Ammonia sorptive properties of plasma polymer films obtained from hexamethyldisiloxane

The ability of plasma polymer films, obtained from hexamethyldisiloxane (HM DSO) to adsorb ammonia vapours in gas phase is studied. For this purpose, t he polymer films are deposited on mass-sensitive quartz resonators. The dep endence between the relative change of resonator's frequency due to the mas s of sorbed ammonia vapours and ammonia concentration in gas phase is estab lished. Ammonia vapours with concentrations from 10 to 10 000 ppm are used. The increase of the polymer thickness in the range of 0.09-0.24 mu m leads to an increase of the ammonia sorption capability of the samples. The char acteristics of sorption process of the polymer films versus ammonia vapours are discussed. (C) 2000 Elsevier Science Ltd. All rights reserved.