Synthesis And Modification Of Novel Hyper-crosslinked Porous Polymer Materials Andthe Research Of Its Adsorption Performance

With the development of industrialization process,a large number of organic contaminants was discarded into the groundwater system,especially antibiotics and chlorophenols.Due to their strong noxious and hard degradation,which not only destroy the natural ecological environment relayed by human existence,but also threaten the human health.Hence,the treatment of organic wastewater has become a hot topic for researchers.Compared with the other methods,such as catalytic degradation,biodegradation,flocculation and coagulation and membrane separation,adsorption is most promising treatment process due to the simple and convenient,high efficiency and low cost.However,the most of traditional material suffers from many defects including the lower adsorption capacity and rate or difficulty in Surface functional groups,while hyper-crosslinked polymer have shown good application prospects in the waste water treatment because of simple reaction,easy operation,low-cost of synthesis and easy obtained for the raw in commercial.Therefore,it is very important to develop adsorbent materials of hyper-crosslinked polymer with high adsorption capacity and fast removal rate,low cost,easy to recycle and good stability.In this paper,four kinds of hyper-crosslinked polymer adsorbent were synthesized and its adsorption properties was investigated,mechanism of these adsorbents was studied by approaches of physical and chemical characterization.The main results are as follows:1).A novel magnetically hyper-crosslinked polymer composite?Fe₃O₄@HCP-NH₂?was prepared in this study,which combined the advantage of the amino-modified HCP-NH₂ and the magnetic Fe₃O₄ nanoparticles.The Fe₃O₄@HCP-NH₂ composite has a high specific surface area(532.62 m²·g^-1),well-developed mesoporous(0.3786cm³·g^-1)and good magnetic property.The adsorption kinetics indicated that the adsorption of TC on HCP-NH₂ and Fe₃O₄@HCP-NH₂ composite followed a pseudo-second-order model,and the adsorption process of TC agreed well with the Langmuir isotherm.This Fe₃O₄@HCP-NH₂ composite exhibits excellent adsorption ability for tetracycline?TC?and the maximum adsorption capacity calculated by Langmuir model at 298 K is up to 694 mg·g^-1,which was increased by than that of the value of HCP-NH₂)(389 mg·g^-1).The possible reason was due to the fact that the adsorption mechanisms of TC onto Fe₃O₄@HCP-NH₂ are related to the complexation interactions and cation exchange expect for the interaction of hydrogen bonding and pore filling.And the dominant interaction was the surface complexation which was elucidated by X-ray photoelectron spectroscopy?XPS?analysis.In addition,the composite can be rapidly separated and maintains approximately 92.3%of the values from the first adsorption experiment after five regeneration cycles.It can be used as a broad-spectrum and highly efficient adsorbent for organic contaminants including methyl orange,methylene blue,bisphenol A,and 2,4-dichlorophenol removal from contaminated water.2).Waste expanded polystyrene is used to achieve waste management waste and convert waste plastic into organic porous material for the treatment of organic wastewater.By utilizing cheap,abundant waste expanded polystyrene?EPS?as the raw material,high-value-added porous organic polymers?POPs?were prepared through a Friedel-Crafts alkylation reaction using two types of crosslinkers?FDA and CC?and applied to the removal of antibiotics and chlorophenols.The structural characterization indicated that the pore structure of the two types of POPs?EPS-FDA and EPS-CC?can be successfully tuned by stepwise crosslinking with dimethyl acetal?FDA?and introducing different doses of cyanuric chloride?CC?as a crosslinker.The specific surface area of EPS-FDA-2 and EPS-CC-3 are 763.65 and 957.88 m²·g^-1,respectively,and their total pore volume of EPS-FDA-2 are 0.9170 and 0.9417 cm³·g^-1.Their adsorption experiment indicates that both the adsorptions of TC onto EPS-FDA and2,4-DCP onto EPS-CC are best described by the pseudo second-order model and its adsorption thermodynamic data reveals that the adsorptions of TC onto EPS-FDA agreed well with the Langmuir isotherm and the adsorptions of 2,4-DCP onto EPS-CC are well represented by Freundlich isotherm.From Langmuir isotherm,the maximum adsorption capacity of TC onto EPS-FDA-2 was 621.12 mg·g^-1 and the equilibrium absorption capacity of 2,4-DCP onto EPS-CC-3 was 680.27 mg·g^-1.Moreover,the adsorption capacities of EPS-FDA-2 for TC were higher than the others due to the abundant mesoporous structure and better match for the molecular size and EPS-CC-3reveals the highest adsorption capacity was ascribed to the high-content microporous structure and the enhancement of hydrogen bonding.Finally,the cost of prepared adsorbent materials is compared with three common commercial activated carbons,the porous adsorbent materials was evaluated for the industrial application of the waste water treatment due to the cost is almost 50%than the advanced activated carbons under the same adsorption conditional.3).The bisphenol A was used as phenolic hydroxy-containing monomer and the sodium hydroxide was used as chemically modified reagents to synthesize highly water-dispersible hyper-cross-linked polymer for the uptake of water-soluble organic contaminants.XPS and static contact angle was applied for characterization of the structure composition and surface hydrophilicity,the results shown that the HCP-BPA-Na was equipped with the abundant oxygenous functional groups and revealed hydrophilic property.The adsorption of TC and MB onto the hyper-cross-linked polymer?HCP-BPA-Na?were fitted well with the pseudo second-order model and the adsorption n rate?the pseudo-second-order rate constant?was 9.90×10^-33 and 5.92×10^-3g·mg^-1·min^-1,respectively.And its adsorption thermodynamic data could be better described by Langmuir model.From the Langmuir model,the equilibrium absorption capacity of TC and MB onto HCP-BPA-Na was up to 645.16 and 268.09 mg·g^-1,respectively.Both TC and MB removed by the HCP-BPA-Na was involved into the multiple interaction mechanism such as ion exchange,electrostatic interaction and?-?electron interactions,the electrostatic interaction play a dominant role.In addition,the adsorption capacity and removal rate of pollutants onto the adsorbent in two kinds of binary solution systems?MB and MO,TC and MB?were studied and then compared with the corresponding data in a single system.The experiment data reveals that co-existence of TC and MB reduced the adsorption via competition for binding sites from HCP-BPA-Na and the MB and MO can enhance the adsorption with the synergy effect.Finally,in order to evaluated the adsorption capacity of prepared adsorbent materials in the practical water treatment,the remove rate of TC and MB in two kinds of environmental conditions?secondary sedimentation tank water and simulated water?were studied,and the result indicated that the removal rate TC and MB was increased by a higher pH and the synergistic effect of the dissolved organic matter.4).Based on the previous chapter,3-Phenyl-2,5-dihydrofuran-2,5-dione was selected as reactive monomer due to its easy chemical-modification in alkaline solution and then cross-linked by the cross-linker of 1,4-bis?chloromethyl?benzene to obtain the hyper-cross-linked polymer.1,4-bis?chloromethyl?benzene acted both as the cross-linker and reactive raw participated in the cross-linking reaction and self-aggregation reaction was benefited for the enhancement about specific surface area and pore structure of the adsorbent material in treatment of alkalization.After modification with the alkalization reaction,the goal product HCP-COOH was synthesized,which possessed abundant surface functional groups and excellent specific surface area and pore volume.After serials characterization of the adsorbent materials,the target contaminants tetracycline?TC?was chosen as to evaluate the adsorption performance of the adsorbent.The kinetic and thermodynamic behaviors of adsorption process were studied by mathematical model of adsorption,and the results showed that the adsorption of TC onto HCP-MAH and HCP-COOH were fitted well with the pseudo second-order model.Simultaneous,according the pseudo-second-order rate constant,the adsorption rate of HCP-COOH was larger than that of HCP-MAH.Both of their adsorption thermodynamic data could be better described by Langmuir model.From the Langmuir model,the equilibrium absorption capacity of TC onto HCP-MAH and HCP-COOH was up to 273.22 and 418.41 mg·g^-1,respectively.Both TC removed by the two adsorbent of HCP-MAH and HCP-COOH was related to the multiple interaction mechanism such as pore filling,electrostatic interaction and?-?electron interactions and the ion exchange also played a important role in the TC uptake by HCP-COOH.