C. M. Shu

Carbon Nanotube Industrial Applications

Since carbon nanotube was discovered by S. Ijima in 1991, it has become one of the main academic research subjects. Carbon nanotube is the thinnest tube human can make presently. It has advantages in lightweight, high strength, high toughness, flexibility, high surface area, high thermal conductivity, good electric conductivity and chemical stability. Carbon nanotube can be applied to manufacture smaller transistors or electronic devices. Samsung Korea has made carbon nanotube into Field Emission Display. When the technology is matured and the cost is reduced, it will replace traditional bulky cathode ray tube (CRT) screen. Carbon nanotube has high toughness, so it can be made into highstrength composite with other materials. Thus, carbon nanotube is a material with high economic value and very worth researching. Besides, carbon nanotube has both conductor and semiconductor properties. Therefore, for electronic circuit, the semiconductor property of carbon nanotube enables its application to field emission transistor (FET) gate electrode, which has 100 times higher electric conductivity than silicon semiconductor when voltage is applied and 1000 times higher operational frequency than current Complementary MetalOxide Semiconductor (CMOS). The conductor property makes carbon nanotube have similar thermal conductivity to diamond and superior current carrying capacity to copper and gold. For the application of display, its long-term reliability is very excellent [Iijima, 1991, Lee et. al., 1977]. In order to create new material systems with superior properties, various nanoparticle morphologies have been used as reinforcing fillers in elastomeric matrices. These nanometerscale reinforcing particles include spherical particles such as silica or titania [McCarthy et. al., 1997, Kohjiya et. al., 2005], platelets such as layered silicates [Osman et. al., 2001, Joly et. al., 2002, Varghese & Karger-Kocsis, 2003, Kim et. al., 2004, Arroyo et. al., 2003, Bala et. al., 2004, Jeon et. al., 2004], carbon [Gauthier et. al., 2005] or clay fibers [Bokobza & Chauvin, 2005] and multiwall or singlewall carbon nanotubes[Barraza et.

Calorimetric evaluation of polymerization thermokinetics of styrene, α-methylstyrene and trans-β-methylstyrene

According to literature and our research, the styrene polymerization mechanism is identified by alpha-methylstyrene (AMS). This study investigated the basic exothermic behavior of styrene and its major derivatives, AMS, and trans-beta-methylstyrene (TBMS), by two calorimeters, differential scanning calorimetry (DSC) and thermal activity monitor (TAM), to compare and evaluate their thermal kinetics on polymerization. DSC and TAM were employed for dynamic scanning and isothermal ageing tests to calculate thermokinetic parameters of styrene and styrene containing 10ppm 4-tertiary-butylcatechol (TBC), AMS, and TBMS. Certain prominent differences were observed and discussed between AMS and TBMS obtained from DSC and TAM. All of the results could be provided to the relevant plants for lessening the degree of hazard. Results indicated that styrene, AMS, and TBMS have potential exothermic hazards, especially during the higher temperature.

Adsorption of Methylene Blue on Multi-Walled Carbon Nanotubes in Sodium Alginate Gel Beads

Surface water contamination by pollutants is common in highly industrialized countries due to direct discharge of industrial effluents into bodies of water or precipitation of air-borne pollutants into surface water [Murakamia et. al., 2008]. Dyes from the pollutants released along with industrial effluents are easily detected because of their inherently high visibility, meaning that concentrations as low as 0.005 mg/L can easily be detected and capture the at‐ tention of the public and the authorities [Ray et. al., 2003, Ray et. al., 2002]. Apart from the aesthetic problems caused by dyes, the greatest environmental concern with dyes is their ab‐ sorption and reflection of sunlight entering the water, which interferes with the growth of bacteria, such that bacteria levels are insufficient to biologically degrade impurities in the water [Pierce, 1994. Ledakowicz et. al., 2001]. Methylene blue (MB) and methyl violet are two common dyes that have been shown to induce harmful effects on living organisms dur‐ ing short periods of exposure [Hameed et. al., 2009]. Oral ingestion of MB results in a burn‐ ing sensation and may cause nausea, vomiting, diarrhea, and gastritis. The accidental consumption of large dose induces abdominal and chest pain, severe headache, profuse sweating, mental confusion, painful micturation, and methemoglobinemia [Yasemin et. al., 2006]. Inhalation of methyl violet may cause irritation to the respiratory tract, vomiting, di‐ arrhea, pain, headaches, and dizziness; long-term exposure may cause damage to the mu‐ cous membranes and gastrointestinal tract [Allen & Koumanova, 2005]. The majority of dyes