Design, Synthesis And Macroscopic Response Properties Of Solvent-free Quantum Dots

Quantum dots (QDs) with unique chemical and physical properties have attracted broad attention during the past decades, and have been widely used in various fields, such as optical sensors, optoelectronics and biological imaging. The synthesized of quantum dots are usually dispersed in chloroform, water,ethanol and so on. It greatly limits its further processing and materialization, which also limits its application in the special field. In order to solve the traditional solvent-dependent quantum dots are difificult to machine and extend its application range. People develop a novel quantum dot material, noted as Solvent-free QDs, which directly synthesis through chemical modification by grafting flexible organic chain or ionic liquids on the surface. Thus given the material with new characteristics such as liquidity, heat stability, machinability and so on. Based on these characteristics make the material has a potential application value in optoelectronic devices, intelligent flowing probe and special solvents, etc. At present, research of Solvent-free quantum dots is still in its primary stage, which focuses on the synthesis of materials. So according to the characteristics of the materials to develop a new application field is an inevitable trend for the development of Solvent-free quantum dots. In this paper, we focus on developing more functional Solvent-free quantum dots, and build a selective macroscopic response of Solvent-free quantum dot system through molecular design and synthetic, in order to realize the practical application value of material. Finally, some innovative research results were achieved. The details are as follows:Firstly, we introduced three amphiphilic surfactants with different lengths of PEG chains, for modifying QDs. Firstly, we transferred quantum dots from the oil phase to the aqueous phase via a simple hydrophobic interaction for preparing three different Solvent-free QDs with high fluorescence properties. We have proved the controlled assembly of Solvent-free quantum dots by TEM, DSC and FL characterization. On the basis of the above,1810-QDs were chosen to further investigate the fluorescent and interfacial response towards different metal ions. The fluorescence and contact angle assays suggested that 1810-QDs exhibited a selective response towards Cu2+. Which may lay a foundation for construct smart fluid probes.Secondly, Solvent-free QDs were obtained by grafting flexible PEG chains on the surface of QDs, via a proton exchange self-assembly technique. Supermolecular Solvent-free QDs were obtained by the inclusion interactions of Pillar[5]arene and PEG. Thus the material of Solvent-free quantum dots realize the selective response to Lys in solution phase and macroscopic.Lastly, chiral flexible PEG chain was synthesized by mandelic acid derivatization, then, the Solvent-free CdSe quantum dots with chiral response function were obtained via a hydrophobic interaction. We further investigate the response of chiral-QDs towards amino alcohol, the result shown chiral-QDs realize a high selectivity response to (1R,2S)-2-amino-l,2-phenyl ethanol on molecular scale, microcosmic scale and macroscopic scale.