An Experimental Investigation on Workability and Bleeding Behaviors of Cement Pastes Doped with Nano Titanium Oxide (n-TiO 2) Nanoparticles and FlyAsh

In this study,the workability of cement-based grouts containing n-TiO 2 nanoparticles and fly ash has been investigated experimentally.Several characteristic quantities(including,but not limited to,the marsh cone flow time,the mini slump spreading diameter and the plate cohesion meter value)have been measured for different percentages of these additives.The use of fly ash as a mineral additive has been found to result in improvements in terms of workability behavior as expected.Moreover,if nano titanium oxide is also used,an improvement can be obtained regarding the bleeding values for the cement-based grout mixes.Using such experimental data,a multi-layer perceptron artificial neural network model has been developed(5 neurons in the hidden layer of the network model have been developed using a total of 42 experimental data).70%of the data employed in this model have been used for training,15%for validation and 15%for the test phase.The results demonstrate that the artificial neural network model can predict Marsh cone flow time,mini slump spreading diameter and plate cohesion meter values with an average error of 0.15%.

Preparation of Bentonite Supported Nano Titanium Dioxide Photocatalysts by Electrostatic Self-assembly Method

Electrostatic self-assembly method （ESAM） was used to prepare bentonite supported-nano titanium dioxide photocatalysts. The materials were characterized by X-ray diffraction （XRD）, fourier transform infrared spectroscopy （FT-IR） and scanning electron microscopy （SEM）. Methyl orange was used to estimate the photocatalytic activity of the materials. The effects of the calcination temperature and silane dosage on the photocatalytic activity of the samples were investigated. The experimental results show that the bentonite facilitates the formation of anatase and restrains the transformation of anatase to rutile. Part of nano-size TiO2 particles insert into the galleries of bentonite. The photocatalysts exhibit a synergistic effect of adsorption and photocatalysis on methyl orange. Photocatalysts prepared by ESAM method exhibit higher photocatalytic activity and better recycle ability than those of the traditional method.

New Applications of Nano Titanium Dioxide

New applications and research progress of nano titanium dioxide （TiO2） in coating, environmental protection, chemical industries, cos- metics industry, electronic industrial products, medicine, health and food processing fields were summarized in the paper. The results showed that nano TiO2 is the most dynamic one in the new nano material study today, which will have a very important impact on our social economic develop- ment in future. The research and utilization will give people＇s lives enormous changes.

Nano-cerium-element-doped titanium dioxide induces apoptosis of Bel 7402 human hepatoma cells in the presence of visible light

AIM： To investigate the apoptotic effect of photoexcited titanium dioxide （TiO2） nanoparticles in the presence of visible light on human hepatoma cell line （Bel 7402） and to study the underlying mechanism. METHODS： Cerium-element-doped titanium dioxide nanoparticles were prepared by impregnation method. Bel 7402 human hepatoma cells were cultured in RPMI 1640 medium in a humidified incubator with 50 mL/L COL at 37℃. A 15 W fluorescent lamp with continuous wavelength light was used as light source in the photocatalytic test. Fluorescence morphology and agarose gel eletrophoresis pattern were performed to analyze apoptotic cells. RESULTS： The Ce （Ⅳ）-doped TiO2 nanoparticles displayed their superiority. The adsorption edge shifted to the 400-450 nm region. With visible light illuminated for 10 min, 10 μg/cm^3 Ce （lV）-doped TiO2 induced micronuclei and significant apoptosis in 4 and 24 h, respectively. Hochest 33 258 staining of the fixed cells revealed typical apoptotic structures （apoptotic bodies）, agarose gel electrophoresis showed typical DNA ladder pattern in treated cells but not in untreated ones. CONCLUSION： Ce （Ⅳ） doped TiO2 nanoparticles can induce apoptosis of Bel 7402 human hepatoma cells in the presence of visible light.

PREPARATION OF POLYSULFONAMIDE AND MODIFIED TITANIUM OXIDE NANOCOMPOSITES BY IN-SITU POLYMERIZATION

A kind of new nano composite with ultraviolet （UV） ray resistance and high temperature stability was prepared by in-situ polymerization in low temperature. Polysulfonamide （PSA） was synthesized with 4, 4＇-diaminodiphenyl sulfone （DDS） and terephthaloyl chloride （TPC） in the common solvent N, N-Dimethyl- -acetamide （DMAc）. Nano filler is a certain nano titanium oxide modified by silicon oxide （TMS）, which plays the role of UV resistance additives. Properties of the novel composite materials were characterized by Atomic Force microscopy （AFM）, thermal gravimetric Analysis （TGA） and Ultraviolet Spectroscopy. AFM had showed the sizes and distributions of TMS particles in the nanocomposite. Ultraviolet Spectroscopy for the nanocomposites showed a large absorption in UV band. TGA showed the decomposition temperature was increased over ten degrees with 0.5% wt TMS for this nanocomposite compared with pure PSA.

Effect of Nano - Titanium Dioxide with Different Antibiotics against Methicillin-Resistant Staphylococcus Aureus

The different investigation has been carried out on the biological activities of titanium dioxide nanoparticle but the effect of this nano product on the antibacterial activity of different antibiotics has not been yet demonstrated. In this study the nano size TiO2 is synthesized using citric acid and alpha dextrose and the enhancement effect of TiO2 nanoparticle on the antibacterial activity of different antibiotics was evaluated against Methicillin-resistant Staphylococcus aureus (MRSA). During the present study, different concentrations of nano-scale TiO2 were tested to find out the best concentration that can have the most effective antibacterial property against the MRSA culture. Disk diffusion method was used to determine the antibacterial activity of these antibiotics in the absence and presence of sub inhibitory concentration of TiO2 nano particle. A clinical isolate of MRSA, isolated from Intensive Care Unit (ICU) was used as test strain. In the presence of sub-inhibitory concentration of TiO2 nanoparticle (20 μg/disc) the antibacterial activities of all antibiotics have been increased against test strain with minimum 2 mm to maximum 10mm. The highest increase in inhibitory zone for MRSA was observed against pencillin G and amikacin (each 10 mm). Conversely, in case of nalidixic acid, TiO2 nanoparticle showed a Synergic effect on the antibacterial activity of this antibiotic against test strain. These results signify that the TiO2 nanoparticle potentate the antimicrobial action of beta lactums, cephalosporins, aminoglycosides, glycopeptides, macrolids and lincosamides, tetracycline a possible utilization of nano compound in combination effect against MRSA.

Application of Prochloraz-nano-titanium Dioxide Complex Fresh-keeping Agent in Refrigeration of Dioscorea alata Lirm. sp.

Prochloraz diluents( 450 ×,475 ×,500 ×) were added with different concentrations of nano-titanium dioxide( Ti O2)( 0. 8%,1. 0%) respectively to prepare complex fresh-keeping agents,which were applied in the refrigeration of Dioscorea alata Lirm. sp. With rot index,weight loss rate,browning degree( BD),total soluble solids( TSS) content,malondialdehyde( MDA) content,polyphenol oxidase( PPO) activity and peroxidase( POD) activity,DPPH· scavenging rate as evaluation indexes,the preservation effect of the prepared freshkeeping agents on D. alata during the cold storage period was analyzed. The results showed that prochloraz added with nano-titanium dioxide significantly prolonged the storage life,reduced the rot rate and weight loss rate,and slowed the loss of pulp of D. alata. The preservation effect of complex fresh-keeping agent of prochloraz diluent( 475 ×) and nano-titanium dioxide( 1. 0%) was better than that of other treatments.

The Effect of Titanium Nano Oxide and Heat Treatment on Physical Properties of Hornbeam (<i>Carpinus betulus</i>) in Golestan Province

The use of wood has been considered for a long time and to this day, it has a special place in human life. Modification of wood and lignocellulosic materials is done by various methods, including modification of physical, mechanical, chemical and thermal, that as a new technology, it leads to the improvement of their undesirable features. Among these methods, heat correction is a useful method to improve dimensional stability and leads to increased resistance to water absorption and decay. The main purpose of this study is to investigate the titanium Nano oxide and heat treatment on the physical properties of hornbeam species. Samples were saturated with titanium Nano oxide solution at a concentration of 5000 ppm and pressurized 7 times in a pressure tank. The samples were divided into three groups: control, heat and Nano thermal treatment. Heat and saturated samples with titanium Nano oxide were heat treated at three temperature levels of 150℃, 175℃ and 200℃ for 4 and 6 hours. All three groups underwent physical tests. Heat and Nano thermal oxide treatments led to reduced water absorption and thickness swelling. Comparison between heat and Nano thermal treatment showed a further decrease in water absorption and thickness swelling in Nano thermal samples.

Effect of a Hybrid Micro/Nano-integrated Titanium Surface on Behavior of Rat Osteoblasts

The objective of this study was to investigate the effect of a new combined micro/nanoscale implant surface feature on osteoblasts＇ behaviors including cell morphology, adhesion, proliferation, differentiation, and mineralization in vitro. A new micro/nano-hybrid topography surface was fabricated on commercial pure titanium（Cp Ti） by a two-step sandblasted acid-etching and subsequent alkali-and heattreatment（SA-AH）. The conventional sandblasted/acid-etching（SA） treatment and alkali and heat（AH） treatment were also carried out on the Cp Ti as controls. Surface microstructures of the Ti disc samples were assessed by scanning electron microscopy（SEM）. The neonatal rat calvaria-derived osteoblasts were seeded on these discs and the initial cell morphology was evaluated by SEM and immunofluorescence. Initial adhesion of the cells was then assayed by DAPI staining at 1, 2, and 4 h after seeding. The Cell Counting Kit-8（CCact K8） assay, gene expression of osteoblastic markers（ALP, Col 1, OCN, BSP, OSX, Cbfα1） and Alizarin Red S staining assays were monitored respectively for cell proliferations, differentiation and mineralization. The results show significant differences in osteoblast＇s behaviors on the four kinds of Ti surfaces. Compared with Cp Ti surface, the SA and AH treatment can significantly promote cell adhesion, differentiation and mineralization of osteoblasts. In particular, the combined SA and AH treatments exhibit synergistic effects in comparison with the treatment of SA and AH individually, and are more favorable for stimulating a series of osteogenous responses from cell adhesion to mineralization of osteoblasts. In summary, this study provides some new evidence that the integrated micro/nanostructure on the Cp Ti surface may promote bone osseointegration between the Ti implantbone interfaces in vitro.

Fabrication of Micro/Nano-textured Titanium Alloy Implant Surface and Its Infl uence on Hydroxyapatite Coatings

We put forward a protocolcombining laser treatment and acid etching to obtain multiscale micro/nano-texture surfaces of titanium alloy implant.Firstly,the operationalparameters of the laser were optimized to obtain an optimum current.Secondly,the laser with the optimum operationalparameters was used to fabricate micro pits.Thirdly,multiple acid etching was used to clean the clinkers of micro pits and generate submicron and nanoscale structures.Finally,the bioactivity of the samples was measured in a simulated body fluid.The results showed that the micropits with a diameter of 150 μm and depth of 50 μm were built successfully with the optimized working current of 13 A.In addition,submicron and nanoscale structures,with 0.5-2 μm microgrooves and 10-20 nm nanopits,were superimposed on micro pits surface by multiple acid etching.There was thick and dense HA coating only observed on the multiscale micro/nano-textured surface compared with polished and micro-textured surface.This indicated that the multiscale micro/nano-texture surface showed better ability toward HA formation,which increased the bioactivity of implants.

TiAlSiN/CrAlSiN纳米多层涂层刀具干切削TC4钛合金切削性能

钛合金因其化学活性和切削高温引起刀具磨损严重。刀具表面施加涂层是有效地延长刀具服役时间的方法。借助PVD阴极电弧蒸发技术,使用TiAlSi靶和CrAlSi靶交替叠加制成TiAlSiN/CrAlSiN纳米多层涂层刀具,并使用这种刀具分别切削常规钛合金和3D打印钛合金。所制成的TiAlSiN/CrAlSiN纳米多层涂层表现了较高的硬度;切削钛合金时,刀具的磨损形式表现为涂层剥离,前刀面月牙洼,后刀面均匀磨损和刀尖崩刃。引起刀具磨损的主因是粘结,其次是高温氧化。三个切削用量中,切削速度对切削力和切削温度的影响要远大于切削深度和进给量对二者的影响。与常规TC4相比,3D打印TC4因伸长率和硬度下降,弹性模量提高促使切削温度和切削力均低于常规TC4,刀具寿命相应的延长。

偶联剂对PP/nano-TiO_2纳米复合抗菌材料性能的影响

分别利用硅烷偶联剂KH–560与KH–570、钛酸酯偶联剂NDZ–105及硬脂酸对纳米二氧化钛(nano-TiO_2)进行表面改性,将这4种改性nano-TiO_2粉体分别与聚丙烯(PP)熔融共混,制得PP/改性nano-TiO_2复合抗菌材料,并通过平板硫化机制得相应的复合抗菌薄膜。通过傅里叶变换红外光谱研究了4种偶联剂对nano-TiO_2的改性效果,利用贴膜抗菌法和力学性能测试研究了4种偶联剂对薄膜抗菌性能和材料力学性能的影响。结果表明,4种偶联剂对nano-TiO_2改性效果从大到小依次为KH–570> NDZ–105> KH–560>硬脂酸;KH–570改性nano-TiO_2与PP复合的体系综合性能最佳,当KH–570改性nano-TiO_2质量分数为2%时,复合抗菌薄膜对大肠杆菌的抗菌率达到90.6%,具备较好的抗菌作用,复合抗菌材料拉伸性能、断裂伸长率、冲击强度、弯曲强度和弯曲弹性模量分别为29.7MPa,612%,80.1kJ/m2,20.3MPa和820MPa,比未改性材料分别提高12%,33%,16%,6.3%和28%。

Preparation of nano-TiO_2/diatomite-based porous ceramics and their photocatalytic kinetics for formaldehyde degradation

Diatomite-based porous ceramics were adopted as carriers to immobilize nano-TiO2 via a hydrolysis-deposition technique. The thermal degradation of as-prepared composites was investigated using thermogravimetric-differential thermal analysis, and the phase and microstructure were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and transmission electron microscopy. The results indicated that the carriers were encapsulated by nano-TiO2 with a thickness of 300-450 nm. The main crystalline phase of TiO2 calcined at 650~C was anatase, and the average grain size was 8.3 nm. The FT-IR absorption bands at 955.38 cm1 suggested that new chemical bonds among Ti, O, and Si had formed in the composites. The photocatalytic （PC） activity of the composites was investigated un- der UV irradiation. Furthermore, the photodegradation kinetics of formaldehyde was investigated using the composites as the cores of an air cleaner. A kinetics study showed that the reaction rate constants of the gas-phase PC reaction of formaldehyde were k = 0.576 mg＇m3·min^-1 and K = 0.048 m3/mg.

明胶/紫甘蓝花青素/纳米二氧化钛指示膜的制备及其在鲜虾保鲜中的应用

以明胶为成膜基材,以紫甘蓝花青素和纳米二氧化钛(titanium oxide,TiO_(2))为新鲜度指示剂和屏蔽紫外防护剂,采用溶液浇铸法制备智能指示膜表征不同含量纳米TiO_(2)对指示膜物理性能、光照稳定性和机械性能的影响。结果表明:TiO_(2)的引入能够明显提高指示膜的光照稳定性,改善指示膜的力学性能和水蒸汽阻隔性,当TiO_(2)添加量为1.0%时,指示膜断裂伸长率为21.55%,拉伸强度为22.73 MPa,,水蒸气透过系数为3.885 g/(m·s·Pa),光照稳定性强,指示膜的综合性能最好。傅里叶变换红外光谱和扫描电子显微镜结果表明,明胶、花青素以及TiO_(2)之间形成新的氢键,指示膜的网络结构变得更加致密。此外,将综合性能最优的指示膜应用于虾(4℃)新鲜度监测,在试验期间指示膜产生明显的颜色变化,并对应鲜度等级划分,相关性分析表明指示膜色差值(ΔE)与挥发性盐基氮(total volatile basic nitrogen,TVB-N)含量存在显著正相关(R^(2)=0.913 3),表明指示膜能够对鲜虾的新鲜度进行可视化实时监测。

纳米钛改性酚醛树脂涂料及耐腐蚀性研究

纳米钛具有优异的耐腐蚀性能,可以广泛应用于耐蚀涂料领域,研究纳米量级钛改性的酚醛树脂涂料及其防腐蚀性能,有助于开发出更先进的耐蚀涂料。文章使用扫描电子显微镜、傅里叶变换红外光谱仪和紫外可见分光光度计,表征了纳米钛改性酚醛树脂涂料的形貌和结构,并测定改性后酚醛树脂涂层的耐腐蚀特性。结果表明:当纳米钛为4%时,纳米钛粉与酚醛树脂会最大限度地结合,涂层结构良好;改性纳米钛的加入提高了涂层的紫外吸收能力;纳米钛改性酚醛树脂的耐蚀性远优于未改性的。

纳米二氧化钛的抗菌机制及临床应用

随着越来越多的侵人性操作应用于重症监护病房(ICU),如使用气管导管、留置导尿管、中心静脉导管等,不可避免地增加了患者感染的风险。制备抗菌涂层是解决这类感染的有效办法。抗菌涂层可以有效阻止植入材料表面生物膜的形成,如银纳米粒子涂层、氧化锌涂层、甲基蓝涂层、抗微生物肽涂层、纳米二氧化钛(TiO_(2))涂层等。TiO_(2)作为一种光催化剂,具有良好的光催化和抗菌活性,无毒性和生物相容性,强大的物理化学稳定性和持久的抗菌性能,有很高的研究价值。现就TiO_(2)的杀菌机制和临床应用方面的研究进展进行总结,以期为临床提供参考。

汽车座椅用抗菌涤纶针织物制备及其性能

为解决汽车座椅用涤纶针织物耐久性抗菌问题,以钛酸四丁酯为钛源、硼酸和尿素为掺杂体,采用快速溶胶-凝胶浸渍负载法,通过优化工艺制备出负载硼氮共掺杂纳米二氧化钛(B-N-TiO_(2))抗菌剂的涤纶针织物。在模拟日光照射条件下采用振荡法测试抗菌涤纶针织物对大肠杆菌和金黄色葡萄球菌的抗菌性能。分析抗菌剂的光谱性质和微观形貌,并测试织物的断裂强力、耐磨性能、拒水性能等。结果表明:当浸渍时间为5 min、焙烘温度为120℃、焙烘时间为15 min时,所制抗菌涤纶针织物对大肠杆菌和金黄色葡萄球菌的抑菌率分别为98.4%和94.4%,其主要性能均符合相关标准要求;经20次洗涤后,其纤维表面仍包覆有大量抗菌剂,且抑菌率分别为91.8%和91.3%,抗菌耐久性优于AA级。

钛酸酯偶联剂改性二氧化钛/环氧树脂基超疏水涂层的制备及其性能研究

针对目前超疏水涂层存在的制备过程复杂及价格高等问题,研究了制备过程简单及价格较低的超疏水涂层.用环氧树脂及聚二甲基硅氧烷(PDMS)形成复合涂层,用钛酸酯偶联剂改性的纳米TiO2与PDMS在涂层表面构筑微纳疏水界面.通过SEM、接触角测量仪、电化学工作站等仪器对疏水涂层进行了结构及性能表征.测试结果表明:所制备涂层的接触角达到了160°,滚动角4°,达到了超疏水的效果.在30次砂纸摩擦循环后仍旧保持超疏水性.电化学和极化测试结果表明涂层的最佳腐蚀电位为330 mV,腐蚀电流密度1.93×10^(-12)A/cm^(2),极化电阻为2.97×10^(10)Ω/cm^(2),总阻抗值为1.03×10^(10)Ω/cm^(2),保护效率为99.95%,在酸碱溶液96 h后仍旧保持超疏水性.本研究制备的超疏水涂层,具有优异的耐腐蚀性能、抗损坏能力和自清洁的功能.同时具有制备方法简单及价格较低等优点,其在超疏水自清洁纺织品、医疗器械及金属制品的抗菌及防腐蚀等方面具有广泛的应用前景.

高温高压染色法负载纳米TiO_(2)制备防紫外线涤纶针织物

为提升普通涤纶织物紫外线防护性能,采用高温高压染色法对涤纶织物染色并进行纳米TiO_(2)的负载,讨论了红、黄、蓝3种颜色分散染料和纳米TiO_(2)用量及一浴法和两浴法对涤纶织物紫外线防护系数(UPF值)、K/S值及耐水洗色牢度的影响。结果显示,10%(owf)TiO_(2)负载白色涤纶针织物时,织物UPF值从14.76提升至50+。3种颜色织物防紫外线能力排序依次为蓝色>红色>黄色。分散黄23和纳米TiO_(2)染色负载涤纶针织物时,一浴法染色负载织物UPF值提升至37.13,两浴法染色负载时织物UPF值提升至40以上,两浴法染色负载织物经耐皂洗色牢度测试工艺后,其UPF值仍在40以上,耐水洗色牢度评级均为4级。

耐高温单组分室温硫化硅橡胶的研制

以自制的不同类型的单组分室温硫化硅橡胶为基础,考察了脱酸型、脱醇型、脱肟型、脱丙酮型硅橡胶在高温老化条件下的性能变化。结果表明,脱丙酮型硅橡胶在高温老化后,其力学性能最好,拉伸强度和断裂伸长率保持率最高。因此在脱丙酮型硅橡胶基础上,考察生胶黏度及结构、白炭黑、耐热助剂等对单组分脱丙酮型室温硫化硅橡胶耐高温性能的影响。结果表明:单组分脱丙酮型室温硫化硅橡胶在200℃高温老化时,主要是侧链发生氧化反应;在300℃高温老化时,主要发生的是主链降解反应。低黏度生胶和侧基为低含量的苯基时,对硅橡胶耐高温性能有利;采用硅氮烷处理的气相法白炭黑作为补强填料时,硅橡胶耐高温性能较好;氧化铁红、氧化铈、氧化钛对硅橡胶耐高温性有小幅度的提高,而二氧化钛与氧化铁红复配使用时,因其协同作用,大幅度提高了硅橡胶的耐高温性能。在300℃×2 h老化后,硅橡胶的拉伸强度和断裂伸长率都保持在90%以上。