Application of ionic liquids in photopolymerizable holographic materials

The influence of ionic liquids in photopolymerizable holographic materials was investigated extensively. The structures of ionic liquids have important effect on the properties of the materials. Although not all tested ionic liquids can improve the properties of the materials, the ionic liquids based on imidazolium, pyridium, or phosphonium with appropriate counter anions can be used as additives to increase the sensitivity, the diffraction efficiency, and the resolution of the materials in the thin hologram. Polymerizable ionic liquids have also been used as additives. Higher sensitivity, higher diffraction efficiency and higher resolution were obtained as well. These ionic liquids can carry out the photopolymerization during exposure to UV light to recording the hologram. They may assist to form a more stable hologram.

Research highlights
► Ionic liquids were used as additives in photopolymeriyable holographic materials.
► The structures of ionic liquids have important effect on the properties of the materials.
► The sensitivity, the resolution and the diffraction efficiency were increased using imidazolium, pyridium or phosphonium based ionic liquids as additives.
► Photopolymerizable ionic liquids were also used as additives to improve the properties of the materials.