Amino-tert-butylcalix [8] Arene Modified In The Fe <sub> 3 </ Sub> O <sub> 4 </ Sub> @ Of Au Core-shell Composite Magnetic Nanoparticles And Their Applications

1. Synthesis of Fe₃O₄@Au core-shell magnetic particlesFirst, Fe₃O₄ magnetic particles were prepared with codeposition. The morphology of Fe₃O₄ particles prepared under dirrerent conditions, for example, the reaction temperature, reaction time, the amount the regents, even the adding methods for the precipitant has been discussed and confirmed by TEM ,X-ray diffraction.Fe₃O₄@Au core-cell particles were produced by the means of Frens' method and the seed-growth method. The deoxidization mechanism of Au atoms on the surface of Fe₃O₄ particles was researched. The effect of the seeds number to Fe₃O₄@Au particle size was also described. The UV spectra also confirmed that the surface of the nanoparticles were covered with Au. In addition, the results showed that the diameter of Fe₃O₄@Au particle was about 30nm, and the particles can respond quickly in magnetic field.2. Synthesis of water-soluble p-tertbutylcalix[8]arene octa-amineUnder the base catalyst, p-tert-butyl calix[8]arene was synthesized with the reaction of p-tertbutyl phenol and formaldehyde. Then refered to the paper references and improved the methods, water-soluble p-tert-butyl calix[8]arene octa-amine was obtained. The product was characterized by ¹HNMR and FTIR spectra. The electrochemical behavior of p-tert-butyl calix[8]arene octa-amine has been investigated by cyclic voltammetry.3. The modification of water-soluble p-tertbutylcalix[8]arene octa-amine on Fe₃O₄@Au core-shell magnetic particlesAs the third generation of the main supermolecular compound, calixarene has a good representative of the molecular recognition. After the introduction of functional group (such as -SH,-NH₂), calixarene derivatives can be modified on the surface of nanoparticles. The Fe₃O₄@Au core-shell magnetic particles have the properties of both magnetic particles and colloidal gold. Here, the Fe₃O₄@Au core-shell magnetic particles were modified by the water-soluble p-tertbutylcalix[8]arene octa-amine . The modification was confirmed to be successful with several methods.4. The adsorption of nitrobenzene on Fe₃O₄@Au core-shell magnetic particles modified with water-soluble p-tertbutylcalix[8]areneocta-amineThe water-soluble p-tertbutylcalix[8]arene octa-amine can react with nitrobenz -ene(NB) to form an inclusion complex which was characterized by FTIR spectra. The ratio of water-soluble p-tertbutylcalix[8]arene octa-amine and NB in inclusion complex was determined as 1:1. At 25℃, the dissociated constant of the inclusion complex, K_D was 4.29×10^-4mol·L^-1. Therefore, the water-soluble p-tertbutylcalix[8]arene octa-amine modified Fe₃O₄@Au core-shell magnetic particles can be used to absorb the guest molecular(NB). At 25℃, the equilibrium for the absorption will arrived at 70 min. The equilibrium amount of NB for the adsorption was 77.8 mg/g when the concentration of NB located at 10μM..