Modelling the Vapor–Liquid Equilibrium of Polymer Solutions Using a Cubic Equation of State

This work presents the vapor–liquid equilibrium calculations in an isothermal flash, applied to polymer solutions, using the Peng–Robinson cubic equation of state modified by Stryjek–Vera, and the mixing rule introduced by Wong–Sandler. This rule allows combining the rigid lattice thermodynamic model of Flory–Huggins to the Peng–Robinson–Stryjek–Vera equation of state. As the Gibbs free energy must be minimum in the equilibrium state, a stochastic optimization method, the simulated annealing algorithm, was used to find out the extreme of this thermodynamic potential.     

Design of smart nanodevices based on N-vinyl caprolactam nanogels for photosensitizers

Smart PVCL-based nanogels for photosensitizers were prepared following the thermo precipitation methodology. PVCL-based imprinted and non-imprinted NGs are reported with different percentages of N,N′-methylenebisacrylamide (BIS) as crosslinker agent. Zn(II)phthalocyanine (ZnPc) is employed as a model photosensitizer and incorporated as a template molecule for imprinted NGs or it loads post-synthesis for non-imprinted NGs. In order to analyze the chemical structure, NGs were characterized using infrared microscopy. Hydrodynamic diameter was determined by dynamic light scattering. The phase transition temperature was measured by UV–vis spectroscopy. The phase transition temperature and D_h values were regulated by the percentage of crosslinker and the presence of the photosensitizer as a template or post-synthesis load. In all cases, the yields were acceptable and the smart nanodevices were stable.