Study of porosity of synthetic polymer nanoparticles using PALS
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Date
2010-08-01
Journal Title
Journal ISSN
Volume Title
Publisher
Institute of Physics
Abstract
Positron annihilation lifetime spectroscopy (PALS) has been used to study the free volume in dry synthetic polymer nanoparticles of various sizes. A series of poly(styrene/divinyl benzene) particles with diameters in the range of 100 to 500 nm were synthesized and then carefully chemically treated using the sulfonation process, to increase their porosity. The particles were characterised by Scanning Electron Microscopy (SEM), light scattering and PALS. Light scattering gave larger size for the treated particles, reflecting the hydration effect and therefore the increase in porosity. PALS spectra of untreated and treated particles gave four and three life-time components, respectively. Analysis by PAScual version 1.3.0 program indicated there was a reduction in the intensity and the type of the micropores in the treated particles. The data suggest PALS is a sensitive tool for detecting changes in microporosity in particles. The conflicting results obtained for light scattering compared to PALS for chemically treated particles is difficult to resolve and suggests sample preparation of polymeric materials for PALS is the critical factor.
Description
Keywords
Positrons, Annihilation, Scanning electron microscopy, Light scattering, Benzene, Particle beams
Citation
Pham, B., Guagliardo, P., Williams, J., Samarin, S., & Smith, S. V. (2010). Study of porosity of synthetic polymer nanoparticles using PALS. Paper presetented to the 12th International Workshop on Slow Positron Beam Techniques for Solids, Surfaces, Atoms and Molecules (SLOPOS12), 1st - 6th August 2010. All Seasons Resort: Magnetic Island, North Queensland, Australia. In Journal of Physics: Conference Series, 262(1), 012048. doi:10.1088/1742-6596/262/1/012048