Incorporation of fluorescent microgels inside calcite single crystals

Abstract

Single crystals have been shown to incorporate guest materials (e.g., gel networks and functional particles) and the incorporated materials endow the crystal hosts with non-intrinsic properties. The acquisition of the non-intrinsic crystal properties impels us to diversify the incorporated guest materials and thus to spread the potential applications of single-crystalline materials. Here, fluorescent NIPAM-based microgels have been selected as the guest materials to be incorporated into the crystal hosts. In the presence of microgels, calcite crystallize from either solution or gel media have been examined. Solution-grown crystals exclude the microgels, while two gel-grown methods have proved effective for incorporating these microgels inside calcite single crystals. On one hand, an additional macroscopic agarose gel-network is introduced to trap the microgels. Crystallization in the agarose gel leads to incorporation of agarose gel-network together with the trapped microgels. The microgel concentration in the crystal reaches 33 mg/mL. On the other hand, dispersions of microgels are concentrated to about 352 mg/mL and the microgels aggregate into non-flowing macroscopic gels (termed as macrogels). Crystallization in a macrogel results in its incorporation. By showing the incorporation of microgels through physical entrapment, this work provides a new platform to functionalize single crystals by the microgels.

Keywords

• Microgel
• Macrogel
• Single-crystal
• Incorporation
• Composite