| Recently, some new types of adsorbent have been developed for bilirubin removement, such as water-soluble cationic polymer adsorbent. This kind of adsorbent is made of polyethyleneimine (PEI) as a matrix and P-cyclodextrin (P-CD) as a functional adsorption molecule, and it shows higher adsorption efficiency for plasma bilirubin. However, the preparation of the water-soluble cationic polymer adsorbent usually needs complicated methods. It adapts dialysis method to separation and purification, and this process consumes too much time, energy and materials. In this paper, we attempted to graft the β-CD on the surface of Fe3O4magnetic nanoparticles to solve the problems of separation and purification. Subseqently, the effect of adsorbent on the removement of toxin, such as bilirubin (BR), was investigated. The work in this thesis includes three parts:(1) In order to fabricate sodium citrate TSC-modified Fe3O4(Fe3O4-TSC) magnetic nanoparticles with small size, ferromagnetism and good dispersibility, we investigated the effect of synthetic method, surfactant addition way, curing temperature and reaction time in nucleation and growth process, ferrous salt dosage, iron precursor salt addition time and magnetic field on the mass recovery of small size nanoparticles, size and magnetism of nanoparticles. The results showed that adaption reverse coprecipitation method, addition sodium citrate with two steps, the1.75specific value bewteen Fe3+and Fe2+was,270seconds of iron precursor saltat25℃for10min without magnetic filed can require the desired Fe3O4-TSC magnetic nanoparticles with a diameter54.8nm of and the saturated magnetic of63.29emu/g.(2) PEI can adsorb on the surface of the Fe3O4-TSC with negative charge by electrostatic interaction. In the experiment, we investigated the effect of PEI’ s concentration on the amount of-NH2, size and potential of PEI-modified Fe3O4(Fe3O4-PEI) nanoparticles, and the stability of the PEI modified layer, besides, the effect of the degree of oxidation of β-CD on the adsorption efficience for freedom BR was studied. Fe3O4-TSC, Fe3O4-PEI and β-CD-modified Fe3O4(Fe3O4-β-CD) were characterized by XRD, FTIR, VSM and TEM. The results showed that the Fe3O4-PEI nanoparticles had a relatively small size, high potential and the amino content of0.783mmol/g when the concentration of PEI was1.0%. Moreover, the PEI can steadily modify on the surface. When the molar ratio between β-CD and NalO4was1:0.1,Fe3O4-β-CD adsorbent has the highest adsorption capacity for freedom BR. (3) Fe3O4-β-CD adsorb BR mainly by hydrophobic interaction. The adsorption kinetics and isothermal adsorption of Fe3O4-β-CD for BR were studied. Furthermore, the adsorption for BSA the efficience of static adsorption and dynamic adsorption for BR binded with BSA, the adsorption efficience for other toxin, and the congestion of dialyser were also investigated.. The results showed that adsorption equilibrium was about90min, the adsorption isotherm was well represented by the Langmuir isotherm model, the association constant of Fe3O4-β-CD for BR was6.14×104L/mol, and the maximum adsorption capacity was250mg/g. It has good biocompatibility without adsorption of BSA, the static adsorption capacity of Fe3O4-β-CD for BSA blinding BR was40.7mg/g, and the adsorbent can not cause the blockage of the dialyzer. It showed high adsorption efficiency for BR binded with BSA, and plasma BR, which displays with removement efficiency of66.3%and31.2%respectively. The adsorption efficiency for other toxin such as total bile acid could get to41.4%. So adsorbent revealed good adsorption effect for hydrophobic toxin. |
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