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Polysiloxanes were functionalized for Langmuir-Blodgett (LB) deposition of films for optical and bioelectronic applications. Azo dye chromophores give second-harmonic generation and phosphatidylcholine (PC) side-groups yield bilayers suitable for inclusion of active proteins. The polymeric forms are better LB materials than their low molecular mass analogues. One of the azo dye functionalized polymers forms LB films of exceptional clarity; waveguide losses for 633 nm light were measured at around 2.5 dB cm−1 in a 1.3 μm thick film. Bilayers of the PC functionalized polymer have low-field conductivities of the order of 10−9S m−1, with a transition to a probable space-charge-limited region and eventual breakdown at above 1.5 × 10−8 V m−1. Absorption measurements indicate that bacteriorhodopsin remains active when mixed with the PC functionalized polymer.

A Langmuir-Blodgett (LB) trough has been developed from the ‘diamond design’ previously reported, by fixing two points of the diamond to facilitate a modular construction which could also be conveniently adapted for alternating-layer and Montal-Mueller studies. With biomolecular applications in mind, the trough was deliberately made small; barriers can vary the surface area between 115 cm 2 and 17.5 cm 2 with a low subphase volume of about 550 cm 3 . The surface flow is channelled by shoulders; this produces near-normal flow at an LB substrate, and yields high quality films for both low molecular mass materials and appropriate polymers with a range of surface viscosities.