Functionalized layered double hydroxides for treatment of contaminated water

A method of preparation of a functionalized layered double hydroxide comprising:

• a. supplying an organofunctional silicon having the following formula:
• R′(CF2)b(CH2)aSi(OR)3
• wherein R′ represents an aromatic, CH2═CH—, —CH3 or —CF3 group and (OR) represents an alkoxy group;
• if b=0, then a≥5 or if b>0 then a≥0;
• b. supplying a layered double hydroxide having the following formula:
• [M2+1-xN3+x(OH2)]x+(An−)x/n
• wherein M2+ and N3+ are metal cations and An− is an exchangeable anion, n is an integer of 1 or greater, 0<x<1;
• c. combining said organofunctional silicon with said layered double hydroxide and forming a functionalized layered double hydroxide having the following formula:
• 3[M2+1-xN3+x(OH)(An−)x/n-O]—Si(CH2)n—(CF2)bR′
• wherein M2+ and N3+ are the metal cations;
• An− is the exchangeable anion, n is the integer of 1 or greater;
• 0<x<1;
• R′ represents the aromatic, CH2═CH—, —CH3 or —CF3 group;
• if b=0, then a≥5;
• and
• if b>0, then a≥0.

A method of removing per- and polyfluoroalkyl substances from contaminated water comprising:

• a. supplying a functionalized layered double hydroxide having the following formula:
• 3[M2+1-xN3+x(OH)(An−)x/n-O]—Si(CH2)n—(CF2)bR′
• wherein M2+ and N3+ are metal cations;
• An− is an exchangeable anion, n is an integer of 1 or greater;
• 0<x<1;
• R′ represents an aromatic, CH2═CH—, —CH3 or —CF3 group;
• if b=0, then a≥5;
• if b>0, then a≥0;
• b. treating said contaminated water with said functionalized layered double hydroxide and removing said per- and polyfluoroalkyl substances.