Chain molecules, kinetic effects

Hikosaka presented a chain sliding diffusion theory and formulated the topological nature in nucleation theory [14,15]. We will define chain sliding diffusion as self-diffusion of a polymer chain molecule along its chain axis in some anisotropic potential field as seen within a nucleus, a crystal or the interface between the crystalline and the isotropic phases . The terminology of diffusion derives from the effect of chain sliding diffusion, which could be successfully formulated as a diffusion coefficient in our kinetic theory. 

The display of intramolecular motion in rigid-chain polymers can also be observed if the kinetics of the Kerr effect is studied for a series of fractions of relatively high molecular we t. In fact, as already mentioned (p. 171), the kinetics of the behavior of a polar chain molecule in the electric fidd is determined by relative values of relaxation times of its orientation tq and deformation tj. Since tq increases with M proportionally to M(rjl, and tj is independent of M, it might be expected that at relatively high M the inequality tq > rj will hold and, hence, the polarization and the anisotropy of the solutmn in the electric field will follow the deformational mechanism. 

C. Kinetic Effects in Solutions of Chain Molecules with Catalytic... 

Effects of terminal functionality and the chain length on the rate of the first equilibrium step of adsorption have been studied. Apparently, intermolecular interactions between functionalized alkanethiols play only a minor role in the kinetics of monolayer adsorption. Alkane and w-hydroxy alkane thiols form monolayers at almost the same rate24,65. Short-chain alkanethiols adsorb faster than their long-chain counterparts18 128 129. This probably reflects the fact that the first step of adsorption includes most of the entropy loss of the process, and this factor slows down the assembly of long-chain molecules. 

The photochemical aspects of carbonyl photochemistry remain important subjects of research. Wagner and Thomas have used CIDNP to elucidate radical formation from a,a,a-trifluoroacetophenone. Irradiation of benzophenone and its derivatives in the presence of molecules with abstractable hydrogen atoms can give rise to intensely fluorescent compounds. This effect may interfere with the observation of nanosecond-domain kinetics.Quantum yields and kinetic isotope effects in nanosecond flash studies of the reduction of benzophenone by aliphatic amines have been measured by Inbar et Rate constant data are given in Tables 13 and 14. Winnik and Maharaj have studied the reaction of benzophenone with n-alkanes through hexane to hexatriacontane is 3.9 0.2kcal for all chain lengths.The effects of substituents on the benzophenone on these reactions have also been examined. The reactions of phenylacetophenone when used as polymerization initiator have been reviewed by Merlin and Fouassier. ... 

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