Synthesis and Characterization of Nanoscopic Entities Based on Poly(caprolactone)-Grafted Cadmium Sulfide Nanoparticles

Abstract

Nanosized CdS clusters have been synthesized using polyester chains with a thiol end group as a covalently attached colloidal stabilizer. Clusters were grown through the reaction of thiourea with cadmium acetate, which was in competition with surface stabilization due to the tethered poly(caprolactone) (PCL) chains. The kinetics of the CdS cluster growth in the presence of poly(caprolactone) ligands were compared with those obtained using a low molecular weight thiol. Control of the particle size was also achieved by varying the ratio of thiourea to PCL ligands. The resulting nanoscopic entities obtained in different solvents (DMF or THF), remained stable in solution for several months and could be cast into films. Homogeneous dispersions of CdS particles in a polymer matrix were obtained by solvent evaporation. The particle size and distribution were characterized using ultraviolet-visible and photoluminescence spectroscopies, and transmission electron microscopy.

Preparation and Characterization of Polyvinyl Alcohol-Capped CdSe Nanoparticles at Room Temperature

“…Recently, polymers with functional groups have also been used as stabilizers for the preparation of semiconductive nanoparticles. These polymers include polyester with thiol end group (13), starburst dendrimers (14), amino-derivatized polysaccharides (15), and double hydrophilic block copolymers (16). Most of the works concentrate on sulfide, due to the easy accessibility of sulfide source in wet chemical control synthetic methods.…”

The Effects of Organisation, Embedding and Surfactants on the Properties of Cadmium Chalcogenide (CdS, CdSe and CdS/CdSe) Semiconductor Nanoparticles

“…Some effort has been made to organise semiconductor nanoparticles, for example by Samokhvalov et al [99] and Lahav et al, [100,101] who have studied the collective electronic properties of self-organised CdS particles in hybrid LangmuirBlodgett films. Similarly, Hilbron et al [102] have obtained an arrangement by polymerisation of the surfactants. Recently, Feng et al [103,104] have fabricated porous CdS frameworks that had been stabilised by metal ions similar to what is found for zeolites.…”

Surface‐initiated living radical polymerization of self‐assembling L‐phenylalanine‐derived monomer from silica for RP‐HPLC application

“…[9][10][11][12] However, the exploitation of these properties may require a homogeneous dispersion of the particles in the polymer matrix and/or long-term stability of the composite materials. One way to avoid agglomeration and increase the stability is to introduce covalently grafted polymer chains onto the particles, [13][14][15] which may increase the compatibility of the nanoparticles with the polymer matrix as well. In principle, there are two approaches to attach polymers onto the surface of inorganic materials: ''grafting to'' method, in which the endfunctionalized polymers react with the surface reactive groups 16,17 and ''grafting from'' technique in which polymer chains are grown from initiator-terminated monolayers.…”

“…Thermogravimetic analysis was performed on a Seiko EXSTAR 6000 TG/DTA 6300 thermobalance in static air from 30 to 800 8C at a heating rate 10 8C/min. Polymer-grafted silica particles were characterized by Varian UnityInova AS400 NMR and solid probe for 13 C CP/MAS NMR at spin rate 4000-4500 Hz. 29 Si Cross-polarization magic angle spinning (CP-MAS) NMR spectra were collected with the same instrument.…”

“…At low temperature, alkyl chains remain as ordered trans-conformational form also contributing to the self-assembly of Compound 4. This ordered structural conformation of the alkyl chain of 4 was evaluated by 13 C CP/MAS NMR measurement at room temperature (see Fig. S2 in the Supporting Information).…”