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二氧化钛纳米管的合成及光催化性能 总被引:1,自引:0,他引:1
以纳米二氧化钛(TiO2,P25)为原料,通过水热法合成TiO2纳米管,同时,采用光沉积法将金属金(Au)或铂(Pt)负载于所合成的TiO2纳米管上,并对其进行了光催化性能的研究.用X射线粉末衍射仪、透射电子显微镜、紫外-可见分光光度计和比表面积法与孔径测定等仪器和方法对合成的样品进行表征.结果表明:合成出管径均匀且比表面积大于400 m2/g的TiO2纳米管.热处理结果表明:随着焙烧温度的增加,样品的比表面积减小.在焙烧过程中,TiO2的晶型由锐钛矿型向金红石型转变,TiO2纳米管的光催化活性高于P25纳米TiO2的.负载Au,Pt后,TiO2纳米管的光催化活性明显增加,且负载Au的样品在可见光区出现明显吸收峰,表明负载Au的Ti02纳米管有望成为可见光光催化剂. 相似文献
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SiO2表面上制备纳米TiO2中水量对TiO2含量和形貌的影响 总被引:2,自引:0,他引:2
利用吸附相反应技术在SiO2表面原位制备了纳米TiO2,研究水的加入量对TiO2粒子制备的影响。用分光光度法测定乙醇体相中Ti含量随反应时间的变化,发现Ti含量呈现先快后慢的变化趋势,且水量在1.0~1.1ml。时Ti含量出现急剧变大。Ti含量的这一突变区域通过电子色散能谱仪对载体SiO2表面Ti含量的测定得到了进一步地确定。由透射电子显微镜观察到SiO2表面TiO2粒子存在着两种不同的形貌:覆盖在SiO2表面黑色区域和直径在1nm左右的单一小粒子。X射线衍射分析表明:TiO2晶粒粒径随着水量的增加而变大。实验结果发现:在不同的水量下,钛酸丁酯能够与吸附层和乙醇体相中的水以及SiO2表面羟基发生水解缩合反应。3种反应的不同反应速率导致了Ti含量曲线中的不同斜率,另外钛酸丁酯在醇体相中的水解也导致体系中Ti含量的急剧变大。 相似文献
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以钛酸四丁酯为原料,采用溶胶-凝胶法制备了锌掺杂纳米TiO2光催化剂,探讨了锌掺杂对TiO2光催化活性的影响.用X射线衍射仪(XRD)、扫描电子显微镜(SEM)表征了产品的微观结构和晶相组成,用综合热分析仪对前驱体凝胶进行了差热分析;以亚甲基蓝为降解对象,考察了锌掺杂、掺杂浓度对TiO2光催化活性的影响.结果表明:锌掺杂对TiO2晶由锐钛矿型向金红石型的相转变有抑制作用,并能够提高纳米TiO2的光催化活性;锌掺杂量具有一个相对最佳比例,当掺杂量3%、热处理温度550℃时,用溶胶-凝胶法可得到粒径分布均匀、锐钛矿晶型含量高、具有较高光催化活性的锌掺杂纳米TiO2. 相似文献
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以钛酸丁酯为钛源、HF为形貌控制剂,采用简单的水热法合成了具有高催化活性表面的{001}面纳米TiO2.利用X射线衍射、紫外-可见光漫反射光谱及透射电镜等技术对样品形貌和结构进行表征,并以罗丹明B的光催化降解为模型反应,考察了不同HF量对{001}面TiO2光催化活性的影响.结果表明,{001}面TiO2具有良好的锐钛矿晶型,为纳米片层结构,在紫外光下具有较{ 101}面TiO2更高的光催化活性,且随着F含量增加,其光催化活性先逐渐增加后减小,F/Ti物质的量比为1.25时其光催化活性最高,紫外光照射20 min后罗丹明B降解率可达80%以上. 相似文献
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以钛酸四丁酯为原料,采用溶胶-凝胶法制备了锌掺杂纳米TiO2光催化剂,探讨了锌掺杂对TiO2光催化活性的影响。用X射线衍射仪(XRD)、扫描电子显微镜(SEM)表征了产品的微观结构和晶相组成,用综合热分析仪对前驱体凝胶进行了差热分析;以亚甲基蓝为降解对象,考察了锌掺杂、掺杂浓度对TiO2光催化活性的影响。结果表明:锌掺杂对TiO2晶由锐钛矿型向金红石型的相转变有抑制作用,并能够提高纳米TiO2的光催化活性;锌掺杂量具有一个相对最佳比例,当掺杂量3%、热处理温度550℃时,用溶胶一凝胶法可得到粒径分布均匀、锐钛矿晶型含量高、具有较高光催化活性的锌掺杂纳米TiO2。 相似文献
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纳米二氧化钛纤维的制备及其光催化活性 总被引:14,自引:2,他引:12
以钛酸丁酯为钛源,用溶胶-乳化-凝胶技术合成了纳米TiO2粉末,将其置入碱溶液中进行回流处理得到了纳米TiO2纤维.用X射线衍射和透射电镜对纳米TiO2的晶型和表面形貌进行表征.结果表明:当氢氧化钠溶液的浓度为10 mol/L时,所制备的纳米TiO2纤维直径为10~15 nm,纤维长径比为20~25.TiO2纤维在750℃热处理后发生由锐钛矿相向金红石相的转变.光催化降解亚甲基蓝的实验显示:未经热处理的TiO2纤维的光催化活性比纳米TiO2粉末的差,而经500℃热处理后的TiO2纤维光催化活性最强,在紫外光照射4 h后,亚甲基蓝降解率达92%.当热处理温度进-步升高后,TiO2纤维光催化活性反而降低. 相似文献
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纳米粒子/纤维新型功能纤维的制备 总被引:2,自引:0,他引:2
以钛酸四丁酯为原料,将制备锐钛矿TiO2纳米无机粒子工艺与纤维化学改性工艺相结合,利用纳米粒子表面的羟基与纤维的活性基团作用而吸附在纤维表面,从而制备出具有光催化抗菌作用的纤维。该纤维织物在较低温度(70℃)下就可制得,结构不受损害,具有广泛的应用前景。 相似文献
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陶艺的具象形态和抽象形态是陶瓷艺术的姐妹花。本文通过比较、探索陶艺具象和抽象的形态特征,揭示她们质和神的差异,从而进一步把握陶艺创作过程中造型、釉色、纹样、技艺之间语境的表达,使陶艺创作尽可能达到抽象显其质,具象传其神,各自形成独树一帜的、不可替代的、各具魅力的艺术特色。 相似文献
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用热分析方法研究国产阻燃剂BY在纯涤纶装饰织物上的阻燃性能。实验表明:纯涤纶经编针织物经阻燃整理或涂层后,其熔融温度比未阻燃的要提前,而且吸热熔程也变宽了;从热重曲线还可看到,由于阻燃剂的作用使开始失重的温度降低。 相似文献
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加氢法合成对乙酰氨基苯酚(扑热息痛) 总被引:8,自引:0,他引:8
以对硝基苯酚为原料,经催化加氢和酰化合成了对乙酰氨基苯酚。讨论了温度、催化剂用量、硝基物浓度等因素对反应的影响,产品收率可达84%。 相似文献
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ABSTRACT This contribution reports on the use of a FT-IR-spectrometer for measuring concentrations during the drying of thin films of Polyvinyl acetate (PVAc) and Methanol. Calibration was carried out by differential weighing. The spectra were taken in transmission mode while dried air was blown over the liquid films. The obtained accuracy was +/? (5% + 0,8 g/m2) for small contents of Methanol and +/? (10 % 2 g/m2) for higher Methanol contents. The content of PVAc could be measured with 5% accuracy. The experiments were carried out at room temperature; the examined films had a thickness of about 30 to 60 microns when completely dry. 相似文献
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M. I Ré 《Drying Technology》2013,31(6):1195-1236
Abstract Spray drying technique has been widely used for drying heat-sensitive foods, pharmaceuticals, and other substances, because of the solvent rapid evaporation from the droplets, Although most often considered a dehydration process, spray drying can also be used as an encapsulation method when it entraps ‘active’ material within a protective matrix, which is essentially inert to the material being encapsulated. Compared to the other conventional microencapsulation techniques, it offers the attractive advantage of producing microcapsules in a relatively simple continuous processing operation. This chapter will present a brief overview of the main considerations involved in the application of spray drying for microencapsulation, with a special emphasis given to microencapsulation of volatile materials. The potential use of spray drying microencapsulation for pharmaceutical applications, particularly the preparation of microparticulate drug delivery systems, will also be discussed 相似文献
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This contribution reports on the use of a FT-IR-spectrometer for measuring concentrations during the drying of thin films of Polyvinyl acetate (PVAc) and Methanol. Calibration was carried out by differential weighing. The spectra were taken in transmission mode while dried air was blown over the liquid films. The obtained accuracy was +/- (5% + 0,8 g/m2) for small contents of Methanol and +/- (10 % 2 g/m2) for higher Methanol contents. The content of PVAc could be measured with 5% accuracy. The experiments were carried out at room temperature; the examined films had a thickness of about 30 to 60 microns when completely dry. 相似文献
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MICROENCAPSULATION BY SPRAY DRYING 总被引:11,自引:0,他引:11
M. I. R 《Drying Technology》1998,16(6):1195-1236
Spray drying technique has been widely used for drying heat-sensitive foods, pharmaceuticals, and other substances, because of the solvent rapid evaporation from the droplets, Although most often considered a dehydration process, spray drying can also be used as an encapsulation method when it entraps 'active' material within a protective matrix, which is essentially inert to the material being encapsulated. Compared to the other conventional microencapsulation techniques, it offers the attractive advantage of producing microcapsules in a relatively simple continuous processing operation. This chapter will present a brief overview of the main considerations involved in the application of spray drying for microencapsulation, with a special emphasis given to microencapsulation of volatile materials. The potential use of spray drying microencapsulation for pharmaceutical applications, particularly the preparation of microparticulate drug delivery systems, will also be discussed 相似文献