Perforated graphene deionization or desalination

A method for deionizing water carrying unwanted ions, said method comprising the steps of:

• providing a first sheet of graphene perforated with plural apertures of a diameter selected to disallow the passage of a selected first one of said unwanted ions, and to allow the passage of water molecules laden with a selected second one of said unwanted ions;
• providing a second sheet of graphene perforated with plural apertures selected to allow the passage of water molecules and to disallow the passage of said selected second one of said unwanted ions, said apertures in said second sheet of graphene having a smaller diameter than said apertures in said first sheet of perforated graphene;
• juxtaposing said first and second sheets of perforated graphene to thereby form a juxtaposed sheet with a first side defined by said first sheet of perforated graphene, a second side defined by said second sheet of perforated graphene, and a path for the flow of liquid therebetween;
• applying said water carrying unwanted ions to said first side of said juxtaposed sheet, so that water molecules flow through said juxtaposed sheet and said path to said second side of said juxtaposed sheet in preference to ions, to thereby produce nominally deionized water;
• and
• collecting said nominally deionized water molecules from said second side of said juxtaposed sheet.

A water deionizer, comprising:

• a graphene sheet perforated with apertures dimensioned to allow the flow of water molecules and to disallow the flow of ions of a particular type;
• a source of water laden with ions of said particular type;
• and
• a path for the flow of said water laden with ions of said particular type through said graphene sheet perforated with apertures.

A separator, comprising:

• a first graphene sheet perforated with apertures dimensioned to allow the flow of water molecules and to disallow the flow of ions of a first type;
• a second graphene sheet perforated with apertures dimensioned to allow the flow of water molecules and to disallow the flow of ions of a second type, where said ions of said second type are smaller than said ions of said first type;
• a source of water laden with ions of said first and second types;
• a path for applying a flow of said water laden with ions of said first and second types to said first graphene sheet perforated with apertures dimensioned to disallow the flow of said ions of said first type, whereby (a) ions of said first type accumulate on an upstream side of said first graphene sheet perforated with apertures dimensioned to disallow the flow of said ions of said first type and (b) water laden with ions of said second type flows through said first graphene sheet perforated with apertures dimensioned to disallow the flow of said ions of said first type to a downstream side of said first graphene sheet perforated with apertures dimensioned to disallow the flow of said ions of said first type;
• a path for applying a flow of said water laden with ions of said second type to an upstream side of said graphene sheet perforated with apertures dimensioned to disallow the flow of said ions of said first type, whereby (a) ions of said second type accumulate on an upstream side of said second graphene sheet perforated with apertures dimensioned to disallow the flow of said ions of said second type and (b) water free of said ions of said first and second types flows through said second graphene sheet perforated with apertures dimensioned to disallow the flow of said ions of said second type;
• and
• a collection arrangement coupled to receive said water free of said ions of said first and second types.