Poly (styrene) latex/modified na-activated bentonite nanocomposite films: a fluorescence study
Yükleniyor...
Dosyalar
Tarih
2008-12
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Elsevier Science BV
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
We studied film formation of composites of surfactant-free polystyrene (PS) nanoparticles and modified Na-activated bentonite (MLB), by steady state fluorescence (SSF) technique. The films were prepared from a mixture of pyrene (P)-labeled PS particles and MLB at various compositions at room temperature. These films were annealed at elevated temperatures above the glass transition (T(g)) temperature of polystyrene for 10 min. Scattered light (I(S)) and fluorescence intensities (I(P)) from P were measured after each annealing step to monitor the stages of film formation. Evolution of transparency of the composite films was monitored by using photon transmission intensity, I(tr) Atomic force microscopy (AFM) was used to detect the variation in physical structure of annealed composite films. The nanocomposite films exhibited a percolation threshold at 20 wt.% MLB content. Below this fraction two distinct film formation stages were observed which are known as void closure and interdiffusion and above this fraction no film formation was detected. At 0-20 wt.% MLB, minimum film formation, T(0), void closure, T(v) and healing, T(h) temperatures were determined. Void closure and interdiffusion stages were modeled and related activation energies were determined. Void closure activation energies decreased as the percent of MLB increased, no variation was observed in backbone activation energies.
Açıklama
Anahtar Kelimeler
Composite, Void closure, Interdiffusion, Fluorescence, Polystyrene latex, Bentonite, Layered silicate nanocomposites, Dtabr surfactants, Montmorillonite, Latex, Clay, Particles, Polymerization, Interdiffusion, Intercalation, Activation energy, Annealing, Carbon fiber reinforced plastics, Chemical activation, Composite materials, Electromagnetic waves, Glass transition, Latexes, Light emission, Luminescence, Nanocomposites, Nanostructured materials, Percolation (fluids), Polystyrenes, Sodium, Styrene, Surface active agents, Atomic force microscopy, Biofilm, Experimental mineralogy, Simulated annealing, Activated bentonites, Atomic forces, Elevated temperatures, Film formations, Fluorescence intensities, Fluorescence studies, Nanocomposite films, Percolation thresholds, Photon transmissions, Physical structures, Room temperatures, Scattered light, Steady state fluorescence techniques, Void closures
Kaynak
WoS Q Değeri
Q1
Scopus Q Değeri
Q1
Cilt
42
Sayı
1-2
Künye
Uğur, Ş., Yargı, Ö., Günister, E. & Pekcan, M. Ö. (2008). Poly (styrene) latex/modified na-activated bentonite nanocomposite films: A fluorescence study. Applied Clay Science, 42(1-2), 39-49. doi:10.1016/j.clay.2008.02.009
