【作者】 王军；

【导师】 李为立；

【作者基本信息】 江苏科技大学 ， 材料科学与工程， 2019， 硕士

【摘要】 传统的有机荧光小分子由于聚集诱导猝灭效应,在高浓度或固体状态下,荧光强度会有明显的降低,因此在使用过程中必须严格控制荧光探针的浓度,而给检测带来不便;此外,有机染料及其中间产物的化学结构比较稳定,在自然界中很难降解,会给人类和水生生物造成很大的危害。为了减弱其影响,我们通过多种方法制备得到了荧光复合材料,进一步拓展了其应用范围。本文的主要研究内容和结果如下:(1)由于采用水作为溶剂,乳液聚合所制得的丙烯酸乳胶具有环保及易于使用等优点。在本文中我们将传统的有机荧光小分子罗丹明B与丙烯酸乳胶相混合,添加到乳液聚合过程中,通过荧光光谱分析对不同乳化剂体系的聚合过程进行了实时监测,发现了罗丹明B分子与阴阳离子乳化剂之间的不同作用机理,并进一步研究了多种因素对所得乳胶荧光强度的影响。利用乳胶粒子周围形成的双电层与荧光分子之间的作用,有效抑制了荧光分子的聚集,从而提高所得荧光丙烯酸乳胶的荧光强度。此外,在不同温度下对所得漆膜的荧光行为进行检测表明了由丙烯酸乳胶所制得的荧光漆膜具有一定的耐热性和温度响应性,进一步扩大了丙烯酸乳胶和荧光分子的应用范围。(2)由于具有特殊的孔道结构和可调节的孔径,介孔材料在催化等领域中获得了广泛的应用。在本文中,我们利用硅烷偶联剂对介孔材料的孔道进行了修饰,并引入荧光分子制得了荧光介孔材料。利用荧光光谱仪对所得荧光介孔材料和传统荧光分子在不同状态下的荧光行为进行表征,表明由于APTES的改性,提高了荧光分子与介孔材料之间的作用力,使所得荧光介孔材料在溶液和粉末状态下具有了很好的稳定性和可重复利用性。此外,对外界环境的响应性测试表明所得荧光介孔材料对氨气及盐酸气体具有一定的响应性,有效拓展了所得材料的应用范围。通过该方法我们有效的促进了荧光小分子的分散,抑制了其在固体状态下的聚集诱导猝灭效应,为传统荧光分子在固体状态下的应用开辟了新的途径。(3)利用新型的静电纺丝技术,人们已经得到了多种纳米纤维,但在纺丝过程中,仍不能很好的避免有机溶剂的使用,本文将聚乙烯醇水溶液与乳液聚合所得的荧光丙烯酸乳胶相混合,采用静电纺丝法制得了直径均匀且能发出较强荧光的纳米纤维。通过改变纺丝液配方及不同的工艺参数制得了荧光纳米纤维,利用扫描电镜等检测手段对其形貌进行观察,明确了纺丝液的最佳比例及纺丝的具体工艺参数。在纺丝过程中,聚乙烯醇分子的乳化作用能够加强其与乳胶粒子之间的相互作用,促进了乳胶粒子在聚乙烯醇纤维上的均匀分散和荧光纳米纤维膜的形成。此外,利用荧光光谱仪对所得纳米纤维的荧光行为进行了进一步研究,表明所得荧光纳米纤维具有较好的稳定性,且能够对外界温度的变化有一定的响应性。通过该研究,我们成功利用丙烯酸乳胶制得了荧光纳米纤维,避免了有机溶剂的使用,并赋予了纳米纤维强烈的荧光和较好的荧光稳定性,进一步拓展了纳米纤维的应用范围。更多还原

【Abstract】 The fluorescent intensity of conventional fluorescent molecules can lead to a significant decrease due to the aggregation caused quench(ACQ)effect,therefore,the content of fluorescent probe must be kept at low concentration that will cause the difficulty in detection.Besides,the structure of organic dyes and intermediates is very stable and hard to degrade in nature,which may cause great harm to human and aquatic organism and limits their application.To overcome this effect and eliminate the damage,in this paper,a series of fluorescent compound materials were synthesized by different methods to expand the application range of traditional fluorescent molecules.The main research contents and results of this paper are as follows:(1)The acrylic latex obtained by emulsion polymerization is environment-friendly and can be used easily owing to the use of water.In this part,a series of water-based fluorescent paints doped with rhodamine B were synthesized and the rhodamine B can be adsorbed onto the shell of latex by ionic attraction force during emulsion polymerization,and hence its aggregation trends can be inhibited,thus emitting fluorescent light effectively.The different emulsion polymerization processes,such as cationic emulsion polymerization and anionic emulsion polymerization of the systems were studied with real-time monitoring according to PL spectrum to explore the mechanism of interaction between rhodamine B and anionic/cationic emulsifiers.Secondly,the factors that affect the luminescence behavior of the fluorescent latexes were studied systematically by varying the different conditions,such as the dispersing forms of rhodamine B,the concentration of rhodamine B and the latex particles,the size,and glass transition temperature of latex particles.Lastly,the relationship between the fluorescence property of the cured fluorescent latex and the testing temperatures were also studied.The research findings herein not only reports a way to inhibit the ACQ effect of traditional fluorescent molecules,but also are predicted to be beneficial to the development of the environment-friendly smart coatings.(2)The mesoporous materials which have high specific surface area,special pore structure and excellent acid and alkali resistance have been widely used.Herein,we report a way to overcome ACQ effect in rhodamine B luminogen by anchoring it to mesoporous silica having a hierarchical structure(MCM-41)with the help of 3-Aminopropyltriethoxysilane(APTES).The strategy explored herein of employing APTES-MCM-41 exposes the cylindrical one-dimensional mesoporous of silica for possible selective anchoring of RhB molecules which helps to overcome the stacking interactions of the fluorophores-thus fluorescent inhibition and improves the stability and reusability in the state of solution and powder.Finally,we went on to show the capabilities of the modified reserved-fluorescencent ACQ RhB-grafted mesoporous silica as a possible concentration indicator for vapors and expand the application scope of traditional fluorescent molecules in solid powder state.(3)As a new technology for preparing nanofibers,electrospinning with the unique advantages of simple device and abundant raw materials has received extensive attention.In this paper,the fluorescent acrylic latex is mixed with polyvinyl alcohol polymers,and fluorescent nanofibers are prepared by electrospinning.The emulsification of the polyvinyl alcohol polymers enhances the interaction between the latex particles and the polyvinyl alcohol polymers,and promotes the uniform dispersion of the latex particles on the polyvinyl alcohol fibers and the formation of the fluorescent nanofiber membrane during the spinning process.Through the study of various spinning influence factors,we have determined the optimum ratio of spinning solution components and the specific process parameters of spinning.In addition,the studies on the responsiveness of the external environment show that the obtained fluorescent nanofibers have good stability and temperature responsiveness property.Through this research,we successfully made fluorescent nanofibers by using acrylic latex,which avoided the use of organic solvents,and gave strong fluorescence and good fluorescence stability of nanofibers,further expanding the application range of nanofibers.更多还原