| Nitroaromatic explosives will threaten national security and social stability when used by criminals.In addition,nitroaromatic explosives can be used in mining ore,construction of water conservancy,seismic survey and other modern industries;it is widely used in dyes,medicine,agriculture and other fields because of its strong electron-drawing and coloring ability.However,these compounds are difficult to self-degrade in the environment and easily cause soil and water pollution.Thus,the realization of highly sensitive detection of nitroaromatic explosives in water phase is of great significance to social security and human health.It is always a difficult problem in the field of fluorescence sensing to realize efficient fluorescence sensing detection of nitro explosives in water phase.In this paper,the aggregation induced emission（AIE）active and electron-rich multi-functionalized monomers（such as tetraphenylethene,triphenylamine,etc.）have been synthesized,and the Suzuki-miniemulsion polymerization of the prepared monomers were carried to prepare the conjugated porous polymer nanoparticles which are homogeneous and stably dispersed in water phase.The fluorescence sensing properties of the polymer nanoparticles in water phase were investigated.Details are as follows:The linear conjugated polymer nanoparticles l-PAn TPE and crosslinked polymer nanoparticles PAn TPE were prepared by Suzuki-miniemulsion polymerization（A2+B2,A2+B4）using 9,10-anthracenediboronic acid bis（pinacol）ester with1,2-bis（4-bromophenyl）-1,2-diphenylethene and 1,1,2,2-tetrakis（4-bromophenyl）ethene,respectively.The average particle sizes of the two polymers are ca.73 nm.The cross-linked polymer PAn TPE has a mesoporous structure with a pore size of 3.5 nm and a BET surface area of 49.3 m2 g-1.In the fluorescence titration towards nitroaromatic explosives in pure water,l-PAn TPE and PAn TPE exhibited larger quenching constants and better selectivity towards 2,4,6-trinitrophenylphenol（TNP）compared with 1,3,5-trinitrobenzene（TNB）and2,4-dinitrotoluene（DNT）.Moreover,the quenching constant of PAn TPE for TNP was larger(4.0×104 M-1)than l-PAn TPE,indicating that the porous structure is beneficial to increase the contacting area between the sensing material and analyte,and promote the adsorption/diffusion of analyte,which could result in an improved fluorescence sensing performance.Two porous polymer nanoparticles PTATE2 and PTATE4 with average particle sizes of90 nm and 64 nm were synthesized by the retaining AIE-active tetraphenylethene group and the electron-rich triphenylamine group.The two polymers have mesoporous structures with pore sizes of 4.3 nm and 4.8 nm,and BET surface areas of 20.3 m2 g-1 and 13.6 m2 g-1,respectively.The sensitivity and selectivity of the two conjugated porous polymers for the detection of TNP in pure water phase were achieved,with the lowest detection limit of 564n M and the quenching constant of 2.4×104 M-1.The spiked recoveries of TNP detection in real environmental water samples were close to 100%,and t-test method demonstrated that there was no significant difference between the results measured by fluorescence sensing method using PTATE2 and PTATE4 nanoparticles and HPLC analysis at 95%confidence level.It indicates the reliable detection of TNP by the polymer fluorescence sensing in water phase was achieved in this thesis. |
