Langmuir−Blodgett (L−B) Multilayer Films

Many multilayer Langmuir−Blodgett films of saturated long-chain fatty acids and multivalent metals reported in the scientific literature are isostructural with bulk soap phases. The conventional view that these films feature the “hairpin” arrangement of double-chain amphiphiles in self-assembled lamellae appears to be invalid beyond the monolayer for many fatty acid/metal (II, III) films. The chains undergo a remarkable conformation transition from a “hairpin” to a “splayed-chain” structure after more monolayers are deposited. This previously undescribed conformational transition is considered to play a major role in the “overturning” phenomena and “island” formation observed in these L−B films.