【作者】 任常宝；

【导师】 程逵；

【作者基本信息】 浙江大学 ， 材料学， 2010， 硕士

【摘要】 纳米TiO₂是一种新型的高性能无机材料,具有独特的物理和化学特性。如优良的光催化活性、光电性能、光致超亲水性以及很好的生物相容性和诱导类骨质矿物沉积的能力等。本文基于纳米TiO₂涂层本身具有良好的生物相容性,加上涂层表面的光致超亲水特性,研究了可光致亲水-憎水转换的自立的TiO₂纳米球表面层的制备与表征。并初步探索TiO₂纳米球表面层这种非连续的结构作为生物医用材料应用,以及表面层的本征性能及光照等外部条件对其生物学应用的影响等。首先,采用溶胶-凝胶法和旋涂分相法相结合的方法制备出了TiO₂纳米球表面层。然后以硅基板为载体,研究了TiO₂纳米球表面层的结构性能以及光致亲水-憎水转换的性能,最后以钛植入体为载体,研究了TiO₂纳米球表面层的生物学应用,以及光致亲水-憎水转换对这一应用的影响。表征手段包括X射线衍射、扫描电镜、透射电镜、X光电子能谱仪、傅立叶红外光谱分析仪、接触角分析仪、模拟体液浸泡以及细胞培养等。结果表明:1.在硅基板表面上成功制备出了一层大小基本一致,分布均匀,致密的TiO₂纳米球表面层,该表面层为单层结构,且厚度与纳米球的直径（50-100nm）相当。分别掺杂La离子,Fe离子,N离子均可以成功地进入TiO₂球状纳米点中,且不会改变TiO₂纳米球表面层的形貌特征。2.硅基板上TiO₂纳米球表面层具有在光照条件下润湿性能转变的特性,并且这一特性能够通过实验条件、离子浓度和离子掺杂得到一定程度的调控。3.在经过硅基板上的模拟,又成功将TiO₂纳米球表面层生长在Ti植入体上。经模拟体液浸泡和细胞培养实验后,发现具有比较优异的磷灰石沉积特性和invitro细胞相容性,表明TiO₂纳米球表面层具有良好的生物活性。同时,在紫外光照射前后,由于表面的憎水/亲水特性的智能化转换,TiO₂纳米球表面层的生物活性随之发生了有规律的变化。具体而言,紫外光的照射有使生物活性增强的趋势。更多还原

【Abstract】 As a new high-performance inorganic material,Nano-TiO₂ shows many unique physical and chemical properties.Such as excellent photocatalytic activity, photoelectric property,photo induced super-hydrophilicity,good biocompatibility and capability of inducing bone mineral deposition.In this thesis,based on the good biocompatibility of nano-TiO₂ coating and photo-induced super-hydrophilicity of the surface,free-standing TiO₂ nanospheres layers with photo switchable hydrophilicity and hydrophobicity were prepared and characterized.The possible biological application of such layers,as well as the effects of material intrinsic property and photo excitation,are explored and discussed.Firstly,TiO₂ nanoparticles are prepared on a Si wafer substrate through a combined method of sol gel processing and spinodal phase separation.Then,on Si wafer substrate,the structure and photo-induced hydrophilic-hydrophobic conversion performance of TiO₂ nanospheres are studied.Finally,on Ti substrate,the in vitro property of TiO₂ nanospheres and the impact of hydrophilicity and hydrophobicity are discussed.Means of characterization include X-ray diffraction,scanning electron microscopy,transmission electron microscopy,X photoelectron spectroscopy,Fourier transform infrared spectroscopy,contact angle measurement,simulated body fluid immersion,as well as in vitro cell culture,etc.The research results show as below:1.The compact layer with randomly distributed TiO₂ nanospheres is formed on the Si substrate.It has single-layer structure.And corresponding to the diameter of nanoparticle,the thickness of TiO₂ nanospheres is 50-100nm.When doping La ions, Fe ions,N ions respectively,they are able to successfully enter the spherical TiO₂, and the surfacing morphology of TiO₂ nanoparticles remains the same.2.TiO₂ nanospheres layer on Si wafer substrate has characteristics of hydrophilic-hydrophobic conversion with photo excitation.Such feature can be regulated by experimental conditions,ion concentration and ion doping to certain extent. 3.The compact layer with randomly distributed TiO₂ nanospheres is also formed on the Ti substrate successfully.Through simulated body fluid immersion and cell culture, TiO₂ nanospheres show excellent characteristics of apatite deposition and in vitro cell compatibility.Meanwhile,after UV irradiation,the biological activity of such surface layers improved due to enhanced hydrophilicity.更多还原