影响喷雾造粒Al_2O_3/nano-TiO_2复合陶瓷粉体流动特性的流变学因素研究

本文研究了分散剂、粘结剂及固相含量等流变学因素对喷雾造粒粉体流动性的影响。结果表明 ,Al2 O3 3wt.%nano TiO2 浆料具有剪切变稀的特性 ,有利于复合陶瓷粉体的喷雾造粒。当固相含量为浆料总质量的6 0 % ,分散剂和粘结剂分别为固相质量的 0 3%和 1 0 %时 ,浆料具有合适的粘度和最佳的分散稳定性 ,喷雾造粒所得到的粉体形状为球形或近球形 ,具有较高的松装密度和良好的流动性 ,满足用于热喷涂的需要。

PS/弹性体/Nano-TiO2复合材料形态及力学性能

采用熔融共混法制备PS/弹性体/nano-TiO2复合材料,利用扫描电子显微镜（SEM）观察材料刻蚀断面和冲击断面的形貌,电子万能拉伸试验机及组合冲击试验机分别表征材料的拉伸和冲击性能,研究对比PS/SEBS/nano-TiO2和PS/SEBS-g-MAH/nano-TiO2复合材料的形态及力学性能.结果表明：PS/SEBS/nano-TiO2复合材料刻蚀断面的分散相SEBS粒径在0.6～1.4 μm之间,而PS/SEBS-g-M AH/nano-TiO2复合材料分散相SEBS-g-MAH粒径显著减小,在0.5 μm以下.与PS/SEBS/nano-TiO2复合材料相比,PS/SEBS-g-MAH/nano-TiO2复合材料的拉伸强度降低幅度减弱,在弹性体质量分数为16％时缺口冲击强度提高20％.复合材料冲击断面显示SEBS-g-MAH粒子比SEBS粒子更细微、更均匀地分散在PS基体中.

谷胱甘肽在nano-TiO_2-咖啡酸复合修饰碳糊电极上的电催化氧化及电分析方法

研究了还原型谷胱甘肽(GSH)在nano-TiO2-咖啡酸(CFA)复合修饰碳糊电极(nano-TiO2-CFA/CPE)上的电催化氧化行为,并进行了测定。结果表明,GSH在CPE和nano-TiO2/CPE上的直接电化学氧化过程十分迟缓,nano-TiO2-CFA/CPE比CFA/CPE对GSH的电化学氧化具有更好的催化作用。采用循环伏安法(CV)、计时电流法(CA)探讨了GSH在nano-TiO2-CFA/CPE上的电极过程动力学性质。用线性扫描伏安法(LSV)测得催化氧化峰电流与GSH的浓度在9.0×10-6～1.0×10-3 mol.L-1范围内呈良好线性,检出限为8.85×10-7 mol.L-1。将该方法用于市售还原型谷胱甘肽药物含量的测定,结果满意。

家电用HIPS/nano-TiO_2多功能复合材料的性能

研究了家电用HIPS/nano TiO2 多功能复合塑料的加工流变性、母料分散性、吸光行为、抗菌、分解内毒素、分解异味气体及自清洁特性。结果表明 ,使用质量分数在0 5 %～ 2 0 %的nano TiO2 的复合材料加工流动性优于HIPS ;经EVA蜡改性的HIPS/nano TiO2 母料可得到良好分散效果 ;HIPS/nano TiO2 制品表现出良好的紫外吸收能力 ,nano TiO2 质量分数在 1 .0 %左右时 ,制品具有较好的抗菌、分解内毒素效果。

痕量Pb^(2+)在nano-TiO_2膜电极上的电化学行为及应用研究

利用纳米二氧化钛(nano-TiO2)的结构特性制备了一种nano-TiO2膜修饰的玻碳电极。采用阳极溶出伏安法详细研究了Pb2+在nano-TiO2膜修饰玻碳电极上的电化学响应行为,并对各种实验参数进行了优化。实验结果表明,在0.10 mol/L HAc-NaAc缓冲体系(pH 4.0)中,于-1.2 V富集搅拌480 s,再静置60 s后阳极化扫描,Pb2+在-0.48 V左右出现一灵敏的阳极溶出峰。Pb2+的溶出峰电流与其浓度在2.0×10-9~1.0×10-7mol/L范围内呈良好的线性关系,检出限可达1.0×10-10mol/L。该修饰电极具有一定的抗干扰能力,将其应用于实际水样中Pb2+的检测,结果令人满意。

新型CNT／nano-TiO2复合膜电极的制备及其异相电催化性能

采用溶胶-凝胶法制备了碳纳米管/纳米TiO2(CNT/nano-TiO2)复合溶胶,通过提拉法将复合溶胶涂覆在Ti基体上制得CNT/nano-TiO2复合膜修饰电极(C电极),其电化学性能经循环伏安、计时库仑、交流阻抗谱(EIS)等方法研究。研究结果表明,CNT可阻碍nano-TiO2粒子团聚。在循环伏安图中,C电极的氧化还原峰电流比nano-TiO2膜修饰电极(P电极)的高出两倍多。通过对草酸溶液的异相电催化反应进一步证明C电极比P电极具有更高的电催化活性,而且对双氧水也有很强的异相电催化还原能力。

Nano-TiO_2掺量对OGFC-13降解尾气效果及路用性能影响

为了评价Nano-TiO_2添加到OGFC-13沥青混合料中对汽车尾气的降解效果及路用性能的影响,配制了Nano-TiO_2掺量分别为30%、50%、70%(矿粉等体积代替比例)的OGFC-13沥青混合料,利用所开发的尾气降解效果模拟评价系统,进行了检测评价.结果表明,在OGFC-13中添加Nano-TiO_2可降解尾气中的NO、HC、CO等有害气体,且降解效果随Nano-TiO_2添加量的增加而提高,而对沥青混合料的路用性能影响较小.相对AC-13而言,OGFC-13对尾气降解效果更明显.综合考虑经济与技术因素,推荐Nano-TiO_2在OGFC-13中的掺量为50%.

Nano-TiO_2系耐高温陶瓷抗菌剂的研究

以ZnO为异质相,采用共沉淀法对nano-TiO2粉体进行了复合改性,并对改性后的nano-TiO2粉体的耐温性能、光催化性能、抗菌性能及复合结构形态进行了研究。结果表明:改性后的nano-TiO2粉体经950℃煅烧后,仍完全以锐钛矿晶型存在,晶粒呈球形,分散较均匀,粒度分布较窄,且粒径较小,平均在30-40nm左右,而且具有与纯nano-TiO2粉体(600℃)基本相同的光催化效能和抗菌效能,是一种新型纳米高温抗菌剂。

Nano-TiO_2/HIPS母料流变性能的研究

采用RosandRheometer流变仪研究了nano -TiO2 /HIPS母料及EVA蜡改性母料的流变性能。结果表明 ,nano TiO2 对母料的表观粘度影响较小 ,在nano TiO2 质量分数低于 2 0 %时 ,表观粘度仅略高于纯HIPS。在低剪切速率下 ,nano TiO2 可加速熔体偏离牛顿流体的速度 ,体系的粘弹性增强 ;而在较高剪切速率下则相反。EVA蜡可在较大范围内调整母料体系的流变性能。在低剪切速率下 ,EVA蜡质量分数超过 5 %就可明显改善体系的流动性 ,且体系流动行为接近牛顿流体 ,粘弹性很弱 ;在高剪切速率下 ,EVA蜡对体系的流动性影响不大 ,流变行为及粘弹行为与纯HIPS相当。原子力显微镜测试表明 ,采用EVA蜡改性的nano TiO2 /HIPS母料 ,可得到表观及分散性良好的制品。

ABS／nano-TiO2复合功能材料的研究

研究了ABS／nano—TiO2复合功能材料的分散性、力学性能、制品表面微观形貌、抗菌、分解内毒素效果和毒理安全性。结果表明，通过二次造粒工艺，nano—TiO2粉体在ABS基体中可得到良好分散水平；在1．0-3．0％的重量含量范围内，复合材料的流动性优于ABS，韧性有显著提高，拉伸强度略有下降；nano—TiO2重量含量为10％时，复合材料就具有较好的抗菌、分解内毒素效果，且属于实际无毒等级，是一种具有良好前途的功能型复合材料。

nano-TiO_2与1,2,4-TCB联合作用对斑马鱼鳃组织结构及染色体损伤研究

采用组织病理切片法、微核及彗星试验研究nano-TiO_2和1,2,4-TCB联合染毒对斑马鱼鳃组织结构、细胞微核率及DNA损伤的毒性效应。结果表明,单独nano-TiO_2暴露不会导致斑马鱼鳃组织结构损伤,也不会引起明显的微核及染色体损伤。1,2,4-TCB(≥10 mg·L^(-1))会引起鳃组织和细胞染色体的损伤。nano-TiO_2与1,2,4-TCB联合作用会加重斑马鱼的鳃组织结构损伤,出现鳃小片排列严重紊乱,表皮细胞断失严重,鳃小片上皮细胞坏死脱落,鳃丝结构模糊等症状。两者联合作用会引起鳃细胞微核率增加和彗星细胞率的增加,呈现一定的剂量-效应关系,且两者间的联合作用具有协同作用。对彗星试验的尾部DNA百分比、尾长及尾距的分析发现,与对照组和单独作用相比,两者联合作用对彗星指标均有显著增强作用,这表明两者联合作用对染色体的损伤属于非特定片段损伤。

纳米TiO_2改性不饱和聚酯树脂(Nano-TiO_2/UPR)的结构与性能

纳米 Ti O2 改性不饱和聚酯树脂 ,其目的是对不饱和聚酯进行同时增韧增强改性。用“反应法”制备的纳米 Ti O2 /UPR,在纳米 Ti O2 与 UPR之间产生的新化学键将纳米 Ti O2 粒子接入 UPR长链上 ,这种新的结构决定了纳米 Ti O2 /UPR的性能。研究结果表明 ,纳米 Ti O2 /UPR的反应活性高于 UPR,纳米 Ti O2 /UPR的冲击韧性和弯曲强度较 UPR分别提高 46%和 5 5 % ,纳米 Ti O2 /UPR的耐热性及介电性与

Sensitive Voltammetric Determination of Captopril Using a Carbon Paste Electrode Modified with Nano-TiO_2/Ferrocene Carboxylic Acid

A carbon paste electrode (CPE) modified with ferrocene carboxylic acid (FcCA) and TiO2 nanoparticles was constructed by incorporating TiO2 nanoparticles and ferrocene carboxylic acid into the carbon paste matrix. The electrochemical behavior of captopril (CAP) at the surface of the modified electrode was investigated using electroanalytical methods. The modified electrode showed excellent electrocatalytic activity for the oxidation of CAP in aqueous solutions at physiological pH values. Cyclic voltammetric curves showed that the oxidation of CAP at the surface of the modified electrode reduced its overpotential by more than 290 mV. The modified electrode was used for detecting captopril using cyclic voltammetry and square wave voltammetry techniques. A calibration curve in the range of 0.03 to 2400 μmol/L was obtained that had a detection limit of 0.0096 μmol/L (3?) under the optimized conditions. The modified electrode was successfully used for the determination of captopril in pharmaceutical and biological samples.

Preparation and properties of nano-TiO2 modified interior wall paint

The modification of the traditional interior wall paint was carried out by means of adding nano-TiO2 as a functional pigment. By regulating the dosage of dispersant, the nano-particles can be dispersed in paint homogeneously. With two aspects of experiments： dosage of nano-TiO2 and pigment volume concentration （PVC）, the paint formulation can be optimized and its properties~ such as hardness, scrub resistance, storage stability, contrast ratio and gloss can be improved. Finally an interior wall paint with high performance and air purification was prepared. Its character of formaldehyde degradation would be discussed in the next article.

Separation and Determination of Trace Amounts of Thallium byNano-TiO_2 Combined with Microwave Irradiation

Nano-TiO2 was employed for the separation and preconcentration of thallium.It was found that the adsorption ratio of thallium ions was more than 98% at pH 4.5 and the desorption ratio reached 99% under microwave irradiation for 3 min at 350 W.The adsorption equilibrium was well described by the Langmuir isotherm model with a maximum adsorption capacity of 4.09 mg/g[（20±0.1） °C].The nano-TiO2 was successfully applied to the determination of element thallium in the certified reference material polymetallic nodule and water samples.

Characteristics and properties of surface coated nano-TiO_2

Nano-TiO2 was coated with A12O3,SiO2 and silane coupling agent by chemical liquid deposition.The coating was characterized by Raman spectroscopy,XRD,TEM and FT-IR.The coating content and anti-ultraviolet capacity of nano-TiO2 were measured by XRF and UV-vis spectrometer.The results show that dense coatings containing 5% Al2O3 or SiO2 can be obtained by mixing slurry at pH 10,adding coating reagent and neutralization reagent into the slurry for 60 min at 85?95 ℃,and finally aging for 120 min.Noncrystal SiO2 was coated on the surface of nano-TiO2 to form silica gel polymer with a Ti—O—Si bond,while aluminum compound exists in the form of AlOOH and part Al(OH)3.The integrated dense film can shield photocatalysis effectively.The inorganic coating film can increase the wettability for xylene and stability in water.The surface modification of nano-TiO2 will not impair its ability for anti-ultraviolet radiation,and more short band ultraviolet radiation can be absorbed.In addition,the optimal coating amount of silane coupling agent should be less than 3% and the best wettability for xylene can be reached when the amount is 1.2%.

A study on water absorption in freestanding polyurethane films filled with nano-TiO_2 pigments by capacitance measurements

The electrochemical impedance spectroscopy （EIS） was used to evaluate the water transport and dielectric properties of polyurethane films filled with nano-TiO2 at different pigment/base （P/B） values in 0.5 mol/L NaCl solutions. EIS results were compared with gravimetric measurements on the freestanding films. The amount of water absorption showed great discrepancy between the two methods. The diffusion coefficient in the polyurethane film with P/B：30% was the smallest among those filled with nano-TiO2 pigments. The dielectric constant ε of the polyurethane varnish film obtained from the initial capacitance was in the range of typical values of polymers. SEM was used to measure the distribution of nano-TiO2 particles in the polyurethane films.

Thermal Behavior of Nano-TiO_2 in Fire-Resistant Coating

The dispersion state of nano-TiO2 particles was studied by using transmission electron microscopy （TEM）and Fourier transform infrared spectroscopy （FT-IR）. Nanoparticles can be fully dispersed by specific hyperdispersant. The improvement of nano-TiO2 in thermal behavior and flame retardation of acrylic polymer and fire-resistant coating was investigated by differential thermal analysis （DTA）, thermogravimetry （TG）and fire-resistant time test. It is demonstrated that nano-TiO2 is helpful for enhancing the thermal stability,anti-oxidation and fire-resistant properties of acrylic polymer and fire-resistant coating.

Powder Quartz/Nano-TiO2 Composite: Mechanochemical Preparation and Photocatalytic Degradation of Formaldehyde

Powder quartz(PQ)/nano-TiO2composite was prepared by a mechanochemical method. Based on as-prepared PQ/nano-TiO2composite, we prepared interior paints and investigated the degradation efficiency of formaldehyde(DEF). Scanning electron microscopy showed that nano-TiO2got well dispersed by the adding of PQ. Thermogravimetric analysis indicated that the mass ratio of 4:1 was a relatively good proportion for the most production of PQ/nano-TiO2composite. Fourier transform-infrared spectrometry showed that the peak position of Ti-O-Si bond varied with the milling time. At the early stage, no characteristic peak of Ti-O-Si bond was observed, while at the later stage, new peaks at 902 cm-1and 937 cm-1appeared. Meanwhile, PQ/nano-TiO2composite-based interior paint exhibited significant DEF of 96.3% compared to that consisting of sole nanoTiO2of 92.0% under visible light illumination. As an abundant mineral resource, PQ would make interior paints with HCHO purifying effect much more efficient and cheaper.

Polar Mineral Tourmaline and Its Effect on the Photocatalysis of Nano-TiO2

The mechanism for tourmaline powder improving the photocatalysis effect of nano-TiO2 was studied by electron-spin resonance (ESR). It is found that the intensity of the signal of hydroxyl free radical produced by the mixture of the tourmaline and nano-TiO2 through 355nm wavelength ultraviolet radiating is increased. Under natural light, the mixture of nano TiO2 and tourmaline powder in a certain weight ratio can improve the effect of decomposing methyl orange that proved that the ESR result was right. The tourmaline particle could promote the photocatalysis of nano-TiO2. This result may be due to the surface electric field of the tourmaline, which can absorb the particle of nano-TiO2 and make the electron inspired by photon transfer from the inner of nano-TiO2 particle to its surface, and even make the electron transfer into tourmaline particle.