Preparation And Property Of Nitrogenous Polymer Nanocomposites

Silica has the features of odorless, non-toxic, non-polluting, good dispersion, large surface area, high purity, and with adsorbed water, a large number of hydroxyl on it’s surface. With its outstanding stability, excellent mechanical and optical properties, silica is widely applied in catalyst support, engineering materials, biomaterials and biological medicine. Nitrogenous polymer is known as a class of polymers having multipurpose usages. In order to synthesis some fine chemicals with special function or purposes, it can be simply coordinated. In recent years contamination of water resources in China are increasingly faced with serious heavy metal ions. Otherwise the advantage of nitrogenous polymer complexation of heavy metal ions excellent performance, lead to its widely application in mental adsorption area. Besides their complex with inorganic nanoparticales to obtain better performance of composite materials has been a heat research. Polymer-metal compound are also an important research in polymer function and development area. Supercritical carbon dioxide(scCO2) of which has the advantage of mild reaction condition, non-toxic, gas-like viscosity and diffusion coefficient, and liquid-like density and solubility is recognized as one of the most promising green solvent. It meet the require of the green chemistry. As a result of fact supercritical carbon dioxide usually be applied in replacing traditional solvent as medium of polymerization reaction, or in supercritical drying.In this thesis, silica as an inorganic material, nitrogenous heterocycle macromolecule as active component, supercritical carbon dioxide as a solvent to prepare a nitrogenous polymer nano-composite materials, and explore its application in terms of wastewater treatment, specifically as follows:(1) Crosslinked PVIm/silica composites were successfully synthesized by precipitation polymerization in scCO2, using 1-vinylimidazole(VIm) as functional monomer, silica as inorganic material, N,N′-Methylenebisacrylamide(BIS) as the crosslinker, azobisisobutyronitrile(AIBN) as initiator. The effects of the silica content, crosslinker amount, the reaction temperature and pressure on the morphology of composites. The composites were characterized. Adsorption properties for Cr(VI) aqueous solution were investigated. The effects of different adsorption conditions on the adsorption capacity of Cr(VI).(2) The gel with an organic-inorganic interpenetrating network structure was prepared by solution polymerization of 4-VP and sol-gel process of TEOS, using 4-vinylpyridine(4-VP) as the functional monomer, diethylene glycol dimethyl methacrylate(DEGDMA) as crosslinker, AIBN as initiator, ethanol as polymerization solvent, precursor tetraethoxysilane(TEOS) was added before polymerization. P4VP/SiO2 composite aerogel was successfully prepared by aging, alcohol replacement and scCO2 drying of the gel. The effects of reaction ratio, crosslinker amount, catalyst amount, solvent amount and aging time on the morphology of the composite aerogel. The composite aerogel was characterized. And its adsorption properties for Cu(II) aqueous solution were investigated.(3) The P4VP-Fe(III)/SiO2 composites were successfully prepared by precipitation polymerization in scCO2, using 4-VP as the functional monomer, modified SiO2 by vinyl triethoxysilane(VTEOS) as inorganic material, AIBN as initiator, BIS as crosslinker, Fe(III) as the metal ions of coordination. The effects of reaction ratios were investigated on the morphology and yield of the prepared composites. And its adsorption properties for BSA aqueous were investigated.