Study On Synthesis, Properties And Application Of Magnetic Polyphosphazene Micro-Nanomaterials

Over the last few years, magnetic micro- and nanomaterials, as one of the important functional materials, are of great interest for researchers because of their strong magnetic responsivity and wide applications in magnetic fluids, catalysis, biotechnology, magnetic resonance imaging, data storage, and environmental remediation. At present, many efforts have been made in research and development of new magnetic micro- and nano- materials. Phosphazene-containing polymers which show excellent thermal stability, biocompatibility and biodegradability have been used as biomaterials, membranes, ceramics, electrical and electrochromic materials, and hybrid materials. Therefore, it is essential and of significant importance to develop approaches of magnetic phosphazene-containing polymer micro- and nano-materials with good magnetic properties under mild conditions.In this paper, based on the characterization of phosphazene chemistry, we present novel routes to synthesize various magnetic phosphazene-containing polymer micro- and nano- materials at room temperature, including magnetic phosphazene-containing polymer nanotubes with magnetic nanoparticles attached on the surfaces, magnetic phosphazene-containing polymer nanotubes with magnetic phase embedded in walls, magnetic phosphazene-containing polymer nanotubes with magnetic phase both in walls and on surfaces, magnetic phosphazene-containing polymer nanofibres with magnetic nanoparticles attached on the surfaces, magnetic phosphazene-containing polymer nanofibres containing magnetic nanoparticles, magnetic phosphazene- containing polymer monodispersed microspheres with active hydroxyl groups and magnetic phosphazene-containing polymer microspheres containing magnetic particles. Moreover, the structures and properties of these materials are discussed in detail and the applications in separating dye like methylene blue and heavy metal ions like nickel from industrial waste water are also studied. By a way, the wave absorbing ability of the magnetic carbon materials obtained from them by carbonization is also studied. The main contents and results are as follows. (1) Magnetic phosphazene-containing polymer nanotubes with magnetic nanoparticles attached on the surfaces were successfully prepared via a new approach at room temperature by ultrasonic irradiation. The structure and morphology were characterized by XRD, EDX, SEM and TEM. The characterization results show that the phosphazene-containing polymer nanotubes are 50-80 nm in outer diameter and 5-10 nm in inner diameter; the Fe3O4 nanoparticles loaded on the surface are 5-10 nm in diameter. The coordination behavior between magnetic nanoparticles and PZS nanotubes was investigated by IR. The experimental results show that the magnetic nanotubes have high magnetism content of 48 %, high magnetization saturation value of 38 emu/g, good thermal stability and superparamagnetic properties.(2) Magnetic poly (cyclotriphosphazene-co-4,4′-sulfonyldiphenol) (PZS) nanotubes with magnetic phase embedded in walls were synthesized by ultrasonic irradiation via an in-situ template approach. The structure and morphology of the magnetic PZS nanotubes were determined by FTIR, XRD, SEM, TEM and EDX. The characterization results show that the magnetic PZS nanotubes are 50-100 nm in outer diameter and 5-10 nm in inner diameter; the Fe3O4 nanoparticles with diameter of 5-10 nm are embedded in the walls of the nanotubes. The morphology of the magnetic PZS nanotubes is highly influenced by the content of Fe3O4 nanoparticles. The TGA results and the magnetic measurements show that the magnetic PZS nanotubes have good thermal stability and superparamagnetic properties.(3) Based on the synthesis of magnetic PZS nanotubes with magnetic phase embedded in walls, magnetic nanotubes with sandwich constructions and very high magnetism content were produced. These magnetic nanotubes are 50-100 nm in outer diameter and 5-10 nm in inner diameter; the Fe3O4 nanoparticles with diameter of 5-10 nm are attached on the surface of the nanotubes. The magnetic nanotubes have very high magnetism content of 82 %, high magnetization saturation value of 44 emu/g, and exhibit superparamagnetic properties.(4) Novel magnetic phosphazene-containing polymer nanofibers including magnetic nanoparticles loaded on the outer surfaces and contained in the inner structures were prepared via a new route. The magnetic polymer nanofibers have good thermal stability and superparamagnetic properties.(5) Magnetic phosphazene-containing polymer microspheres with active hydroxyl groups were prepared at room temperature by ultrasonic irradiation. TGA results show that the magnetic microspheres have good thermostable properties and high magnetism content of about 66.5 %. The magnetic measurements reveal that the magnetic microspheres are superparamagnetic with saturation magnetization of 34.9emu/g.(6) Fe3O4 nanoparticles were first prepared and then covered by PZS polymers to obtain magnetic PZS microspheres. The morphology of the products is not irregular and the diameter is about 300-500 nm.(7) The magnetic phosphazene-containing polymer nanotubes in application of separating dye like methylene blue and heavy metal ions like nickel from industrial waste water are studied. The results show that the separation efficiency is very good.(8) The wave absorbing ability of the magnetic carbon materials obtained from them by carbonization is studied. The results show that the wave absorbing ability is good.