Comparative thermodynamic study of functional polymeric latex particles with different morphologies

In this work, the thermodynamic behavior of three series of functionalized polymeric particles with different morphologies and different functional group concentrations were compared. Partial volumes and partial adiabatic compressibilities of particles at infinite dilution were calculated from density and sound speed data. These properties were interpreted in terms of the atomic, free volume and hydration contributions. In addition, this interpretation was extended to the particle components (polar and non-polar groups), developing a new thermodynamic methodology. For homogeneous particles without forced gradient, functional groups are located from the surface to the interior and the voidness effect plays an important role in the swelling process. In multilayer particles, functional groups are located at the boundary of each layer and they are completely hydrated while non-polar groups behave as a permeable membrane at high functional groups concentrations. Homogeneous particles with forced gradient behave as homogeneous particles without forced gradient at low functional groups concentrations and as a multilayer particle at higher concentrations of functional groups. In conclusion the shown thermodynamic tool allowed understanding the role played by each particle component and its interactions inside the particle.