含芘的超支化介孔聚合物的合成及对硝基芳烃的荧光传感性能

合成了以金刚烷为核心,以二苯乙炔基芘为连接臂的超支化聚合物P。金刚烷的三维立体结构及分子骨架的刚性结构特点,赋予了聚合物多孔的结构特点。研究结果表明,聚合物P具有均匀的狭缝孔道结构,其孔径多分布在10 nm左右,属于介孔材料。此外还合成了共聚单体二苯乙炔基芘(M)用于对比研究其光学性质及对硝基芳烃的荧光猝灭性能。聚合物P与单体M相比具有更大的Stokes位移,二者在含有三硝基甲苯(TNT)的溶液中,其平衡时的猝灭率几乎相同。然而二者在相同条件下制备的旋涂膜在二硝基甲苯(DNT)饱和蒸汽中,当达到猝灭平衡时,聚合物P的猝灭率为82%,而化合物M的猝灭率仅为22%。说明聚合物P多孔的特点使其透气性大大提高。以不同浓度的聚合物溶液制备出一系列厚度不同的薄膜,发现随着薄膜厚度的增加,荧光峰发生红移,但在DNT饱和蒸汽中的猝灭率变化不大。这种介孔的结构特点在一定程度上克服了旋涂膜传感器的猝灭率对厚度的依赖性。

Synthesis of Hyperbranched Mesoporous Polymer Containing Pyrene and Sensing Performance for Nitroaromatics

A hyperbranched polymer P with adamantane as core and diphenyl ethynyl pyrene as tether was synthesized.The three-dimensional structure and rigid molecular skeleton of adamantane make the polymer porous.The results show that the polymer P exhibits uniform slit pore structure,the aperture distribution is about 10 nm,belonging to mesoporous materials.The comonomers diphenyl ethinyl pyrene (M) was also synthesized to study its optical properties and investigate the fluorescence quenching properties for nitro-aromatics.Compared with the monomer M,polymer P shows a larger Stokes shift,the quenching efficiencies at equilibrium is almost the same in 2,4,6-trinitrotoluene (TNT) solution.However,in the saturated 2,4-dinitrotoluene (DNT) vapour,the quenching efficiencies of the P and M spin-coated film prepared under the same conditions are 82％ and 22％6,respectively,which demonstrate that the porous of polymer P makes its permeability greatly improved.In addition,a series of different thickness of the film with different polymer concentrations were prepared.It is found that the emission spectra exhibit remarkable red-shifts with the film thickness increasing,however,the quenching efficiencies in saturated DNT vapor change little.The mesoporous structure overcomes the dependence of quenching efficiencies for the spin-coating film sensor on thickness.