Void closure and interdiffusion in latex film formation by photon transmission and fluorescence methods
Küçük Resim Yok
Tarih
1999
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Elsevier Science Bv
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
Steady state fluorescence (SSF) and photon transmission methods were used to study void closure and interdiffusion processes during film formation from hard latex particles. Latex films were prepared separately by annealing pyrene (P-y) labeled and unlabeled poly (methyl methacrylate) (PMMA) particles above the glass transition temperature. Direct fluorescence emission of excited pyrene from labeled latex films was monitored as a function of annealing temperature to detect void closure and interdiffusion. The increase in fluorescence intensity against temperature was used to determine the activation energy for viscous flow (Delta H congruent to 47 kcal/mol). The decrease in I-op above the void closure temperature was used to produce the backbone activation energy (Delta E congruent to 44 kcaI/moi) for the interdiffusing chains. Unlabeled PMMA particles were used to prepare films for UW measurements. Transmitted photon intensity from these films increased as the annealing temperature was increased. Monte Carlo simulations were performed for photon transmission through a rectangular lattice. The number of transmitted and scattered photons were calculated as a function of disappeared particle-particle interfaces. The increase in the transmitted photon intensity (I-tr) is attributed to the increase in 'crossing density' at the junction surface. The backbone activation energy (LTE) was measured and found to be around 33 kcal/mol for a diffusing polymer chain across the junction surface. (C) 1999 Elsevier Science B.V. All rights reserved.
Açıklama
7th Iketani Conference/International Symposium on Advanced Technology of Fine Particles -- OCT 12-16, 1997 -- YOKOHAMA, JAPAN
Anahtar Kelimeler
Fluorescence, Photon Transmission, Interdiffusion, Void Closure, Latex, Polymer-Polymer Interface, Energy-Transfer, Particles, Diffusion, Sans
Kaynak
Colloids And Surfaces A-Physicochemical And Engineering Aspects
WoS Q Değeri
Q3
Scopus Q Değeri
Q1
Cilt
153
Sayı
1-3
