Liquid crystalline block copolymers as adaptive agents for compatibility between CdSe/ZnS quantum dots and low-molecular-weight liquid crystals

Abstract

Liquid crystalline (LC) triblock copolymers were used either as (i) a nematic matrix, which can be loaded with 10 wt% of CdSe/ZnS QDs, or (ii) a compatibilizer, which allows more than 1 wt% of QDs to be introduced in low-molecular-weight cholesteric LCs.

Hybrid fluorescent liquid crystalline composites: directed assembly of quantum dots in liquid crystalline block copolymer matrices

“…The LC polymer-QD composites were prepared by a two-step ligand exchange procedure described in our previous paper. 37 QDs initially capped with OLA were treated with pyridine three times, and then the labile pyridine ligands were exchanged for polymer ligand bearing the same binding groups, a block copolymer or a random copolymer. Each stage of the ligand exchange was conrmed by the change in solubility of QDs in the respective solvent ( Fig.…”

“…24,35 The same results were obtained for ABA LC triblock copolymers with end pVP blocks in our previous work. 37 From this viewpoint, it is most interesting to consider the morphology of the composites based on host block copolymers that form ne microphase separation structures: pVP 60 -b-pPhM 40 -b-pVP 60 , pVP 120 -b-pPhM 40 and pVP 120 -b-pPhM 100 . The morphology of the composite lms as thin slices were investigated with TEM without staining.…”

“…In our recent report we have tested ABA LC triblock copolymers containing two end poly(4-vinylpyridine) blocks as the host matrix for hybrid uorescent LC polymer-QD composites. 37 The aim of that work was to achieve a significant concentration of QDs embedded into the polymer matrix while keeping their dispersion stable. We have demonstrated that these block copolymers allow preparation of composites with the loading of QDs up to 10 wt%.…”

Optimization of Chemical Structure of Compatibilizers Based on Liquid Crystalline Diblock Copolymers for Reconciliation Between Inorganic Quantum Dots and Organic Cholesteric Liquid Crystals

“…CdSe/ZnS QDs covered with oleylamine and surrounded by TOPO matrix were synthesized according to a previous literature [27]. To prepare QDs coated with LC block copolymers a ligand exchange procedure was used [24]. In the course of this procedure, oleylamine on the surface of CdSe/ZnS QDs was replaced by pyridine which was exchanged to a LC block copolymer containing poly(vinylpyridine) block.…”

“…Recently, we have developed an approach to the design of hybrid CLC materials based on specially designed LC triblock copolymers [24]. CdSe/Zns QDs coated with these LC triblock copolymers could form stable dispersions in low molecular weight CLCs and QD loading was as high as 1 wt.…”