Preparation and Characterization of Theophylline Molecularly Imprinted Polyimide Nanofiber Membrane

Polyamide acid nanofiber membrane (PAAM) was prepared through electrospinning method using polyamide acid (PAA) solution as the raw material.Polyimide nanofiber membrane (PIM) was prepared by heat dehydration from PAAM.Using theophylline (THO) as the template molecule,azobisisobutyronitrile (AIBN) as the initiator,ethylene glycol dimethacrylate (EDMA) as the crosslinker,chloroform as the solvent,THO molecularly imprinted polyimide nanofiber composite membrane (PIMIM) were synthesized by surface thermal crosslinking reaction on PIM,which was pre-coated by polymethacrylic acid (PMAA).Electrospinning conditions were investigated.The structure and morphology of PIMIM were characterized by FT-IR and SEM.Methods of THO elution were compared.Results showed that better electrospinning conditions were electrospun voltage 15.0 kV,receiving distance 12.0 cm,and spinning dope flow rate 0.5 mL/h.Using PIM as the support,PIMIM was a composite membrane containing the molecularly imprinted layer.Static adsorption binding capacity of PIMIM for THO was 144 μmol/g,and the selective separation factor of THO and theobromine (TB) was 1.96.For the cyclic regeneration of PIMIM,Soxhlet extraction method was superior compared to ultrasound washing method.