Trimethylsilyl permodified cyclodextrins: Hydrolysis at the air-water interface

The behavior at the air-water interface of amphiphilic α, β and γ trimethylsilyl per-modified cyclodextrin (pTMS-CD) monolayers is reported, as a first step towards the building up of a Langmuir-Blodgett assembly with potential gas sensor properties. The pTMS-CDs form stable monolayers with unusually high collapse pressure. It is shown that this peculiar behavior arises from a partial hydrolysis of TMS groups at the air-water interface. This hydrolysis reaction was confirmed by infrared spectroscopy and the departure of TMS groups was evidenced by weight loss measurements through quartz crystal microbalance carried out on the pTMS-CD monolayers deposited through the Langmuir-Blodgett technique.