Monomer separation energies

Figure 4.2 Monomer separation energies, Dj yv (see Eq. (42)), from singly cationic Kyv clusters in the range 5 < N <21. Solid dots theoretical results derived from the SE-SCM method. Open squares experimental measurements from Ref. [75]. Top panel the spherical model compared to experimental data. Middle panel the spheroidal (axially symmetric) model compared to experimental data. Lower panel the ellipsoidal (triaxial) model compared to experimental data...

Figure 4.16 Monomer separation energies of Kyv" clusters at two temperatures, 7 = 10 K and 300 K. Solid dots theoretical FT-SE-SCM results. Open squares experimental measurements [75]. To facilitate comparison, the SE-SCM results at the higher temperature have been shifted by 0.07 eV, so that the theoretical curves at both temperatures refer to the same point at A = 10...

All results for chain size are now written in terms of the excluded volume. To understand how the chain size changes with temperature, we simply need the temperature dependence of the excluded volume. There are two important parts of the Mayer /-function, from which the excluded volume is calculated [Eq. (3.7)]. The first part is the hard-core repulsion, encountered when two monomers try to overlap each other (monomer separation rhard-core repulsion, the interaction energy is enormous compared to the thermal energy, so the Mayer /-function for r < 6 is — I ... 

The second part is for monomer separations larger than their size (r > b), where the magnitude of the interaction potential is small compared to the thermal energy. In this regime, the exponential can be expanded and the Mayer /-function is approximated by the ratio of the interaction energy and the thermal energy ... 

E is the value of Eq at infinite distance, i.e. E = Fa + Fg. where Fa and Eg are the respective energies of the individual fragments A and B. Eq. (69) now contains the interaction energy K, shown with explicit dependence upon the monomer-monomer separation R, and is defined as... 

Curves for the energy, dipole moment, field gradient at N and field gradients at the two Br atoms were computed and are shown in Figure 1. Although these SCF calculations which neglect both electron corre-lation/dispersion interactions and monomer relaxation are undoubtedly crude, they are expected to give a reasonable qualitative picture of the trends in properties with monomer separation. The potential curve has a minimum at a distance of 5.6 a0 ( 2.96 A) between N and Br,- the experimental separation is somewhat shorter, at 2.72 A. As the monomers approach more closely the dipole moment rises monotonically, with a computed dipole enhancement of 0.59 eao (1.50 D) at the SCF minimum and 0.83 eao (2.12 D) at the experimental separation. 

Electronic Shell Effects in Monomer and Dimer Separation Energies... 

Monomer and dimer separation energies associated with the unimolecular reactions Kyv-i + K, Kyv+ Ka -2 + K2, and Nayv+ Na v-i + Na can be calculated as follows ... 

During release of the substrate with cured information layer from the mold, it is warped in a complicated way. One part of the total separation energy is required for the actual separation (release of adhesion), the remaining part for the (in)elastic deformation of the substrate with information layer. Table 3 shows that the release is easiest for the one-monomer system, although satisfactory results were obtained in all three cases. 

Other reasons for a wide propagation of polymerization in water include (1) reduction of energy consumed to separate the initial monomer in crystal form (acrylamide is produced and used in the aqueous solution form), which, in addition, is associated with the probability of its spontaneous polymerization, and (2) recovery of the organic solvents, which results in less environmental pollution and the elimination of the stage of solution of polymer reagents used, as a rule, in the form of the aqueous solutions. 

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