P（St-NIPAm）核壳纳米粒子光子晶体薄膜的制备及其在荧光增强中的应用

发布时间：2018-05-19 04:01

本文选题：聚(苯乙烯-N-异丙基丙烯酰胺)纳米粒子 + 光子晶体　；参考：《东华大学》2014年硕士论文

【摘要】：光子晶体是两种或两种以上介质材料周期排列的人工晶体,由于其特殊周期性结构的布拉格衍射而具有光子禁带的特性,从而可以对特定频率光的传播进行调控,在新型光学器件方面具有广阔的应用前景。光子晶体特殊的性质,使其在荧光增强方面有一定的应用。本文采用无皂乳液聚合法,制备了单分散的聚(苯乙烯-N-异丙基丙烯酰胺)(P(St-NIPAm))核壳纳米粒子；荧光染料罗丹明B(RhB)与P(St-NIPAm)纳米粒子混合,然后采用垂直沉积法,在载玻片上自组装成掺杂RhB的P(St-NIPAm)纳米粒子光子晶体薄膜,研究该薄膜对荧光增强效应的影响规律。本文主要的研究内容与结论如下： (1)采用一步无皂乳液聚合法,以过硫酸铵为引发剂,固定反应单体的摩尔比,通过调节反应单体的用量,制备不同粒径单分散的P(St-NIPAm)纳米粒子。结果表明,P(St-NIPAm)纳米粒子呈单分散、球形,且具有明显的核壳结构；纳米粒子的粒径与反应单体用量呈线性关系；P(St-NIPAm)纳米粒子的聚合机理与均相成核理论基本吻合。 (2)采用垂直沉积法,P(St-NIPAm)纳米粒子在载玻片上自组装成光子晶体薄膜。结果表明,薄膜中纳米粒子呈面心立方结构紧密堆积,薄膜厚度约8μm,纳米粒子层数约为50层。薄膜的光子禁带位于可见光波段,其实验测量值与理论计算值基本一致,且与纳米粒子粒径呈线性关系；不同粒径纳米粒子制得的薄膜分别显示为蓝紫、蓝绿、黄绿、橘红色。 (3)根据以上结论,基于荧光染料RhB的光谱特点,确定反应单体的用量,合成粒径分别为280.7、284.1、288.7nm的P(St-NIPAm)纳米粒子,并采用垂直沉积法,自组装得带隙处于RhB激发和发射波长的光子晶体薄膜；荧光染料RhB与P(St-NIPAm)纳米粒子混合,然后采用垂直沉积法,在载玻片上自组装成掺杂RhB的P(St-NIPAm)纳米粒子光子晶体薄膜。结果表明,光子晶体薄膜的光子带隙与RhB发射波长一致时,能够提高RhB的荧光强度,当带隙同时覆盖RhB的激发和发射波长时,其荧光强度进一步提高近一倍。然而,本文中P(St-NIPAm)纳米粒子光子晶体薄膜对RhB的荧光增强,并没达到其它文献所报道的极高增强效果,其原因还有待后续的研究。
[Abstract]:Photonic crystal is an intraocular crystal with two or more kinds of dielectric materials arranged periodically. Because of its special periodic Bragg diffraction, it has the characteristic of photonic band gap, so it can regulate the propagation of light at a specific frequency. It has a wide application prospect in new optical devices. The special properties of photonic crystals make them useful in fluorescence enhancement. In this paper, monodisperse poly (styrene-N-isopropylacrylamide) core-shell nanoparticles were prepared by soap-free emulsion polymerization. The photonic crystal thin films doped with RhB were self-assembled on glass substrates, and the effect of the films on the fluorescence enhancement was studied. The main contents and conclusions of this paper are as follows: 1) One-step soap-free emulsion polymerization with ammonium persulfate as initiator, the molar ratio of reactive monomer was fixed, and the monodisperse Pu St-NIPA nanoparticles with different particle sizes were prepared by adjusting the amount of reactive monomer. The results show that the nanoparticles are monodisperse, spherical and have obvious core-shell structure, and the polymerization mechanism of the nanoparticles is in good agreement with the homogeneous nucleation theory. (2) Photonic crystal thin films were self-assembled on glass substrates by vertical deposition method. The results show that the nanocrystalline particles in the films are packed tightly with a face-centered cubic structure. The thickness of the films is about 8 渭 m, and the number of layers is about 50. The photonic band gap of the thin films is located in the visible light band, and the experimental values are in good agreement with the theoretical calculated values, and there is a linear relationship between the measured values and the size of nanoparticles, and the films prepared by different particle sizes show blue and purple, blue and green, yellow and green, and orange respectively. (3) according to the above conclusion and based on the spectral characteristics of fluorescent dye RhB, the amount of reactive monomer was determined, the particle size of Pu St-NIPA was 280.7284.1nm and 288.7nm, respectively, and the vertical deposition method was used. Photonic crystal films with band gap at RhB excitation and emission wavelengths were self-assembled, and photonic crystal films doped with RhB were self-assembled on glass substrates by mixing fluorescent dye RhB with Pu St-NIPA nanoparticles. The results show that the photonic band gap of the photonic crystal film can increase the fluorescence intensity of RhB when the photonic band gap is the same as the emission wavelength of RhB. When the band gap covers the excitation and emission wavelengths of RhB, the fluorescence intensity of the photonic crystal film is further doubled. However, in this paper, the fluorescence enhancement of RhB by photonic crystal thin films of PhanSt-NIPA nanoparticles has not reached the very high enhancement effect reported in other literatures, and the reasons need to be studied in the future.
【学位授予单位】：东华大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB383.2;O734

【参考文献】