Preparation Of Triazine Conjugated Microporous Polymers And Their Iodine Adsorption And Fluorescence Sensing Properties

The radioactive iodine ¹²⁹I,¹³¹I is an important isotope in medical diagnosis and nuclear industry.With the development of industry and diagnosis and treatment technology,inevitable production of radioactive iodine waste,therefore the radioactive iodine waste discharge is urgently needed to be controlled.The traditional adsorbents have good selectivity and high adsorption capacity for radioiodine in iodine vapor and solution iodine.However,it is difficult to reuse these adsorbents because of the defects in the performance of the material itself.The nitryl aromatic compound?NACs?,as an important pollutant,will have great harm to the environment and the health of human body without treatment,and it has developed the means of chromatographic analysis,optical analysis,electrochemical analysis and so on,and has specific identification ability on the NACs.The results show that the microporous polymer has the advantages of high thermal stability,high specific surface area and large pore volume,selective fluorescence detection of various ions and molecules,and good application prospect in the adsorption and fluorescence sensing.Based on this background,we have synthesized a variety of nitrogen-rich triazine-based microcellular polymers,which show excellent performance in the detection of NACs with iodine adsorption and selective fluorescence.First,the paper introduce a covalent triazine-based framework with tetraphenylthiophene?TPT? backbone?TTPT? was prepared by the AlCl₃ catalyzed Friedel-Crafts reaction of commercially available materials 2,4,6-trichloro-1,3,5-triazine?TCT? with tetraphenylthiophene in 1,2-dichloroethane.The chemical structure of the network was examined by Fourier transform infrared?FT-IR? spectroscopy,solid-state ¹³C cross-polarization magic-angle spinning ¹³C?CP/MAS?NMR,elemental analysis?EA?,and UV-Vis.As shown in the FT-IR spectrum.The results show that?-conjugation is extended in TTPT.The morphology of polymer network was studied by scanning electron microscope?SEM?.It was found that ttpt had no uniform shape and showed soft and porous shape.The thermal stability of conjugated microporous polymers was tested by thermogravimetric analysis?TGA?.The results show that the thermal stability of the synthesized polymer network is very good,and the polymer network begins to decompose rapidly at 525?.The porosity and pore structure of ttpa were analyzed by nitrogen adsorption desorption test,Specific surface areas up to 361.0 and 315.5 m² g^-1,Iodine adsorption capacity can reach 1.77 g g^-1.TTPT showed abundant micropores,and the main pore width was concentrated at 1.428 nm,its specific surface area is 315.5 m² g^-1.TTPT possesses a unique microporous character with ideal chemical and thermal stability.It exhibits fluorescence sensing for o-nitrophenol and outstanding performance for the reversible adsorption of iodine in both vapor-and liquid-phases.Then,three new triazine-based conjugated microporous polymers with nitrogen as core containing triphenylamine?TPA?,4,4',4"-tris?N,N-diphenylamino?triphenylamine?TDATA? and 4,4',4"-tri[phenyl?m-tonyl? amino]triphenylamine moieties?TMDATA??TTPA,TTDATA and TTMDATA? were constructed via Friedel-Crafts reaction catalyzed by methanesulfonic acid.The resulting CMPs possess high BET surface area of over 308,491 and 456 m² g^-1,The influence of ratio triazine units with TPA units and methyl on the property were investigated.Large pore volumes,good stability,and display highly efficient and reversible guest uptake ofin iodine vapour than that of the CMPs with benzene as core.Furthermore,luminescent study indicated that TTPA exhibits high sensitivity to electron-deficient I₂ via fluorescence quenching.TTPA shows the largest amount of iodine adsorption and was the first CMPs used fluorescence sensing iodine.These results suggest that this conjugated microporous polymer may be a promising high capacity radioactive iodine absorber and NACs or I₂ sensitive fluorescent sensor.