Ptfe Fiber Irradiation Grafting Modification And Its Application

The novel adsorbent of PTFE-g-GMA-PEI fiber based on PTFE fiber was prepared by ⁶⁰Co radiation-induced graft polymerization with GMA and by subsequent chemical modification of the epoxy group of PTFE-g-GMA fiber with PEL The aim of this dissertation is to study systematically the adsorption characteristics of the bilirubin and some metal ions on the PTFE-g-GMA-PEI fiber, and apply it to the separation/preconcentration and speciationa analysis of trace heavy metal elements. The major contents are described as follows:The effect of pH, ionic strength, temperature, BSA, initial bilirubin concentration and adsorption dynamics on the adsorption capacity of PTFE-g-GMA-PEI fiber for bilirubin was investigated in a batch system. The maximum adsorption capacity of the grafted fiber was 9.6 mg g^-1 at pH = 6.5. The bilirubin adsorption on this fiber obeyed the Langmuir model. Besides, this fiber possessed the ability to selectively adsorb bilirubin in the co-presence of BSA.Comparison with other bilirubin sorbents showed that the PTFE-g-GMA-PEI fiber had good adsorption capacity and high selective adsorption for bilirubin. The new adsorbent had the advantage of fiber material. In addition, this adsorbent was inexpensive , easy to prepare and had no toxicity. So the PTFE-g-GMA-PEI fiber as the biomedical adsorbent was promising for removing bilirubin through hemoperfusion technique.The chelating adsorption characteristics of some metal ions (Cu, Pb, Cd) on PTFE-g-GMA-PEI Fiber under the static and dynamic condition were studied, and the adsorption conditions were optimized. The PTFE-g-GMA-PEI fiber possesses very strong chelating adsorption ability for heavy-metal ions, and the saturated adsorption capacity can reach 28.3 mg·g^-1,32.4 mg·g^-1 and 5.8 mg·g^-1 for Cu²⁺ , Cd²⁺ and Pb²⁺ under dynamic conditions, respectively. The isothermal adsorption data fit to Langmuir equation, and the adsorption is typical chemical adsorption with monomolecular layer. The adsorbing ability of the PTFE-g-GMA-PEI fiber towards the three kinds of the ions follows the order of Cd²⁺ > Cu²⁺ > Pb²⁺. The pH value has great influence on the sorption. The fact that adsorption capacity increases with temperature rising indicates the adsorbing process of the PTFE-g-GMA-PEI fiber for metal ions is endothermic. As diluted nitric acid is used as eluent, the adsorbed heavy-metal ions are eluted easily from the PTFE-g-GMA-PEI fiber.Using a micro-column packed with PTFE-g-GMA-PEI Fiber made by ourselves as the adsorption material, the adsorption behaviors of Pb and Cd on the above material under different conditions were studied by inductively coupled plasma optical emission Spectrometry ICP-OES). The conditions for the preconcentration of Pb and Cd such as pH, flow-rate, timer eluention agent and its acidity were optimized. A new method of PTFE-g-GMA-PEI Fiber as the adsorbent separation/ preconcentration coupled with ICP-OES for simultaneous determination of Pb and Cd in traditional Chinese Medicine was proposed.At last, a PTFE microcolumn packed with PTFE-g-GMA-PEI Fiber was used in a Fl-ICP-OES system for the speciation of Chromium.Based on the difference of adsorption behavior of Cr(III) and Cr(VI) on the PTFE-g-GMA-PEI Fiber, a simple and convenient method was developed for the speciation of chromium by selective adsorption of Cr(III) and Cr(VI) on PTFE-g-GMA-PEI Fiber at different pH.The proposed method was applied to the analysis of real water samples.