• Environmental Analysis Health and Toxicology
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• 제23권4호
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• pp.285-290
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• 2008

Effects of titanium dioxide nanoparticles on blood coagulation and platelet aggregation were investigated using diluted whole blood and platelet rich plasma (PRP) solution prepared from human and rat blood, respectively. Blood coagulation was monitored by using a whole blood impedance aggregometer and titanium dioxide nanoparticle (10, 20, and 40 ppm) did not show any effect on the coagulation both in human and in rat blood. When platelet aggregation was measured by turbidometric method after addition of titanium dioxide nanoparticles to PRP solution with final concentrations of 1, 5 and 10 ppm. no aggregation was observed.

• Journal of Electrical Engineering and Technology
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• 제10권6호
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• pp.2343-2347
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• 2015

This paper reports the effect of Titanium dioxide (TiO₂) nanoparticles on a TiO₂ sol-gel Schottky diode. TiO₂ nanoparticles were blended with TiO₂ sol-gel to fabricate the Schottky diode. TiO₂ nanoparticles showed strong anatase and rutile X-ray diffraction peaks. However, the mixture of TiO₂ sol-gel and TiO₂ nanoparticles exhibited no anatase and rutile peaks. The forward current of the Schottky diode drastically increased as the concentration of TiO₂ nanoparticles increased up to 10 wt. % and decreased after that. The possible conduction mechanism is more likely space charge limited conduction.

• Advances in nano research
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• 제5권1호
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• pp.27-34
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• 2017

One of the methods of removing cyanide from wastewater is surface adsorption. We simulated the removal of cyanide from a synthetic wastewater in the presence of Titanium dioxide nano-particles absorbent uses VISUAL MINTEQ 3.1 software. Our aim was to determine the factors affecting the adsorption of cyanide from synthetic wastewater applying simulation. Synthetic wastewater with a concentration of 100 mg/l of potassium cyanide was used for simulation. The amount of titanium dioxide was 1 g/l under the temperature of $25^{\circ}C$. The simulation was performed using an adsorption model of Freundlich and constant capacitance model. The results of simulation indicated that three factors including pH, nanoparticles of titanium dioxide and the primary concentration of cyanide affect the adsorption level of cyanide. The simulation and experimental results had a good agreement. Also by increasing the pH level of adsorption increases 11 units and then almost did not change. An increase in cyanide concentration, the adsorption level was decreased. In simulation process, rising the concentrations of titanium dioxide nanoparticles to 1 g/l, the rate of adsorption was increased and afterward no any change was observed. In all cases, the coefficient of determination between the experimental data and simulation data was above 0.9.

• Membrane and Water Treatment
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• 제9권6호
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• pp.481-487
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• 2018

Membrane clogging or fouling of the membrane caused by organic, inorganic, and biological on the surface is one of the main obstacles to achieve high flux over a long period of the membrane filtration process. So researchers have been many attempts to reduce membrane fouling and found that there is a close relationship between membrane surface hydrophilicity and membrane fouling, such that the same conditions, a greater hydrophilicity were less prone to fouling. Nanotechnology in the past decade is provided numerous opportunities to examine the effects of metal nanoparticles on the both hydrophilic and antibacterial properties of the membrane. In the present study the improvement of hydrophilic and antimicrobial properties of the membrane was evaluated by adding nanoparticles of titanium dioxide and copper oxide. For this purpose, 4% copper oxide and titanium dioxide nanoparticles with a ratio of 0, 30, 50, and 70% of copper oxide added to the polymeric membrane and compare to the pure polymeric membrane. Comparison experiments were performed on E. coli PTCC1998 in two ways disc and tube and also to evaluate membrane hydrophilic by measuring the contact angle and diameter of pores and analysis point SEM has been made. The results show that the membrane-containing nanoparticle has antibacterial properties and its impact by increasing the percentage of copper oxide nanoparticles increases.

• Proceedings of the Korean Society For Composite Materials Conference
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• 한국복합재료학회 2005년도 추계학술발표대회 논문집
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• pp.87-90
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• 2005

This paper presents an evaluation of the effect of titanium dioxide nanoparticles in sulfonated poly(ether ether ketone) (SPEEK) with sulfonation degree of 57%. A series of inorganic-organic hybrid membranes were prepared with a systematic variation of titanium dioxide nanoparticles content. Their water uptake, methanol permeability and proton conductivity as a function of temperature were investigated. The results obtained show that the inorganic oxide network decreases the proton conductivity and water swelling. It is also found that increase in inorganic oxide content leads to decrease of methanol permeability. In terms of morphology, membranes are homogeneous and exhibit a good adhesion between inorganic domains and the polymer matrix. The properties of the composite membranes are compared with standard nafion membrane.

• Toxicological Research
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• 제25권4호
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• pp.195-201
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• 2009

Recent publications showed that metal nanoparticles which are made from $TiO_2,\;CeO_2,\;Al_2O_3,\;CuCl_2,\;AgNO_3$ and $ZnO_2$ induced oxidative stress and pro-inflammatory effects in cultured cells and the responses seemed to be common toxic pathway of metal nanoparticles to the ultimate toxicity in animals as well as cellular level. In this study, we compared the gene expression induced by two different types of metal oxide nanoparticles, titanium dioxide nanoparticles (TNP) and cerium dioxide nanoparticles (CNP) using microarray analysis. About 50 genes including interleukin 6, interleukin 1, platelet-derived growth factor $\beta$, and leukemia inhibitory factor were induced in cultured BEAS2B cells treated with TNP 40 ppm. When we compared the induction levels of genes in TNP-treated cells to those in CNP-treated cells, the induction levels were very correlated in various gene categories (r=0.645). This may suggest a possible common toxic mechanism of metal oxide nanoparticles.

• Bulletin of the Korean Chemical Society
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• 제35권8호
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• pp.2477-2480
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• 2014

Thermal degradation of titanium-containing metal-organic frameworks (MOFs; MIL-125 and MIL-125-$NH_2$ at $350^{\circ}C$ for 6 h in air produced $TiO_2$ nanoparticles of ca. 10 nm in diameter. Scanning electron and transmission electron microscope analyses indicated that those nanoparticles were aggregated randomly within each crystalline particle of their MOF precursors. The $TiO_2$ nanoparticles prepared from MIL-125-$NH_2$ exhibited higher activity for the degradation of 4-chlorophenol under visible light.

• Journal of the Korean Society of Clothing and Textiles
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• 제35권11호
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• pp.1297-1308
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• 2011

This research investigates the application of ZnO (zinc oxide) nanoparticles and $TiO_2$ (titanium dioxide) nanoparticles to polypropylene nonwoven fabrics via an electrospinning technique for the development of textile materials that can decompose harmful gases. To fabricate uniform ZnO nanocomposite fibers, two types of ZnO nanoparticles were applied. Colloidal $TiO_2$ nanoparticles were chosen to fabricate $TiO_2$ nano- composite fibers. ZnO/poly(vinyl alcohol) (PVA) and $TiO_2$/PVA nanocomposite fibers were electrospun under a variety of conditions that include various feed rates, electric voltages, and capillary diameters. The morphology of electrospun nanocomposite fibers was examined with a field-emission scanning electron micro- scope and a transmission electron microscope. Decomposition efficiency of gaseous materials (formaldehyde, ammonia, toluene, benzene, nitrogen dioxide, sulfur dioxide) by nanocomposite fiber webs with 3wt% nano-particles (ZnO or $TiO_2$) and 7$g/m^2$ web area density was assessed. This study shows that ZnO nanoparticles in colloid were more suitable for fabricating nanocomposite fibers in which nanoparticles are evenly dispersed than in powder. A heat treatment was applied to water-soluble PVA nanofiber webs in order to stabilize the electrospun nanocomposite fibrous structure against dissolution in water. ZnO/PVA and $TiO_2$/PVA nanofiber webs exhibited a range of degradation efficiency for different types of gases. For nitrogen dioxide, the degradation efficiency was 92.2% for ZnO nanocomposite fiber web and 87% for $TiO_2$ nanocomposite fiber web after 20 hours of UV light irradiation. The results indicate that ZnO/PVA and $TiO_2$/PVA nano- composite fiber webs have possible uses in functional textiles that can decompose harmful gases.

• Toxicological Research
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• 제28권4호
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• pp.217-224
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• 2012

In recent decades, titanium dioxide ($TiO_2$) nanoparticles have been used in various applications, including paints, coatings, and food. However, data are lacking on the toxicological aspects associated with their use. The aim of this study was to assess the inhalation toxicity of $TiO_2$ nanoparticles in rats by using inhalation exposure. Male Wistar rats were exposed to $TiO_2$ nanoparticles for 2 weeks (6 hr/day, 5 days/week) at a mean mass concentration of $11.39{\pm}0.31mg/m^3$. We performed time-course necropsies at 1, 7, and 15 days after exposure. Lung inflammation and injury were assessed on the basis of the total and individual cell counts in bronchoalveolar lavage fluid (BALF), and by biochemical assays, including an assay for lactate dehydrogenase (LDH). Furthermore, histopathological examination was performed to investigate the lungs and nasal cavity of rats. There were no statistically significant changes in the number of BALF cells, results of biochemical assays of BALF and serum, and results of cytokine analysis. However, we did observe histopathological changes in the nasal cavity tissue. Lesions were observed at post-exposure days 1 and 7, which resolved at post-exposure day 15. We also calculated the actual amounts of $TiO_2$ nanoparticles inhaled by the rats. The results showed that the degree of toxicity induced by $TiO_2$ nanoparticles correlated with the delivered quantities. In particular, exposure to small particles with a size of approximately 20 nm resulted in toxicity, even if the total particle number was relatively low.

• Membrane and Water Treatment
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• 제7권5호
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• pp.377-401
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• 2016

To study the effect of titanium dioxide ($TiO_2$) nanoparticles on membrane performance and structure and to explore possible improvement of using mixed solvents in the casting solution, composite polyvinylidene fluoride (PVDF) ultrafiltration membranes were prepared via immersion precipitation method using a mixture of two solvents triethyl phosphate (TEP) and dimethylacetamide (DMAc) and addition of $TiO_2$ nanoparticles. Properties of the neat and composite membranes were characterized using scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), Atomic force microscopy (AFM) and contact angle and membrane porosity measurements. The neat and composite membranes were further investigated in terms of BSA rejection and flux decline in cross flow filtration experiments. Following hydrophilicity improvement of the PVDF membrane by addition of 0.25 wt.% $TiO_2$, (from $70.53^{\circ}$ to $60.5^{\circ}$) degree of flux decline due to irreversible fouling resistance of the composite membrane reduced significantly and the flux recovery ratio (FRR) of 96.85% was obtained. The results showed that using mixed solvents (DMAc/TEP) with lower content of $TiO_2$ nanoparticles (0.25 wt.%) affected the sedimentation rate of nanoparticles and consequently the distribution of nanoparticles in the casting solution and membrane formation which influenced the properties of the ultimate composite membranes.