A great deal of polymerizable double bond was chemically introduced onto crosslinked polyvinyl akohol (CPVA) microspheres via molecular design

and then monomer sodium p-styrenesulfonate was graft-polymerized on the surfaces of CPVA microspheres by grafting through method

resulting in the grafted microspheres CPVA-g-PSSS

which have anionic polyelectrolyte brush structure.These grafted microspheres were characterized by FTIR and scanning electron microscopy (SEM)

and their zeta potential curves were determined.The grafted microspheres CPVA-g-PSSS were used for the adsorption of two basic proteins

trypsin (TRY) and lysozyme (LZM).The effects of main factors on the adsorption properties were examined

the adsorption mechanism was explored

and the adsorption thermodynamics was investigated.The results show that by using the method in this work

the graft-polymerization of SSS on the surfaces of CPVA microspheres can be realized smoothly.The anionic polyelectrolyte brush CPVA-g-PSSS possesses very strong adsorption ability for TRY and LZM by the driving of strong electrostatic interaction.The pH value of the medium affects the adsorption property greatly.The adsorption capacities of TRY and LZM on CPVA-g-PSSS first increases and then declines with the increase of pH value

and there are maximum adsorption capacities (82 mg/g for TRY and 78 mg/g for LZM) as the pH value of the medium is equal to their isoelectric points.The ion strength also affects the property of CPVA-g-PSSS microspheres for the two basic proteins.On both sides of the isoelectric point

the effects of ion strength on the adsorption capacity are opposite.The adsorption capacities of TRY and LZM decrease with the increase of the electrolyte NaCl as pH value isoelectric point

and the adsorption capacities of TRY and LZM increase with the increase of the electrolyte NaCl as pH value isoelectric point.As pH value is equal to the isoelectric point

the ion strength does not affect the adsorption capacities.During the adsorption process

the entropy of the system increases and the process is exothermic.