Font Size: a A A

Study On The Preparation Of Porous Plastic Fiber Optical Probe And Its Application

Posted on:2006-11-27Degree:DoctorType:Dissertation
Country:ChinaCandidate:Z H XieFull Text:PDF
GTID:1118360152966567Subject:Physical chemistry
Abstract/Summary:PDF Full Text Request
The development of fiber-optical chemical sensors (FOCS), which is the combination of fiber wave-guide technology and fluorescence analysis method, provides prosperously future for the acquisition of on-line, fast and highly sensitive chemical information. Today, FOCS becomes one of the most important research orientation of analytical science. The probe, which is the hard core of FOCS, can selectively identify the analyte as well as assumes the expression of optics signal. So the preparation of probe is the crux for the development of FOCS. Generally, the probe was achieved by covering the sensitive membrane on the end of fiber, and the lifetime of FOCS was restricted by the insufficiency, bleaching and leakage of indicator in the probe.In this thesis, a new porous plastic fiber optical probe was developed. The indicator was embedded or covalently reacted with the monomer in the porous polymer monolith fiber by copolymerization, while inert solvent didn't react during the course of polymerization and a cross-linking porous network came into being inside the probe. When the analyte passed through the pore and reacted with the indicator inside the probe, the optical character of indicator in the probe was changed. This thesis includes five chapters. In Chapter one, the development and principle of FOCS, and the load of indicator in probe were introduced. The main work and innovation of this thesis were brought forward in the end of chapter.In chapter two, the principle, material and the course of preparation of porous plastic fiber optical probe were dissertated and the influence factors of the preparation were throughly discussed.In chapter three, the porous plastic fiber optical probe for ammonia was prepared by copolymerization of hydrophobic methyl methacrylate or styrene as monomer, diethylene glycol dimethacrylate as cross-linking reagent and tetra-iodo-fluorescein or amidofluorescein as fluorescent indicator. The response character for ammonia of porous plastic fiber optical probe with different cross-linking degree, different amount of porogen and indicator were particularly investigated. And the stability, reproduction and reversibility of the probe were also discussed. Since the porous plastic fiber optical probe was hydrophobic,the pH didn't interfere the determination of ammonia. Under the optimal condition, the calibration curve of the porous plastic fiber probe ranged from 2.0×10-4mol/L~9.1×10-3mol/L range of and from 1 ppm~ 20 ppm of ammonia concentration for the fluorescent indicator tetra-iodo-fluorescein or amidofluorescein, respectively. In chapter four, the porous plastic fiber optical probe for pH was prepared by copolymerization of hydrophile methacrylic acid as monomer, diethylene glycol dimethacrylate as cross-linking reagent, heptane as porogen and fluorescent dye Eosin as indicator. And the response characteristic of probe for pH was studied. Under the optimal condition, the calibration curve covered the range of pH0.0~3.0.In chapter five, the porous plastic fiber optical probe for dissolved oxygen was prepared by copolymerization of hydrophobic and ventilative 2,2,3,3-tetrafluoropropyl methacrylate and butyl methacrylate as admixture monomer, diethylene glycol dimethacrylate as cross-linking reagent and tris(4,7-diphenyl-1,10-phenanthroline) ruthenium(II) perchlorate as fluorescent indicator. The response characteristic for dissolved oxygen of porous plastic fiber optical probe with different cross-linking degree, different amount of porogen and indicator were particularly investigated. Under the optimal condition, the calibration curve ranged from 0~10 ppm of dissolved oxygen concentration and t95 was 1.5 min. The leakage of indicator, reproduction and reversibility of the probe were also discussed in this chapter.
Keywords/Search Tags:Fiber optical chemical sensor, Porous plastic fiber optical probe, Sensor, Ammonia, Dissolved oxygen, pH, Functional polymer
PDF Full Text Request
Related items