| Polystyrene (PSt) functional microspheres have been synthesized by dispersion polymerization in an ethanol/water mixed solvent. The functional microspheres are made with 2-acrylanmido-2-methyl propane sulfonic acid (AMPS) on their surface. Two kinds of the functional microspheres are synthesized, one of them includes poly (N-vinylpyrrolidone) (PVP) and another does not. Their structures are characterised by means of two methods, involving fourier transform infrared (FTIR) and nuclear magnetic resonance (1HNMR). The morphology and particular size of the microspheres are characterized by using laser light scattering (LLS) and scanning electron microscopy (SEM). It is indicated that the products are spherical and have fine monodispersion.The reaction parameters, such as polymerization solvent, time, temperature, rotational speed, styrene concentration [St], AMPS concentration [AMPS] and initiator concentration [AIBN] are found to be able to affect the final diameter of the functional microspheres. The optimum reaction factors are: V(ethanol):V(water) = 6∶4, reaction time 24 h, reaction temperature 60℃, rotational speed 160 r/min. The particular size is shown to increase with the initial concentration [St]. On the other hand, it decreases with [AMPS] and [AIBN]. The particular size in diameter follows the relationship:The adsorption of bovine serum albumin (BSA) by the microspheres reaches their balanced adsorption concentration in 120 min. Adsorption of BSA in solvent with the different pH values, from 4.0 to 7.0, is displayed by the first increase and then decrease. It shows that proteins reaches their highest adsorption content with approaching the isoelectric point (PI=4.7), which indicates that hydrophobic force plays the main factor in BSA adsorption.Three adsorption models (Langmuir Model, Freundlich Model and Temkin Model) are used to fit the obtained adsorption curves. Freundlich Model and Temkin Model are shown to have the better results than Langmuir Model. |
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