Preparation Of Fe₃O₄-Based Photothermal Composite Material And Research Of Photothermal Property

The cancer,as a disease of extremely high mortality,seriously affect healthy of people.Although many measures,including aggressive surgery,chemotherapy and radiotherapy,have been taken to solve it,the effectiveness of current methods is still limited especially they have a considerable side effect.Photothermal therapy?PTT?based on the development of nanotechnology and nanomedicine has received tremendous attentions in recent years.The therapeutic effect of photothermal therapy cannot be obtained without the aid of photothermal agents?PTAs?with unique optical properties.However,these photothermal agents need a multi-functional composite with other materials due to their single function.The Fe₃O₄ nanoparticles are used as effective drug carrier to apply in targeted therapy because of its good stability,strong targeting and controlled release rate.We envision that the composition of the photothermal agents with superparamagnetic iron oxide nanoparticles has potential function in targeting and photothermal treatment of cancers with improved therapeutic effects.The main points of the dissertations are summarized as follows:Photothermal functional Fe₃O₄@CuS microspheres have been prepared successfully by a simple chemical deposition method.The adsorption of cetyltrimethyl-ammonium bromide?CTAB?on the magnetic microspheres played an important role in forming the structure of the composites.The present materials were characterized with XRD,TEM,SEM,FTIR,and UV-VIS-NIR spectrophotometer.The results showed that Fe₃O₄ microspheres were coated by CuS layer with thickness of 10 nm.The saturation magnetization value of Fe₃O₄@CuS core-shell microspheres was 27 emu/g at room temperature and the sample possessed excellent magnetic response in the presence of applied magnetic field.Moreover,these microspheres exhibited good dispersion,suitable size and significant photothermal conversion efficiency up to 44.6% at 808 nm laser irradiation.Fluctuation value of the highest temperature of Fe₃O₄@CuS dispersion over four times LASER ON/OFF indicated that photothermal stability of Fe₃O₄@CuS microspheres was good.And the antibacterial progress of Fe₃O₄@CuS composited particles showed good bacteriostasis.In this paper,Fe₃O₄/C nanocomposite particles were prepared by different methods.Firstly,200 nm Fe₃O₄ nanoparticles were synthesized by solvent thermal process and The core-shell structure Fe₃O₄/C magnetic nanoparticles were prepared with above magnetic Fe₃O₄ particles as a magnetic core,glucose as carbon source via hydrothermal reaction.Secondly,one-step synthesis of the Fe₃O₄/C composites was prepared via reaction of FeCl3 with glucose It explored the effect of amount of Fe Cl3 on the Fe₃O₄/C composite particles.Thirdly,Fe₃O₄/C composites were prepared by hydrothermal with ferrous gluconate as reactants and it explored the effect of different reactants on structure.In order to study the structure,morphology and photothermal effect of samples,X-ray diffraction?XRD?,transmission electron microscopy?TEM?and scanning electron microscopy?SEM?were employed to characterize the sample The results showed that carbon shell of Fe₃O₄/C composite particles prepared by first method increased with the glucose increasing.The system temperature increased 9.8 °C at 808 nm laser irradiation and photothermal conversion efficiency was up to 25.42%.The temperature of FeCl3 system and ferrous gluconate system can make the system temperature degrees increase 13.8 °C and 14.1 °C.The photothermal conversion efficiency was up to 33.19%,34.43%,respectively.The cytotoxicity analysis of Fe₃O₄/C synthesized by system and first method showed that Fe₃O₄/C composited particles possessed low cytotoxicity and good biocompatible.The SmBO₃ rob-like particles were prepared successfully by hydrothermal method and the effects of different factors on the structure and morphology were investigated.The structure of samples was characterized by XRD,TEM and SEM.It was showed that the morphology of SmBO₃ particles was like robe,only when the hydrothermal time,the mass of oleic acid sodium,the ratio of samarium nitrate and sodium tetraborate were 16 h,0.2 g,3:4,respectively.The SmBO₃ material was in-situ composited on the surface of Fe₃O₄ and Fe₃O₄@SiO₂ microspheres by hydrothermal method.It was found that the composite materials possessed multiple strong absorption band in the NIR region,however the photothermal conversion effective was poor.The incident laser energy mostly was transformed to luminescence,rather than heat.The SmBO₃ material showed up conversion fluorescence property.