GELATION MECHANISMS
Küçük Resim Yok
Tarih
2012
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
World Scientific Publ Co Pte Ltd
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
In this paper, we survey the gelation mechanisms for various polymeric systems which are classified by the type and the strength of the cross-linkages. These are the irreversible gels that are cross-linked chemically by covalent bonds and the reversible gels that are cross-linked physically by hydrogen or ionic bonds and by the physical entanglement of polymer chains. Some of the natural polymer gels fall into the class of physical gels, among which the red algae that has attracted attention for various applications is discussed in detail. Various composite gels, formed from mixture of physical and chemical gels are also discussed in the last section of the article. Theoretical models describe the gelation as a process of random linking of subunits to larger and larger molecules by formation of an infinite network, where no matter what type of objects are linked, there is always a critical gel point at which the system behaves neither as a liquid nor as a solid on any length scale. The Flory-Stockmayer theory and percolation theory provide bases for modeling this sol-gel phase transition. The experimental techniques for measuring the critical exponents for sol-gel phase transitions in different polymeric systems are introduced and the validation of various theoretical predictions are surveyed.
Açıklama
Anahtar Kelimeler
Gelation, Percolation, Chemical Gels, Physical Gels, Composite Gels, Sol-Gel Transition, Semiinterpenetrating Polymer Networks, Cross-Linking Copolymerization, Molecular-Size Distribution, Thermal Phase-Transitions, Carrageenan-Water System, In-Situ Release, Kappa-Carrageenan, Critical Exponents, Fluorescence Technique
Kaynak
Modern Physics Letters B
WoS Q Değeri
Q4
Scopus Q Değeri
Q3
Cilt
26
Sayı
27
