Notes On Material Science Engineering

This unique chemical nature of the diamond is what makes them so desirable. The uniqueness is what makes them so rare. This is what led to the need for manufactured diamonds. The earliest known reports of artificial diamonds came in 1913. This is when M.E. de Boismenu ran a current of 800 amps and 24 volts through molten carbide. These diamonds were microscopic and produced with carbide crystals in a large brick furnace in Paris (Scientific American). For about forty more years diamond making never caught on. However, as technology increased so did the ability to submit materials to higher pressures. Percy Williams Bridgman received the Nobel Prize in physics for his work with materials under high pressures but never created diamonds. Then on February 16, 1953 a Swedish team made diamonds. They did so by subjecting graphite to 8,4100 kPa of pressures with an unspecified amount of heat. Although they were the first to produce diamonds reliably they did not release their results for several years. For this reason, Herb Strong is credited with the first reliable creation of diamonds. He did so 1954 while working for General Electric. To do it, he used iron foil, carbon powder and seed crystals and submitted them to 51,000 kPa and 1600*C for 38 minutes (Depew). More

In 1779, Carl Wilhelm Scheele showed another allotrope of carbon graphite, which were known as a form of lead in early times. He found out that graphite was almost identical to charcoal except a small admixture of iron, and when it oxidized with nitric acid, it gave out “aerial acid” (carbon dioxide). In 1786, the French scientists Claude Louis Berthollet, Gaspard Monge and Vandermonde confirmed that graphite was mostly carbon by oxidizing with oxygen in the same way

Thomson did many experiments and found that the mass of one of these electrons was nearly 2000 times lighter than the element Hydrogen. Thomson then disproved Dalton in stating that atoms cannot be divided into smaller pieces. (Born,

Carbon has six total electrons; two of the electrons it has are in its first electron shell while the other four are its valence electrons. Due to its four valence electrons, it rarely gains and/or loses electrons and/or form ionic bonds due to the fact it would have to give away or take four other electrons. In order to complete its outer shell, carbons shares its valence electrons with other atoms by having four separate covalent bonds. The carbon atom then becomes the crossing point where each molecule branches off into four separate directions.Carbon’s electron configuration allows it to bond frequently with oxygen, hydrogen, nitrogen, and phosphorus. If the carbon atom forms only a single covalent bond, The electrons form so that its bonds angle towards an imaginary tetrahedron.

Rosalind Franklin was able to take an x-ray image of the DNA strand and see how it was shaped. After seeing her work James Watson and Francis Crick took her image and began researching into it. This led them to discover the double helix.

Rosalind Franklin and Maurice Wilkins used x rays to study DNA. Their research let James Watson study the structure of DNA. Watson ended up discovering that the structure of DNA is a double helix in 1953. All their research helped develop the DNA theory.

Graphene synthesis usually utilise a method called exfoliation, which is defined as taking the outermost layer of graphite. There are three major types of exfoliation: chemical, mechanical, and thermal. The paper mainly focuses on chemical and mechanical exfoliation for graphene synthesis, which are the methods with highest number of experiments done.

Over the past millennia, our understanding of the atom has evolved through eager hypothesizing, numerous trials and startling discoveries. From the first atomic theories of the Democritus in Ancient Greece to the gold foil experiment that allowed Ernest Rutherford to discover the atomic nucleus in 1909, humanity has come far on the path to crack the mysteries of the atomic structure and the hidden secrets that lie within. However, it was only in the 1930s that the full basic structure of the atom was finally completed with the discovery of the neutrally charged particle known as the neutron.

To begin, the discovery of ceria was made in 1803 by Jons J. Berzelius in 1803 from the mineral cerite. His apprentice, Carl G. Mosander, took this discovery further suggesting that other rare earth metals might exist within ceria. By infusing nitric acid to cerium nitrate, Mosander, tested his belief. Consequently, some of the cerium nitrates bonded with the acid providing the results that he was looking for. Mosander separated the results using both sodium oxalate and heat, thus, making the first discovery of lanthanum in 1839. Lanthanum was first created in the pure metal form by H. Kremers and R. Stevens in 1923. The element is mined from a variety of ore minerals and deposits in the USA, China, Russia, Australia, and India. (1)

Different structural arrangements in the carbon atoms determine the outcome of the mineral. Diamonds are the hardest mineral; they are formed under a covalent bond which is very strong. Graphite on the other hand is one of the softest; it is held with a softer bond. Despite the difference in structure, both of these minerals are made from the same substance, pure carbon.

The Discovery of the Atom first came from the Greeks which made a theory “The idea that all matter is made up of tiny, indivisible particles, or atoms, is believed to have originated with the Greek philosopher Leucippus of Miletus and his student Democritus of Abdera in the 5th century B.C. (The word atom comes from the Greek word atomos, which means “indivisible.”)” (InfoPlease Atomic theory)

Scientists before Einstein had discovered that a bright beam of light striking a metal caused the metal to release electrons, which could form

“Recently we 've shown how you can make graphene a home in a blender using pencils and a household detergent. The silly putty: we made it ourselves using a homemade recipe of oil and boric acid. Everything is doable at home,” he added.

Graphene is a form of carbon which has recently been receiving a great deal of attention. Some have come to call it “the wonder material” due to its many extraordinary properties. Although isolated in 2004, graphene's properties had been calculated decades earlier. It consists of a single layer of carbon atoms arranged in a hexagonal lattice. A single sheet of graphene is stronger than steel and yet remains very flexible, retaining all of its properties despite being bent and unbent multiple times. It is able to sustain extremely high electric current densities, is impermeable to all gasses, has a thermal conductivity double that of diamond and a very high electron mobility at room temperature. It is also easily chemically functionalized,

Material chemistry is important as it leads to synthesis of advanced materials with new and superior properties and improved compositions. It is one of the integral parts of material science. It mainly deals with four components. (i)Materials, (ii) Synthesis and processing by different possible routes, (iii) Structure and Properties and finally (iv) Characterization and evaluation. Here the oxygen carrier chosen for the experiment is a mixed oxide of both Cu and Mn. Cu and Mn both belong to transition metal category with atomic numbers 29 and 25 respectively. Oxides of Cu and Mn are not at all toxic in nature and are environmental benign. Also they are less costly compared to other metal oxides. Copper oxides always show better reactivity and Manganese oxides have the ability to change to various oxidation states. Cu has atomic mass of both Cu and Mn oxides separately have showed high reactivity being an oxygen carrier, but literature shows that these oxides have limitations when used individually like limited recyclability, agglomeration, sintering etc. This lead to exploring the use of these single metal oxides in a mixed form.