Presence Of TiO2 Nanoparticles Research Articles

Electrophoresis of Phosphoproteins on a Tandem Polymerized Gel.

A substrate with n phosphorylated sites may have 2n phosphor-forms for temporal-spatial regulation of biological events. Because phosphates do not significantly change molecular masses but net charges of proteins, those isoforms cannot be separated by regular mass-based sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS PAGE). A tandem polymerized gel was developed to resolve phosphor-isoforms with different masses, charges, and posttranslational modifications. Without the usage of SDS, the electrophoresis was primarily performed on three adjacent acidic polyacrylamide gels. After being concentrated on a stacking gel, protonated proteins were then separated on the Zr4+ immobilized gel through the coordination of metal ions with phosphates followed by further charge and mass (z/m)-based electrophoretic separation on a TiO2 containing gel. The presence of TiO2 nanoparticles in the third gel is aimed for the initiation of the polymerization of acrylamide in acidic conditions upon ultraviolet irradiation. Distinct isoforms of α-S1-casein, α-S2-casein, β-casein, and κ casein model proteins located on 11, 8, 8, and 7 different bands of the tandem gel were unambiguously identified, respectively. With the tandem polymerized gel electrophoresis, new phosphorylation events that may occur simultaneously or sequentially were discovered in not only model proteins but also complex biological samples including human saliva, chicken egg, and sprouting maize. This provides a new tool to dissect complex biological processes that are triggered by dynamic phosphorylation events.

Study the structural and electrical properties of prepared PANI/TiO2 nanocomposites for electronic devices

Structural and electrical properties of pure Polyaniline (PANI), that doped with dodecyl benzene sulfonic acid (DBSA) and nanocomposite films Synthesized by insitu chemical polymerization method in the presence of TiO2 nanoparticles. All the prepared samples have been investigated by x-ray diffraction (XRD), fuorier transformation infra-red (FTIR), and electrical conductivity studies. The results noticeably establish that the composites films have good crystallinity increase with increasing the TiO2 content in the polymer matrix. Also, there are physiochemical interactions between PANI and TiO2 nanoparticles that revealed by FTIR tests.

Nano-TiO2 Adsorbed Decabromodiphenyl Ethane and Changed Its Bioavailability, Biotransformation and Biotoxicity in Zebrafish Embryos/Larvae

Decabromodiphenyl ethane (DBDPE), a novel brominated flame retardant, may co-exist with other pollutants including nanoparticles (NPs) in aquatic environment. Due to structural similarity with decabromodiphenyl ether, DBDPE has been reported to exhibit thyroid disrupting effects and neurotoxicity. This study further evaluated the behavior of DBDPE in aqueous environments along with the bioavailability and toxicity of DBDPE in aquatic organisms in the presence of TiO2 nanoparticles (n-TiO2). When co-existing in an aqueous environment, DBDPE was adsorbed by n-TiO2, potentially facilitating the sedimentation of DBDPE from the aqueous phase. Co-exposure to DBDPE and n-TiO2 significantly increased the uptake of DBDPE by zebrafish (Danio rerio) embryos and altered the composition of metabolites in zebrafish larvae compared to zebrafish exposed to DBDPE alone. The DBDPE-induced increases in heart rate, tail bending frequency, average speed under dark/light stimulation, and thyroid hormone levels in zebrafish embryos/larvae were further enhanced in the presence of n-TiO2. Overall, the results demonstrate that n-TiO2 affected the behavior of DBDPE in the aqueous phase and increased the bioavailability and biotoxicity of DBDPE in zebrafish embryos/larvae. These results could be helpful for understanding the environmental behavior and toxicity of DBDPE.

Cotransport of titanium dioxide nanoparticles and formaldehyde in saturated and unsaturated columns packed with quartz sand

AbstractLaboratory‐scale experiments were conducted to investigate the simultaneous transport of titanium dioxide (TiO2) nanoparticles and formaldehyde (FA) in columns packed with quartz sand under water saturated and unsaturated flow conditions. The effects of interstitial velocity and solution ionic strength on the TiO2 and FA cotransport were examined. The experimental results indicated that substantial retention of TiO2 nanoparticles occurs in both saturated and unsaturated porous media. The solution ionic strength was found to have a noticeable effect on the retention of TiO2 nanoparticles in the packed columns. Moreover, the results from the TiO2 nanoparticle transport experiments in water‐saturated packed columns suggested that the TiO2 nanoparticle mass recoveries increased with increasing flow rate. The results from the TiO2 nanoparticles and FA cotransport experiments in both water saturated and unsaturated packed columns did not reveal a distinct relationship between mass recoveries and flow rate. The transport of FA in both saturated and unsaturated packed columns was hindered in the presence of TiO2 nanoparticles, especially at high ionic strength. This work provides useful insights into fate and transport of TiO2 nanoparticles and FA in saturated and unsaturated porous media.

Pyroelectric Nanogenerator Based on an SbSI-TiO2 Nanocomposite.

For the first time, a composite of ferroelectric antimony sulfoiodide (SbSI) nanowires and non-ferroelectric titanium dioxide (TiO2) nanoparticles was applied as a pyroelectric nanogenerator. SbSI nanowires were fabricated under ultrasonic treatment. Sonochemical synthesis was performed in the presence of TiO2 nanoparticles. The mean lateral dimension da = 68(2) nm and the length La = 2.52(7) µm of the SbSI nanowires were determined. TiO2 nanoparticles served as binders in the synthesized nanocomposite, which allowed for the preparation of dense films via the simple drop-casting method. The SbSI–TiO2 nanocomposite film was sandwiched between gold and indium tin oxide (ITO) electrodes. The Curie temperature of TC = 294(2) K was evaluated and confirmed to be consistent with the data reported in the literature for ferroelectric SbSI. The SbSI–TiO2 device was subjected to periodic thermal fluctuations. The measured pyroelectric signals were highly correlated with the temperature change waveforms. The magnitude of the pyroelectric current was found to be a linear function of the temperature change rate. The high value of the pyroelectric coefficient p = 264(7) nC/(cm2·K) was determined for the SbSI–TiO2 nanocomposite. When the rate of temperature change was equal dT/dt = 62.5 mK/s, the maximum and average surface power densities of the SbSI–TiO2 nanogenerator reached 8.39(2) and 2.57(2) µW/m2, respectively.

New Strategy for Creating TiO2 Thin Films with Embedded Au Nanoparticles

This paper proposes a new strategy for producing thin films of TiO2 with embedded gold nanoparticles (TiO2/AuNP). One of the main tasks was the synthesis of a stable dispersion of TiO2 and gold nanoparticles in an aqueous solution of ethylene glycol, suitable for inkjet printing—ink with complex gold nanoparticles (AuCNP ink). The AuCNP were synthesized by a reduction from tetrachloroauric acid in the presence of TiO2 nanoparticles and ethylene glycol (EG). The final formation of TiO2/AuNP films occurred during the annealing of AuCNP layers, inkjet printed on a glass substrate. The TiO2/AuNP films demonstrate absorbance in the yellow-green range due to the localized surface plasmon resonance (LSPR) and are promising for solar cell application.

Schottky DC generators with considerable enhanced power output and energy conversion efficiency based on polypyrrole-TiO2 nanocomposite

Conversion of small mechanical energy into electricity using a Schottky diode is an emerging technology showing great potential in energy harvesting, sensors, and power generation because of the unique direct current (DC) output characteristic. However, it is still challenging to develop Schottky DC generators with ample power output and energy conversion efficiency. Herein, we, for the first time, demonstrate a novel approach to improve the electrical outputs of a Schottky DC generator using a nanocomposite from polypyrrole and titanium dioxide (TiO2) nanoparticles, a high dielectric material, and aluminum metal. The nanocomposite device showed a current output of 572.70 μA (working area 1.33 cm2) and peak voltage output of 0.84 V with a power density of 0.62 W m−2 and an energy conversion efficiency of as high as 27.29%, which 48 times higher in current outputs, 167 times higher in power density, and 20 times higher in conversion efficiency in comparison to the device made of pure polypyrrole and aluminum metal. We further showed that the presence of TiO2 nanoparticles considerably increased the dielectric constant but slightly reduced the dielectric loss of the polypyrrole composite, leading to a reduction in the Schottky junction internal resistance. However, the Schottky barrier height was little changed, the effect mechanism of which is significantly different from the Schottky DC devices made of polypyrrole-containing graphene oxides and nano carbons. These novel understandings may form a novel concept for the development of high-performance Schottky DC generators.

A novel design of wound bandage using heparin-polyvinylpyrrolidone/TiO2 nanocomposite to improved antibacterial treatment and burn wound healing effect: In vitro and in vivo evaluation

In our current study, porous heparin-polyvinylpyrrolidone/TiO2 nanocomposite (HpPVP/TiO2) bandage were prepared via the incorporation of TiO2 into HpPVP hydrogels for biomedical applications such as burn infection. The effect of the HpPVP hydrogels and the nanoparticles of TiO2 composition on the functional group and the surface properties of the as-fabricated bandages were characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray diffractometry (XRD). The presence of TiO2 nanoparticles created the internal structure of the HpPVP hydrogel that aids in a homogeneous porous structure, as indicated by the scanning electron microscope (SEM). The size distribution of the TiO2 nanoparticles was measured using a transmission electron microscope (TEM). The studies on the mechanical properties of the HpPVP hydrogel indicate that the addition of TiO2 nanoparticles increases its strength. The prepared HpPVP/TiO2 nanocomposite dressing has excellent antimicrobial activity were tested against bacterial species (Staphylococcus aureus and Escherichia coli) and has good biocompatibility against human dermal fibroblast cells (HFFF2) for biological applications. In addition, in vivo evaluations in Kunming mice exposed that the as-fabricated HpPVP/TiO2 nanocomposite bandages increased the wound curing and facilitated accelerate skin cell construction along with collagen development. The synergistic effects of the HpPVP/TiO2 nanocomposite hydrogel dressing material, such as its excellent hydrophilic nature, good bactericidal activity, biocompatibility and wound closure rate through in vivo test makes it a suitable candidate for burn infections.

TiO2-enhanced chitosan/cassava starch biofilms for sustainable food packaging

Biopolymeric films with the addition of nanoparticles have been studied as an alternative to replace petroleum-based synthetic packaging, which is difficult to recycle and leads to a major environmental problem. The goal of this study is to develop and characterise biopolymeric films of chitosan and cassava starch with the addition of titanium dioxide (TiO2) nanoparticles for use as food packaging. Chitosan film (2% w/w), cassava starch film (2% w/w), and chitosan/cassava starch (1:1) blend were developed in the absence and presence of TiO2 nanoparticles (0.25% and 1% w/w) and characterised in terms of physicochemical properties. The results indicate that the properties of films related to water (permeability, solubility, and water sorption) and mechanical (tension, elongation, and Young's modulus) are strongly influenced by the characteristics of the biopolymers used and can be improved with the introduction of TiO2. The water sorption was reduced with the addition of TiO2, which makes the film more hydrophobic and exhibits a higher tensile strength by more than 15% and elongation by more than 100%. The addition of 1% TiO2 also leads to a reduction in transmittance of 97% in UVA, UVB, and UVC regions, which is a valuable feature for food preservation.

Influence of wastewater type in the effects caused by titanium dioxide nanoparticles in the removal of macronutrients by activated sludge.

The imminent arrival of nanoparticles (NPs) to the wastewater treatment plants (WWTP) brings concern about their effects, which can be related to the wastewater composition. In this work, the effects of titanium dioxide (TiO2) NPs in the removal of carbon, nitrogen, and phosphorus by activated sludge bioreactors during the treatment of synthetic, raw, and filtered wastewaters were evaluated. Floc size, compaction of sludge, and morphological interactions between sludge and NPs were also determined. The main effect of TiO2 NPs was the inhibition of up to 22% in the removal of ammonia nitrogen for all types of wastewaters. This effect is strong dependent on combined factors of TiO2 NPs concentration and content of organic matter and ammonia in wastewater. The removal of dissolved organic carbon was affected by TiO2 NPs in lower level (up to 6%) than nitrogen removal for all types of wastewaters. Conversely to adverse effects, the removals of orthophosphate in the presence of TiO2 NPs were improved by 34%, 16%, and 55% for synthetic, raw, and filtered wastewater, respectively. Compaction of the sludge was also enhanced as the concentrations of NPs increased without alterations in the floc size for all types of wastewaters. Based on TEM and STEM imaging, the main interaction between TiO2 NPs and the activated sludge flocs was the adsorption of NPs on cell membrane. This means that NPs can be attached to cell membrane during aerobic wastewater treatment, and potentially disrupt this membrane. The effects of TiO2 NPs on macronutrient removal clearly depended on wastewater characteristics; hence, the use of realistic media is highly encouraged for ecotoxicological experiments involving NPs.

Impact of Polyphenol Interactions with Titanium Dioxide Nanoparticles on Their Bioavailability and Antioxidant Activity.

Titanium dioxide is widely utilized as a pigment in the food industry to enhance the whiteness or brightness of foods and beverages. The powdered forms of titanium dioxide used as food ingredients contain a substantial fraction of nanoparticles (d < 100 nm), which may have adverse effects on human health. This is a model study that investigated the molecular interactions between TiO2 nanoparticles and selected polyphenols, as well as their influence on the in vitro bioavailability and antioxidant activity of the polyphenols. Our results showed that the chemical structure of polyphenols significantly influenced their binding affinity to TiO2 nanoparticle surfaces, with those possessing vicinal trihydroxy groups having the highest binding affinities. The presence of TiO2 nanoparticles was shown to reduce the bioavailability of polyphenols using an in vitro digestion model. This effect was mainly ascribed to the formation of large TiO2 nanoparticle-polyphenol complex agglomerates that could not pass through the pores in the dialysis tube used to simulate the epithelium layer. Additionally, the binding of polyphenols to the surfaces of TiO2 nanoparticles reduced their antioxidant activity. This study provides valuable insights into the impact of inorganic nanoparticles on the bioavailability and bioactivity of polyphenols.

Disclosing the thermal reactions of aliphatic amines in the presence of TiO2 nanoparticles by multi-shot analytical pyrolysis

Analytical pyrolysis is a powerful tool to study the thermal behaviour of organic compounds, but relatively little information is available on the pyrolysis of amines, especially when bound to inorganic systems. In this study, we analysed aliphatic amines (propylamine, dipropylamine, tripropylamine, and tert-butylamine), both as pure compounds and bound to titania nanoparticles, using multi-shot analytical pyrolysis-gas chromatography coupled to mass spectrometry (Py-GC–MS) with a liquid nitrogen cryo-trap system. Desorption of amines was observed at 260 °C, while pyrolysis reactions were mostly observed at 600 °C. Pure amines underwent intermolecular reactions, generating heavier nitrogen-containing compounds. Conversely, amines bound to titania nanoparticles underwent loss of ammonia and hydrogen, and both inter- and intramolecular couplings generate unsaturated hydrocarbons and aromatics. Differences in the pyrolysis mechanisms were attributed to the catalytic effect of the nanoparticles. The present work provides fundamental information on the pyrolytic behaviour of aliphatic amines and on the catalytic effect of titania nanoparticles.

Degradation of pharmaceutical antibiotic (ciprofloxacin) by photocatalysis process using sol-gel based titanium dioxide nanoparticles

Abstract This study is an attempt to the removal of Ciprofloxacin (CIP) antibiotic from simulated wastewater using a photocatalytic process. The photocatalytic process was carried out in a photocatalytic reactor in the presence of TiO2 nanoparticles. TiO2 nanoparticles were successfully prepared in a laboratory scale using sol-gel method with titanium-isopropoxide (TTIP) as titanium precursor. Prepared material was found very effective to the removal of CIP antibiotic. The maximum removal efficiency of 87.95% of ciprofloxacin from aqueous solution was achieved at the pH 5, catalyst doze of 40 mg L−1 with initial concentration of ciprofloxacin 5 mg L−1, and the reaction time of 100 min additionally; material characterization of TiO2 was presented in detail in terms of XRD, SEM, UV, and FTIR. It has been found that at the optimum condition the total operating cost indicated for the removal of ciprofloxacin from aqueous solution is 786.56 (INR/kg of CIP removal). This technique demonstrated that photocatalytic reaction in presence of TiO2 nanoparticles is well applicable to treat pharmaceutical wastewater.

Synthesis and Evaluation of Physicochemical and Antimicrobial Properties of Bionanocomposites Based on Carboxymethylchitosan Biopolymer - Montmorillonite Nanoclay in the Presence of TiO₂ Nanoparticles

Synthesis and Evaluation of Physicochemical and Antimicrobial Properties of Bionanocomposites Based on Carboxymethylchitosan Biopolymer - Montmorillonite Nanoclay in the Presence of TiO₂ Nanoparticles

Effects of Al2O3-NiO, TiO2 and (Mg,Ni)O particles on the viscosity of heavy oil during aquathermolysis

Heavy and extra heavy oils make up 70% of the world's reserves, due to their high viscosity and complex composition, they have problems for recovering. Conventional methods are responsible for approximately 30% recovery of crude oil from reservoir. The enhanced oil recovery (EOR) techniques can reach higher values. The steam injection is the most used technique which heats the oil and reduces de viscosity. The thermal reduction of the viscosity is also followed an incipient cracking, a phenomenon promoted by the presence of hot steam water. This work studies the effect of presence of nanoparticles during steam injection (aquathermolysis), that can generate a more effective catalytic effect, which enhances the incipient cracking and the decreasing of the crude oil viscosity. A heavy oil with a viscosity of 4730 cP at 25 °C was used on a bench scale reactor to evaluate the effects of residence time, temperature, type and concentration of three different nanoparticles (Al2O3-NiO, TiO2 and (Mg, Ni) O) on viscosity and composition of crude oil. The addition of (Mg,Ni)O and TiO2 provided similar viscosity and sulfur content reductions during the aquathermolysis. The results showed that the presence of TiO2 nanoparticles during aquathermolysis can improve the quality of the oil, by reducing the heavy fractions, and its viscosity up to 13.4%.

De-Emulsification and Gravity Separation of Micro-Emulsion Produced with Enhanced Oil Recovery Chemicals Flooding

The present study investigates the effect of TiO2 nanoparticles on the stability of Enhanced Oil Recovery (EOR)-produced stable emulsion. The chemical precipitation method is used to synthesize TiO2 nanoparticles, and their properties were determined using various analytical characterization techniques such as X-ray Diffraction (XRD), High-Resolution Transmission Electron Microscopy (HRTEM), and Field Emission Scanning Electron Microscopy (FESEM). The effect of TiO2 nanoparticles is evaluated by measuring oil/water (o/w) separation, rag layer formation, oil droplet size, and zeta potential of the residual EOR produced emulsion. The laser scattering technique is used to determine the o/w separation. The results showed that spherical-shaped anatase phase TiO2 nanoparticles were produced with an average particle size of 122 nm. The TiO2 nanoparticles had a positive effect on o/w separation and the clarity of the separated water. The separated aqueous phases’ clarity is 75% and 45% with and without TiO2 nanoparticles, respectively. Laser scattering analysis revealed enhanced light transmission in the presence of TiO2 nanoparticles, suggesting higher o/w separation of the ASP-produced emulsion. The overall increase in the o/w separation was recorded to be 19% in the presence of TiO2 nanoparticles, indicating a decrease in the stability of ASP-produced emulsion. This decrease in the stability can be attributed to the improved coalescence’ action between the adjacent oil droplets and improved behavior of o/w interfacial film. An observable difference was found between the oil droplet size before and after the addition of TiO2 nanoparticles, where the oil droplet size increased from 3 µm to 35 µm. A similar trend of zeta potential is also noticed in the presence of TiO2 nanoparticles. Zeta potential was −13 mV to −7 mV, which is in the unstable emulsion range. Overall, the o/w separation is enhanced by introducing TiO2 nanoparticles into ASP-produced stable emulsion.

Aging Studies on Food Packaging Films Containing β-Cyclodextrin-Grafted TiO2 Nanoparticles.

Polymeric materials, such as polyvinyl alcohol (PVA) and ethylene–PVA copolymers (EVOH) are widely used in the food sector as packaging materials because of their excellent properties. TiO2 nanoparticles (NPs) show photocatalytic activity; when added to the aforementioned polymers, on the one hand, they are expected to provide bactericidal capacity, whereas on the other hand, they could favor nanocomposite degradation. These types of nanoparticles can be derivatized with cyclodextrin macromolecules (CDs), which can act as food preservative carriers, increasing the packaging food protective properties. In this work, films containing β-Cyclodextrin (βCD)-grafted TiO2 nanoparticles and PVA or EVOH were prepared. Regarding the photocatalytic activity of the nanoparticles and the possible environmental protection, accelerated aging tests for PVA, EVOH, and their composites with cyclodextrin-grafted TiO2 nanoparticle (NP) films were performed by two methods, namely, stability chamber experiments at different conditions of temperature and relative humidity and UV light irradiation at different intensities. After analyzing the systems color changes (CIELAB) and Fourier transform infrared spectroscopy (FTIR) spectra, it was observed that the film degradation became more evident when increasing the temperature (25–80 °C) and relative humidity percentage (28–80%). There was no significant influence of the presence of CDs during the degradation process. When irradiating the films with UV light, the largest color variation was observed in the nanocomposite films, as expected. Moreover, the color change was more relevant with increasing NP percentages (1–5%) due to the high photocatalytic activity of TiO2. In addition, films were characterized by FTIR spectroscopy and variation in the signal intensities was observed, suggesting the increase of the material degradation in the presence of TiO2 NPs.

MODERN METHODS FOR WASTEWATER TREATMENT

The article considers the photochemical degradation of the phenol solution in the presence of TiO2 nanoparticles, which synthesized in moderate conditions and dimensions vary between 10-30 nm and the 100 mg/ml NH4OH solution. The appearance of photochemical dissociation was confirmed on the basis of the absorption curves taken before and after the process and Abs curves were drawn on the “Varian” device. Phenol's photochemical dissociation in UV-visible area has been confirmed by experiments.

TiO2–SiO2 nanocomposite thin films deposited by direct liquid injection of colloidal solution in an O2/HMDSO low-pressure plasma

TiO2 nanoparticles (NPs), 3 nm in size, were injected inside a very-low-pressure O2 plasma reactor using a liquid injector and following an iterative injection sequence. Simultaneously, hexamethyldisiloxane (HMDSO) vapor precursor was added to create a SiO2 matrix and a TiO2–SiO2 nanocomposite (NC) thin film. Both the liquid injection and vapor precursor parameters were established to address the main challenges observed when creating NCs. In contrast to most aerosol-assisted plasma deposition processes, scanning/transmission electron microscopy (S/TEM) indicated isolated (i.e. non-agglomerated) NPs distributed in a rather uniform way in the matrix. The fraction of the TiO2 NPs inside the SiO2 matrix was estimated by SEM, spectroscopic ellipsometry (SE), and x-ray photoelectron spectroscopy. All techniques provided coherent values, with percentages between 12% and 19%. Despite the presence of TiO2 NPs, SE measurements confirmed that the plasma-deposited SiO2 matrix was dense with an optical quality similar to the one of thermal silica. Finally, the percentage of TiO2 NPs inside the SiO2 matrix and the effective refractive index of the NCs can be tuned through judicious control of the injection sequence.

TİTANYUM DİOKSİT SENTEZİ (TİO2)

Titanium dioxide (TiO2) is regarded as an environmentally friendly, easy-to-synthesis, stable and inexpensive catalyst, often as a mildly active catalyst for environmental improvement purposes such as water treatment. In this study, TiO2 was synthesized and characterized using X-Ray diffraction instrument (XRD) to determine the crystal structures, scanning electron microscopy (SEM), equipped with energy-dispersive X-ray spectroscopy (EDX), BET analysis to determine particles size, and FT-IR analysis to determine bonds TiO2. Results show that while the presence of TiO2 nanoparticles at 25o, 38o, 48o at 2θ peaks was detected, TiO was detected at 65o and 70o peaks. According to the results of EDX analysis; Ti, O, Au, and C elements are detected. According to FT-IR analysis, the peak formed at 450 cm-1 shows the presence of TiO2. According to BET analysis; the surface region of TiO2 was identified as 65 m2/g which was significantly higher than that of commercial TiO2 (40 m2/g). The results show that it is acceptable to achieve TiO2 at decrease temperatures according to those used in the literature. Additionally, the characterization of synthesized TiO2 at room temperature is similar compared to the results obtained from previous study results that has been conducted under high temperatures (&gt;400Co).