Patent ID: 8574420

Claim:
A method for controlling the release of one or more anions (as a function of time) from a film which comprises the steps of: (i) forming a polyelectrolyte assembly wherein the polyelectrolyte assembly comprises at least two anion/cationic polymer bilayers comprising one or more different anion/cationic polymer bilayers where at least a first bilayer is formed from a first cationic polymer and at least a second bilayer is formed from a second cationic polymer wherein the cationic polymers are selected from (a) a polymer of formula I: where: n+m+l+k+i=N, the total number of repeat units in the polymer; n, m, l, k and i are all integers; or m and l are integers, n is zero or an integer and i and k are zero; or m and l are integers, and n, i or k is zero or an integer; A 1-3 , B 1-3 , C 1-3 , D 1-3 and E 1-3 are linkers which may be the same or each may be different; Z 1 -Z 5 are covalent bonds which may or may not be degradable bonds; R 1-4 and R 11-19 , independently, can be hydrogen, alkyl groups, alkenyl groups, alkyny groups, cycloalkyl groups, heterocyclic groups, aryl groups, or heteroaryl groups, all of which groups are optionally substituted, with the exception that R 1-4 are not esters; and R 5 -R 10 are linkers or covalent bonds which may be the same or each may be different; or (b) a polymer of formula II: where n+m=N is the number of repeating units in the polymer; each y, independently, is 1, 2 or 3; each x, independently, is an integer ranging from 1-10; each R 1 , each R 2 , each R 3 and each R 4 , independently, is selected from the group consisting of hydrogen, alkyl groups, alkenyl groups, alkynyl groups, carbocyclic groups, heterocyclic groups, aryl groups, heteroaryl groups, ether groups, all of which may be substituted or unsubstituted, wherein the first cationic polymer is selected from cationic polymers of formula I and the second cationic polymer is selected from cationic polymers of formula II, or wherein the first and second polymers are selected from cationic polymers of formula II and differ from each other in the value of (n)/N; and (ii) subjecting the polyelectrolyte assembly formed to conditions in which ester functions in the polymer of formula I or in the polymer of formula II are hydrolyzed to release the one or more anions.