Intramolecular nucleation model

Hu WB, Mathot VBF, Frenkel D (2003a) Lattice model study of the thermodynamic interplay of polymer crystallization and liquid-liquid demixing. J Chem Phys 118 10343-10348 Hu WB, Frenkel D, Mathot VBF (2003b) Sectorization of a lamellar polymer crystal studied by dynamic Monte Carlo simulations. Macromolecules 36 549-552 Hu WB, Frenkel D, Mathot VBF (2003c) Intramolecular nucleation model for polymer crystallization. Macromolecules 36 8178-8183... 

According to this intramolecular-nucleation model, when the melt of long-chain macromolecules is quenched to low temperatures for fast crystallization, each macromolecule may perform multiple local intramolecular nucleation events and hence will be included in several lamellae or several positions of the same lamellae, with only little changes of their unperturbed coil-size scaling. At each position, intramolecular nucleation yields folded-chain clusters. This picture is quite consistent with Hoffman s proposition of a variable-cluster model for the conformation of macromolecules in the semi-crystalline state [50[. 

From the classical Lauritzen-Hoffman model to the molecular-nucleation concept, and then the intramolecular-nucleation model, polymer crystal nude-... 

Under a low temperature, the critical chain length for secondary nucleation may be much smaller than the chain length, and several events of intramolecular nucleation could happen along the same chains. If they occur in the same lamellar crystal, loops are formed and if in different lamellar crystals, tie molecules are formed. The intramolecular nucleation model allows a statistical treatment on the semicrystalline texture. 

Hu W, Frenkel D, Mathot VB. Intramolecular nucleation model for polymer crystallization. Macromolecules 2003 36 8178-8183. 

Abstract. We review how the nucleation mechanism of polymer crystallization could be assigned to intramolecular processes and what are the preliminary benefits for understanding some fundamental crystallization behaviors. The speculative concept of molecular nucleation and the theoretical model of intramolecular nucleation have been elucidated in a broad context of classical nucleation theory. The focus is on explaining the phenomenon of molecular segregation caused by polymer crystal growth. 

Molecular simulations have reproduced regime-transition phenomena (Hu and Cai 2008). However, the growth front of Regime 1 is rather rough, favoring an alternative interpretation based on the intramolecular secondary nucleation model (Hu and Cai 2008). 

The regime-transition phenomena of polymer crystal growth have been well explained on the basis of the Lauritzen-Hoffman model [14,15]. Nevertheless, the assumptions about the details of secondary crystal nucleation can be replaced by the intramolecular crystal nucleation, without a substantial loss of semi-quantitative predictions about regime transitions. 

Hu W (1998) Structural transformation in the collapse transition of the single flexible homopolymer model. J Chem Phys 109(9) 3686-3690 Hu W (20(X)) The melting point of chain polymers. J Chem Phys 113(9) 3901-3908 Hu W (2005) Molecular segregation in polymer melt crystallization simulation evidence and unified-scheme interpretation. Macromolecules 38(21) 8712-8718 Hu W (2007) Intramolecular crystal nucleation. In Reiter G, Strobl GR (eds) Lecture notes in physics progress in understanding of polymer crystallization. Springer, Berlin, pp 47-63 Hu W (2013) Polymer physics a molecular approach. Springer, Wien... 

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