Preparation Of Metal Nano Oxide And Its Application In Photocatalysis And Magnetic Resonance Imaging

Engineering nanomaterial is usually defined as at least one dimension in three dimensional space in nano size(1-100 nm)or by them as the basic units of materials,such as surface effect,volume effect and macroscopic quantum tunnel effect and so on characteristics,make its physical and chemical properties of different conventional materials,theory of nanotechnology research and development of the nanometer materials got rapid development,and the traditional materials,medical equipment,electronic equipment,environmental control,and other industries widely used.The research of this paper includes the following two aspects:1.The organic dye methyl orange in wastewater was degraded to improve water quality.Here,a uniform layer of Ti O₂ nanoparticles coated on the surface of natural micrometer-sized fibers was obtained when using polar wood cellulose fibers as templates and titanium butoxide(Ti(On Bu)₄)as precursor through a simple one-step solvothermal method.And the morphology and degradation efficiency of Ti(ONBU)₄ and cellulose at different ratios of0.5:1,1:1 and 2:1 were investigated.The results show the cellulose microfibers were coated with layer of highly crystalline anatase Ti O₂ nanoparticles whose diameter varies from 5 to10 nm.Moreover,the resultant Ti O₂/cellulose composite shows an excellent photocatalytic activity in degrading methyl orange dye.More importantly,the method provides a great potential for other natural cellulose substances like straw,hemp and cotton to load titania,thus,enlarging the source of templates.2.In order to improve the effect of magnetic resonance imaging to obtain accurate diagnostic images.we developed a highly efficient T₁-T₂ dual-mode MRI CA using an ultra-small gadolinium oxide-decorated magnetic iron oxide nanocrystal(GMIO).The gadolinium element could effectively alter the magnetic properties of the GMIO from soft-ferromagnetism to superparamagnetism.In addition,when the Gd/Fe ratio was 15%(designated as GMIO-2),the GMIO-2 possessed the best superparamagnetism and highest magnetism.Subsequently,T₁ and T₂ values of GMIO-2 were measured through a series of turbo spin-echo images and then multi-spin echo(MSE)sequence,respectively.Based on this,T₁ and T₂ relaxivities of GMIO-2 were calculated and were the highest(r₁:1.306 m M^-1 s^-1 and r₂:234.5 m M^-1 s^-1)when compared to other groups.The cytotoxicity of GMIO-2was negligible under a wide range of dosages,thus exhibiting excellent cell biocompatibility.Moreover,GMIO-2 could quickly diffuse into cells,leading to its effective accumulation.The systemic delivery of GMIO-2 resulted in an excellent T₁-T₂ dual-mode MRI contrast effect in kidneys,which is expected to improve the diagnosis of kidney lesions.Therefore,this work provides a promising candidate for the development of a T₁-T₂ dual-mode MRI CA.