The Investigation Of The APTMS-NTA/PVDF Metal Affinity Membrane Towards Bovine Serum Albumin

The polyvinylidene fluoride （PVDF） powders were used as the materials for thepristine membrane preparation. The3-Aminopropyltrimethoxysilane （APTMS） andNitilotriacetic acid （NTA） form the covalent amide bond at a certain temperature, and thenthe APTMS-NTA colloids were blended into PVDF membrane. The3-Aminopropyltrimethoxysilane-Nitilotriacetic acid/polyvinylidene fluoride（APTMS-NTA/PVDF） affinity membrane was prepared using the combined technique ofphysical blending/phase inversion. The structure and chemical groups of the affinitymembrane was characterized. The immobilized metal affinity membranes （IMAM）loading Cu（Ⅱ）, Co（Ⅱ） and Ni（Ⅱ） via the chemical complexing, were prepared to recoverbovine serum albumin （BSA） from the solutions. The BSA adsorption characteristics ofthe above-mentioned three IMAM membranes were investigated, respectively. The IMAMmembranes are competent for the removal of proteins, amino acids and other biologicalmacromolecules from aqueous solutions.The parameters for affinity membrane preparation were optimized by the orthogonaltest. The functional groups and thermal performance of the affinity membrane wereanalyzed using thermogravimetric （TG） and infrared spectrometry （FTIR）, nuclearmagnetic resonance spectroscopy （NMR） techniques. The adsorption characteristics ofCu（Ⅱ）-IMAM, Co（Ⅱ）-IMAM and Ni（Ⅱ）-IMAM affinity membranes towards bovineserum albumin （BSA） were studied. The influences of the coexistent ions including Ca（Ⅱ）and PO4^3–on the BSA uptake of the membrane were evaluated. FTIR and NMR resultssuggest the polyaminecarboxylate groups have been blended to the PVDF pristinemembrane successfully. Also, the metals involving Cu（Ⅱ）, Co（Ⅱ） and Ni（Ⅱ） and BSA arealso sorbed to the affinity membrane successively. The uptakes of Cu（Ⅱ）, Co（Ⅱ） and Ni（Ⅱ）were1.68,0.565,1.354umol/cm², the adsorption capacities of Cu（Ⅱ）-, Co（Ⅱ）-andNi（Ⅱ）-IMAM metal affinity membranes for BSA uptake are0.062,0.13,0.047mg/μmolM（Ⅱ）. So, the adsorption performance for BSA of the membranes follows theorder of Co（Ⅱ）-IMAM> Cu（Ⅱ）-IMAM> Ni（Ⅱ）-IMAM. The existent PO43–exhibits alarger interference on BSA uptake than Ca（Ⅱ）. The adsorption isotherm fits better to the Langmuir isotherm model. The batch sorption kinetics accords with thepseudo-second-order kinetics model. The negative G⁰and positive H⁰, indicates thespontaneous and endothermic nature of the adsorption. The adsorption/desorptionexperiment indicates that the metal affinity membrane possesses an excellent property ofreuse.