Abstract

1. Synthesis and Characterization of Inorganic Fullerene Tungsten Disulfide Composites Anajely Morales¹and Maritza Martin¹Ashley Maxson²,Claudia Luhrs², ¹Engineering Department, Hartnell College, Salinas, CA 93901 ²Mechanical and Aerospace Engineering Department, Naval Postgraduate School, Monterey CA 93943 Abstract Conclusions The experimental results show that by oxidizing the tungsten nanoparticles using microwave plasma methods, more spherical shapes were obtained in comparison to the furnace. When passing through the microwave plasma the particles maintained their spherical shape. The SEM pictures have mostly graphene sheets visible, but the presence of the angular specimen in the lower right and the sphere in the upper left look to be two different variants of tungsten.  The sphere is what formed WS2, and the trapezoidal shape remained WO3, however, the hypothesis is still trying to be proved. Thermally exfoliated Graphene Commercial Products to be crushed as a source for WO3 The overall project explored the possibility of using spherical Inorganic fullerene type Tungsten Disulfide nanostructures (IF-WS2) as shock absorbers, and the use of Graphene to strengthen it. This work focused on protocols to fabricate Nano metric spherical Tungsten Oxide (WO3 ) and the production of Graphene, to then be transformed into a Graphene/IF-WS2 composite. Microwave plasma methods were used to produce the tungsten oxide, thermal exfoliation of graphitic oxide to generate the Graphene and an in situ sulfidization step to create the composite. X-ray diffraction (XRD) techniques helped identify the crystalline phases in the samples and Scanning Electron Microscopy (SEM) the morphological features of the products. Surface area analysis of samples were conducted in a physisorption analyzer (BET) to verify size and degree of sphericity. The experiments demonstrated that WS2 created the spherical shapes and the WO3 created the trapezoidal shapes. This still remains a hypothesis and it is in process. Apply heat Tungsten Disulfide Crushed WO₃ WO₃ Results IF-WS₂ nanoparticle [1]. Materials and methods Graphene + Tungsten Disulfide Literature cited [1]Tenne R. et al. Nature 1, 103-110. 2006 Chen, J. et al. Synthesis and characterization of WS2 nanotubes. Chem. Mater. 15, 1012-1019 (2003). Spherical tungsten oxide generation Glow discharge region Atmospheric Microwave Plasma System Transmission electron microscopy image of tungsten disulfide inorganic fullerenes. It is possible to see the hollow interior of the particle as well as the layers that comprise the onion like structure. Scanning Electron Microscopy Gases present: Argon plasma Argon carrier and air Graphene Graphite + acids Acknowledgments Mentor, Dr. Claudia Luhrs, Ashley Maxson, Michael Moberg, and interns Edwin Gonzalez and Margaret Kane. Alison Kerr, Joe Welch, and Andy Newton. This internship was funded by a National Science Foundation Advanced Technology Education Grant. Precursor (NH4)2WS4 (tungsten salt) Product collected in filter: WO₃ A fullerene consisting of bonded carbon atoms in sheet form one atom thick WO3 to WS2 transformation and Graphene production WO₃ placed in ceramic boat inside quartz tube WO₃ +GO 800˚ᶜ, N₂ (20 min) For further information Please contact ccluhrs@nps.edu. Anajely Morales anajelymorales@gmail.com Maritza Martin, martin.maritza@yahoo.com Graphene + WO₃ (5%) Graphitic oxide 900˚ᶜ, H₂S, N₂ (1 hr) X-Ray Diffraction Tubular furnace with atmosphere control: Nitrogen used for Graphene exfoliation and Nitrogen/H2S for sulfidization WS₂ + Graphene (IF)