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1.
PVA/SiO2-TiO2杂化电纺纤维膜的形态与性能 总被引:1,自引:0,他引:1
以正硅酸乙酯(TEOS)、钛酸四丁酯(TBT)和聚乙烯醇(PVA)为原料, 用溶胶凝胶法制备了PVA/(SiO2-TiO2)杂化纺丝液, 将其电纺成纤维膜. 红外光谱结果证实, PVA的羟基与TEOS和TBT水解后的羟基发生了缩合反应, 杂化电纺纤维膜以网络结构形式相结合; X射线衍射分析表明, 杂化电纺纤维膜的结晶度比纯PVA电纺纤维膜小; 扫描电镜表明, 随杂化纤维膜中无机相含量的增加, 纤维的直径不断增加, 纤维出现一定的弯曲和扭曲, 并伴有少量带状结构的纤维; 紫外-可见光谱结果表明, TiO2的引入增加了纤维膜的抗紫外性; TGA热分析结果表明, 杂化纤维膜的耐热性能优于纯PVA电纺纤维膜的; 耐水性和稳定性测试表明, 杂化纤维膜的耐水性和稳定性优于纯PVA和PVA/SiO2电纺纤维膜的. 相似文献
2.
Crystallization Behavior of SiO2-TiO2 Sol-Gel Thin Films 总被引:1,自引:0,他引:1
The aim of this work was to investigate the crystallization behavior of thin films of SiO2−TiO2 made by the sol-gel process as function of the TiO2 content and the temperature and time of heat treatment. Precursor solutions were prepared by hydrolysis of TEOS (tetraethoxysilane)
and TPOT (titaniums tetraisopropoxide). Multilayer films were spun on single crystal silicon wafers. The compositions studied
were (on a molar percentage basis) 20TiO2−80SiO2, 30TiO2−70SiO2, 40TiO2−60SiO2 and pure TiO2. The films were heat treated at different temperatures between 300°C and 1200°C, for different periods of time (30 s-90 h).
The crystallization kinetics were followed by micro-Raman spectrometry. Grazing incidence X-ray diffraction showed that the
films crystallized into one or both of two crystalline phase of TiO2: anatase and rutile (for pure TiO2 only). The volume fractions of the crystalline phase varied from very low values (<1%), up to 100%, for a TiO2 sample heat treated at 800°C for 8 hours. The results show that the volume fraction of crystalline phase is strongly influenced
by the heat treatment temperature and also, to a smaller extent, by the heat treatment time. The most important parameter,
however, is the composition of the films: the higher their TiO2 concentration, the lower is the crystallization temperature and the larger is the crystallized fraction. 相似文献
3.
Fe3+-TiO2/SiO2光催化降解罗丹明B的研究 总被引:25,自引:0,他引:25
以硅胶为载体,采用溶胶-凝胶法制备了不同掺杂量的Fe3+-TiO2/SiO2光催化剂,并采用SEM,Raman和DRS等手段对其进行了分析和表征.以氙灯为光源,通过对可溶性染料罗丹明B的降解反应,考察了Fe3+-TiO2/SiO2催化剂的光催化活性,探讨了光催化反应中溶液pH值和起始浓度对催化反应的影响. 相似文献
4.
Study on the Superhydrophilicity of the SiO2-TiO2 Thin Films Prepared by Sol-Gel Method at Room Temperature 总被引:2,自引:0,他引:2
Dasen Ren Xiaoli Cui Jie Shen Qun Zhang Xiliang Yang Zhuangjian Zhang Lu Ming 《Journal of Sol-Gel Science and Technology》2004,29(3):131-136
Nanoscale SiO2-TiO2 composite thin films with the thickness of about 100 nm were prepared by sol-gel method at room temperature in air. The chemical states of the elements on the surface and near the surface were measured by XPS. The results showed that the Ti on/near the surface of the thin films existed not only as TiO2 but also as Ti2O3. Part of the TiO2 was changed to Ti2O3 after UV irradiation. The crystalline structure of the TiO2 in the SiO2-TiO2 thin films was anatase with the crystallite size of 14–20 nm. It was found that the thin film prepared at room temperature in air has good superhydrophilic property and has strong adherence to the substrate. 相似文献
5.
Anucha Wannagon Rikuo Ota Takashi Wakasugi Jiro Fukunaga 《Journal of Sol-Gel Science and Technology》2000,19(1-3):795-798
SiO2-TiO2-ZrO2 and 5Na2O·95(SiO2 + TiO2 + ZrO2) gels were synthesized and role of Na2O in gel formation and crystallization behavior of gels were studied. From Si(OC2H5)4, Ti(iso-OC3H7)4, Zr(n-OC3H7)4 and NaOCH3 solutions in EtOH without H2O, transparent and opaque gels were obtained. Opaque bulk gels, rich in TiO2 or ZrO2 composition in Na2O containing SiO2-TiO2-ZrO2 system, contain agglomerated spherical particles of diameter small <10 m, in contrast with opaque gels having large particles <30 m in alkali-free SiO2-TiO2-ZrO2 system. Crystallization temperature (Tc) was measured by DTA on dried gels. Compared with the alkali-free SiO2-TiO2-ZrO2 gels, 5 mol% Na2O containing gels gave lower Tc in SiO2 rich compositions and higher in TiO2 rich or ZrO2 rich compositions. 相似文献
6.
通过溶胶 凝胶(Sol-Gel)法制备了ZnTiO3-TiO2纳米复合光催化剂,利用透射电子显微镜、X射线衍射、紫外-可见吸收光谱和ζ电位等测试技术对其形貌、晶体结构及其光谱响应特性进行了表征。 以亚甲基蓝(MB)溶液的脱色降解为模型反应,考察了光源和焙烧温度对该纳米复合材料光催化性能的影响。 结果表明,所得纳米复合材料的催化性能与材料的尺寸、在介质中的分散性能、表面荷电性质等有关。 600 ℃下焙烧3 h所得的ZnTiO3-TiO2纳米复合材料尺寸小(约60 nm)、分散性能好、表面荷负电荷量最高、催化性能最好,且在太阳光下的活性高于紫外光下的。 如太阳光下7 h可使亚甲基蓝(MB)溶液的脱色降解率达到93%,而在紫外光下只有82%;并且其催化活性高于纯TiO2和ZnO的。 该纳米复合催化剂重复使用4次仍能使亚甲基蓝(MB)溶液的脱色降解率在80%以上。 因此,具有较好的光催化稳定性能。 相似文献
7.
We propose the novel preparation method, Self-seeding Process, based on the following concept for low temperature crystallization of oxide films. Introduction of desirable inhomogeneity should give lowering of a crystallization temperature through heterogeneous nucleation accompanied with reduced activation energy. We carried out inspection of the above concept through use of PZT films. PZT gel films with the desirable inhomogeneity of microstructure were prepared, and their crystallization behaviors was examined. The PZT film was successfully crystallized at 500°C by the self-seeding process. The single phase (001) oriented PZT film with 0.55 m in thickness was obtained at 550°C for 5 min. The self-seeding process by microstructure control is efficient for the low temperature process of the oxide thin film. 相似文献
8.
以钛酸正丁酯为前驱体, 采用溶胶-凝胶-水热晶化法在不锈钢(SS)表面制备TiO2纳米膜. 利用X射线衍射(XRD)、Raman光谱、场发射扫描电子显微镜(SEM)、原子力显微镜(AFM)和俄歇电子能谱(AES)表征了TiO2纳米膜的晶型、表面形貌和表面化学组成. 通过极化曲线和电化学阻抗谱(EIS)研究了TiO2纳米膜的耐蚀性能. 170 °C下水热晶化制备的锐钛矿TiO2与450 °C焙烧制备的锐钛矿TiO2的结晶度类似, 但两种TiO2薄膜的表面结构存在明显差异, 水热晶化法制备的TiO2纳米膜在3.5% (w) NaCl溶液中的耐蚀性能优于焙烧法制备的. 相似文献
9.
A. Pirson A. Mohsine P. Marchot B. Michaux O. van Cantfort J. P. Pirard A. J. Lecloux 《Journal of Sol-Gel Science and Technology》1995,4(3):179-185
A new method to synthesize SiO2-TiO2 gels by sol-gel process has been developed. This technique uses tetraisopropylorthotitanate [Ti(O
i
Pr)4] and tetraethylorthosilicate [TEOS]: they are mixed in the same solvent and then directly hydrolysed. This one-step reaction is possible because of the use of 2-methoxyethanol, a protic polar solvent. This alcohol plays two different specific roles: it acts as a solvent as well as a stabilizer of titanium alkoxide towards the hydrolysis-precipitation reaction. So, by an accurate adjustment of the quantity of methoxyethanol in the mixture, we can control the reactivity of the titanium precursor.Monolithic and transparent xerogels were obtained whatever the composition. Three monolithic SiO2-TiO2 gels containing 20, 50 and 75 mol% of TiO2 were prepared and studied in details.By using the TG-DSC analysis, we can follow the evolution of the loss of water and organic residues.The structural evolution of gels during calcination is characterized by IR spectroscopy and X-Ray diffraction. 相似文献
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复合型固体超强酸SO2-4/SnO2-TiO2催化合成乙酸松油酯的研究 总被引:4,自引:0,他引:4
采用溶胶一凝胶法制备了新型复合固体超强酸SO2-4/SnO2-TiO2,通过XRD和IR 对其结构进行了表征.以该固体酸为催化剂、松油醇和乙酸酐为原料合成乙酸松油酯,考察了影响反应的因素.结果表明:反应温度40-50℃、催化剂用量1.8-2.2%、醇酐摩尔比1:1.6、反应时间4-5h是最适宜的反应条件,其松油醇转化率达到98%以上,产物中乙酸松油酯含量为88%.与普通单氧化物固体酸比较,该复合型固体酸有更高的催化活性和选择性. 相似文献
12.
溶胶-凝胶法制备掺Sm3+的SiO2玻璃的结构及发光性能 总被引:1,自引:0,他引:1
利用溶胶-凝胶技术制备了掺不同量Sm3+和不同退火温度下的SiO2凝胶和玻璃,通过三维荧光光谱、激发光谱、发射光谱的测试,确定了Sm3+在SiO2凝胶玻璃中的最佳激发波长为360 nm,最强发射波长为610 nm,激发光谱的峰位置在360、393、464 nm处,发射光谱的峰位置在578、591、595、610、732nm处,分别归属于4G5/2-6H5/2、4G5/2-6H7/2、4G5/2-6H11/2跃迁,并证明当掺杂量达到1.15%时,Sm3+的发光最强,当Sm3+的掺杂量超过1.15%时,发生浓度猝灭效应. 相似文献
13.
ZrO2-TiO2-CeO2的制备及其在NH3选择性催化还原NO中的应用 总被引:1,自引:0,他引:1
采用共沉淀法制备了载体材料TiO2、ZrO2-TiO2及ZrO2-TiO2-CeO2, 并利用X射线衍射(XRD)实验、比表面积测定(BET)、程序升温脱附(NH3-TPD)、储氧性能测定(OSC)及程序升温还原(H2-TPR)等方法对三种载体材料进行了表征. 结果表明, ZrO2-TiO2-CeO2具有较多的表面强酸位, 并具有一定的储氧性能和较强的氧化还原性能. 以三种材料为载体, 制备了质量分数分别为1%、9%的V2O5、WO3的整体式催化剂. 研究了三种催化剂在富氧条件下用NH3选择性催化还原NO的催化性能. 结果表明, 以ZrO2-TiO2-CeO2为载体的催化剂在反应空速为10000 h-1, 275 ℃时, NO的转化率接近100%, 具有最好的催化活性,并有良好的应用前景。 相似文献
14.
本文以聚苯乙烯(PS)胶球为模板,通过一步水浴法结合煅烧后处理制备了不同比例的In_2O_3/ZrO_2-TiO_2空心球状复合材料(简写为In_2O_3/ZrO_2-TiO_2-H)。通过X-射线衍射、扫描电镜、X-射线光电子能谱、紫外-可见漫反射吸收光谱和氮气吸附-脱附等测试手段对该系列复合材料的结构、组成和形貌进行了表征。结果表明,In_2O_3/ZrO_2-TiO_2复合材料经PS模板处理后呈现空心球状结构,球壁由纳米粒子堆积而成。将In_2O_3与ZrO_2-TiO_2复合后其光吸收性能呈现了一定的红移现象,且In_2O_3/ZrO_2-TiO_2-H(1∶4)的比表面积较大(66.92m~2·g~(-1))。同时,为了考察该复合材料的光催化性能,在多模式光催化条件下对甲基橙的降解情况进行了研究。结果表明,In_2O_3/ZrO_2-TiO_2-H(1∶4)表现出较好的光催化性能,其光催化活性高于P25、ZrO_2、In_2O_3/ZrO_2-TiO_2及其他体积比的In_2O_3/ZrO_2-TiO_2-H。 相似文献
15.
I. Jaymes A. Douy M. Gervais J.P. Coutures 《Journal of Sol-Gel Science and Technology》1997,8(1-3):415-418
The crystallization of amorphous chemically homogeneous powders in the SiO2.Al2O3 system has been studied by differential scanning calorimetry and X-ray diffraction. Up to 1300°C only one exotherm has been
observed. Only mullite crystallizes for compositions ≤69 mol% Al2O3 and spinel for those ≤80%. The crystallizations into mullite and spinel are sharp and exothermic, with an enthalpy of 250–300
J/g. The chemical composition of the crystallized mullite regularly increases from 68 to 76 mol% Al2O3 with increasing bulk composition from 60 to 75 mol% Al2O3. 相似文献
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采用真空镀膜法在玻碳(GC)电极表面修饰SnO2-TiO2薄膜, 在SnO2-TiO2/GC复合电极表面组装Au-Pt双金属纳米颗粒, 制得Au-Pt/SnO2-TiO2/GC复合电极. 通过循环伏安法(CV)研究了SnO2-TiO2薄膜载体对Au-Pt双金属纳米颗粒电化学性能的影响; 采用扫描电镜(SEM)及X射线光电子能谱(XPS)对Au-Pt在SnO2-TiO2薄膜沉积的形貌及结构进行了表征. 研究结果表明, 10 nm的Au-Pt双金属纳米颗粒均匀地组装于SnO2-TiO2薄膜表面; SnO2-TiO2薄膜载体改善了复合电极抗CO中毒能力; Au-Pt双金属合金的形成提高了Pt 对甲醇氧化的电催化能力, SnO2-TiO2薄膜载体又使Pt纳米粒子d空轨道增多, 提高了Au-Pt双金属纳米颗粒的稳定性和催化性能. 相似文献
18.
以ZrO2-TiO2为载体的整体式锰基催化剂应用于低温NH3-SCR反应 总被引:4,自引:0,他引:4
以MnO2为活性组分,Fe2O3为助剂,制备了以TiO2及ZrO2-TiO2为载体的整体式催化剂.考察了它们在不同温度焙烧后应用于富氧条件下,NH3选择性催化还原.(NH3-SCR)氮氧化物的低温反应性能和高温稳定性.用X射线衍射(XRD)实验、比表面积测定(BET)、储氧性能测定(OSC)及程序升温还原(H2-TPR)等方法对催化剂进行了表征.结果表明,以ZrO2-TiO2为载体的催化剂具有很好的高温热稳定性,并具有较高的比表面积和储氧能力.同时具有较强的氧化能力.催化剂的活性测试结果表明,以ZrO2-TiO2为载体的整体式锰基催化剂明显地提高了NH3-SCR反应的低温活性,具有良好的应用前景. 相似文献
19.
A white substance was got by directly heating TiSi powder on Ti foil, under Ar+O2 atmosphere. ED, EDX, SEM and HRTEM studies reveal that the white substance consists of amorphous SiO2nanowires of smooth surface and uniform diameter (40-90 nm). X-ray-induced luminescent emission experiment shows that two broad peaks are at 430 and 570 nm. A one-dimensional growth mechanism, on the basis of the one-dimensional thermal flow during nanowire formation, is discussed. 相似文献
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