摘要 |
<p>There is described a polymeric quaternary alkyl ammonium cation of general formula (I), or a salt thereof; in which R1, R2, R3 and R4, which may be the same or different are each alkyl C1 to 20; m is an integer from 1 to 100; and n is an integer from 1 to 7. There is also described a film formulation comprising a cation of formula (I), a colorimetric sensor device comprising said film and an endotracheal intubation apparatus comprising a sensor.</p> |