MOLECULAR RECOGNITION THROUGH INTERCALATION CHEMISTRY - IMMOBILIZATION OF ORGANOCLAYS ON PIEZOELECTRIC DEVICES

Novel chemical sensors based on thin films of different alkylammonium-hectorite clays on quartz crystal microbalances (QCM) are reported. Only the sodium and TMA (tetramethylammonium) forms show nitrogen type I isotherms indicating access into micropores. Water at low partial pressure is strongly sorbed in the TMA form and to a small extent in the Na form, but effectively excluded from hosts with longer alkylammonium ions. In contrast, benzene and other aromatic molecules are most strongly sorbed in octadecylammonium and TMA forms but are excluded from the sodium form.