Ceramics

MRS Bulletin ◽  
1987 ◽  
Vol 12 (7) ◽  
pp. 25-28
Author(s):  
Robert J. Eagan
Keyword(s):  
High Performance ◽  
Space Shuttle ◽  
Raw Materials ◽  
Low Cost ◽  
Flat Glass ◽  
Grain Morphology ◽  
Heat Engines ◽  
Structural Applications ◽  
Simple Processing ◽  
Traditional Ceramics

Until the 1980s, most people thought of ceramics as artware and artifacts. The recent development of advanced ceramics for high performance thermal insulation (space shuttle tiles), high temperature structures (heat engines), and electronics (superconductors) has dramatically changed perceptions about the utility of ceramics.High technology ceramics are related to “traditional” ceramics only to the extent that they are inorganic, nonmetallic materials. Traditional ceramics are derived from minerals. For example, dinnerware and bricks consist mostly of clay, while sand is the major ingredient in flat glass and containers. Abundant raw materials, simple processing, adequate performance at low cost, and technological evolution have kept these industries viable for several thousand years.But, for demanding electronic or structural applications, synthesizing ceramics from minerals is often unacceptable. The chemical variability of mineral deposits, the difficulty of obtaining a homogeneous mixture of powders, and the problems of consolidating the powders into a uniform ceramic with desirable grain morphology, chemistry and grain boundary phases have stimulated the development of chemically derived ceramic precursors.

scholarly journals Molecular design revitalizes the low-cost PTV-polymer for highly efficient organic solar cells

2021 ◽  
Author(s):  
Junzhen Ren ◽  
Pengqing Bi ◽  
Jianqi Zhang ◽  
Jiao Liu ◽  
Jingwen Wang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Organic Solar Cells ◽  
High Performance ◽  
Molecular Design ◽  
Raw Materials ◽  
Low Cost ◽  
Stable Conformation ◽  
Chemical Structures ◽  
Aggregation Effect ◽  
Industrialization Process

Abstract Developing photovoltaic materials with simple chemical structures and easy synthesis still remains a major challenge in the industrialization process of organic solar cells (OSCs). Herein, an ester substituted poly(thiophene vinylene) derivative, PTVT-T, was designed and synthesized in very few steps by adopting commercially available raw materials. The ester groups on the thiophene units enable PTVT-T to have a planar and stable conformation. Moreover, PTVT-T presents a wide absorption band and strong aggregation effect in solution, which are the key characteristics needed to realize high performance in non-fullerene-acceptor (NFA)-based OSCs. We then prepared OSCs by blending PTVT-T with three representative fullerene- and NF-based acceptors, PC71BM, IT-4F and BTP-eC9. It was found that PTVT-T can work well with all the acceptors, showing great potential to match new emerging NFAs. Particularly, a remarkable power conversion efficiency of 16.20% is achieved in a PTVT-T:BTP-eC9-based device, which is the highest value among the counterparts based on PTV derivatives. This work demonstrates that PTVT-T shows great potential for the future commercialization of OSCs.

Lignin-based polymers

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Fan Qi ◽  
Zhang Chaoqun ◽  
Yang Weijun ◽  
Wang Qingwen ◽  
Ou Rongxian
Keyword(s):  
High Performance ◽  
Raw Materials ◽  
Structural Characteristics ◽  
Low Cost ◽  
Polymer Matrices ◽  
Terrestrial Plants ◽  
Polyester Resins ◽  
Sustainable Resources ◽  
Reinforced Polymer ◽  
New Ideas

Abstract On the basis of the world’s continuing consumption of raw materials, there was an urgent need to seek sustainable resources. Lignin, the second naturally abundant biomass, accounts for 15–35% of the cell walls of terrestrial plants and is considered waste for low-cost applications such as thermal and electricity generation. The impressive characteristics of lignin, such as its high abundance, low density, biodegradability, antioxidation, antibacterial capability, and its CO2 neutrality and enhancement, render it an ideal candidate for developing new polymer/composite materials. In past decades, considerable works have been conducted to effectively utilize waste lignin as a component in polymer matrices for the production of high-performance lignin-based polymers. This chapter is intended to provide an overview of the recent advances and challenges involving lignin-based polymers utilizing lignin macromonomer and its derived monolignols. These lignin-based polymers include phenol resins, polyurethane resins, polyester resins, epoxy resins, etc. The structural characteristics and functions of lignin-based polymers are discussed in each section. In addition, we also try to divide various lignin reinforced polymer composites into different polymer matrices, which can be separated into thermoplastics, rubber, and thermosets composites. This chapter is expected to increase the interest of researchers worldwide in lignin-based polymers and develop new ideas in this field.

Preparation and characterization of low-cost high-performance mullite-quartz ceramic proppants for coal bed methane wells

2018 ◽  
Vol 25 (5) ◽  
pp. 957-961 ◽  
Author(s):  
Kaiyue Wang ◽  
Huijun Wang ◽  
Yi Zhou ◽  
Guomin Li ◽  
Yaqiao Wu ◽  
...  
Keyword(s):  
High Performance ◽  
Sintering Temperature ◽  
Raw Materials ◽  
Low Cost ◽  
Quartz Ceramic ◽  
Coal Bed ◽  
Coal Bed Methane ◽  
Sintering Process ◽  
Flow Mechanism

AbstractIn this study, the mullite-quartz-based proppants were successfully prepared by using the coal gangue as the raw materials. Then, the effects of the additive and the sintering temperature on the composition, microstructure, and properties of the proppants were investigated. Results showed that the proppants sintered at 1250°C with the 10 wt% bauxite additive presented the best performance, which was very close to that of the quartz-proppant, and met the operational requirements of the 52 MPa coal bed methane wells. The viscous flow mechanism of the liquid phase formed during the sintering process also promoted the arrangement of the grains, thus benefiting the densification and the strength of the proppants.

scholarly journals Properties of Foamed Lightweight High-Performance Phosphogypsum-Based Ternary System Binder

2020 ◽  
Vol 10 (18) ◽  
pp. 6222 ◽  
Author(s):  
Girts Bumanis ◽  
Jelizaveta Zorica ◽  
Diana Bajare
Keyword(s):  
Ternary System ◽  
High Performance ◽  
Raw Materials ◽  
Low Cost ◽  
Construction Materials ◽  
Mineralogical Composition ◽  
Point Of View ◽  
Raw Material ◽  
Total Energy Consumption ◽  
And Performance

The potential of phosphogypsum (PG) as secondary raw material in construction industry is high if compared to other raw materials from the point of view of availability, total energy consumption, and CO2 emissions created during material processing. This work investigates a green hydraulic ternary system binder based on waste phosphogypsum (PG) for the development of sustainable high-performance construction materials. Moreover, a simple, reproducible, and low-cost manufacture is followed by reaching PG utilization up to 50 wt.% of the binder. Commercial gypsum plaster was used for comparison. High-performance binder was obtained and on a basis of it foamed lightweight material was developed. Low water-binder ratio mixture compositions were prepared. Binder paste, mortar, and foamed binder were used for sample preparation. Chemical, mineralogical composition and performance of the binder were evaluated. Results indicate that the used waste may be successfully employed to produce high-performance binder pastes and even mortars with a compression strength up to 90 MPa. With the use of foaming agent, lightweight (370–700 kg/m3) foam concrete was produced with a thermal conductivity from 0.086 to 0.153 W/mK. Water tightness (softening coefficient) of such foamed material was 0.5–0.64. Proposed approach represents a viable solution to reduce the environmental footprint associated with waste disposal.

A cobalt–nitrogen complex on N-doped three-dimensional graphene framework as a highly efficient electrocatalyst for oxygen reduction reaction

Nanoscale ◽  
2014 ◽  
Vol 6 (24) ◽  
pp. 15066-15072 ◽  
Author(s):  
Yuanyuan Jiang ◽  
Yizhong Lu ◽  
Xiaodan Wang ◽  
Yu Bao ◽  
Wei Chen ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Precious Metal ◽  
High Performance ◽  
Raw Materials ◽  
Low Cost ◽  
Three Dimensional ◽  
Reduction Reaction ◽  
Highly Efficient ◽  
Doped Graphene

Effective preparation of a high-performance non-precious metal oxygen reduction electrocatalyst (a Co–N complex on 3D N-doped graphene) by a facile method from low-cost raw materials.

High Performance Humidity Sensor Based on ZnO Nanoparticles Synthesized by Co-Precipitation Method

2016 ◽  
Vol 848 ◽  
pp. 99-102 ◽  
Author(s):  
Theerapong Santhaveesuk ◽  
Kwunta Siwawongkasem ◽  
Siriwimon Pommek ◽  
Supab Choopun
Keyword(s):  
Sodium Hydroxide ◽  
Zno Nanoparticles ◽  
High Performance ◽  
Humidity Sensor ◽  
Raw Materials ◽  
Low Cost ◽  
Zinc Nitrate ◽  
Precipitation Method ◽  
Zno Particles ◽  
Co Precipitation

ZnO nanoparticles were successfully synthesized by a low cost co-precipitation method using zinc nitrate and sodium hydroxide as the raw materials. It was observed that the synthesized temperatures greatly effect on the size of ZnO nanoparticles. The lower synthesized temperatures resulted in the smaller nanoparticles. By adjusting the mole ratio of sodium hydroxide, the size of ZnO nanoparticles was also changed. The smallest ZnO particles was 47 nm obtained with 0.7 mole of sodium hydroxide. The smallest ZnO nanoparticles from each synthesized temperatures were fabricated as humidity sensor, showing an impressive performance under different relative humidity (17-94% RH). It should be noticed that the ZnO nanoparticles humidity sensor synthesized at 75 °C exhibited high response for 2 times higher than that of synthesized at 95 °C. This is attributed to the higher surface area of ZnO nanoparticles for absorbed water molecule.

scholarly journals Compression Behaviour of Polypropylene Fibre Reinforced Cellular Light Weight Concrete Masonry Prism

2020 ◽  
Vol 30 (1) ◽  
pp. 145-160
Author(s):  
Ramalingam Vijayalakshmi ◽  
Srinivasan Ramanagopal
Keyword(s):  
Sustainable Development ◽  
Rural Areas ◽  
High Performance ◽  
Building Materials ◽  
Lightweight Concrete ◽  
Low Cost ◽  
Polypropylene Fibre ◽  
Clay Bricks ◽  
Structural Applications ◽  
Urban And Rural Areas

AbstractSustainable development of the built environment in developing countries is a major challenge in the 21st century. The use of local materials in the construction of buildings is one of the potential ways to support sustainable development in both urban and rural areas where burnt clay bricks are used predominantly. This work focuses mainly on the use of polypropylene micro fibers in ordinary Cellular Lightweight Concrete blocks. The main objective is to develop a high-performance fibre reinforced cellular concrete to provide a better alternative than clay bricks for structural applications of masonry. This paper presents the stress-strain behaviour of polypropylene fibre reinforced Cellular Lightweight Concrete stack bonded prisms under axial compression. Masonry compressive strength is typically obtained by testing stack bonded prisms under compression normal to its bed joint. Use of micro-fibres enhances the pre-cracking behaviour of masonry by arresting cracks at micro-scale in the post-peak region. These efforts are necessary to ensure that CLC blocks become more accepted in the world of building materials and considered as a reliable option for providing low-cost housing.

Salt-free Chromium Tanning: Practical Approaches

2022 ◽  
Vol 117 (1) ◽  
Author(s):  
M. Sathish ◽  
R. Aravindhan ◽  
J. Raghava Rao
Keyword(s):  
High Performance ◽  
Current Practice ◽  
Raw Materials ◽  
Low Cost ◽  
Physical Strength ◽  
Environmentally Sustainable ◽  
Environmental Threats ◽  
Matrix Stabilization ◽  
Efficient Alternative ◽  
Alternative Approaches

Chromium tanning finds a prominant place in leather manufacturing for permanent stabilization of hide/skin matrix. Though, it has multiple advantages in terms of high thermal stability, easy process and low cost etc., the current practice is not environmentally sustainable. Poor chromium exhaustion and TDS load generation are the major environmental threats of conventional chromium tanning systems. On the other hand, salt-free chromium tanning is identified as one of the efficient alternative approaches for hide/skin matrix stabilization. However, it has not been commercially practiced due to the several practical difficulties. In this work attempts have been made to develop a practically viable high-performance salt-free chromium tanning system using deliming liquor as tanning float and changing the order of addition of masking salt. The developed methodologies completely avoid the use of salt/basification process and it is suitable for all kinds of raw materials and tannery houses. Besides, the process enjoys 71-77% reduction in TDS load and the uptake of chromium is around 90%. The physical strength characteristics are on par with conventional process and the leathers exhibit good grain tightness and roundness. The developed methodologies are simple and do not require any specialty chemicals.     

Production of DMR 249A Steel at SAIL, Bokaro Steel Plant

2012 ◽  
Vol 710 ◽  
pp. 149-154 ◽  
Author(s):  
Subrata Mallik ◽  
Biswasi Sunita Minz ◽  
Basudev Mishra
Keyword(s):  
Hydrogen Content ◽  
High Performance ◽  
Raw Materials ◽  
Vacuum Treatment ◽  
Steel Plant ◽  
Low Alloy Steels ◽  
Low Carbon ◽  
Hot Strip Rolling ◽  
Strip Rolling ◽  
Structural Applications

Low alloy steels are an attractive option for high performance structural applications due to cost and availability factors. A low carbon low alloyed steel, DMR 249A, was developed for strategic applications by Indian Navy at Steel Melting Shop II, Bokaro Steel Plant (SMS II, BSL). This paper enumerates the detail process variables modified for this development. DMR 249A grade was having the specified gas contents of hydrogen <2 ppm in final product for the avoidance of detrimental phenomenon like “Hair Line Cracks”. So the Hydrogen content of liquid steel was to be less than 3 ppm and this demand vacuum treatment of the steel. In absence of any Degassing unit at SMS II, BSL, making of DMR 249A steel was a challenging task. The hydrogen content of steel was controlled through restriction of hydrogen in input raw materials, control in degree of deoxidation during tapping, slag basicity at ladle furnace, argon rinsing regime and cooling of slabs i.e. control over diffusion of H2. The steel was produced with the existing infrastructure at Bokaro Steel Plant with various alloying elements and processed suitably to obtain the desired yield strength, toughness and gaseous content. The control was exercised at various stages of steel making and hot strip rolling to enable achievement of a higher degree of consistency in mechanical properties and microstructure. Quality fulfillment was a great challenge without vacuum degasser unit but Bokaro successfully made the steel with 100% customer satisfaction.

Modeling the Flow of Molten Silicon in Porous Carbon Preforms and the Subsequent Formation of Silicon Carbide

1994 ◽  
Vol 365 ◽  
Author(s):  
G. Rajesh ◽  
Ram B. Bhagat ◽  
Emily Nelson
Keyword(s):  
Silicon Carbide ◽  
High Performance ◽  
Space Shuttle ◽  
Low Cost ◽  
Fuel Efficiency ◽  
Ceramic Matrix Composites ◽  
Aircraft Engine ◽  
Molten Silicon ◽  
Subsequent Formation ◽  
Silicon Based

Ceramic matrix composites (CMCs) are being considered for a broad range of aerospace applications that include various structural components for the aircraft engine and the space shuttle main engine. Use of silicon-based CMCs which have high thermal conductivity, allows for improvements in fuel efficiency due to increased engine temperatures and pressures, which in turn generate more power and thrust. Furthermore, CMCs offer significant potential for raising the thrust-to-weight of gas turbine engines by tailoring directions of high specific reliability using design-based fiber architecture. One of the low-cost processing techniques for the silicon-based CMCs is the reactive melt infiltration [1] of silicon into the preform of carbon-coated silicon carbide fiber. However, fabrication of high performance SiC/SiC composites requires a deeper understanding of the infiltration kinetics such that fibers are protected from adverse reaction with the molten metal, that the preform is thoroughly infiltrated, and that there is no residual silicon left unreacted.

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