Graphite nanosheet (GNS) was prepared by physical/chemical method. The polyaniline (PANI)/graphite nanocomposites were synthesized by in situ polymerization of aniline monomer using different amounts (1 to 5 wt%) of g...
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Graphite nanosheet (GNS) was prepared by physical/chemical method. The polyaniline (PANI)/graphite nanocomposites were synthesized by in situ polymerization of aniline monomer using different amounts (1 to 5 wt%) of graphite nanosheets. The formation of graphite nanosheets was confirmed by Transmission Electron Microscope (TEM) and X-ray Diffraction (XRD). The surface morphology of exfoliated graphite and PANI/GNS nanocomposites were studied by the Scanning Electronic Microscopy (SEM). A device for electrical conductivity measurements was developed in this work and the results show that the conductivity of PANI/GNS is dependent of the GNS contents.
In this work we studied the Indirect Carbonation of concrete waste and steel slag in order to find the best conditions of each of then aims the CO 2 storage and find a useful destination of the waste. A complete study...
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In this work we studied the Indirect Carbonation of concrete waste and steel slag in order to find the best conditions of each of then aims the CO 2 storage and find a useful destination of the waste. A complete study was developed with steel slag and the best results were adopted to concrete waste owing the expansion of construction industry in Brazil. The lixiviation with HCl acid, time, rate Liquid/Solid, temperature and concentration of acid was deep studied with a goal to use milder conditions avoiding energy penalty in the industrial process. Therefore a Calcium Carbonate was obtained and the feedstock could be re-used in the industries. The experiments were performed in a glass reactor at atmospheric pressure. The solutions and solid phases were characterized by Flame Atomic Absorption Spectroscopy (FAAS), Scanning Electron Microscopy (SEM) and Inductively Coupled Plasma - Optical Emission Spectrometry (ICP-OES).
Polymeric sponge replication technique is the most used process to obtain ceramic foams with a cellular structure for filtration applications. The most used route to produce a closed-cell structure for filter applicat...
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Polymeric sponge replication technique is the most used process to obtain ceramic foams with a cellular structure for filtration applications. The most used route to produce a closed-cell structure for filter applications is the replication of polymer foam by application of ceramic slurry [1-3]. This method consists in the impregnation of polymeric foam with ceramic slurry followed by a heating treatment that will burn out the organic elements and sintering the material, resulting of a replication of the original foam. Morphology, size of the cell and the degree of interconnectedness, permeability and mechanical properties at room and high temperatures are important parameters that influence significantly the application of these materials. In this work X-ray diffraction, scanning electron microscopy and thermal shock have been investigated for a cellular ceramic material with 10, 15 and 20 ppi (pores per linear inch). The results obtained in this work indicated that the mechanical properties show a significant dependence on the cell size and thermal shock temperature.
This work presents the synthesis of polypropylene/graphite nanocomposites by in situ polymerization using the catalytic system C 20 H 16 Cl 2 Zr ( rac -ethylenebis (indenyl)zirconium(IV)) dichloride/Methyoluminoxane (...
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This work presents the synthesis of polypropylene/graphite nanocomposites by in situ polymerization using the catalytic system C 20 H 16 Cl 2 Zr ( rac -ethylenebis (indenyl)zirconium(IV)) dichloride/Methyoluminoxane (MAO). 60 nm graphite nanosheets (GNS) were obtained by means of the chemical exfoliation, thermal and ultrasound treatment. GNS previously treated with MAO were added into the reactor at percentages of 0.3, 1.0 and 2.2% (w/w) in relation to nanocomposite yields. The morphology of graphite nanosheets and nanocomposites was studied by Scanning Electron Microscopy (SEM). Moreover, the structural properties of natural graphite flake (NGF), graphite nanosheets (GNS) and nanocomposites were observed through the X-Ray diffraction (XRD) analysis and by Transmission Electron Microscopy (TEM).
Ceramic porous structures are specially indicated for filters for molten metals, hot gases, thermal protection systems and heat exchangers, due their high permeability, good retention capacity, low density and high th...
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ISBN:
(纸本)9788880800842
Ceramic porous structures are specially indicated for filters for molten metals, hot gases, thermal protection systems and heat exchangers, due their high permeability, good retention capacity, low density and high thermal insulation. This work describes the research carried out on mechanical properties of two different types of a commercial porous ceramic material (10 and 40 ppi). The ceramic material was characterized in terms of microstructural aspects, crystalline phases, density, porosity, strength and thermal shock behaviour. The results have indicated that the strength of the material remain practically constant, regardless of the temperature. The fracture analyses indicated that the fracture is normally caused by the presence of microcracks and also by the presence of a large amount of pores in the ceramic filaments.
Characteristics of both thermoplastic and thermoset composite materials as they pertain to marine vehicle applications are discussed. Comparison of various material selection factors such as strength, damage and moist...
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Characteristics of both thermoplastic and thermoset composite materials as they pertain to marine vehicle applications are discussed. Comparison of various material selection factors such as strength, damage and moisture resistance, and flammability and toxicity as well as cost and availability of thermoset and thermoplastic composite materials are presented. Methods for testing and reducing the flammability and toxicity are discussed. Many commercially available composite systems are reported to provide favorable characteristics for marine applications. Although there seems to be a need for improved production technology for thermoplastics, they present potential advantages in physical properties over thermoset composites.
作者：
LITVIN, DASMITH, DEDavid A. Litvin
a native of Baltimore graduated in 1969 from Drexel Institute of Technology with a Degree in Metallurgical Engineering. While attending Drexel he worked as a co-op student at NSRDL in Annapolis Md. where he developed a special interest in stress-corrosion cracking of titanium alloys. Upon graduation he joined the Naval Ship Engineering Center as a Materials Engineer. He is a member of the Association of Senior Engineers the American Society for Metals the American Institute of Mining Metallurgical and Petroleum Engineers and the Alpha Sigma Mu Metallurgy Honorary Fraternity. David E. Smith was born in Brooklyn
and attended Rensselaer Polytechnic Institute where he graduated in 1959 with a Degree in Metallurgical Engineering. After spending three years as a communications officer for the Air Force he joined the Dow Chemical Company as a Welding Engineer. After two and a half years he then worked for Ling-Tempco-Vought prior to joining the Naval Ship Engineering Center as a Materials Engineer in 1967. One of his most important projects has been the Structural Titanium Alloy Development Program which he has monitored over the lost three years. He is a member of the American Society for Metals the American Welding Society and the Association of Senior Engineers.
Titanium, “the wonder metal of the future” is rapidly becoming the metal of the seventies. The high strength to weight ratio, the excellent corrosion resistance in many aggressive environments, and good elevated tem...
Titanium, “the wonder metal of the future” is rapidly becoming the metal of the seventies. The high strength to weight ratio, the excellent corrosion resistance in many aggressive environments, and good elevated temperature properties have resulted in the widespread use of titanium and its alloys, particularly in the aerospace and chemical industries. Titanium has demonstrated its superiority in sea water environments, yet the marine industry has been slow to utilize titanium's benefits. The intent of this paper is twofold—First to inform the marine industry on many advantages of titanium alloys for sea water use by describing properties and successful applications. Second, to show how susceptibility to stress corrosion cracking of certain titanium alloys, which became evident several years ago, is now understood and controllable. Well documented research has substituted knowledge for doubt and fear. Titanium and several titanium alloys are considered ready for use as engineeringmaterials in the marine industry. Today, they are competitive with nickel base alloys in cost. Naval architects and design engineers may now use titanium in certain applications to provide superior performance over traditional marine materials.
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