Interfacial layer monolayer formation

Frequently, e.g. in the case of alkane thiol monolayers, the electrode is modified with a low-dielectric-constant layer. Film formation causes the Helmholtz layer to change from a mixture of ions and solvent with a high dielectric constant to an ion-free, often organic, layer with a low dielectric constant. The interfacial capacitance... 

Extensive neutron reflectivity studies on surfactant adsorption at the air-water interface show that a surfactant monolayer is formed at the interface. Even for concentration cmc, where complex sub-surface ordering of micelles may exist,the interfacial layer remains a monolayer. This is in marked contrast to the situation for amphiphilic block copolymers, where recent measurements by Richards et al. on polystyrene polyethylene oxide block copolymers (PS-b-PEO) and by Thomas et al. on poly(2-(dimethyl-amino)ethylmethacrylamide-b-methyl methacrylate) (DMAEMA-b-MMA) show the formation of surface micelles at a concentration block copolymer, where an abrupt change in thickness is observed at a finite concentration, and signals the onset of surface micellisation. 

The main hypotheses for developing the EHD impedance theory are that the electrode interface is uniformly accessible and the electrode surface has uniform reactivity. However, in many cases, real interfaces deviate from this ideal picture due, for example, either to incomplete monolayer adsorption leading to the concept of partial blocking (2-D adsorption) or to the formation of layers of finite thickness (3-D phenomena). These effects do not involve the interfacial kinetics on bare portions of the metal, which, for simplification, will be assumed to be inherently fast. The changes will affect only the local mass transport toward the reaction sites. Before presenting an application of practical interest, the theoretical EHD impedance for partially blocked electrodes and for electrodes coated by a porous layer will be analyzed. 

In the present paper. Static Secondary Ion Mass Spectrometry (SSIMS) is used to investigate the interfacial chemistry between vacuum-deposited Al and Cu on PET by following the initial stages of metallization in the submonolayer and monolayer regimes. From the SIMS intensity variations with the deposited metal flux, information on the initial growth mechanisms of the metal layer Is expected. Two metals, copper and aluminum, have been chosen In order to investigate the influence of the metal reactivity on the metal-polymer interface formation. Aluminum with its electropositive sp band is known to react strongly with the carbonyl functionalities of the whereas copper is an inert metal and its Interaction is believed to be much weaker. ... 

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