Preparation Of Sulfonic Acid Type Functional Microspheres And Study On Their Adsorption Properties For Cationic Dyes

Dyes add infinite color to our life,at the same time,they cause huge destruction to the environment.Dye is not only toxic to aquatic organisms,but also seriously affects human health,such as kidney dysfunction,reproductive system disorders,skin irritation,liver and central nervous system function damage.Therefore,it is urgent to effectively and quickly remove organic dyes from wastewater.Biopolymer-based adsorbents have been recognized as the most popular adsorbents because of their non-toxic,renewable,inexhaustible,degradable,low cost and environmental friendliness.Chitosan is a kind of natural amino polysaccharide with abundant amino and hydroxyl groups.It is a promising raw material for adsorbent.In this study,three kinds of graft materials were prepared on the basis of economic and environmental friendly industrial resin materials and natural macromolecule chitosan with good biocompatibility,as well as cheap sulfonic acid sodium as functional monomer.The materials were characterized by Fourier transform infrared spectroscopy（FT-IR）,scanning electron microscopy（SEM）,X-ray photoelectron spectroscopy（XPS）,Zeta potential and particle size analyzer,and vibrating sample magnetometer（VSM）.The adsorption properties of cationic dyes were also investigated.（1）Cross-linked polyacrylamide（CPAM）microspheres were acted as the base material,ammonium persulfate（Aps）as the initiator,sodium styrene sulfonate（SSS）as anionic functional monomer,graft-polymerization functional microspheres（CPAM-g-PSSS）were prepared.Then,the adsorption performance and mechanism functional microspheres CPAM-g-PSSS for MB by CPAM-g-PSSS were explored and analyzed.The experimental results show that the redox system with Aps as the initiator could effectively initiate graft-polymerization of SSS onto CPAM microspheres.Under suitable conditions,functional microspheres with graft degree of 12.36 g/100 g can be prepared.The functional microspheres had good adsorption performance for MB at alkaline conditions,and the adsorption capacity can reach 55 mg/g.（2）Glutaraldehyde crosslinked chitosan microspheres（GCS）are prepared via inversephase suspension polymerization.Then,GCS microspheres are acted as the basematerial,Aps as the initiator,SSS as anionic functional monomer,functional microspheres（GCS-g-PSSS）are prepared by surface grafting polymerization.The adsorption kinetic at different temperature and initial concentration is studied and fitted.The adsorption isotherms of GCS-g-PSSS for MB are explored at different p H,temperature and salinity.The adsorption capacity of GCS-g-PSSS for MB is 820.1 mg/g at 318 K.The adsorption isotherms at different temperature are fitted by Langmuir,Freundlich,Dubinin-Radushkevich and Temkin.Thermodynamic parameters imply that adsorption is a spontaneous and endothermic process.And this adsorbent has good reusability.The adsorption ability of GCS-g-PSSS microspheres is also excellent for other cationic dyes.Thus,GCS-g-PSSS microspheres might serve as a promising adsorbent for contaminated water scavenging.（3）Fe₃O₄nanoparticles are prepared using chemical co-precipitation.Then,glutaraldehyde crosslinked managic chitosan microspheres（MCS）are prepared via inversephase suspension polymerization.Next,MCS microspheres are acted as the basematerial,Aps as the initiator,SSS as anionic functional monomer,managic functional microspheres（MCS-g-PSSS）are prepared by surface grafting polymerization.The adsorption results of MCS-g-PSSS for MB indicates the adsorption capacity increases with rising temperature,adsorbate concentration and p H.When the mass fraction of Na Cl is increased,the adsorption amount decreases first and then increase,resulting in a"fake"adsorption phenomenon.The adsorption kinetics data at different temperatures conforms to the pseudo-second-order adsorption kinetics model.The adsorption isotherm of MCS-g-PSSS for MB Four adsorption isotherm models are used to fit the adsorption isotherm data at different temperatures,and the Langmuir adsorption isotherm model is found to be consistent with adsorption isotherm model.