Study On Synthesis Of Separation Membrane With Molecular Recognition Property And Its Selective Permeance Mechanism

Membrane separation technique is one of the most promising unit operation in twenty-first century, but the foundation of separation is the cut-off molecular weight. When used in complex system liking the natural materials solution, it is difficult to accomplish the accurate separation, because the molecular weight containing in the solution is nearly. So the objective of this paper is to prepare the separation membrane with molecular recognition property and study the selective permeance mechanism.According to the molecular imprinted technique, the functional precursor was gained by the reaction of the puerarin and theγ-aminopropylthriethoxysilane which were used as template molecule and functional monomer. After the hydrolysis between the functional precursor and tetraethyl orthosicate taking as the cross-linker, the functional silica sol was appeared. The separation membrane was prepared by washing the template molecule out from the membrane. In experiments, the factors affecting the forming of the functional precursor, functional silica sol and the separation membrane were analyzed, and the preparation technique was confirmed. The membrane was characterized by the tests of separation experiments, selective experiments, SEM and FTIR, meanwhile the permeance mechanism was studied.The results show that the separation membrane is smooth and defect-free. It can recognize the template molecule and has a special selective permeance property, but the other materials with similar structure can not permeate this membrane freely. The functional film connects the supported membrane tightly in the whole process. So the character of the membrane is steadily.The selective permeance mechanism indicates that the channels composed by lots of recognition sites whose shape and size matches the template molecule and the ionic interactions between the corresponding functional groups existing in the template molecule and recognition sites are the main reasons.The creative ideas of this paper are that an inorganic separation membrane with molecular recognizing property is prepared for the first time, meanwhile the selectivity permeance mechanism of the membrane is studied at molecular level.