Preparation of Photoluminescent Nano-Biocomposite Nacre from Graphene Oxide and Polylactic Acid.

Nano-biocomposites of inorganic and organic components wereprepared to produce long-persistent phosphorescent artificial nacre-like materials. Biodegradable polylactic acid (PLA), graphene oxide (GO), and nanoparticles (13-20 nm) of lanthanide-doped aluminate pigment (NLAP) were used in a simple production procedure of an organic/inorganic hybrid nano-biocomposite. Both polylactic acid and GO nanosheets were chemically modified to form covalent and hydrogen bonding. The high toughness, good tensile strength, and great endurance of those bonds were achieved by their interactions at the interfaces. Long-persistent and reversible photoluminescence was shown by the prepared nacre substrates. Upon excitation at 365 nm, the nacre substrates generated an emission peak at 517 nm. When ultraviolet light was shone on luminescent nacres, they displayed a bright green colour. The high superhydrophobicity of the generated nacres was obtained without altering their mechanical characteristics. Polylactic acid-based photochromic and afterglow artificial nacre was prepared. Graphene oxide nanosheets were applied as a cross-linking agent. Lanthanide aluminate nanoparticles (13-20 nm) were embedded into colorless nacre as a photoluminescent agent. Biodegradable smart nacre showed reversible color change to green under UV irradiation. Photoluminescent nano-biocomposite nacre exhibited superhydrophobicity and UV protection. image