Investigating Polymer Nanocomposites Using Positron Annihilation Lifetime Spectroscopy

Presentation Type

Poster/Portfolio

Presenter Major(s)

Physics, Mathematics

Mentor Information

Richard Vallery, valleryr@gvsu.edu

Department

Physics

Location

Kirkhof Center KC 68

Start Date

13-4-2011 12:00 PM

End Date

13-4-2011 1:00 PM

Keywords

Physical Science

Abstract

By determining the characteristics of the porosity of a polymer, one can gain a greater understanding of its properties as a whole. We can alter the free volume and mobility of strands in a polymer without altering its chemistry through the incorporation of inorganic nanoparticles, forming a polymer nanocomposite (PNC). Positron Annihilation Lifetime Spectroscopy (PALS) provides an effective means of determining the characteristics of the porosity of a sample PNC. Positrons from a radioactive source (Na-22) are directed into a PNC, where they form positronium (Ps). There the Ps tends to localize in voids, where the size of the pore directly affects its lifetime. By measuring the mean Ps lifetime in a PNC, we gain insight into the sample's porosity, and as a result, the sample's properties as a whole. We have formed pristine samples of a DGEBA/DDS based polymer and have examined them using our constructed PALS system. These results and the basis of further studies will be discussed.

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Apr 13th, 12:00 PM Apr 13th, 1:00 PM

Investigating Polymer Nanocomposites Using Positron Annihilation Lifetime Spectroscopy

Kirkhof Center KC 68

By determining the characteristics of the porosity of a polymer, one can gain a greater understanding of its properties as a whole. We can alter the free volume and mobility of strands in a polymer without altering its chemistry through the incorporation of inorganic nanoparticles, forming a polymer nanocomposite (PNC). Positron Annihilation Lifetime Spectroscopy (PALS) provides an effective means of determining the characteristics of the porosity of a sample PNC. Positrons from a radioactive source (Na-22) are directed into a PNC, where they form positronium (Ps). There the Ps tends to localize in voids, where the size of the pore directly affects its lifetime. By measuring the mean Ps lifetime in a PNC, we gain insight into the sample's porosity, and as a result, the sample's properties as a whole. We have formed pristine samples of a DGEBA/DDS based polymer and have examined them using our constructed PALS system. These results and the basis of further studies will be discussed.