Chemical reactions at aqueous interfaces play major roles in Earth terrestrial and subsurface cycles of most reactive elements, trace elements, heavy/radioactive ions, and environmental pollutants. Surface Complexation Models appear to be one of the most successful models in geochemistry to predict the chemical equilibrium state of a given interface in contact with solution. They have provided the ability to understand, predict, and explain the sorption of protons, aqueous ions, and molecules to hydrated mineral surfaces using physical models for interfacial processes and energies. Volume 91B (in addition to Vol 91A, 978-1-946850-16-4) describes the foundational science, illustrate the state-of-the art experimental and molecular modeling methods for determining structural and energetic data, and demonstrate how these thermodynamic models may be developed for increasingly complex systems such as nanoscale confinement. The volumes are intended to provide instruction and guidance to new scientists, suggest new problems and methods for experienced practitioners, and identify opportunities for new collaborations between fields.