Free-volume analysis of the structural and dielectric properties of PMMA/TeO2 composites via positron annihilation lifetime spectroscopy

Kuzeci S., Ozcan E., KAYA A. U., Bakar R., TAV C., YAHŞİ U., ...Daha Fazla

Journal of Alloys and Compounds, cilt.1004, 2024 (SCI-Expanded) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 1004
  • Basım Tarihi: 2024
  • Doi Numarası: 10.1016/j.jallcom.2024.175938
  • Dergi Adı: Journal of Alloys and Compounds
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, PASCAL, Aerospace Database, Chemical Abstracts Core, Chimica, Communication Abstracts, Compendex, INSPEC, Metadex, Public Affairs Index, Civil Engineering Abstracts
  • Anahtar Kelimeler: Dielectric, Free Volume, PMMA, Positron Annihilation Lifetime Spectroscopy, Simha-Somcynsky Theory, TeO2
  • Marmara Üniversitesi Adresli: Evet

Özet

PMMA (Poly methyl methacrylate) composites have promising potential for applications in optics and dielectric energy storage. To investigate the effects of TeO2 contents in PMMA in this respect, we studied their composites on light absorption in the UV[sbnd]visible range, structural analysis via X-ray diffraction, dielectric characteristics, and free volume behavior. We added up to approximately 7 % of the weight concentration of the TeO2 micropowder to the PMMA matrix for effective dispersion because of the limitations of ultrasonic agitation. The XRD data demonstrate a widening of the peaks with a filler content of up to 4.8 % and agglomeration at 7 %, indicating TeO2 particle contact. An increase in absorbance was observed in the UV[sbnd]visible spectrum of the PMMA/TeO2 composites with increasing TeO2 content up to 4.8 %. The dielectric constants exhibit a positive correlation with higher quantities of TeO2, and the polarization mechanism is interpreted by interface polarization and free volume. The free volume measured by positron annihilation lifetime spectroscopy (PALS) increases to 4.8 % but decreases to 7 %. The effect of the free volume within the matrix on the polarization distribution of TeO2 influenced the dielectric constant and the loss factor, which increased to 4.8 % and then decreased to 7 % due to agglomeration.