm. By comparison, it could be observed that the specific total electromagnetic shield effectiveness (SSETotal) of PAEK-m-CNTs/PEEK foam with a filler content of 0.440 vol% was 687.9 % higher than that of PAEK-m-CNTs/PEEK composite with a filler content of 0.496 vol%. Moreover, the introduction of the porous structure transformed the electromagnetic shielding material from reflective to absorptive. In addition, PAEK-m-CNTs/PEEK foams demonstrated the capacity to maintain stable performance even in high temperatures of up to 315 °C and in the presence of strong corrosive media.
{"title":"Poly aryletherketone chemically modified multi-walled carbon nanotubes/poly etheretherketone electromagnetic interference shielding foam suitable for high temperature and strong corrosive media","authors":"Xiaohan Mei, Tonghua Wu, Liubo Liang, Yu Bai, Jianpeng Jiao, Chunqi Guo, Yanchao Yang, Guibin Wang, Shuling Zhang","doi":"10.1016/j.mtnano.2024.100538","DOIUrl":"10.1016/j.mtnano.2024.100538","url":null,"abstract":"<div><div>Poly aryletherketone chemically modified multi-walled carbon nanotubes/poly etheretherketone <strong>(</strong>PAEK-m-CNTs/PEEK) electromagnetic interference (EMI) shielding foams were fabricated using supercritical carbon dioxide (Sc-CO<sub>2</sub>) foaming technique saturated near-melting point (<em>T</em><sub><em>m</em></sub>). The percolation thresholds for conductivity and EMI shielding of PAEK-m-CNTs/PEEK foams were both significantly reduced by the presence of the porous structure, reaching to 0.0457 vol% and 0.123 vol%, respectively. These reductions were observed to be 87.72 % and 75.20 % of those of PAEK-m-CNTs/PEEK composites. This could be attributed to the heterogeneous nucleation of PAEK-m-CNTs, which are uniformly dispersed in PEEK, in addition to the Sc-CO<sub>2</sub> foaming technique saturated near <em>T</em><sub><em>m</em></sub>. By comparison, it could be observed that the specific total electromagnetic shield effectiveness (<em>SSE</em><sub><em>Total</em></sub>) of PAEK-m-CNTs/PEEK foam with a filler content of 0.440 vol% was 687.9 % higher than that of PAEK-m-CNTs/PEEK composite with a filler content of 0.496 vol%. Moreover, the introduction of the porous structure transformed the electromagnetic shielding material from reflective to absorptive. In addition, PAEK-m-CNTs/PEEK foams demonstrated the capacity to maintain stable performance even in high temperatures of up to 315 °C and in the presence of strong corrosive media.</div></div>","PeriodicalId":48517,"journal":{"name":"Materials Today Nano","volume":"28 ","pages":"Article 100538"},"PeriodicalIF":8.2,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663712","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 : 2024-11-09DOI: 10.1016/j.mtnano.2024.100537
Lianjun Wen , Dunyuan Liao , Lei Liu , Fengyue He , Ran Zhuo , Xiyu Hou , Dong Pan , Jianhua Zhao
Scalable in-plane InAsSb nanowires and networks have attracted intense research interest in optoelectronics and quantum computation. However, the poor crystalline quality of InAsSb nanowires and networks limits the development of high-performance nanodevices. Here, we report the growth of high crystalline quality InAsSb nanowires and networks on patterned Ge substrates by molecular-beam epitaxy. We find that high crystalline quality InAsSb nanowires can be successfully achieved by the conventional selective area growth route. But continuous nanowires and networks cannot be obtained by this growth manner. To overcome this problem, a metal-sown selective area growth route is developed. By precisely tuning the growth parameters, the well-aligned InAsSb nanowires and networks have been successfully fabricated. It is determined that the morphologies of nanowires and networks are dependent on the local growth rate and the V/III ratio, and the V/III ratio has an obvious effect on the polarity of nanowires and networks. Detailed structural studies confirm that these well-faceted nanowires are pure zinc blende single crystals, and there is a strict epitaxial relationship between the nanowire and the substrate. The energy dispersive spectroscopy analyses indicate that the Sb content is evenly distributed along the in-plane direction and has an obvious gradient along the out-of-plane direction. The successful fabrication of high crystalline quality InAsSb nanowires and networks provides new opportunities for exploring potential optoelectronic applications.
{"title":"Metal-sown selective area growth of high crystalline quality InAsSb nanowires and networks by molecular-beam epitaxy","authors":"Lianjun Wen , Dunyuan Liao , Lei Liu , Fengyue He , Ran Zhuo , Xiyu Hou , Dong Pan , Jianhua Zhao","doi":"10.1016/j.mtnano.2024.100537","DOIUrl":"10.1016/j.mtnano.2024.100537","url":null,"abstract":"<div><div>Scalable in-plane InAsSb nanowires and networks have attracted intense research interest in optoelectronics and quantum computation. However, the poor crystalline quality of InAsSb nanowires and networks limits the development of high-performance nanodevices. Here, we report the growth of high crystalline quality InAsSb nanowires and networks on patterned Ge substrates by molecular-beam epitaxy. We find that high crystalline quality InAsSb nanowires can be successfully achieved by the conventional selective area growth route. But continuous nanowires and networks cannot be obtained by this growth manner. To overcome this problem, a metal-sown selective area growth route is developed. By precisely tuning the growth parameters, the well-aligned InAsSb nanowires and networks have been successfully fabricated. It is determined that the morphologies of nanowires and networks are dependent on the local growth rate and the V/III ratio, and the V/III ratio has an obvious effect on the polarity of nanowires and networks. Detailed structural studies confirm that these well-faceted nanowires are pure zinc blende single crystals, and there is a strict epitaxial relationship between the nanowire and the substrate. The energy dispersive spectroscopy analyses indicate that the Sb content is evenly distributed along the in-plane direction and has an obvious gradient along the out-of-plane direction. The successful fabrication of high crystalline quality InAsSb nanowires and networks provides new opportunities for exploring potential optoelectronic applications.</div></div>","PeriodicalId":48517,"journal":{"name":"Materials Today Nano","volume":"28 ","pages":"Article 100537"},"PeriodicalIF":8.2,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663710","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 : 2024-10-28DOI: 10.1016/j.mtnano.2024.100536
Jesús Cebollada , David Sebastián , Jun Yamasaki , Javier Agúndez , Maria Jesús Lázaro , Maria Victoria Martínez-Huerta
This study explores the synthesis and electrocatalytic performance of copper-nitrogen-carbon composites formed by Cu single atoms/clusters embedded in nitrogen-doped carbon with Cu/Cu2O nanoparticles (Cu-X-NC) for the oxygen reduction reaction (ORR). The catalysts were synthesized using polydopamine as a carbon and nitrogen source via the solvothermal carbonization (STC) method, followed by pyrolysis and acid washing. The effect of solvothermal carbonization temperature (120, 150, and 180 °C) on the structure and ORR activity was investigated. The physicochemical characterization showed that higher STC temperatures reduced the size of copper crystallites, slightly increased the formation of copper(I) oxide, and led to the creation of well-dispersed copper single atoms/clusters at 150 °C. This optimal dispersion enhances the interaction between the copper single atoms and the reactants, leading to faster ORR kinetics, as demonstrated by the lower charge transfer resistance values in electrochemical impedance spectroscopy measurements. Additionally, the balance between micropore and mesopore structures at this temperature facilitates efficient mass transport, which is critical for achieving higher ORR activity. Moreover, accelerated stability tests showed excellent durability for Cu-150-NC, with negligible loss in onset potential after 10,000 cycles. The solvothermal process significantly increased the electrochemically active surface area (ECSA), with Cu-150-NC displaying the highest specific activity and mass activity per gram of copper, indicating superior performance. Overall, these findings underscore the importance of synthesis optimization and provide valuable insights for designing eco-friendly and high-performance copper catalysts for fuel cell applications.
{"title":"Building robust copper nanostructures via carbon coating derived from polydopamine for oxygen reduction reaction","authors":"Jesús Cebollada , David Sebastián , Jun Yamasaki , Javier Agúndez , Maria Jesús Lázaro , Maria Victoria Martínez-Huerta","doi":"10.1016/j.mtnano.2024.100536","DOIUrl":"10.1016/j.mtnano.2024.100536","url":null,"abstract":"<div><div>This study explores the synthesis and electrocatalytic performance of copper-nitrogen-carbon composites formed by Cu single atoms/clusters embedded in nitrogen-doped carbon with Cu/Cu<sub>2</sub>O nanoparticles (Cu-X-NC) for the oxygen reduction reaction (ORR). The catalysts were synthesized using polydopamine as a carbon and nitrogen source via the solvothermal carbonization (STC) method, followed by pyrolysis and acid washing. The effect of solvothermal carbonization temperature (120, 150, and 180 °C) on the structure and ORR activity was investigated. The physicochemical characterization showed that higher STC temperatures reduced the size of copper crystallites, slightly increased the formation of copper(I) oxide, and led to the creation of well-dispersed copper single atoms/clusters at 150 °C. This optimal dispersion enhances the interaction between the copper single atoms and the reactants, leading to faster ORR kinetics, as demonstrated by the lower charge transfer resistance values in electrochemical impedance spectroscopy measurements. Additionally, the balance between micropore and mesopore structures at this temperature facilitates efficient mass transport, which is critical for achieving higher ORR activity. Moreover, accelerated stability tests showed excellent durability for Cu-150-NC, with negligible loss in onset potential after 10,000 cycles. The solvothermal process significantly increased the electrochemically active surface area (ECSA), with Cu-150-NC displaying the highest specific activity and mass activity per gram of copper, indicating superior performance. Overall, these findings underscore the importance of synthesis optimization and provide valuable insights for designing eco-friendly and high-performance copper catalysts for fuel cell applications.</div></div>","PeriodicalId":48517,"journal":{"name":"Materials Today Nano","volume":"28 ","pages":"Article 100536"},"PeriodicalIF":8.2,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572439","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}
Pub Date : 2024-10-24DOI: 10.1016/j.mtnano.2024.100535
Bibo Zhou , Xiaoming Zhao , Yuanjun Liu
To effectively reduce the damage caused by flame burns or heat transfer to the human body during fire, we used PAM aqueous solution as the matrix, XG as the thickener, HPMC as the water-retaining agent to form the basic material system, and added different functional particles (APP, PTW, HCB) to prepare a fire-proof and heat-insulating PAM flame-retardant material for fire emergency rescue. Ordinary cotton fabrics were impregnated into PAM flame-retardant materials using a simple impregnation process. After the impregnation, the test was performed in a non-dropping state (simulating the thermal protection effect of PAM flame retardant materials directly acting on the outside of the human body at the fire scene). The results show that the PAM flame retardant material prepared by adding 4 wt% HCB has the best comprehensive performance. TPP test shows that spraying PAM flame retardant material on the outside of the fabric can instantly give the fabric a higher thermal protection performance. Under the total heat flux of 84 kW/m2, the thermal performance protection value of the fabric is 2641.8 kW s/m2, and the second-degree burn time can reach 31.45 s. PAM flame retardant material does not damage the fabric. After soaping, the air permeability of the fabric decreases slightly, the moisture permeability and wettability are improved, and the breaking strength is almost unchanged. The CCT test showed that the thermal radiation flux was 50 kW/m2, the PHRR value of PAM flame retardant material was 10.64552 kW/m2, the THR was 6.9 MJ/m2, and the flame retardant performance was excellent. The PAM flame retardant material prepared in this project can be applied to the fire scene and directly sprayed on the outside of the clothing of rescuers and recipients, giving the fabric a better thermal protection effect. It can also be used to extinguish fires in the external environment. This material offers a novel solution for enhancing fire rescuers' and victims' safety protection levels.
{"title":"PAM material that instantly gives ordinary fabrics excellent flame retardant and thermal insulation properties for fire rescue","authors":"Bibo Zhou , Xiaoming Zhao , Yuanjun Liu","doi":"10.1016/j.mtnano.2024.100535","DOIUrl":"10.1016/j.mtnano.2024.100535","url":null,"abstract":"<div><div>To effectively reduce the damage caused by flame burns or heat transfer to the human body during fire, we used PAM aqueous solution as the matrix, XG as the thickener, HPMC as the water-retaining agent to form the basic material system, and added different functional particles (APP, PTW, HCB) to prepare a fire-proof and heat-insulating PAM flame-retardant material for fire emergency rescue. Ordinary cotton fabrics were impregnated into PAM flame-retardant materials using a simple impregnation process. After the impregnation, the test was performed in a non-dropping state (simulating the thermal protection effect of PAM flame retardant materials directly acting on the outside of the human body at the fire scene). The results show that the PAM flame retardant material prepared by adding 4 wt% HCB has the best comprehensive performance. TPP test shows that spraying PAM flame retardant material on the outside of the fabric can instantly give the fabric a higher thermal protection performance. Under the total heat flux of 84 kW/m<sup>2</sup>, the thermal performance protection value of the fabric is 2641.8 kW s/m<sup>2</sup>, and the second-degree burn time can reach 31.45 s. PAM flame retardant material does not damage the fabric. After soaping, the air permeability of the fabric decreases slightly, the moisture permeability and wettability are improved, and the breaking strength is almost unchanged. The CCT test showed that the thermal radiation flux was 50 kW/m<sup>2</sup>, the PHRR value of PAM flame retardant material was 10.64552 kW/m<sup>2</sup>, the THR was 6.9 MJ/m<sup>2</sup>, and the flame retardant performance was excellent. The PAM flame retardant material prepared in this project can be applied to the fire scene and directly sprayed on the outside of the clothing of rescuers and recipients, giving the fabric a better thermal protection effect. It can also be used to extinguish fires in the external environment. This material offers a novel solution for enhancing fire rescuers' and victims' safety protection levels.</div></div>","PeriodicalId":48517,"journal":{"name":"Materials Today Nano","volume":"28 ","pages":"Article 100535"},"PeriodicalIF":8.2,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142539683","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 : 2024-10-20DOI: 10.1016/j.mtnano.2024.100534
Yi Gao , Qian Yang , Li Ma , Tian Li , Qing Qi , Tian Yang , Fanbin Meng
Nowadays, multifunctional detection systems and reverse detection technologies play a dominant role in military reconnaissance and stealth gaming operations. Therefore, stealth technology, as the most powerful means of reverse detection, has increasingly become a research hot spot. In particular, when the detection weapons are equipped with radar and infrared detection, how to achieve effective compatibility of stealth to minimize the loss and the success of military operations is still a major challenge in current research. Therefore, this review provides an indepth discussion and distinction between the mechanisms of radar and infrared detection technologies, respectively, while emphasizing the technical challenges involved in achieving compatible stealth. Besides, the review explores the microwave absorption and infrared stealth properties of innovative advanced nano-composites materials (MXene, graphene, and metal-organic frameworks (MOFs)) reported to date. Subsequently, the review analyzes the properties, structural design, and optimization strategies of recently reported compatible stealth materials, ranging from low-dimensional to high-dimensional structures, and discusses in detail the recent advances in compatible stealth materials. Finally, the review summarizes the advantages of developing various materials and structures in this promising field, providing a comprehensive overview of their potential and efficacy.
{"title":"Radar-infrared compatible stealth technology in advanced nano-composite materials: Mechanisms and structural optimization","authors":"Yi Gao , Qian Yang , Li Ma , Tian Li , Qing Qi , Tian Yang , Fanbin Meng","doi":"10.1016/j.mtnano.2024.100534","DOIUrl":"10.1016/j.mtnano.2024.100534","url":null,"abstract":"<div><div>Nowadays, multifunctional detection systems and reverse detection technologies play a dominant role in military reconnaissance and stealth gaming operations. Therefore, stealth technology, as the most powerful means of reverse detection, has increasingly become a research hot spot. In particular, when the detection weapons are equipped with radar and infrared detection, how to achieve effective compatibility of stealth to minimize the loss and the success of military operations is still a major challenge in current research. Therefore, this review provides an indepth discussion and distinction between the mechanisms of radar and infrared detection technologies, respectively, while emphasizing the technical challenges involved in achieving compatible stealth. Besides, the review explores the microwave absorption and infrared stealth properties of innovative advanced nano-composites materials (MXene, graphene, and metal-organic frameworks (MOFs)) reported to date. Subsequently, the review analyzes the properties, structural design, and optimization strategies of recently reported compatible stealth materials, ranging from low-dimensional to high-dimensional structures, and discusses in detail the recent advances in compatible stealth materials. Finally, the review summarizes the advantages of developing various materials and structures in this promising field, providing a comprehensive overview of their potential and efficacy.</div></div>","PeriodicalId":48517,"journal":{"name":"Materials Today Nano","volume":"28 ","pages":"Article 100534"},"PeriodicalIF":8.2,"publicationDate":"2024-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142527946","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}
The far-infrared (FIR) spectrum, covering wavelengths from 20 to 1000 , presents significant challenges for the manipulation and detection of polarized light, especially in the short-wavelength FIR range of 20–100 . This study investigates the effectiveness of truncated pyramidal GaAs quantum dots in improving the absorption coefficient of polarized light within this range. Utilizing the finite difference method to obtain numerical solutions of the Schrödinger equation within the adiabatic approximation, we analyze the effects of various base shapes—equilateral hexagon, irregular hexagon, and equilateral triangle—on the optical absorption coefficients when subjected to an electric field with different directions and magnitudes. Our results reveal that triangular pyramidal quantum dots offer enhanced polarization sensitivity and greater tunability of absorption peaks compared to structures with other base shapes. Moreover, the direction of the applied electric field is crucial for tuning the absorption peaks in the desired range of FIR wavelength. These findings demonstrate the potential of truncated pyramidal GaAs quantum dots not only for improving sensing technologies but also for managing electromagnetic interference in advanced communication systems.
远红外线（FIR）光谱的波长从 20 微米到 1000 微米不等，这给偏振光的操纵和探测带来了重大挑战，尤其是在 20-100 微米的短波长 FIR 范围内。本研究探讨了截顶金字塔砷化镓量子点在改善该范围内偏振光吸收系数方面的有效性。利用有限差分法在绝热近似条件下获得薛定谔方程的数值解，我们分析了不同基底形状（四边形六角形、不规则六角形和等边三角形）在不同方向和大小的电场作用下对光吸收系数的影响。研究结果表明，与其他基底形状的结构相比，三角形金字塔量子点具有更高的偏振灵敏度和更强的吸收峰可调性。此外，外加电场的方向对于在所需的红外波长范围内调节吸收峰至关重要。这些研究结果表明，截顶金字塔砷化镓量子点不仅具有改进传感技术的潜力，还具有管理先进通信系统中电磁干扰的潜力。
{"title":"Enhanced polarization sensitivity and tunability in truncated pyramidal GaAs quantum dots for FIR applications","authors":"Suphawich Jindanate , Phatlada Sathongpaen , Attapon Amthong","doi":"10.1016/j.mtnano.2024.100533","DOIUrl":"10.1016/j.mtnano.2024.100533","url":null,"abstract":"<div><div>The far-infrared (FIR) spectrum, covering wavelengths from 20 to 1000 <span><math><mrow><mi>μ</mi><mi>m</mi></mrow></math></span>, presents significant challenges for the manipulation and detection of polarized light, especially in the short-wavelength FIR range of 20–100 <span><math><mrow><mi>μ</mi><mi>m</mi></mrow></math></span>. This study investigates the effectiveness of truncated pyramidal GaAs quantum dots in improving the absorption coefficient of polarized light within this range. Utilizing the finite difference method to obtain numerical solutions of the Schrödinger equation within the adiabatic approximation, we analyze the effects of various base shapes—equilateral hexagon, irregular hexagon, and equilateral triangle—on the optical absorption coefficients when subjected to an electric field with different directions and magnitudes. Our results reveal that triangular pyramidal quantum dots offer enhanced polarization sensitivity and greater tunability of absorption peaks compared to structures with other base shapes. Moreover, the direction of the applied electric field is crucial for tuning the absorption peaks in the desired range of FIR wavelength. These findings demonstrate the potential of truncated pyramidal GaAs quantum dots not only for improving sensing technologies but also for managing electromagnetic interference in advanced communication systems.</div></div>","PeriodicalId":48517,"journal":{"name":"Materials Today Nano","volume":"28 ","pages":"Article 100533"},"PeriodicalIF":8.2,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142527947","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}
Reactive oxygen species (ROS)-based antitumor strategies, particularly chemodynamic therapy, have garnered considerable attention. However, challenges such as difficulties in achieving deep penetration, relatively low H2O2 levels in the tumor microenvironment, the requirement for low pH by the Fenton reaction, and their short lifespan have impeded satisfactory therapeutic outcomes. Hence, we have developed a nanoplatform with enhanced permeability that not only generates significant amounts of ROS but also converts them into longer-lasting reactive nitrogen species (RNS), thereby improving tumor therapy efficacy. In our study, carbon dots were functionalized by doping with gold atoms and grafting nitrosoglutathione (GSNO) to form ACN, which exhibits glucose oxidase-like properties and enables laser-responsive NO release. ACN and indocyanine green (ICG) were then loaded onto MnO2 nanoflowers to form MnO2@AI. Upon arrival at the tumor site, MnO2 reacts with H2O2 and GSH, leading to its degradation and the subsequent release of ACN, which is characterized by three permeation-promoting properties: ultra-small size, positive charge, and NO content. In addition, ACN promotes H2O2 production through glucose metabolism and reduces pH, both of which enhance the Fenton-like reaction of MnO2, thereby amplifying ROS generation. The ICG in MnO2@AI enhances its photothermal properties, leading to the responsive release of NO from GSNO grafted onto ACN, which then reacts with the increased ROS to generate more toxic RNS. Collectively, the approach described herein offers substantial potential for advancing the treatment of malignant tumors.
{"title":"A highly permeable nanoplatform based on functionalized carbon dots for synergistic reactive oxygen/nitrogen species tumor therapy","authors":"Jiangyong Li, Qin Li, Qian Yang, Qi Tang, Xiaoyi Hu, Qing Liu, Liangke Zhang","doi":"10.1016/j.mtnano.2024.100532","DOIUrl":"10.1016/j.mtnano.2024.100532","url":null,"abstract":"<div><div>Reactive oxygen species (ROS)-based antitumor strategies, particularly chemodynamic therapy, have garnered considerable attention. However, challenges such as difficulties in achieving deep penetration, relatively low H<sub>2</sub>O<sub>2</sub> levels in the tumor microenvironment, the requirement for low pH by the Fenton reaction, and their short lifespan have impeded satisfactory therapeutic outcomes. Hence, we have developed a nanoplatform with enhanced permeability that not only generates significant amounts of ROS but also converts them into longer-lasting reactive nitrogen species (RNS), thereby improving tumor therapy efficacy. In our study, carbon dots were functionalized by doping with gold atoms and grafting nitrosoglutathione (GSNO) to form ACN, which exhibits glucose oxidase-like properties and enables laser-responsive NO release. ACN and indocyanine green (ICG) were then loaded onto MnO<sub>2</sub> nanoflowers to form MnO<sub>2</sub>@AI. Upon arrival at the tumor site, MnO<sub>2</sub> reacts with H<sub>2</sub>O<sub>2</sub> and GSH, leading to its degradation and the subsequent release of ACN, which is characterized by three permeation-promoting properties: ultra-small size, positive charge, and NO content. In addition, ACN promotes H<sub>2</sub>O<sub>2</sub> production through glucose metabolism and reduces pH, both of which enhance the Fenton-like reaction of MnO<sub>2</sub>, thereby amplifying ROS generation. The ICG in MnO<sub>2</sub>@AI enhances its photothermal properties, leading to the responsive release of NO from GSNO grafted onto ACN, which then reacts with the increased ROS to generate more toxic RNS. Collectively, the approach described herein offers substantial potential for advancing the treatment of malignant tumors.</div></div>","PeriodicalId":48517,"journal":{"name":"Materials Today Nano","volume":"28 ","pages":"Article 100532"},"PeriodicalIF":8.2,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142527944","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 : 2024-10-18DOI: 10.1016/j.mtnano.2024.100531
Akshay Arjun , H.B. Premkumar , Lalitha S. Jairam , S.C. Sharma , H. Nagabhushana , G.P. Darshan
The cracked tooth syndrome poses a significant challenge in dentistry, thereafter untreated cases often lead to severe complications, such as pulpitis or complete tooth fracture, ultimately contributing to tooth loss. However, the conventional diagnostic methods to visualize microcracks in the tooth suffer from severe drawbacks, such as inaccurate cold stimulation, discomfort with probing, impractical staining techniques, and difficulty in distinguishing harmless craze lines from pathological cracks. To address this challenge, for the first time, we are proposing a novel approach by utilizing luminescent Ba2ZnWO6:Eu3+ (3 mol %), K+ (1 wt %) nanophosphor for improved imaging and diagnosis of cracked tooth syndrome. Herein, the double perovskite structured Ba2ZnWO6:Eu3+ (1–11 mol %), M+ (M+ = Na, K, and Li (1 wt %)) nanophosphors were synthesized via the sonochemical route. The photoluminescence emission spectra of the prepared Ba2ZnWO6:Eu3+ (1–11 mol %) nanophosphors displaying distinct peaks at 583, 595, 613, 662, and 720 nm, which ascribed to transitions from state 5D0 to 7FJ (J = 1–4) state of the Eu3+ ions, respectively. By adopting a strategic charge compensation mechanism, the enhancement in the luminescence emission intensity of about 1.5-fold was achieved after co-doping K+ (1 wt %) with Ba2ZnWO6:Eu3+ (3 mol %) nanophosphor. The photometric studies of the phosphors portray their orange-red emission with excellent quantum efficiency (82.52 %), and color purity (∼ 99 %). The emission intensity was sustained up to 73.71 % at 473 K, indicating excellent thermal stability of the phosphor. The in vitro cytotoxicity assessments of the optimized nanophosphor demonstrated its biocompatibility on normal non-malignant oral fibroblasts. The visualized microcracks in the tooth using optimized Ba2ZnWO6:Eu3+ (3 mol %), K+ (1 wt %) nanophosphor under UV excitation of UV 365 and 395 nm light revealed the orientation of microcracks, crack width, depth of the crack, and microcrack branching without any stain. The aforementioned results demonstrated that the proposed methodology paves the way for a new avenue in dental imaging technology with the potential to revolutionize and improve patient care outcomes.
{"title":"Leveraging photosensitive and thermally stable luminescent Ba2ZnWO6:Eu3+, M+ (M+= Na, K , and Li) nanophosphor for targeted non-invasive and stain-free visualization of cracked tooth syndrome","authors":"Akshay Arjun , H.B. Premkumar , Lalitha S. Jairam , S.C. Sharma , H. Nagabhushana , G.P. Darshan","doi":"10.1016/j.mtnano.2024.100531","DOIUrl":"10.1016/j.mtnano.2024.100531","url":null,"abstract":"<div><div>The cracked tooth syndrome poses a significant challenge in dentistry, thereafter untreated cases often lead to severe complications, such as pulpitis or complete tooth fracture, ultimately contributing to tooth loss. However, the conventional diagnostic methods to visualize microcracks in the tooth suffer from severe drawbacks, such as inaccurate cold stimulation, discomfort with probing, impractical staining techniques, and difficulty in distinguishing harmless craze lines from pathological cracks. To address this challenge, for the first time, we are proposing a novel approach by utilizing luminescent Ba<sub>2</sub>ZnWO<sub>6</sub>:Eu<sup>3+</sup> (3 mol %), K<sup>+</sup> (1 wt %) nanophosphor for improved imaging and diagnosis of cracked tooth syndrome. Herein, the double perovskite structured Ba<sub>2</sub>ZnWO<sub>6</sub>:Eu<sup>3+</sup> (1–11 mol %), M<sup>+</sup> (M<sup>+</sup> = Na, K, and Li (1 wt %)) nanophosphors were synthesized via the sonochemical route. The photoluminescence emission spectra of the prepared Ba<sub>2</sub>ZnWO<sub>6</sub>:Eu<sup>3+</sup> (1–11 mol %) nanophosphors displaying distinct peaks at 583, 595, 613, 662, and 720 nm, which ascribed to transitions from state <sup>5</sup>D<sub>0</sub> to <sup>7</sup>F<sub>J</sub> (J = 1–4) state of the Eu<sup>3+</sup> ions, respectively. By adopting a strategic charge compensation mechanism, the enhancement in the luminescence emission intensity of about 1.5-fold was achieved after co-doping K<sup>+</sup> (1 wt %) with Ba<sub>2</sub>ZnWO<sub>6</sub>:Eu<sup>3+</sup> (3 mol %) nanophosphor. The photometric studies of the phosphors portray their orange-red emission with excellent quantum efficiency (82.52 %), and color purity (∼ 99 %). The emission intensity was sustained up to 73.71 % at 473 K, indicating excellent thermal stability of the phosphor. The <em>in vitro</em> cytotoxicity assessments of the optimized nanophosphor demonstrated its biocompatibility on normal non-malignant oral fibroblasts. The visualized microcracks in the tooth using optimized Ba<sub>2</sub>ZnWO<sub>6</sub>:Eu<sup>3+</sup> (3 mol %), K<sup>+</sup> (1 wt %) nanophosphor under UV excitation of UV 365 and 395 nm light revealed the orientation of microcracks, crack width, depth of the crack, and microcrack branching without any stain. The aforementioned results demonstrated that the proposed methodology paves the way for a new avenue in dental imaging technology with the potential to revolutionize and improve patient care outcomes.</div></div>","PeriodicalId":48517,"journal":{"name":"Materials Today Nano","volume":"28 ","pages":"Article 100531"},"PeriodicalIF":8.2,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142527945","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 : 2024-10-10DOI: 10.1016/j.mtnano.2024.100523
Yang Yang , Xianhui Li , Cheng Xiang
The emerging of two-dimensional (2D) isoporous materials forwarded the applications of membrane materials in cutting-edge fields such as refined separation, atom uptake and single-molecule detection. The key to the design of these materials lies in the precise tailoring of the pore structures. This review presents the state-of-the-art advancements of 2D isoporous materials, highlights the construction of isoporous structures in 2D materials through the bottom-up and top-down synthesis strategies, and reviews various fabrication routes. It comprehensively summarizes the impact of interface selection, precursor design and post-processing on pore formation, pore geometry and edge structures. The feasibility of the material scale-up, current challenges and future development prospects are outlined.
{"title":"2D isoporous materials: From precursor molecular structures to post-processing methods","authors":"Yang Yang , Xianhui Li , Cheng Xiang","doi":"10.1016/j.mtnano.2024.100523","DOIUrl":"10.1016/j.mtnano.2024.100523","url":null,"abstract":"<div><div>The emerging of two-dimensional (2D) isoporous materials forwarded the applications of membrane materials in cutting-edge fields such as refined separation, atom uptake and single-molecule detection. The key to the design of these materials lies in the precise tailoring of the pore structures. This review presents the state-of-the-art advancements of 2D isoporous materials, highlights the construction of isoporous structures in 2D materials through the bottom-up and top-down synthesis strategies, and reviews various fabrication routes. It comprehensively summarizes the impact of interface selection, precursor design and post-processing on pore formation, pore geometry and edge structures. The feasibility of the material scale-up, current challenges and future development prospects are outlined.</div></div>","PeriodicalId":48517,"journal":{"name":"Materials Today Nano","volume":"28 ","pages":"Article 100523"},"PeriodicalIF":8.2,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142434390","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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