Directed Self-Assembly in Laponite/CdSe/Polyaniline Nanocomposites

Abstract

Laponite films provide versatile inorganic scaffolds with materials architectures that direct the self-assembly of CdSe quantum dots (QDs or EviTags) and catalytic surfaces that promote the in situ polymerization of polyaniline (PANI) to yield novel nanocomposites for light emitting diodes (LEDs) and solar cell applications. Water-soluble CdSe EviTags with varying, overlapping emission wavelengths in the visible spectrum were incorporated using soft chemistry routes within Na-Laponite host film platforms to achieve broadband emission in the visible spectrum. QD concentrations, composition and synthesis approach were varied to optimize photophysical properties of the films and to mediate self-assembly, optical cascading and energy transfer. In addition, aniline tetramers coupled to CdSe (QD-AT) surfaces using a dithioate linker were embedded within Cu-Laponite nanoscaffolds and electronically coupled to PANI via vapor phase exposure. Nanotethering and specific host-guest and guest-guest interactions that mediate nanocomposite photophysical behavior were probed using electronic absorption and fluorescence spectroscopies, optical microscopy, AFM, SEM, powder XRD, NMR and ATR-FTIR. Morphology studies indicated that Lap/QD-AT films synthesized using mixed solvent, layer by layer (LbL) methods exhibited anisotropic supramolecular structures with unique mesoscopic ordering that affords bifunctional networks to optimize charge transport.

Simple preparation of a cadmium selenide–montmorillonite hybrid

“…4). The PL bands of the other hybrid systems of cadmium selenide such as starch-capped CdSe, cysteine-capped CdSe nanoparticle, CdSe-polymers, and CdSe-mesoporous materials were also observed at a wavelength of 400-700 nm [8][9][10][11][12][13]. The emission peaks of CdSe-HDTMA-montmorillonite due to the near bandedge (507 nm) and deep-trap (550 nm) emissions can be attributed to the presence of CdSe nanoparticles in the hybrid material [10,17].…”

“…Accordingly, the organization of photoactive species, including molecular species, polymers, and semiconductor particles, on the surfaces of organic and inorganic materials has been conducted [7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Cadmium selenide (CdSe), one of the useful II-VI group semiconductors, has attracted much interest because of its unique optical and electronic properties that may find applications as photocatalysts and photoluminescent materials [21,22].…”

Fabrication of electric-stimuli responsive polyaniline/laponite composite and its viscoelastic and dielectric characteristics

“…Conducting polymers have promising applications in electrochemical devices, photodiodes, antistatic and anticorrosion coatings, batteries, sensors, and solar cells [17,18]. Polyaniline (PANI), as an applicable conducting polymer, has been used as an ER material because of its low cost, good environmental and chemical stability, ease of synthesis, high sensitivity to an electric field, controlled conductivity by doping/dedoping process, and various other potential applications [19].…”

Optical and structural properties of electrodeposited polyaniline/Q‐CdS composites

“…PANI has a wide area of applications in electromagnetic shielding materials, light emitting devices, sensors, batteries, and solar cells . There are several reports describing nanocomposites of PANI with semiconducting nanoparticles such as CdSe, ZnSe, ZnO, and CdS . A comprehensive investigation of the size dependent properties of the PANI/semiconductor nanoparticle‐based composites is however, not available.…”