Inks including segment copolymer grafted pigments via azide chemistry

In combination, an electronic display and an electronic ink, wherein the electronic display includes:

• a first electrode;
• a second electrode;
• and
• a display cell having a recess defined by a dielectric material, the first electrode, and the second electrode, the display cell containing the electronic ink;
• and wherein the electronic ink includes:
• a non-polar carrier fluid;
• and a surface-functionalized pigment particle including a nitrogen-linked moiety to the surface of the pigment particle through a nitrogen link at one end of the nitrogen-linked moiety and a segment copolymer having at least two blocks attached at another end, wherein the segment copolymer is formed on a tetrafluorophenyl azide-based initiator as shown below:
• wherein the nitrogen link is formed from the N3 group of the tetrafluorophenyl azide-based initiator, wherein the pigment particle is suspended in the non-polar carrier fluid.

A method for making a nitrogen-linked surface functionalized pigment particle including:

• providing an azide;
• causing the azide to initiate polymerization of a first block monomer to give a first block azide living polymer;
• adding a second monomer to the first block living polymer to give a two-block azide living copolymer and form a first segment;
• forming at least one additional segment by adding, in any order, a first block monomer and a second block monomer to form a two-block living segment copolymer;
• wherein the two-block living segment copolymer is formed on a tetrafluorophenyl azide-based initiator as shown below:
• wherein the nitrogen link is formed from the N3 group of the tetrafluorophenyl azide-based initiator;
• causing an inorganic or organic pigment particle to undergo a coupling reaction with the azide on the two-block living segment copolymer to form a functionalized di-block segment copolymer coupled to the pigment particle through a nitrogen link.