Ionic conductivity of PVdF-co-HFP/LiClO4 in terms of free volume defects probed by positron annihilation lifetime spectroscopy
     
Yazarlar (10)
Ugur Yahsi Marmara Üniversitesi, Türkiye
Hüseyin Deligöz Istanbul Üniversitesi, Türkiye
Cumali Tav Marmara Üniversitesi, Türkiye
Kemal Ulutaş Istanbul Üniversitesi, Türkiye
Deniz Değer Istanbul Üniversitesi, Türkiye
Serpil Yılmaztürk Istanbul Üniversitesi, Türkiye
Gonca Erdemci Marmara Üniversitesi, Türkiye
Bilgehan Coşkun Marmara Üniversitesi, Türkiye
Doç. Dr. Mesut YILMAZOĞLU Yalova Üniversitesi, Türkiye
Şahin Yakut Istanbul Üniversitesi, Türkiye
Makale Türü Özgün Makale (SSCI, AHCI, SCI, SCI-Exp dergilerinde yayınlanan tam makale)
Dergi Adı Radiation Effects and Defects in Solids (Q2)
Dergi ISSN 1042-0150 Wos Dergi Scopus Dergi
Dergi Tarandığı Indeksler SCI-Expanded
Makale Dili İngilizce Basım Tarihi 12-2018
Cilt / Sayı / Sayfa 174 / 3 / 214–228 DOI 10.1080/10420150.2018.1552959
Makale Linki http://dx.doi.org/10.1080/10420150.2018.1552959
Özet
Polymers based on ionic conducting materials have important interest because of their potential applications in polymer electrolytes and membranes for fuel cell application. PVdF-co-HFP poly(viniliden-co-hexafluoropropylene) was chosen as a polymer matrix because of its high ionic conductivity and better mechanical properties. Polymer matrix composites were prepared with various amounts of LiClO 4 salt by a solution casting method. The sample-ionic conductivity measurements were recorded by AC impedance analyzer at different frequencies from 0.1 Hz to 20 MHz and at different temperatures from 273 to 373 K. The changes of nanoscopic free volume and free volume fraction in these materials were investigated in terms of temperature from 273 to 373 K using Positron Annihilation Lifetime Spectroscopy (PALS) and Simha-Somcynsky (SS) Hole Theory. The free volume had a bump at about 3% in weight percentage of the salt and there is a slight increase after 10%. The effects of weight percentages of LiClO 4 and temperature were investigated. The mechanism of the ac ionic conductivity was presented in terms of the free volume models, however thermo-occupancy function justifies the best accurate representation of the data.
Anahtar Kelimeler
Positron annihilation lifetime spectroscopy | free volume | PVdF-co-HFP | LiClO4 | ionic conductivity | Simha-Somcynsky theory