Preparation of High-Performance Continuous Boron Nitride Fibers from Boracic Acid

2014 ◽  
Vol 602-603 ◽  
pp. 151-154 ◽  
Author(s):  
Chuan Shan Li ◽  
Ru Li ◽  
Xiao Yong Du ◽  
Ming Xia Zhang ◽  
Jie Tang ◽  
...  

Continuous multi-filament boron nitride fibers have been prepared on a large scale using the melt drawn technique from a low-cost boracic acid. Boracic acid was heated to obtain the molten boric oxide in a melting tank. Molten boric oxide was melt spun in a conventional manner through an 200-tip bushing to produce a continuous multifilament yarn consisting of 200 filaments of boric oxide. Boric oxide fibers were nitrided in an ammonia and were annealed in an inert atmosphere while simultaneously subjecting the fibers to sufficient longitudinal tension as to at least prevent longitudinal shrinkage of the fibers. The resulting fibers, consisting essentially of boron nitride, were less than about 8 μm in diameter and greater than 500 m in length. It indicated that the boron nitride fibers has a sound mechanical function with tensile strength of 1.40 GPa. The continuous boron nitride fibers of high-performance were especially suitable for reinforcing plastic, ceramic or metal matrices in the preparation of fiber reinforced composites.

2021 ◽  
Vol 7 (2) ◽  
pp. 58
Author(s):  
Celal Çakıroğlu ◽  
Gebrail Bekdaş

In the recent years natural fiber reinforced composites are increasingly receiving attention from the researchers and engineers due to their mechanical properties comparable to the conventional synthetic fibers and due to their ease of preparation, low cost and density, eco-friendliness and bio-degradability. Natural fibers such as kenaf or flux are being considered as a viable replacement for glass, aramid or carbon. Extensive experimental studies have been carried out to determine the mechanical behavior of different natural fiber types such as the elastic modulus, tensile strength, flexural strength and the Poisson’s ratio. This paper presents a review of the various experimental studies in the field of fiber reinforced composites while summarizing the research outcome about the elastic properties of the major types of natural fiber reinforced composites. Furthermore, the performance of a kenaf reinforced composite plate is demonstrated using finite element analysis and results are compared to a glass fiber reinforced laminated composite plate.


2019 ◽  
Vol 16 (3) ◽  
pp. 117-123
Author(s):  
Tsung-Ching Huang ◽  
Ting Lei ◽  
Leilai Shao ◽  
Sridhar Sivapurapu ◽  
Madhavan Swaminathan ◽  
...  

Abstract High-performance low-cost flexible hybrid electronics (FHE) are desirable for applications such as internet of things and wearable electronics. Carbon nanotube (CNT) thin-film transistor (TFT) is a promising candidate for high-performance FHE because of its high carrier mobility, superior mechanical flexibility, and material compatibility with low-cost printing and solution processes. Flexible sensors and peripheral CNT-TFT circuits, such as decoders, drivers, and sense amplifiers, can be printed and hybrid-integrated with thinned (<50 μm) silicon chips on soft, thin, and flexible substrates for a wide range of applications, from flexible displays to wearable medical devices. Here, we report (1) a process design kit (PDK) to enable FHE design automation for large-scale FHE circuits and (2) solution process-proven intellectual property blocks for TFT circuits design, including Pseudo-Complementary Metal-Oxide-Semiconductor (Pseudo-CMOS) flexible digital logic and analog amplifiers. The FHE-PDK is fully compatible with popular silicon design tools for design and simulation of hybrid-integrated flexible circuits.


Author(s):  
Guixiang Wang ◽  
Haitao Zou ◽  
Xiaobo Zhu ◽  
Mei Ding ◽  
Chuankun Jia

Abstract Zinc-based redox flow batteries (ZRFBs) have been considered as ones of the most promising large-scale energy storage technologies owing to their low cost, high safety, and environmental friendliness. However, their commercial application is still hindered by a few key problems. First, the hydrogen evolution and zinc dendrite formation cause poor cycling life, of which needs to ameliorated or overcome by finding suitable anolytes. Second, the stability and energy density of catholytes are unsatisfactory due to oxidation, corrosion, and low electrolyte concentration. Meanwhile, highly catalytic electrode materials remain to be explored and the ion selectivity and cost efficiency of membrane materials demands further improvement. In this review, we summarize different types of ZRFBs according to their electrolyte environments including ZRFBs using neutral, acidic, and alkaline electrolytes, then highlight the advances of key materials including electrode and membrane materials for ZRFBs, and finally discuss the challenges and perspectives for the future development of high-performance ZRFBs.


Author(s):  
Vijay Kumar Mahakur ◽  
Sumit Bhowmik ◽  
Promod Kumar Patowari

Nowadays, the utilization of natural fiber reinforced composite has increased frequently. These natural fibers have significant features like low cost, renewable, and, more importantly, biodegradable in nature, making them to be utilized for various industrial sectors. However, the massive demand for natural fiber reinforced composites (NFRC), forces them to be machined and operated, which is required for countless areas in multiple industries like automotive, marine, aerospace and constructions. But before obtaining the final shape of any specimen, this specimen should come across numerous machining processes to get the desired shape and structure. Therefore, the present review paper focused on the various aspects during conventional and unconventional machining of the NFRC. It covers the work by exploring the influence of all input variables on the outcome produced after machining the NFRC. Various methodologies and tools are also discussed in this article for reducing the machining defects. The machining of the NFRC is found as a challenging task due to insufficient interlocking between the matrix and fibers, and minimum knowledge in machining characteristics and appropriate input parameters. Thus, this review is trying to assist the readers to grasp a basic understanding and information during the machining of the NFRC in every aspect.


NANO ◽  
2020 ◽  
Vol 15 (05) ◽  
pp. 2050062
Author(s):  
Zhaolei Meng ◽  
Xiaojian He ◽  
Song Han ◽  
Zijian Hu

Carbon materials are generally employed as supercapacitor electrodes due to their low- cost, high-chemical stability and environmental friendliness. However, the design of carbon structures with large surface area and controllable porous structure remains a daunt challenge. In this work, a three-dimensional (3D) hybrid aerogel with different contents of MoS2 nanosheets in 3D graphene aerogel (MoS2-GA) was synthesized through a facial hydrothermal process. The influences of MoS2 content on microstructure and subsequently on electrochemical properties of MoS2-GA are systematically investigated and an optimized mass ratio with MoS2: GA of 1:2 is chosen to achieve high mechanical robustness and outstanding electrochemical performance in the hybrid structure. Due to the large specific surface area, porous structure and continuous charge transfer network, such MoS2-GA electrodes exhibit high specific capacitance, good rate capability and excellent cyclic stability, showing great potential in large-scale and low-cost fabrication of high-performance supercapacitors.


2018 ◽  
Vol 217 ◽  
pp. 291-299 ◽  
Author(s):  
Yingyuan Zhao ◽  
Nian Jiang ◽  
Xu Zhang ◽  
Jing Guo ◽  
Yanqiang Li ◽  
...  

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5558
Author(s):  
Dimitra Vernardou ◽  
Charalampos Drosos ◽  
Andreas Kafizas ◽  
Martyn E. Pemble ◽  
Emmanouel Koudoumas

The need for clean and efficient energy storage has become the center of attention due to the eminent global energy crisis and growing ecological concerns. A key component in this effort is the ultra-high performance battery, which will play a major role in the energy industry. To meet the demands in portable electronic devices, electric vehicles, and large-scale energy storage systems, it is necessary to prepare advanced batteries with high safety, fast charge ratios, and discharge capabilities at a low cost. Cathode materials play a significant role in determining the performance of batteries. Among the possible electrode materials is vanadium pentoxide, which will be discussed in this review, due to its low cost and high theoretical capacity. Additionally, aqueous electrolytes, which are environmentally safe, provide an alternative approach compared to organic media for safe, cost-effective, and scalable energy storage. In this review, we will reveal the industrial potential of competitive methods to grow cathodes with excellent stability and enhanced electrochemical performance in aqueous media and lay the foundation for the large-scale production of electrode materials.


RSC Advances ◽  
2015 ◽  
Vol 5 (112) ◽  
pp. 92648-92655 ◽  
Author(s):  
Sankararao Mutyala ◽  
Jayaraman Mathiyarasu ◽  
Ashok Mulchandani

Here, we report a low-cost, noble metal free Fe–N–C catalyst prepared using carbonized polyaniline (PANI) and ferric chloride as precursors in an inert atmosphere for oxygen reduction reaction.


Nanoscale ◽  
2013 ◽  
Vol 5 (13) ◽  
pp. 6173 ◽  
Author(s):  
Irene Emmanuelawati ◽  
Jie Yang ◽  
Jun Zhang ◽  
Hongwei Zhang ◽  
Liang Zhou ◽  
...  

2016 ◽  
Vol 47 (8) ◽  
pp. 2153-2183 ◽  
Author(s):  
Azam Ali ◽  
Khubab Shaker ◽  
Yasir Nawab ◽  
Madeha Jabbar ◽  
Tanveer Hussain ◽  
...  

There is a growing interest in the development of natural fiber-reinforced composites, most likely due to their wide availability, low cost, environment friendliness, and sustainability. The market size for natural fiber-reinforced composites is projected to reach $5.83 billion by 2019, with a compound annual growth rate of 12.3%. The composite materials reinforced with wood, cotton, jute, flax or other natural fibers fall under this category. Meanwhile, some major factors limiting the large scale production of natural fiber composites include the tendency of natural fiber to absorb water, degradation by microorganisms and sunlight and ultimately low strength and service life. This paper has focused to review the different natural fiber treatments used to reduce the moisture absorption and fiber degradation. The effect of these treatments on the mechanical properties of these composites has also been summarized.


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