Preperation Of Porous Polymer Microspheres And Its Application In Wastewater Treatment

Porous Polymer Microspheres are a kind of spherical particles with porous structure, which are prepared by polymerization. Because of their small particles size, large specific surface areas, controllable pore structure and good suspension in disperse system, porous polymer microspheres have exhibited extensive application prospect in biological system, medical science, cytology and environmental engineering. Suspension polymerization is the traditional method of preparing porous polymer microspheres, whose system generally consists of monomer, crosslinker, pore forming agent, initiator and water. Porous polymer microspheres can be got by adding inert solvent as pore forming agent in the process of polymerization and extracting the solvent when the polymerization is completed. Through the preparation process, we can also directly introduce some functional materials to the pore structure in an easy way. In this dissertation, porous polystyrene particles with nanopore, micropore and magnetism are prepared by suspension polymerization on the base of other's research and a systematical discussion is focused on the effective factors of monodispersity, magnetic responsivity and pore property. The results are helpful for the exchange adsorption of high concentration of copper ion in waste water.For studying the factors of dispersity of microspheres, first of all, we set up a suspension polymerization experiment as a reference. We study the effect of crosslinking degree, concentration of dispersant and agitation etc on preparing monodisperse porous polystyrene particles. The result indicates that: agitation and the concentration of dispersant are main factors to size distribution. When we use liquid paraffin as pore forming agent and polyvinyl alcohol as dispersant, porous polystyrene microspheres with better particle size distribution are prepared under the condition of agitation speed: 182.9rpm and the concentration of polyvinyl alcohol: 0.15%.For studying the factors of pore property of microspheres, different kind and proportion of pore forming agent are focused on discussion. We set up a series of experiments on comparing the effect of single pore forming agent with that of mixture pore forming agent under the condition of different proportion. In this paper, we use liquid paraffin and ethyl acetate as non-benign solvent, toluene as benign solvent. The result indicates that: to the extent of some crosslinking degree, when we use liquid paraffin and toluene as mixture pore forming agent, porous polystyrene microspheres with nanopore , better particle distribution, and pore surface area are prepared.For studying the factors of preparing magnetic porous composite polymer microspheres, the magnetic Fe3O4 nanoparticles are prepared by chemical coprecipitation method. The morphology, crystal , size distribution and magnetic responsivity of Fe3O4 are studied with TEM, XRD and VSM technology. The TEM image of Fe3O4 and the size distribution chart analyzed from TEM image show that the diameter interval of Fe3O4 is 8-20nm, the average diameter is 14nm, and the size distribution is also well. The XRD spectrum of Fe3O4 shows that the outcome is pure. Combined with the conclusion of the reference experiment, we study the effect of concentration of dispersant, initiator and magnetic particles etc on the preparation of magnetic porous composite polystyrene particles. Basically command the preparation technology and further study the morphology and magnetic responsivity by TEM and VSM. The result indicates that: by increasing the concentration of dispersant which can improve the dispersion stability of magnetic composite microspheres, magnetic porous polystyrene microspheres with higher magnetic content, better particle size distribution and magnetic response are prepared.In this dissertation, we also study the appliciation of two kinds of microspheres in waste water with high concentration of copper ion by DDTC spectrophotometry. Compare the exchange absorption and desorption capabilities of them under different concentration and pH value of copper ion. The result indicates that: the two types of ion exchange resins have strong absorption of copper ion solvents with different concentration and pH value, the absorption rate reaches more than 99%. By washing out the columns several times with 8% HCl solvent, the desorption rate reaches 90% above. So the two types of ion exchange resins have the ability of recycling. Based on the experimental results, the two resins are applied to the absorption of the industrial wastewater treatment which containing high concentration of copper ion. The result shows that the absorption rate reaches more than 99%, and the result has the value for the practical application.