Preparation Based On Porphyrin Functional Membrane And Its Detection Of Cadmium Ions

Porphyrin has been widely used in biology,chemistry,and physics,because of their special chemical structure and optoelectronic properties.Based on the charges of TMPyP,we immobilized TMPyP on the surface of PSF-PNaSS and PAN membrane.We emphatically studied the detection of PSF PNaSS/TMPyP and PAN-TMPyP-?PAH-PSS?n membrane to Cd²⁺,according to the characteristics easily coordination with the heavy metal ions of TMPyP.Under the dynamic condition,the functional membrane showed good preconcentration property for Cd²⁺ due to the coordination interaction between TMPyP and Cd²⁺.The spectral and the apparent color changes enabled the detection function of the membrane and the reversible coordination endowed the membrane with good regeneration ability.Lower initial concentration of Cd²⁺ solution and lower flow rate led to lower absorption and detection rate of the functional membrane.The preconcentration and detection for ultratrace Cd²⁺ can be achieved by controlling the capacity of TMPyP.Compared with the static adsorption,the function membrane showed faster detection for Cd²⁺ under the dynamic condition which favored the diffusion and adsorption of Cd²⁺ on the membrane surface.The time about detection of Cd²⁺ from 6h reduced to 60min which the concentration of Cd²⁺is 0.01mg/L.On the surface of PAN-TMPyP function membrane alternately adsorption positively charged polyelectrolytes polypropylene amine hydrochloride?PAH?and negatively charged polyelectrolyte styrene sulfonate?PSS?,through the layers of self-assembly technology which make the TMPyP more stable on membrane surface.The spectral and the apparent color changes enabled the detection function of the membrane.At the same time,we solve the problem:TMPyP maldistribution.the percent grafting of membrane surface with SI-ATRP and the stable of TMPyP on membrane surface.Researches show that:higher initial concentration of Cd²⁺solution and higher flow rate and lower capacity of TMPyP led to higher detection rate of the functional membrane.Compared with the static adsorption,the function membrane showed faster detection for Cd²⁺ under the dynamic condition.The time about detection of Cd²⁺ from 3h reduced to 100min which the concentration of Cd²⁺is 0.001mg/L.The function membrane of PAN-TMPyP-?PAH-PSS?n can Intercept cadmium ion through regulating membrane structure.The speed of detection can be improved by improve the concentration of cadmium ion in feed liquid.The volume about PAN-TMPyP-?PAH-PSS?n function membrane detection of Cd²⁺ from 75mL reduced to 25mL along with the reject rate improve from 55%to 80%which the concentration of Cd²⁺ is 1mg/L.