ABSTRACT
The understanding of the behavior of nanoparticles in electric fields requires a knowledge of not only their average electric charge but also their dipole moments. The description of the electric dipole moments of nanoparticles, including macromolecules is much more complicated than that for simple molecules. Permanent or electrically induced polar nanoparticles are characterized by permanent and induced dipole moments. Most of the macromolecules and colloid particles are of nanometer dimensions and thus they might be considered to be typical nanoparticles. The increased complexity of the electric description of polar nanoparticles in aqueous medium and especially of their interfacial dipole moment (IDM) has led to considerable misunderstanding, starting from their terminology and their classification. The causes for the poor correspondence of the values for the IDM communicated by different authors are discussed and the need for a more detailed characterization and description of the samples is highly recommended.
