Flexible chain molecules

Rosenbluth algorithm can also be used as the basis for a more efficient way to perform ite Carlo sampling for fully flexible chain molecules [Siepmann and Frenkel 1992], ch, as we have seen, is difficult to do as bond rotations often give rise to high energy rlaps with the rest of the system. 

We consider a fluid of flexible chain molecules made of tangent hard sphere monomers. Each chain consists of m monomers of diameter ctq] the distance between centers of adjacent monomers in a chain is fixed and equals ctq. However, the angle formed by any three consecutive monomers in a chain is not fixed. The only restriction is that monomers belonging to a given chain do not overlap each other. Let us describe first a computer simulation procedure. 

Hence, the main aim of the technological process in obtaining fibres from flexible-chain polymers is to extend flexible-chain molecules and to fix their oriented state by subsequent crystallization. The filaments obtained by this method exhibit a fibrillar structure and high tenacity, because the structure of the filament is similar to that of fibres prepared from rigid-chain polymers (for a detailed thermodynamic treatment of orientation processes in polymer solutions and the thermokinetic analysis of jet-fibre transition in longitudinal solution flow see monograph3. ... 

Isihara, A. Intramolecular Statistics of a Flexible Chain Molecule. Vol. 7, pp. 449-476. 

Let us examine briefly some of the more important consequences of this treatment of the frictional coefficient of flexible chain molecules. It is evident from Eq. (29) and the previous discussion of the manner... 

Diffusion and sedimentation measurements on dilute solutions of flexible chain molecules could be used to determine the molecular extension or the expansion factor a. However, the same information may be obtained with greater precision and with far less labor from viscosity measurements alone. For anisometric particles such as are common among proteins, on the other hand, sedimentation velocity measurements used in conjunction with the intrinsic viscosity may yield important information on the effective particle size and shape. ... 

Rostov, K.S. Freed, K.F., Mode coupling theory for calculating the memory functions of flexible chain molecules influence on the long time dynamics of oligoglycines, J. Chem. Phys. 1997,106, 771-783... 

Finally, there is a large body of experimental and theoretical contributions from investigators who are mainly interested in the dynamic and conformational properties of chain molecules. The basic idea is that the cyclisation probability of a chain is related to the mean separation of the chain ends (Morawetz, 1975). Up to date comprehensive review articles are available on the subject (Semiyen, 1976 Winnik, 1977, 1981a Imanishi, 1979). Rates and equilibria of the chemical reactions occurring between functional groups attached to the ends or to the interior of a flexible chain molecule are believed to provide a convenient testing ground for theories of chain conformations and chain dynamics in solution. 

The conformations of flexible chain molecules incorporated in a nematic environment are investigated. Proton-proton and carbon-carbon dipolar coupling constant measurements are attempted for 1,2-dimethoxyethane and 1,2-diphenoxyethane, in addition to 2H NMR observations of quadrupolar splittings. These conformation-dependent properties are analyzed according to the RIS scheme. Studies are further extended to a mixture of 1,2-diphenoxyethane with a nematic liquid crystal, 4,4 -azoxyanisole. 

Flory, P. J. Statistical thermodynamics of semi-flexible chain molecules. Proc. Roy. Soc. (London) A234,60-73 (1956). 

Simha,R., Zakin.J.L. Compression of flexible chain molecules in solution. J. Chem. Phys. 33,1791-1793 (I960). 

Isihara,A. Intramolecular Statistics of a Flexible Chain Molecule. Vol. 7, pp. 449—476. Isihara,A. Irreversible Processes in Solutions of Chain Polymers. Vol. 5, pp. 531—567. Isihara,A. andGuTH,E. Theory of Dilute Macromolecular Solutions. Vol. 5, pp. 233—260. Janeschitz-Kriegl.H. Flow Birefringence of Elastico-Viscous Polymer Systems. Vol. 6, pp. 170—318. 

In this case a large value of V2/Vi would make mixing impossible if x had an appreciable positive value. Thus, endothermic mixing of high molecular weight polymers with solvents is possible only because of the conformational entropy gained by flexible chain molecules in the process of dilution. 

Hyaluronic acid Unsubstituted S. D. Buffer 3 8(10)° co. 20,000 Flexible chain molecule 130... 

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