P-Phenyleneethynylene copolymer CdS quantum dot Superstructures. Synthesis, photophysics and vesicle formation

Abstract

CdS QDs were synthesized by using (3-mercaptopropyl)trimethoxysilane (MPS) as ligand to form CdS(MPS) and mixed with an amphiphilic p(phenyleneethynylene) copolymer, coPE, which presents alternating p(phenyleneethynylene) moieties bearing dodecanoxy and 1-OH undecanoate lateral chains, at different pHs. SS NMR and XPS spectroscopy confirmed the functionalization of CdS(MPS) with coPE at pH 5.5 to yield an inorganic–organic hybrid, CdS(MPS)-coPE but they also revealed hydrolysis and successive polymerization of the silane group of MPS, which leads to spherical superstructures, as found by STEM. STEM tomography confirms the 3D nature of the superstructures and demonstrates that they are stable under high vacuum conditions. AFM revealed that they are preserved even in spun films, which tunes the fluorescence from yellow (copolymer) to green (hybrid). This peculiar supramolecular behavior could be profited for host–guest white light emission or biosensing.