Achieving Solidification and Redispersion of Semiconducting Polymer Dots by Layered Double Hydroxide Incorporation

Abstract

Solidification and aqueous redispersion of fluorophores are characteristically challenging because of aggregation quenching and random shifts of emission. Carbon-based polymer dots (PDs) have recently shown photoluminescent (PL) performances superior to those of conventional dyes and inorganic quantum dots (QDs) but suffer from significant fluorescence (FL) quenching and irreversible aqueous dispersion after solidification, which limits their applications in practical biomedicine and optical devices. In this work, we have compared three strategies by utilizing layered double hydroxides (LDHs) to effectively solidify PDs as robust and redispersible composites with well-preserved high brightness against wide pH (pH = 4−12) and strong ionic strength conditions, more stable than the pristine PDs. The resulting PD−LDH nanocomposites also show in vitro/in vivo bioimaging ability with low cytotoxicity and improved photostability. In addition, these composites exhibit high thermal stability at 150 °C for at least 96 h. The composites produced by a one-step physical mixing approach (∼10 min) of LDHs and PDs (p-PLDH) exhibited PL performances comparable to those of the conventional multistep composites (m-PLDH), which require tremendous effort (at least 7 days) to prepare. Structural studies further revealed that the deshaping behavior of PDs and the interflake sandwich assembly of LDHs contributed to the robust FL properties. Because of the simple synthesis, durable photostability, high aqueous redispersion, and multicolor emissions (ranging from blue to near-IR) of these PD−LDH nanocomposites, we believe that they are promising candidates for advanced biorelated technologies and optoelectronics.

Three-Dimensional Rice Straw-Structured Magnetic Nanoclay-Decorated Tripolymeric Nanohydrogels as Superadsorbent of Dye Pollutants

“…Moreover, this quick gelation approach was used to entrap two different nanostructures. The first one is organically modified Cloisite30B, which is incorporated to enhance the removal efficiency of the hydrogel, as these nanostructures are highly acknowledged because of their unique layered dimension, − low cost, high surface area (up to 750–800 m 2 /g), and high cation exchange capacity . On the one hand, nanoclays are widely used with polymers like cellulose, chitosan, poly­(acrylic acid) (PAA)/poly­(ethylene glycol) (PEG) hydrogels, and poly­(vinylidene fluoride) (PVDF)/chitosan to remove cationic pollutants.…”

Conjugation of polyethylenimine and its derivatives to carbon-encapsulated iron nanoparticles

“…polymers, 23 biomolecules, 24 and target drugs. 25,26 The surface modication of nanomaterials (introducing functionalities) is being widely studied, due to the further possibility of covalent-type functionalization using various macromolecules. So far, many ways of introducing such functional groups (most commonly carboxylic functionalities) were proposed, for fullerenes, 17 nanotubes, 27,28 and graphene.…”