Filtration apparatus containing graphene oxide membrane

A filtration apparatus, comprising:

• a support substrate;
• and
• a graphene oxide membrane disposed on the support substrate, the graphene oxide membrane including a plurality of graphene oxide sheets, each of the graphene oxide sheets coupled to an adjacent graphene oxide sheet via a chemical linker,
• wherein the chemical linker has the Formula Ib:
• wherein:
• L3 is selected from —C(═O)—NH—(CH2)m—, —C(═O)—NH—C(═O)—(CH3)2—S—(CH2)m—, or —NH—C(═O)—(CH3)2—S—(CH2)m—;
• A2 is selected from aryl, heteroaryl, C4-C10 heterocycloalkyl, C4-C10 cycloalkyl, or C4-C10 alkyl, wherein the aryl, heteroaryl, heterocycloalkyl, cycloalkyl, and alkyl can each be optionally substituted by one or more substituents selected from halo, C1-C4 alkoxy, or C1-C4 alkyl;
• m is 0-4;
• and
• denotes the point of coupling with a carbon atom on a graphene oxide;
• the graphene oxide membrane has a flux of at least about 2.5+10-3 gallons per square foot per day per psi (GFD/psi) with a 1 wt. % lactose solution at room temperature;
• and
• the graphene oxide membrane includes about 0.1 mg to 6 mg of the graphene oxide membrane per 5000 mm2 membrane area.