Synthesis,Functionalization And Application Of Amino Polyphosphazene Microspheres

Polymer nanomaterials not only have rich structure but also have unique physicochemical properties.They can be prepared polymer-based nanocomposites with special functions through modification and they can also be used precursors to afford porous nano-carbon materials.Based on these unique structures and properties,functional polymer nanomaterials have been widely used in many aspects,such as environment,catalysis,biology,medicine,energy and so on.Therefore,the research of polymer nanomaterials has potential research value and application value,which is one of the hot research focuses at present.Therefore,it is very important to prepare polymer nanomaterials with special functionality.Moreover,it is also important to explore their applications.In this paper,the amino-riched polyphosphazene microspheres were synthesized.Meanwhile,based on the as-prepared polyphosphazene microspheres,two kinds of nano-materials,metal nanoparticle/polyphosphazene hybrids and porous N,P-codoped carbon materials,were fabricated respectively.The application studies of these nanomaterials were studied in the field of dye adsorption,catalysis and electrochemistry,respectively.The main research contents and results are as follows:(1)Solid multi-amino polymer microspheres were facilely synthesized under the condition of ultrasound by precipitation polymerization between hexachlorocyclotriphosphazene(HCCP)and polyethyleneimine(bPEI)using triethylamine(TEA)as the acid-acceptor and acetonitrile as the solvent.After soaking the solid microspheres for 60 min with acetone,hollow multi-amino polymer microspheres can be obtained.The structure and properties of the hollow microspheres were characterized by a series of characterization methods,such as SEM,TEM,FITR,BET and Zeta-potential.The synthetic mechanism was also described in detail.(2)The as-prepared hollow polyphosphazene microspheres were used as adsorbents to adsorb the eosin-Y(EY),acid chrome blue K(ACBK),methyl orange(MO),eosin-B(EB),neutral red(NR),safranine T(ST),rhodamine B(RhB)and methylene blue(MB).It was found that the adsorption capacities of the PCP-NH2 microspheres towards anionic dye EY,ACBK and MO were all above 1000 mg/g.We systematically studied various effects on EY,ACBK and MO adsorption including initial PH,temperature,initial concentration of dyes and adsorption time.And the adsorption isotherm,kinetics andthermodynamics of adsorption process were thoroughly studied.Based on the experimental results,we proposed high-efficiency adsorption mechanism.(3)Based on the structure property of solid amino polyphosphazene microspheres(PCP-NH2),we use it as a support to load Au NPs,Ag NPs and bimetallic Au-Ag NPs respectively by in situ reduction method.Characterization results show that Au-Ag bimetallic nanoparticales with good dispersibility were well anchored onto the surface of the PCP-NH2 microspheres mainly due to the abundant amino functional groups.Also,the reduction of 4-NP by NaBH4 was chosen as a model reaction to characterize the catalytic performance of the synthesized metal/PCP-NH2 hybrid catalyst.The catalytic results show that the catalytic property of bimetallic alloy is significantly higher than those of supported mono-alloys,due to the synergistic effect of bimetallic Au and Ag.(4)With the solid amino polyphosphazene microspheres prepared by different monomer ratios as precursors,carbon microspheres with different element-doped contents were obtained by controlling different carbonation processes.When the carbon microspheres were used as the supercapacitor anode materials,some necessary electrochemical tests were made.It was found that the specific capacitance of C-PCP-750 microspheres reached 348 F/g at a current density of 1 A/g and 200 F/g at a current density of 20 A/g(57.5% capacitance retention).And it also exhibits an extremely excellent cycling performance(96.7% capacitance retention even after10000 cycles at 20 A/g).