Hydrogen bond acidic polycarbosilanes with

Comparative chemical sensor vapor testing of the hydrogen bond acidic polycarbosilanes with polysiloxane analogues has shown a significant enhancement in sensitivity toward hydrogen bond basic vapors relative to the... 

This work describes recent advances in the preparation of hydrogen bond acidic polycarbosilanes and their application as chemical sensor coatings. We have prepared hydrogen bond acidic polymers based on polycarbosilanes with the goal of improving upon the chemical and thermal properties of this class of functionalized polymer (3-5). Results pertaining to the preparation of selected model compounds are also described. 

A sorbent polymer film is applied to a SAW device by spray coating a dilute polymer solution onto the surface of the resonator while monitoring the frequency shift to estimate the thickness of the applied polymer film. The polymer-coated SAWs are then placed in a flow chamber and exposed to organic vapors under controlled conditions. These tests have shown that the new hydrogen bond acidic polycarbosilanes have high sensitivity to hydrogen bond basic vapors such as DMMP and 2,4-DNT. A comparison of the DMMP and 2,4-DNT vapor sorptive properties of HC and NMA revealed that these two polymers have similar responses to DMMP, while NMA is substantially more responsive to 2,4-DNT vapor (Figure 6). The observed decrease in SAW frequency is a result of the increase in mass of the polymer film associated with uptake of analyte vapors. 

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