基于辉光放电电解等离子体对双波长响应荧光温敏水凝胶的可控合成及荧光温敏特性与影响机制研究

In this project, the NaYF4:Yb,Er-NaYF4:Eu/PAAm-PNIPAM hydrogels of dual wavelength fluorescence/temperature response were synthesized using glow discharge electrolysis plasma as initiator, NIPAM and AAm as monomers, ricinoleic acid modified NaYF4:Yb,Er and NaYF4:Eu as fluorescence nanocrystals, as well as the water as solvent. The emission spectrometer and high-speed numerically controlled camera were used to detect synchronously the discharge process. The internal relation of the discharge parameters, the contrast intensity of emission spectrum of hydroxyl radicals in the discharge process, and the discharge plasma images were analyzed. The micromorphology of hydrogels under various discharge conditions were observed by TEM and SEM, the key factor for the micromorphology of hydrogels and the controllable synthesis conditions were obtained. Moreover, the relationship between discharge characteristics and fluorescence/temperature response of hydrogels was obtained with DSC and fluorescence spectrophotometer, thus, it can be realized the influencing mechanism of ambient temperature variations on dual wavelength fluorescence/temperature response, as a result to establish the dual wavelength fluorescence/temperature reversible response mechanism model and realized the effective combination of temperature and dual wavelength fluorescence response.

本项目拟以辉光放电电解等离子体为引发源，对具有不同波长响应蓖麻油酸修饰的上转换(NaYF4:Yb,Er)和下转换(NaYF4:Eu)荧光纳米晶、温敏单体(NIPAM)、丙烯酰胺(AAm)同时存在的水溶液体系进行放电电解，引发合成具有双波长荧光和温度响应性能的NaYF4:Yb,Er-NaYF4:Eu/PAAm-PNIPAM水凝胶。采用发射光谱仪和高速数控摄像机对放电过程同步检测拍摄 ，分析放电参数、放电过程中产生的羟基自由基发射光谱强度、放电等离子体图像之间的关系；采用TEM和SEM观察不同放电条件下制得的水凝胶的微观结构，找出影响水凝胶微观结构的关键因素，得到水凝胶可控合成条件。结合DSC和荧光光谱仪分析放电特性与水凝胶荧光温度响应性能之间的关系，揭示环境温度变化对水凝胶双波长荧光性能的影响机制，建立水凝胶的双波长荧光温度可逆响应模型，实现温度和双波长荧光的高效复合。

利用辉光放电电解等离子体技术制备水凝胶材料是当今低温等离子体应用领域的前沿热点课题。本项目首先采用溶剂热法和高温热解法合成出蓖麻油酸修饰的NaYF4:Yb/Er等上转换荧光纳米晶和巯基丙醇修饰的CdTe/CdS等量子点。将这些荧光纳米粒子加入到含有有机单体和交联剂的水溶液中，对其进行辉光放电电解制备出系列具有荧光/温度敏感的多功能水凝胶材料。借助X射线衍射仪、扫描电子显微镜、透射电子显微镜、红外光谱仪等对制得的水凝胶成分、形貌、结构等进行表征，同时，借助荧光光谱仪、差热扫描分析仪、万能试验机等现代仪器对水凝胶的荧光、温度、压缩强度、循环使用稳定性等性能进行测试表征分析，揭示了液相辉光放电电解过程及对多功能水凝胶合成机制，获得了改变外电路参数对多功能水凝胶的结构和性能影响规律,得到了具有良好的上/下转换荧光/温度多重敏感型的水凝胶材料。这些研究结果为利用液相辉光放电电解等离子体技术合成多功能水凝胶领域提供参考。课题组经过三年时间的研究，基本完成了项目计划书中的研究内容，取得了一系列重要的原创性成果。三年间，课题组已在国内外重要学术期刊发表SCI学术论文8篇，授权国家实用新型专利一项，2018年获得河北省杰出青年基金资助，同年，获得河北省青年拔尖人才称号，培养毕业硕士生5名，本科生10名。