The molecular interactions of monosulfonate tetraphenylporphyrin (TPPS1) and meso-tetra(4-sulfonatophenyl)porphyrin (TPPS) with dimethyl methylphosphonate (DMMP) have been investigated by UV–vis and fluorescence spectroscopies. The association constants and interaction stoichiometries of the bindings were obtained through Benesi–Hildebrand (B–H) method. Particularly, both linear and nonlinear fitting procedures were performed to evaluate the possible 1:2 interactions. Experimental results showed that hydrogen-bonding interactions existed in both of the two systems, resulting in regular changes in the absorbance and fluorescence characteristics of the porphyrins. The association constants and stoichiometries determined from absorbance and fluorescence studies were in excellent agreement. Using a nonlinear fitting method, we demonstrated that the one-step 1:2 interaction took place in the TPPS1–DMMP system, and the association constants were determined to be 71.4 M−1 by absorbance measurements and 70.92 M−1 by fluorescence measurements. The interaction stoichiometry of the TPPS–DMMP system was 1:1, and the association constants were determined to be 16.06 M−1 by absorbance measurements and 16.03 M−1 by fluorescence measurements. It was concluded that the interaction between TPPS1 and DMMP was stronger than that between TPPS and DMMP. 相似文献
From the constitutive model with generalized force fields for a viscoelastic body with damage, the differential equations of motion for thin and thick plates with damage are derived under arbitrary boundary conditions. The convolution-type functionals for the bending of viscoelastic thin and thick plates with damage are presented, and the corresponding generalized variational principles are given. From these generalized principles, all the basic equations of the displacement and damage variables and initial and boundary conditions can be deduced. As an example, we compare the difference between the dynamical properties of plates with and without damage and consider the effect of damage on the dynamical properties of plates. 相似文献
Summary: Monte Carlo simulation on a simple lattice model has been used to study the adsorption of asymmetrical triblock copolymers from a non‐selective solvent at the solid‐liquid interface. The size distributions of train, loop and tail configurations for those copolymers are obtained as well as other details of the adsorption layer microstructure. Also the influence of adsorption energy and the role of molecular symmetry are investigated. A segment‐density profile, the adsorption amount, the surface coverage, and the adsorption layer thickness have been determined. Finally, it is shown that the adsorption behavior of an asymmetrical copolymer can be predicted from the symmetrical copolymer.
Size distributions of the tail configuration for A8−kB20Ak. 相似文献