The Fabrication And Modification Of Microstructured Polymer Optical Fiber And Its Application In The Field Of Chemical Sensing

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.