Ion pair and larger ion cluster formation in water interfacial regions: An atomic force microscopy study

Interfacial regions attached to hydrophobic and hydrophilic surfaces have very low relative permittivities (ε ∼ 3–5), these values induce the formation of ion pairs. A detailed description pairing will be possible only after development adequate experimental probing methods. The scheme described in this work detects pair (or multistage association) water solutions interfacial region. Forces acting on tip when immersed region substrates, such as mica where ε < 7, are attractive (AFM dielectric constant = 7). These force steps with extensions equal or smaller than Bjerrum length at substrates associated regions. Measurements show that molecular arrangement pairs form an ordered structure 7) induced by charges. however, separated arrangements structures observed repulsive > intercalated between