title: Superparamagnetic polymer emulsion particles from a soap-free seeded emulsion polymerization and their application for lipase immobilization.
abstract: Using emulsion copolymer of styrene (St), glycidyl methacrylate (GMA) and 2-hydroxyethyl methacrylate (HEMA) as seed latexes, the superparamagnetic polymer emulsion particles were prepared by seeded emulsion copolymerization of butyl methacrylate (BMA), vinyl acetate (VAc) and ethylene glycol dimethacrylate in the presence of the seed latexes and superparamagnetic Fe3O4/SiOx nanoparticles (or Fe3O4-APTS nanoparticles) through a two-step process, without addition of any emulsifier. The magnetic emulsion particles named P(St-GMA-HEMA)/P(BMA-VAc) were characterized by transmission electron microscope and vibrating sample magnetometry. The results showed that the magnetic emulsion particles held a structure with a thinner shell (around 100 nm) and a bigger cavity (around 200 nm), and possessed a certain level of magnetic response. The resulting magnetic emulsion particles were employed in the immobilization of lipase by two strategies to immobilized lipase onto the resulting magnetic composites directly (S-1) or using glutaraldehyde as a coupling agent (S-2), thus, experimental data showed that the thermal stability and reusability of immobilized lipase based on S-2 were higher than that of S-1.
authors.affiliation: State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000, China.
authors.forename: Yanjun
authors.initials: Y
authors.lastname: Cui
authors.forename: Xia
authors.initials: X
authors.lastname: Chen
authors.forename: Yanfeng
authors.initials: Y
authors.lastname: Li
authors.forename: Xiao
authors.initials: X
authors.lastname: Liu
authors.forename: Lin
authors.initials: L
authors.lastname: Lei
authors.forename: Yakui
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jiayu
authors.initials: J
authors.lastname: Qian
mesh_terms: D003911:Dextrans / Q000737:chemistry*; D004655:Emulsions / Q000737:chemistry*; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000378:metabolism*; D007700:Kinetics; D008049:Lipase / Q000378:metabolism*; D058185:Magnetite Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D052638:Particulate Matter / Q000737:chemistry; D058105:Polymerization; D011108:Polymers / Q000737:chemistry*; D059027:Recycling; D012915:Soaps / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D014961:X-Ray Diffraction
chemical_list: D003911:Dextrans; D004655:Emulsions; D004800:Enzymes, Immobilized; D058185:Magnetite Nanoparticles; D052638:Particulate Matter; D011108:Polymers; D012915:Soaps; D008049:Lipase; C065507:ferumoxides