Department of Physics, Yildiz Technical University, Istanbul, Turkey.
J Fluoresc. 2013 May;23(3):357-66. doi: 10.1007/s10895-013-1157-2. Epub 2013 Jan 19.
This study examines the oxygen diffusion into polystyrene (PS) latex/multiwalled carbon nanotube (MWNT) nanocomposite films (PS/MWNT) consisting of various amounts of MWNT via steady state fluorescence technique (SSF). PS/MWNT films were prepared from the mixture of MWNT and pyrene (P)-labeled PS latexes at various compositions at room temperature. These films were then annealed at 170 °C above glass transition (Tg) temperature of PS. Fluorescence quenching measurements were performed for each film separately to evaluate the effect of MWNT content on oxygen diffusion. The Stern-Volmer equation for fluorescence quenching is combined with Fick's law for diffusion to derive the mathematical expressions. Diffusion coefficients (D) were produced and found to be increased from 1.1 × 10(-12) to 41 × 10(-12) cm(2)s(-1) with increasing MWNT content. This increase was explained via the existence of large amounts of pores in composite films which facilitate oxygen penetration into the structure.
本研究通过稳态荧光技术（SSF）研究了不同含量多壁碳纳米管（MWNT）在聚苯乙烯（PS）胶乳/MWNT 纳米复合材料薄膜（PS/MWNT）中的氧扩散。PS/MWNT 薄膜是由 MWNT 和芘（P）标记的 PS 乳胶在室温下以不同组成混合制备的。然后将这些薄膜在高于 PS 的玻璃化转变（Tg）温度 170°C 下退火。对每个薄膜分别进行荧光猝灭测量，以评估 MWNT 含量对氧扩散的影响。将荧光猝灭的 Stern-Volmer 方程与扩散的 Fick 定律结合起来，推导出数学表达式。得出扩散系数（D），并发现随着 MWNT 含量的增加，扩散系数从 1.1×10^(-12)cm^2s^(-1)增加到 41×10^(-12)cm^2s^(-1)。这种增加可以通过复合材料薄膜中存在大量的孔来解释，这些孔有利于氧气渗透到结构中。
