Polymer00039 - oxidation and thermal expansion of graphite....

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28 silica equals to 7m 2 /g and minimum coating area of the used amino-silane is 353 m 2 /g (Advanced Polymer, INC., 2009). Silica was first dispersed in distilled water and then silane was slowly added to the suspension until the required silane concentration and amount were reached. The suspension was stirred for 24 h at room temperature and the treated silica was separated by centrifuge and dried at 100 o C for 3 h. This treated silica (T-SiO 2 ) was used as one of the nanofillers for the preparation of fluoroelastomer nanocomposites. Natural graphite flake can be turned into functionalized graphene single sheets through oxidation in a mixture of concentrated sulfuric acid and concentrated nitric acid and then followed by rapid thermal exfoliation (Schniepp, et al. 2006). McAllister et al. (2007) reported similar method to produce single sheet functionalized graphene by
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Unformatted text preview: oxidation and thermal expansion of graphite. We followed this oxidation and expansion method and the following steps were used to process graphite flake to produce treated graphite (T-G) (McAllister, et al. 2007) 1. prepare sulfuric acid (98.0%) and nitric acid (63.0%) mixture (4:1 v/v), 2. add graphite flake into the mixture and stirred the suspension continuously for 16 hours at room temperature, 4. wash the sample with distilled water until neutralization was reached, 5. dry the sample at 100 o C in a convection oven, 6. heat the dried sample at 1050 o C for 45s for fast expansion. The obtained TG was used to prepare fluoroelastomer nanocomposites. 2.3.3 Study of Vulcanization by Torque Rheometry and DSC...
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This note was uploaded on 08/18/2011 for the course MATSE 447 taught by Professor Colby,r during the Spring '08 term at Penn State.

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