Journal of Materials Science

Carter, C. Barry

doi: 10.1007/s10853-021-06778-1pmid: N/A

Jackson, Caitlin E.; Johnson, Liam S. J.; Williams, Dominic A.; Laasch, Hans-Ulrich; Edwards, Derek W.; Harvey, Alison G.

doi: 10.1007/s10853-021-06700-9pmid: N/A

Oesophageal stents are meshed tubular implants designed to maintain patency of the oesophageal lumen and attenuate the symptoms of oesophageal cancer. Oesophageal cancers account for one in twenty cancer diagnoses and can lead to dysphasia, malnutrition and the diminishment of patient quality of life (QOL). Self-expanding oesophageal stents are the most common approach to attenuate these symptoms. Recent advances in oncological therapy have enabled patient survival beyond the lifetime of current devices. This introduces new complications for palliation, driving the need for innovation in stent design. This review identifies the factors responsible for stent failure. It explores the challenges of enhancing the longevity of stent therapies and outlines solutions to improving clinical outcomes. Discussions focus on the role of stent materials, construction methods, and coatings upon device performance. We found three key stent enhancement strategies currently used; material surface treatments, anti-migratory modifications, and biodegradable skeletons. Furthermore, radioactive and drug eluting stent designs were identified as emerging novel treatments. In conclusion, the review offers an overview of remaining key challenges in oesophageal stent design and potential solutions. It is clear that further research is needed to improve the clinical outcome of stents and patient QOL.

Della Gatta, Roberta; Perna, Alessia Serena; Viscusi, Antonio; Pasquino, Germana; Astarita, Antonello

doi: 10.1007/s10853-021-06561-2pmid: N/A

Cold spray deposition, which can be framed in the wider family of additive manufacturing, is a manufacturing technique that is able to produce coatings on diverse types of substrates through the deposition of feedstock powder. As a low-temperature process, cold spray represents a potential solution for the metallization of temperature-sensitive materials, i.e. polymers and polymer matrix composites. The study of the cold spray technology for the metallization of polymers is still in its early stage, and the deposition mechanisms of metals on polymer-based materials are not thoroughly understood yet. On these premises, a review on this topic is needed to systematically depict the actual state of the art and to provide a reliable and well-organized overview discussing all the theories arisen in these years. In summary, this review aims: i) to collect all the available literature and enucleate the most discussed and interesting points (the most prevailing theories regarding the bonding mechanisms, the influence of the different process parameters and the main characteristics of cold-sprayed coating), providing a reliable and well-organized state of the art; ii) to define the open questions and to delineate the directions of future work.

Guo, Yajin; Wang, Xinyu; Shen, Ying; Dong, Kuo; Shen, Linyi; Alzalab, Asmaa Ahmed Abdullah

doi: 10.1007/s10853-021-06575-wpmid: 34658418

In recent years, nanomaterials have aroused extensive research interest in the world's material science community. Electrospinning has the advantages of wide range of available raw materials, simple process, small fiber diameter and high porosity. Electrospinning as a nanomaterial preparation technology with obvious advantages has been studied, such as its influencing parameters, physical models and computer simulation. In this review, the influencing parameters, simulation and models of electrospinning technology are summarized. In addition, the progresses in applications of the technology in biomedicine, energy and catalysis are reported. This technology has many applications in many fields, such as electrospun polymers in various aspects of biomedical engineering. The latest achievements in recent years are summarized, and the existing problems and development trends are analyzed and discussed.

Kagatikar, Sneha; Sunil, Dhanya

doi: 10.1007/s10853-021-06602-wpmid: N/A

Organic light-emitting devices (OLEDs) have garnered significant research attention owing to their immense application prospects in leading technologies for full-color flat panel displays and eco-friendly solid-state lighting. They demonstrate exceptional features such as mercury-free construction, wide viewing angle, superior color quality and captivating flexibility. The requirements of light-emitting organic materials pertaining to high stability, lifetime and luminescence quantum yield, combined with the fabrication of devices with high performance efficiency, are highly challenging. Rational molecular design of 1,8-naphthalimide (NI) derivatives can offer quite promising results in achieving standard-light-emitting materials with a wide range of colors for OLED applications. This review is mainly focused on the synthesis and usage of varyingly substituted NI frameworks as luminescent host, dopant, hole-blocking and electron-transporting materials for OLEDs that emit not only red, orange, green and blue colors, but also function as white emitters, which can really have an impact on reducing the energy consumption. The future prospects that could be explored to improve the research in the highly promising field of OLEDs are also discussed.Graphical abstract[graphic not available: see fulltext]

Wajahat, Muhammad; Kouzani, Abbas Z.; Khoo, Sui Yang; Mahmud, M. A. Parvez

doi: 10.1007/s10853-021-06637-zpmid: N/A

Energy harvesting technologies now play a significant role in the successful deployment of self-powered electronic devices. Researchers are working on small-scale energy generators fabricated with nanomaterials to harvest ambient energy. Triboelectric nanogenerator (TENG) is an efficient method for harvesting mechanical energy and powering battery-less tiny devices for wearable, implantable medical sensing and internet of things (IoT) sensing applications. So far, many fabrication technologies have been discussed in the literature for the fabrication of TENG including traditional micro/nano-fabrication technologies and 3D printing or additive manufacturing technologies. Extrusion-based 3D printing is a reliable approach for developing a fast, economical and controllable TENG device. This article provides a detailed analysis of recently used material combinations, design and structure formation, and output performance of extrusion-based 3D-printed triboelectric nanogenerators (EB-3DP-TENGs). Also, it presents their latest applications, including powering of electronic devices, silent speech recognition, voice print sensing and gait monitoring. Moreover, it discusses the crucial challenges and approaches used to enhance the performance efficiency of EB-3DP-TENGs. Finally, a visionary roadmap for the future development of EB-3DP-TENGs is provided, which will accelerate research and development.

Oliveira, Nagyla A.; Bispo-Jr, Airton G.; Lima, Sergio A. Marques; Pires, Ana M.

doi: 10.1007/s10853-021-06633-3pmid: N/A

UV-to-red downshifting phosphors such as BaAl2O4:Eu3+ find broad range of application in sensors, displays, and in solid-state lighting, yet new synthetic routes to improve their luminescence are envisaged. In this regard, herein, it is introduced two new methods to synthesize this environmentally friendly BaAl2O4:Eu3+, by an adapted sol–gel route and a modified Pechini synthesis. Additionally, a systematic study was carried out about the Eu3+ doping concentration and charge compensation effects on the structural, morphological and spectroscopic features. Both routes enabled high-crystalline and nanostructured phosphors displaying optic bandgap near to 4.4 eV, although the sol–gel route also led to low amounts of BaCO3 spurious phase. Upon UV (250 nm) excitation, all Eu3+-doped samples emit red light displaying high emission color purity, characteristic of the 5D0 → 7F0-4 electronic transitions of Eu3+. The Pechini method led to the highest intrinsic emission quantum yield (85% for the 3%-doped sample). Eu3+ replaces Ba2+ within the BaAl2O4 lattice, but in the sol–gel-derived samples, the dopant may also replace Ba2+ into the BaCO3 spurious phase, confirming that the Pechini route is the best one to optimize the luminescence and structure of the phosphor.Graphical abstract[graphic not available: see fulltext]

Zhezhera, T.; Gluchowski, P.; Nowicki, M.; Chrunik, M.; Majchrowski, A.; Kosyl, K. M.; Kasprowicz, D.

doi: 10.1007/s10853-021-06642-2pmid: N/A

An efficient near-infrared quantum cutting process by cooperative down-conversion of active Bi3+ and Nd3+ ions was demonstrated in Bi3TeBO9:Nd3+ phosphors. In particular, the near-infrared emission of Nd3+ ions enhanced by Bi3+ ions of a series of novel Bi3TeBO9:Nd3+ microcrystalline powders doped with Nd3+ ions in various concentrations was investigated. In order to investigate the luminescent properties of BTBO:Nd3+ powders, the excitation and emission spectra and the fluorescence decay time were measured and analyzed. In particular, the emission of Bi3TeBO9:Nd3+ at 890 and 1064 nm was excited at 327 nm (via energy transfer from Bi3+ ions) and at 586.4 nm (directly by Nd3+ ions). The highest intensity emission bands in near-infrared were detected in the spectra of Bi3TeBO9:Nd3+ doped with 5.0 and 0.5 at.% of Nd3+ ions upon excitation in ultraviolet and visible spectral range, respectively. The fluorescence decay lifetime monitored at 1064 nm for Bi3TeBO9:Nd3+ powders shows the single- or double-exponential character depending on the concentrations of Nd3+ ions. The possible mechanisms of energy relaxation after excitation Bi3TeBO9:Nd3+ powders in ultraviolet or visible spectral range were discussed. The investigated Bi3TeBO9:Nd3+ phosphors efficiently concentrate the ultraviolet/visible radiation in the near-infrared spectral range and can be potentially used as effective spectral converters.Graphical abstract[graphic not available: see fulltext]

Feng, Yingrui; Hu, Kang; Zhang, Min; Ding, Wei; Kong, Xiangkai; Sheng, Zhigao; Liu, Qiangchun

doi: 10.1007/s10853-021-06650-2pmid: N/A

Rationally designing microwave absorption materials with highly efficient and tunable bandwidth is in great demand but remains a huge challenge. In this study, perovskite oxide LaCoO3 thin sheets have been obtained by the hydrothermal synthesis and subsequent annealing process. Then, cation deficiency is introduced to the A-site of LaCoO3 via a selectively etching strategy by FeCl3 solution. The phase characteristics, morphologies, structures, and microwave absorption performance of LaCoO3 thin sheets with A-site cation deficiency have been systematically investigated. The results indicate that a suitable introduction of the A-site cation deficiency is beneficial to induce more dipole polarization, leading to the enhancement of the microwave absorption performance. When the amount of FeCl3 is 0.3 g, the LaCoO3 thin sheets exhibited superior reflection loss characteristics in the range of test frequency. Exhilaratingly, a minimum reflection loss (RL) value of − 56.9 dB at 15.1 GHz can be achieved with a thin thickness of 2.0 mm. Meanwhile, a broad effective absorption bandwidth reaches 5.9 GHz, covering the range of 12.1–18.0 GHz. It is believed that introducing the A-site cation deficiency of LaCoO3 can be used as an effective means for tuning microwave absorption.

Ma, Ziyue; Su, Qian; Zhu, Jianye; Meng, Xiangjun; Zhao, Ye; Xin, Guoxiang; Li, Yong; Hao, Xihong

doi: 10.1007/s10853-021-06684-6pmid: N/A

Ferroelectrics are considered as the most promising energy-storage materials applied in advance power electronic devices due to excellent charge–discharge properties. However, the unsatisfactory energy-storage density is the paramount issue that limits their practical applications. In this work, the excellent energy-storage properties are achieved in (1-x)Na0.5Bi0.5TiO3-xSr0.7Nd0.2TiO3 ((1-x)NBT-xSNT) ferroelectric ceramics by a synergistic strategy, where SNT improves breakdown strength and enhances relaxation characteristic simultaneously. A high recoverable energy-storage density of 3.85 J cm−3 and an energy-storage efficiency of 85.3% under an applied electric field of 305 kV cm−1 are acquired in 0.5NBT-0.5SNT ceramic. Moreover, excellent temperature stability and frequency stability were also observed. The change rate of energy density is less than 10%, where the temperature and frequency in the range of 20–120 °C and 20–180 Hz, respectively. Meanwhile, an ultrahigh power density of 175 MW cm−3 together with a fast discharge time of 136 ns is realized at 250 kV cm−1. These excellent performances show that (1-x)NBT-xSNT ceramics have the potential to be used in pulsed power systems.