“Macromolecules – ghosts” in dynamic light scattering analysis: An approach to study interaction between CdSe quantum dots and RAFT-based poly(methyl methacrylate)

RAFT-Based Polymers for Click Reactions

The parallel development of reversible deactivation radical polymerization and click reaction concepts significantly enriches the toolbox of synthetic polymer chemistry. The synergistic effect of combining these approaches manifests itself in a growth of interest to the design of well-defined functional polymers and their controlled conjugation with biomolecules, drugs, and inorganic surfaces. In this review, we discuss the results obtained with reversible addition–fragmentation chain transfer (RAFT) polymerization and different types of click reactions on low- and high-molar-mass reactants. Our classification of literature sources is based on the typical structure of macromolecules produced by the RAFT technique. The review addresses click reactions, immediate or preceded by a modification of another type, on the leaving and stabilizing groups inherited by a growing macromolecule from the chain transfer agent, as well as on the side groups coming from monomers entering the polymerization process. Architecture and self-assembling properties of the resulting polymers are briefly discussed with regard to their potential functional applications, which include drug delivery, protein recognition, anti-fouling and anti-corrosion coatings, the compatibilization of polymer blends, the modification of fillers to increase their dispersibility in polymer matrices, etc.

Polymers as Versatile Players in the Stabilization, Capping, and Design of Inorganic Nanostructures

The integration of simple components to generate sophisticated hybrid materials with fine-tuned properties represents a significant scientific challenge. Herein, we present recent advances in the use of polymers to control the synthesis and properties of three of the most relevant inorganic nanoparticles, namely, quantum dots (QDs), magnetic nanoparticles (MNPs), and noble metal nanoparticles (NMNPs). We show relevant examples of how polymeric structures synthesized by techniques such as ATRP, RAFT, and living cationic polymerization are used to aid in the synthesis and stabilization of the nanostructures to generate nanocomposites with outstanding capabilities. Special emphasis is placed on describing how some of the exceptional physicochemical properties of polymers are used as nanoreactors to facilitate the synthesis of the nanostructure by providing an adequate chemical environment. Additionally, we also describe how polymers are utilized to protect the integrity of the nanostructure from chemical degradation. The integration of polymeric structures and the nanostructures has a strong impact on the dispersion and morphology of the latter and, consequently, endow them with novel and promising features. The advances described here, particularly the use of polymers to modulate and provide new properties to nanoparticles, exemplify the great versatility of polymers and how these may expand the capabilities of inorganic nanostructures that can be used to generate novel and sophisticated hybrid materials.

Monochelic Versus Telechelic Poly(Methyl Methacrylate) as a Matrix for Photoluminescent Nanocomposites with Quantum Dots

Nanocomposites based on CdSe or CdSe/ZnS quantum dots (QDs) and poly(methyl methacrylate) (PMMA) of different molecular weights and functionality were synthesized by ligand exchange of oleic acid with RAFT-based PMMA. The successful ligand exchange was confirmed by dynamic light scattering in combination with the approach "macromolecules-ghosts" and transmission electron microscopy. Comparative study of mono- and telechelics of PMMA revealed the similarities and differences in their behavior in formation of complexes with QDs and the optical properties of the corresponding nanocomposites. Telechelics exhibited higher efficiency in the complex formation and seemed to be promising candidates for the construction of devices based on QDs and polymer matrix for optical applications.