新型苝酰亚胺/海泡石纤维荧光复合材料的制备及其光谱调控

This project aims to investigate a method for preparing perylene/sepiolite fibers composites with high photoluminescence quatum yield and to obtain an assembly model between perylene derives and modified sepiolite fibers. As raw materials,hydrthermal-type sepiolite should be converted to single modified fibers after disociation，ion-exchang with hydrogen ions in acid solution and framework replacement by aluminium ions.A series of perylene derivatives should be synthesized and structurally analysized through substituent group on the condensed ring of perylene and nuclear magnetic resonance (NMR),infrared spectra (IR),mass spectra (MS) and ultraviolet-visable spectra (UV-vis) technologies. The controllable PL spectra of composites should be modified through controlling PL spectra of perylene derivatives and its assemblies.Crystal structure and configuration of modified sepiolite fibers should be characterized by means of small angle X-ray diffraction (SAXRD),scanning electron microscope (SEM), high resolution transmission electron microscope (HRTEM), solid nuclear magnetic resonance(NMR).The specific surface area and surface pore distribution of porous fibers should be calculated by Brunaer-Emmett-Teller (BET) method and Barrett-Joyner-Halenda (BJH) method.The surface acid centers of modified fibers should be investigated through infrared spectra (IR),temperature-programming desorption (TPD) and differential scanning caborimetry (DSC) using ammonia and pyrodine as probe gas.Consequently,the active sites which could adsobe the target molecules should be confirmed based on the data of surface acid sites,and the results should promote our understanding of the assembling mechanism of perylene derivatives into porous fibers.The process conditions of preparation of porous sepiolite fibers,framwork replacement and surface assembly of perylene derivatives should be optimized.The effects of metallic ions in fibers, magnesium ions, polarity of modified framework,suface hydroxyl and pore size distributions on PL performance and Stokes shift should be studied by means of photoluminescence spectra (PL) and UV-Vis technologies.A model of interaction between perylene molecules and surface of fibers should be established after investigation of interactive force of perylene molecules with inner and outer surface of porous fibers.This study will provide a new application idea of fibrous minerals and fundmentals of host-guest incoporation into porous fibers,and also provide a novel method for preparation and application of solid monomeric perylene derivatives.It is noteable that the study will promote combination of inorganic non-metallic materials and other high technologies, develop the new technologies of manufacture of new energy materials,of the processing method and application of sepiolite minerals with high added value, and broaden the research fields of natural silicate minerals as well.

以热液型海泡石为原料，通过解离、酸交换层间离子和骨架置换得到单分散的改性多孔海泡石纤维，然后利用高量子产率的苝酰亚胺类染料改性纳米纤维，得到高荧光量子产率的染料/海泡石纤维发光复合材料。通过控制苝酰亚胺类染料的光谱特性和聚集态光谱特性调控染料改性纤维发光光谱，研究优化海泡纤维制备、骨架置换和染料改性工艺以及光谱调控技术，查明海泡石纤维中重金属杂质离子、镁离子、骨架极性、表面羟基和孔径大小对改性纤维的发光性能的影响规律，查明染料分子与海泡石纤维内表面和外表面的相互作用方式，构建染料分子与纤维表面相互作用模型。本项目的研究为纤维类矿物原料开辟新的应用领域，对固态单分子态苝酰亚胺类染料的制备和应用提供新方案，对纤维类硅酸盐矿物资源的深加工、天然资源的高价值利用以及节能材料具有重要的理论意义和应用价值；同时本项目的研究对促进无机非金属材料学科与其他高新技术的交叉融合具有重要理论意义。

海泡石具有多孔纤维结构，苝类染料高浓度或固态时以分子集聚状态存在降低荧光效率；以热液型海泡石为原料，通过脱镁、层间离子交换、骨架置换、结构转型、灼烧后得到Al取代海泡石、介孔分子筛MCM-41，研究了脱镁、骨架置换和结构转型工艺条件，获得了工艺条件；采用IR,XRD,BET,SEM,HRTEM,29Si NMR，27Al NMR等表征了海泡石脱镁过程中的结构变化，Al-取代海泡石、纯硅介孔MCM-41的晶体结构、孔道结构等基本性质，用Zeta电位表征海泡石纤维离子取代和骨架置换后的表面性能，结果表明Al-改性海泡石仍保持纤维结构，29SiNMR显示改性海泡石中的化学位移在-87.4ppm处的Si原子比例升高，部分骨架Si原子骨架取代反应转变成Q1结构的Si原子；27AlNMR显示Al原子为两种化学环境，分别为四配位骨架Al原子和八配位平衡Al离子，其原子比为AlOct/AlTetra=1.12。通过元素分析和NMR结果分析可得到改性海泡石的晶体结构式为Mg(8-1.5m)AlmSi(12-0.75n)AlnO30(OH)4(H2O)2，结构式中的m和n可调；采用吸收和荧光光谱分析了N,N-双十二烷基苝酰亚胺（DDPDI）在甲苯溶液中聚集时不同电子振动态之间的跃迁相对强度的变化规律，提出了根据S0-1 / S0-0跃迁强度比值判断聚集体形成的方法，S0-1 / S0-0为0.67时，染料分子开始聚集；在此基础上采用液相组装的技术在MCM-41及改性海泡石表面组装N,N-双十二烷基苝酰亚胺单分子荧光染料，制备N,N-双十二烷基苝酰亚胺/MCM-41复合物，N,N-双十二烷基苝酰亚胺/海泡石复合物，并利用吸收光谱分析N,N-双十二烷基苝酰亚胺的负载状态，获得单分子态的固体荧光染料，采用介电常数和表面分子Stokes位移变化规律确定单分子在多孔结构表面的锚定位置，获得Stokes位移（Y）和环境介电常数（x）的函数关系。对复合材料进行荧光寿命分析，拟合荧光衰减曲线，获得三种不同状态荧光染料的发光参数，荧光寿命按DDPDI/海泡石<DDPDI<DDPDI/MCM-41升高，海泡石中金属离子的存在降低DDPDI的荧光寿命，纯硅MCM-41中升高DDPDI单分子的荧光寿命。研究结果对矿物多孔材料组装中客体分子的位点确定以及多孔材料骨架置换原子的控制具有借鉴和指导意义。