| Ferrimagnetic glass-ceramics with magnetism and biological activity could be used as thermoseeds for the hyperthermia threatment of cancer.Since the 80's of the 20th centuries,people started implanting the thermoseeds into human tumors,when an alternating magnetic field is applied,they heat the tissues by means of magnetic losses,making the cancerous cells die and the normal cells uninjured.Large amounts of research about bone caner,kidney cancer,brain caner,breast cancer on the animal bodies has proved that this hyperthermia threatment can focus on heating the tissue,heat uniformly,easily control the temperature and good safety.In the near future,the application will get a breakthrough on the research.In this thesis,Ferrimagnetic glass-ceramics were prepared by traditional melting, sol-gel,coprecipitation-melting methods,compare and anlysis the influence on the magnetic properties of the three preparation.In the first chapters,the definiton,species of the glass-ceramics,preparation present situation and the application of the ferromagnetic glass-ceramics were introduced briefly.The composition of the samples,the optimic technological condition and test methods were determined in our experiments.In chapter3,we prepared ferromagnetic glass-ceramics by traditional melting.The composition of the samples were Fe2O3-CaO-SiO2-B2O3-P2O5 system.Through the exeperiments,the samples need reducing atmosphere during the heat treatment to make sure the magnetite form.Nuclearation can't play a beneficial role on the magnetic properties of the samples.The heat treatment time can not remain too long.We can prepare qualified ferromagnetic glass-ceramics by heat treatment at 1060℃for 2 hours.The saturated magnetic of the samples can reach at 26.27 Am2/kg. The bioactivity of the glass-ceramic prepared in this work was evaluated in vitro by examinging the formation of bone-like hydroxyapatite on its surfaces after soaking in SBF.In chapter 4,the SiO2-CaO-Fe2O3 base glass-ceramics powders were prepared by sol- gel and sintered after tablet.meanwhile,the Na2O,P2O5,FeO oxide was be properly introduced,compare the magnetic properties the samples. The saturated magnetic of the samples can reach at 37.04 Am2/kg after sintered.Additionally,the gel-powder was melted,the obtained samples were heat treatment in the same condition.The magnetic properteis were improved obivously.,the saturated magnetic reaches upto 41.4 Am2/kg.They also show good biological activity after soaked in the SBF.In chapter 5, the ferrimagnetic glass-ceramic powder was prepared by copreci- pitation-melting method. The results show that the glass-ceramic contains a unique crystalline phase of magnetite during nature cool process,without any nucleation and growth thermal treatment. the saturated magnetic is up to 36.74 A·m2/kg and shows a bioactive behaviour.Finally,the effect of different preparation methods on the sample's magnetic properties were compared.The traditional melting prepare shows weak magnetic and the sol-gel prepare can reach higher magnetic properties,the coprecipitation-melting can get both high magnetic and good bioactivity without any heat treatment.
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