【作者】 杨兴华；

【导师】 王丽莉；

【作者基本信息】 中国科学院研究生院（西安光学精密机械研究所） ， 光学， 2008， 博士

【摘要】 微结构光纤（Microstructured optical fiber,MOF）技术是利用光子晶体作包层,实现操控光子在光纤芯中运动,达到传送光波目的。因为MOF比传统光纤具有更广阔的应用前景,所以是目前光学界最热门的研究领域之一。本文以通用光学聚合物材料—有机玻璃（学名:聚甲基丙烯酸甲酯,英文缩写:PMMA）为基材,研究制备微结构聚合物光纤（Microstructured polymeroptical fiber,MPOF）的新方法、MPOF包层中阵列化孔洞的修饰技术、以及孔洞被修饰MPOF在化学传感、生物传感领域的应用基础研究。光纤制备技术研究包括了大尺寸预制棒制造技术研究与大尺寸预制棒拉伸技术研究两个重要的方面:1.预制棒制备技术中,作者首先探索了以单体为原料的原位聚合法的最佳工艺与条件。然后对以PMMA颗粒料为基材的挤出法工艺进行了研究,建立了独特的MPOF专用制造系统设备以及与之配套的优化工艺条件。2.对用两种方法制作的大尺寸MPOF预制棒的拉伸工艺进行系统研究,对不同直径的预制棒、不同用途的预制棒采用不同方法拉伸:分别为直接拉伸法、二次预制棒拉伸法。MPOF包层中阵列化孔洞的修饰技术研究主要包括了三方面的工作:多孔性聚合物薄膜修饰、多孔性氧化物薄膜修饰、以及纳米金属薄膜修饰技术研究。为了探索被修饰MPOF在化学以及生物传感领域的潜在应用,作者以自行设计、研制的18孔六方结构MPOF为材料,探索了在不同类型的修饰MPOF内部掺杂不同种类的功能有机色素分子,分别制备了MPOF pH值测定探头、氟离子（F^-）浓度传感探头:1.pH传感探头采用曙红为指示剂,将其包埋于醋酸纤维素（Cellulose acetate,CA）采取负压吸入方法在MPOF内成膜。SEM表征结果显示曙红-CA敏感膜具有疏松多孔结构,膜厚度约210nm,厚度均匀。该MPOF-曙红探头在570nm处荧光强度随pH值强烈变化。在pH=2.5-4.5范围内,响应呈线性。此外,以1∶1比例共固定阳离子表面活性剂CTAB可使响应范围从原来的2.5-4.5变为1.5-4.5,表观pKa分别为3.5和2.8。2.将传统凝胶（gel）传感膜技术与MPOF特殊结构进行有机结合,构建出了新颖的光纤传感体系。MPOF-gel氟离子传感探头采用实验室合成的桑色素-Al配合物为指示剂。敏感膜的性能通过水硅比及掺杂的共前躯体KH-560含量进行调节。SEM形貌表征显示溶胶（sol）可以在MPOF内部形成结构完好的高强度gel敏感膜。探头响应受pH影响,pH越低,荧光强度越高,过低pH值会引起桑色素-Al泄漏。发现正硅酸乙酯、KH-560、水、乙醇配比为1.1 ml、1.9 ml、1.2 ml、2 ml的MPOF探头在pH=4.6缓冲体系中具有较好响应特性,响应范围是5-50 mol/L,在160 s内达到响应平衡。最后研究了纳米Ag的修饰MPOF中的纳米金属粒子对荧光色素的荧光增强效应及作为电化学传感探头的初步结果。纳米Ag层通过葡萄糖还原银氨络离子（Ag（NH₃）₂⁺）实现。XRD结果显示MPOF内部物质为单质Ag。SEM结果表明Ag的生长状态可以从不连续的岛状到控制到连续的银层。Ag层连续分布的Ag-MPOF探头被制成纳米电极,以NO₃^-为检测对象。初步循环伏安法研究结果显示硝酸根（NO₃^-）在Ag-MPOF微电极表面表现出良好的可逆氧化-还原特性,表明具有高电化学活性。另外,岛状纳米Ag分布的Ag-MPOF探头对Hemi cyanine溶液产生了较明显的纳米金属粒子对荧光色素的荧光增强效应。更多还原

【Abstract】 Photons were operated and controlled to realize the aim of light transmission in microstructured optical fiber（MOF） by the cladding structure of photonic crystals. MOF was a very popular research field because of its broad prospects for applications.In this thesis,new method for fabricating microstructured polymer optical fiber （MPOF）,basic application research for modified MPOF in the fields of chemical sensing and biosensing were studied.The study of MPOF fabrication included the fabrication of big size preform and its drawing:1.The author first explored the best conditions for the in-situ monomer polymerization technology of fabricating preforms.Then studied the extrusion technique,established an unique MPOF fabrication system and optimized extrusion conditions.2.Studied drawing process of the preforms fabricated by the two methods. Different methods were practiced.One was directly drawing,the other was drawing through secondary preforms.Modification of array holes in MPOF included three aspects:porous polymer layer modification,porous oxides layer modification and nano-metal layer modification.To study the potential of modified MPOF in applications of chemical and biosensing,the author designed 18 hexagonal hole MPOF,doped with different kinds of indicators in different modified MPOFs,and fabricated pH probe and fluoride probe.1.Indictor was eosin in pH probe and was dissolved in cellulose acetate（CA） solutions.It was immobilized in MPOF by inhaling.SEM result shew eosin-CA film was porous with the thickness of 210 nm.The signal at 570 nm of probe changed with pH value greatly.The linear region was pH=2.5-4.5.With the addition of 1:1 CTAB,the linear region could be expanded to 1.5-4.5.Apparent pKa values were 3.5 and 2.8,respectively.2.Novel optical fiber sensor was obtained by combining gel sensing film with MPOF structures.Morin-Al was chosen as the indicator of MPOF-gel-fluoride probe. The properties of gel film were adjusted by the proportion of silicon to water and the concentration of co-precursor of KH-560.SEM results shew the gel film was uniform with high mechanical strength.Responds of probe were sensitive to pH. Intensity was proportion to pH value.Over low pH solutions could induce the leakage of morin-Al.When the proportion in volume of TEOS:KH-560:H₂O:EtOH was 1.1:1.9:1.2:2,the MPOF probe shew favorable response to F^- with concentration of 5-50 mmol/L within 160 s.In the end,metal enhanced fluorescence effect of pigment by nano-metal particles in MPOF and the application as electrochemical sensing probe were preliminary studied.MPOF was modified with silver by reducing silver ammonia with glucose.XRD result exhibitted the material in MPOF was pure silver phase. SEM photos shew the silver layer could be controlled to form continuous or isolate morphologies.Probe with continuous silver layer was fabricated into nanoelectrode to detect nitrate.Nitrate shew reversible oxidation-reduction characterization on Ag-MPOF electrode.Including this,island silver in MPOF probe shew obvious MEF to hemi cyanine solution.更多还原