Quaternary ammonium compounds cell membrane effects

Increasing pH values also affect the surfaces of the microbe cells they become more negatively charged. This, in turn, naturally increases the affinity of cationogenic, membrane-active substances, to the cell surface and hence the intensity of their effects on it. Examples are provided by quaternary ammonium compounds (III.16.1), biguanides (III.16.2) and dibenzamidines (III.IO). 

Quaternary ammonium chlorides display their antimicrobial activity even being immobilized on inert supports because they can act on the membranes of various cells. The effects of surface-bonded organosilicon QAC on bacteria, yeasts, fungi, algaes have been extensively investigated (4, 5, 6, 7, 8). However, the activity against viruses of these immobilized compounds has not been demonstrated. 

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