CdSe量子点的光物理性质研究与荧光杂化纤维的制备

半导体纳米晶体（NCs）具有良好的光稳定性，广泛的发射持久性和高消光系数，在过去几年被广泛研究报道，其中，硒化镉半导体纳米晶体(CdSe NCs)被广泛用于电子照明、太阳能发电、光电传感等领域。然而CdSe NCs的电学、热力学和光物理性质具有较强的尺寸依赖性，在传统的制备方法及应用中容易出现晶体表面缺陷和悬空键以及较为严重的生物毒性和环境毒性。为了实现量子点在各个领域的应用，必须严格控制CdSe NCs的发光波长，尺寸分布以及荧光性能。本研究通过高温热注射法合成了单分散的胶体发光CdSe NCs，使用表面配体对CdSe NCs进行修饰，研究了不同烷基链长度的配体对CdSe NCs尺寸分布和荧光性能的影响，并通过改变溶剂配比制备了纺丝溶液，将其与聚乙烯吡咯烷酮（PVP）进行杂化，制备了PVP/CdSe QDs荧光杂化纤维。结果表明，与传统CdSe NCs相比，经表面配体的修饰的CdSe NCs在有机溶液中因分子间吸附的降低在溶液中有良好的稳定性，具有可调节的溶解度，弥补了缺陷和悬空键造成的荧光性能下降。在CdSe晶体结构的形成过程中，表面配体也有着显著的调控作用。并且更为重要的是，该研究将表面配体修饰与杂化相结合，改善了表面配体的附着，在杂化材料的制备过程中避免了硒化镉纳米晶体与高分子基体直接接触，为荧光团提供了良好的发光微环境，保证了CdSe NCs的荧光性能，使杂化纤维具有良好而稳定的荧光性能。同时，PVP的引入使CdSe NCs的生物毒性和环境毒性得以改善，使材料更加环境友好且具有更好的生物相容性，大大提升了材料的应用范围。事实证明，PVP/CdSe QDs杂化微纤维杂化相容性和分散性良好，具有优异的荧光性能和材料成型性，纤维合成方式简便易行且造价低廉，可应用于溶液处理，光学照明，电极材料，和生物成像等各个领域。

Optimal Fluorescence Property of CdSe Quantum Dots and Electrospinning Polyvinylpyrrolidone Hybrid Microfibers

Semiconductor nanocrystals(NCs)have been widely researched and reported in the past few years due to their excellent light stability,wide emission persistence and high extinction coefficient.Among them,CdSe NCs are widely used in electronic lighting,solar power generation,photoelectric sensing and other fields.However,the electrical,thermodynamic and photophysical properties of CdSe NCs have a size dependence,crystal surface defects and dangling bonds,and serious biological and environmental toxicity are prone to occur in traditional preparation methods applications,which limit their direct application.To realize the application of quantum dots in various fields,the emission wavelength,size distribution and fluorescence properties of CdSe NCs must be strictly controlled.In this study,monodisperse colloidal luminescent CdSe quantum dots were synthesized by high-temperature thermal injection method,and CdSe NCs were modified with surface ligands,and the effects of ligands with different alkyl chain lengths on the size distribution and fluorescence properties of CdSe NCs were studied.In addition,the spinning solution was prepared by changing the solvent ratio and hybridized with polyvinylpyrrolidone(PVP)to prepare PVP/CdSe QDs hybrid fibers.The results show that the CdSe NCs modified by surface ligands have good stability in the organic solution due to the decrease of intermolecular adsorption the modification of surface ligands,as well as adjustable solubility,which compensate for defects and dangling bonds caused by the decline in fluorescence performance,and play an important regulatory role in the formation of CdSe crystal structure.More importantly,this study combines surface ligand modification and hybridization to improve the adhesion of surface ligands and avoid direct contact between cadmium selenide nanocrystals and the polymer matrix during the preparation of hybrid materials.The fluorophore provides a good microenvironment and ensures the fluorescence performance of CdSe NCs,and the hybrid fiber also has stable fluorescence performance.The introduction of PVP has reduced the biotoxicity and environmental toxicity of CdSe NCs,made the material more environmentally friendly has better biocompatibility,and greatly increased the material’s application range.The experimental results show that PVP/CdSe QDs hybrid microfibers have good hybrid compatibility and dispersion,excellent fluorescence performance and material formability,simple synthesis ways and low cost,and applied to solution processing,optical lighting,Electrode materials,and biological imaging and other fields.