Evaluation of dispersion degree of nanoparticles in TiO2/epoxy resin nanocomposites Nam, Ki-Woo; Moon, Chang-Kwon;
The purpose of this study was to evaluate the dispersion degree of particles using a nanoindentation test for titanium oxide nanoparticles/epoxy resin nanocomposites. Thus, the effects of the particle size and weight fraction, dispersion agent, and position of the sample on the modulus and degree of particle dispersion in the nanocomposites were investigated. As a result, the dispersion degree of large particles was found to be better than that of smaller particles in composites. It could be found that the aggregation or agglomeration of small particles with large surface energy occurred more easily in nanocomposites because of the large specific surface area. The moduli of the upper side of the film-shaped sample obtained from a nanoindentation test were low scattering, while the values for the bottom side were high scattering. Thus, the dispersion situation of the nanoparticles on the upper side of film-shaped samples could be considered to be better than that for the bottom side. This could be concluded due to the non-uniform nanoparticle dispersion in the same sample. The modulus obtained from nanoindentation test increased slightly with the content of nanoparticles and increased with the indented depth for the same sample. The latter is presumably due to the increase in the accumulated particles facing the indenter with the indented depth. The nanoindentation test was found to be a useful method to evaluate the dispersion status of nanoparticles in nanocomposites.
Ash, B.J., Stone, J., Rogers, D.F., Schadler, L.S., Siegel. Appl 2001. Investigation into the Thermal and Mechanical Beha- vior of PMMA/Alumina Nanocomposites-Materials Research Society Symposium Proceedings, 661, KK2.10.1 - KK2.10.6.
Ash. B.J., Richard W.S., Linda, S.S., 2004. Mechanical Behavior of Alumina/Poly (methyl methacrylate) Nanocomposites. Macromolecules, 37, 1358-1369.
Becker, C., Krug, H., Schmidt, H., 1996. Tailoring of Thermomech-Anical Properties of Thermoplastic Nanocomposite by Surface Modification of Nanoscale Silica Particles. Materials Research Society Symposium Proceedings, 435, 237-242.
Gersappe, D., 2002. Molecular Mechanisms of Failure in Polymer Nanocomposites. Physics Review. Letters, 89, 058301-1-4.
Ma, D., Akpalu, Y.A., Li, Y., Siegel, R.W., Schadler, L.S., 2005. Effect of Titania Nanoparticles on the Morphology of Low Density Polyethylene. Journal of Polymer Science Part B: Polymer Physics, 43, 488-497.
Ng, C.B., Ash, B.J., Schadler, L.S., Siegel, R.W., 2001. A Study of the Mechanical and Permeability Properties of Nano- and Micron-$TiO_2$ Filled Epoxy Composites. Advanced Composites Letters, 10, 101-111.
Ou, Y., Yang, F., Yu, Z., 1998. A New Conception on the Toughness of Nylon 6/Silica Nanocomposite Prepared Via in Situ Polymerization. Journal of Polymer Science Part B, 36, 789-795.
Park, J.H., Jana, S.C., 2003. The Relationship Between Nano- and Micro-structures and Mechanical Properties in PMMA-epoxy-nanoclay Composites. Polymer, 44, 2091-2100.
Reynaud, E., Jouen, T., Gauthier, C., Vigier, G., Varlet, J., 2001. Nanofillers in Polymeric Matrix: a Study on Silica Reinforced PA6. Journal of Polymer, 42, 8759-8768.
Shah, D., Maiti, P., Jiang, D.D., Batt, C.A., Giannelis, E.P., 2005. Effect of Nanoparticle Mobility on Toughness of Polymer Nanocomposites. Advanced Materials, 17(5), 525-528.
Su, S., Jiang, D.D., Wilkie, C.A., 2004. Methacrylate Modified Clays and Their Polystyrene and Poly(Methyl Methacrylate) Nanocomposites. Polymers for Advanced Technologies, 15(5), 225-231.
Vollenberg, P.H.T., Heikens, D., 1989. Particle Size Dependence of the Young's Modulus of Filled Polymers: 1. Preliminary Experiments. Polymer, 30, 1656-1662.