Incorporation Of TiO2 Nanoparticles Research Articles

Allometry of nanoparticles in diesel-biodiesel blends for CI engine performance, combustion and emissions

Most countries in the world are facing two major challenges, one is the increase in the demand for energy consumption difficult to fulfill because of limited fossil fuel, and the second is the emission norms specified by many countries. Various methods are adopted to reduce emissions from engines but that leads to sacrificing the performance of CI engines. To eradicate this problem in the present study, the nanoparticles like (TiO2) are used with different particle sizes 10–30 nm, 30–50 nm and 50–70 nm induced in B20 (20% biodiesel and 80% diesel) with the constant volume fraction of 100 ppm, and utilized in the diesel engine without any modifications. The results showed that the incorporation of TiO2 nanoparticles improves the combustion of hydrocarbons and reduces the emissions of CO, unburned hydrocarbon concentration, NOx and soot. Moreover, among three sizes of the nanoparticles, those with size 30–50 nm showed interesting results with the reduction in brake-specific energy consumption, NOx, smoke and HC by 2.9%, 16.2%, 35% and 10%, respectively, com-pared to other blends used in the study, and hence the blend with the nanoparticle of size 30–50 nm is expected to be a more promising fuel for commercial application in CI engines.

Novel chitosan-based smart bio-nanocomposite films incorporating TiO2 nanoparticles for white bread preservation

Chitosan (CS)-based bio-nanocomposite food packaging films were prepared via solvent-casting method by incorporating a unique combination of additives and fillers, including polyvinyl alcohol (PVA), glycerol, Tween 80, castor oil (CO), and nano titanium dioxide (TiO2) in various proportions to enhance film properties. For a comprehensive analysis of the synthesized films, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), tensile testing, field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDS), and UV–vis spectrophotometry were employed. Furthermore, the antimicrobial efficacy of the films against S. aureus, E. coli, and A. niger was examined to assess their potential to preserve food from foodborne pathogens. The results claimed that the inclusion of castor oil and TiO2 nanoparticles considerably improved antimicrobial properties, UV–vis light barrier properties, thermal stability, optical transparency, and mechanical strength of the films, while reducing their water solubility, moisture content, water vapor and oxygen permeability. Based on the overall analysis, CS/PVA/CO/TiO2–0.3 film can be selected as the optimal one for practical applications. Furthermore, the practical application of the optimum film was evaluated using white bread as a model food product. The modified film successfully extended the shelf life of bread to 10 days, surpassing the performance of commercial LDPE packaging (6 days), and showed promising attributes for applications in the food packaging sector. These films exhibit superior antimicrobial properties, improved mechanical strength, and extended shelf life for food products, marking a sustainable and efficient alternative to conventional plastic packaging in both scientific research and industrial applications.

Development and electrochemical investigations of enhanced corrosion-resistant Polyvinylcarbazole-TiO2 hybrid nanocomposite coatings on 316L SS for marine applications

The present study focuses on evaluating the corrosion resistance of 316L stainless steel substrates with Polyvinylcarbazole (PVK)/TiO2 hybrid nanocomposite coatings (HNC). Using the chronoamperometry approach, the HNC were electrochemically synthesized on 316L stainless steel substrates, incorporating various weight (%) 1 %, 2 %, 3 % of TiO2 nanoparticles into the PVK matrix. The findings of the surface morphology investigation verified that the 316L SS had a dense and smooth PVK/TiO2 coating. A low surface roughness and high contact value of the PVK/TiO2 coatings are also responsible for the decrease in corrosion rate of the 316L SS. The corrosion protection efficiency of the PVK/TiO2 HNC were investigated through open circuit potential (OCP) measurement, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) analysis in 3.5 wt% NaCl solution. The corrosion rate obtained from the polarization studies of the HNC coatings as follows PVKT-2 < PVKT-3 < PVKT-1 < PVK < 316L SS. Results revealed that an optimal loading of 2 wt% TiO2 nanoparticles significantly enhanced the corrosion resistance of the coating. The enhanced electrochemical impedance response for PVK/TiO2 coatings was verified by EIS experiments. The study demonstrates that the incorporation of TiO2 nanoparticles into the PVK matrix effectively creates a barrier layer at the coating-metal interface, inhibiting the entry of aggressive ions. Microhardness studies revealed the increase in hardness value of the PVK and PVK/TiO2 coatings indicated the protective nature of the coating and provided high mechanical strength to 316L SS. The tape adhesion tests carried out on the coated specimens also indicated a good adhesion of the PVK/TiO2 on the 316L SS surface.

Positional Isomeric Effects on the Physicochemical Properties of Polymeric Matrix and Polymer@TiO2 Nanocomposites

This study investigates the influence of positional isomerism on the physicochemical characteristics of polymeric matrices by examining polyo-anisidine (POA) and polyp-anisidine (PPA) in conjunction with TiO2 nanoparticles. The synthesis of POA@TiO2 and PPA@TiO2 involved chemical oxidative polymerization. X-ray diffraction analysis revealed the anatase structure of TiO2 nanoparticles. Transmission electron microscopy confirmed the successful integration of TiO2 nanoparticles within the polymer matrix. Moreover, FTIR and UV–Vis spectroscopy confirmed the effective interaction between the nanoparticle and the polymer. TGA indicated that POA@TiO2 exhibited a lower weight loss than PPA@TiO2, suggesting an enhancement in thermal stability. Although the incorporation of TiO2 nanoparticles led to a reduction in the electrical conductivity of the pristine polymers (PPA and POA), the resultant nanocomposites retained high conductivities within the range of 0.08 to 0.34 S.cm−1. Furthermore, the POA-based polymer matrix displayed promising electrochemical properties. Significantly, the adherence of the POA layer to TiO2 nanoparticles suggests potential practical applications.

PVA-TiO2 Nanocomposite Hydrogel as Immobilization Carrier for Gas-to-Liquid Wastewater Treatment

This study investigates the development of polyvinyl alcohol (PVA) gel matrices for biomass immobilization in wastewater treatment. The PVA hydrogels were prepared through a freezing–thawing (F-T) cross-linking process and reinforced with high surface area nanoparticles to improve their mechanical stability and porosity. The PVA/nanocomposite hydrogels were prepared using two different nanoparticle materials: iron oxide (Fe3O2) and titanium oxide (TiO2). The effects of the metal oxide nanoparticle type and content on the pore structure, hydrogel bonding, and mechanical and viscoelastic properties of the cross-linked hydrogel composites were investigated. The most durable PVA/nanoparticles matrix was then tested in the bioreactor for the biological treatment of wastewater. Morphological analysis showed that the reinforcement of PVA gel with Fe2O3 and TiO2 nanoparticles resulted in a compact nanocomposite hydrogel with regular pore distribution. The FTIR analysis highlighted the formation of bonds between nanoparticles and hydrogel, which caused more interaction within the polymeric matrix. Furthermore, the mechanical strength and Young’s modulus of the hydrogel composites were found to depend on the type and content of the nanoparticles. The most remarkable improvement in the mechanical strength of the PVA/nanoparticles composites was obtained by incorporating 0.1 wt% TiO2 and 1.0 wt% Fe2O3 nanoparticles. However, TiO2 showed more influence on the mechanical strength, with more than 900% improvement in Young’s modulus for TiO2-reinforced PVA hydrogel. Furthermore, incorporating TiO2 nanoparticles enhanced hydrogel stability but did not affect the biodegradation of organic pollutants in wastewater. These results suggest that the PVA-TiO2 hydrogel has the potential to be used as an effective carrier for biomass immobilization and wastewater treatment.

Study on preparation, structure, and cooling properties of TiO2/acrylonitrile–styrene–acrylate terpolymer solar reflective nanocomposite

AbstractPreparation, characterization, and cooling properties of TiO2 /acrylonitrile–styrene‐acrylate (ASA) terpolymer solar reflective nanocomposites with various contents of titanium dioxide (TiO2) nanoparticles were investigated. The formation of nanocomposites was monitored by Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and contact angle measurements. The cooling features were characterized via ultraviolet–visible–near infrared (UV–vis–NIR) spectrophotometry and heat build‐up tests. FTIR spectra show the disappearance of the vinylic absorption peak at 1636 cm−1 of the modified TiO2 which signifies good chemical interaction between the poly (butyl acrylate) chains and the nanoparticles. DLS measurements revealed relative enlargement in the diameter of nanocomposite latex particles from 107 to 184 nm as the percentage of mineral nanoparticles increased. SEM and TEM analysis revealed the formation of a core‐shell morphology with an almost uniform distribution of nanoparticles in the polymer chains. Spectral properties details obtained using UV–vis–NIR spectrophotometry revealed that surface modification of TiO2 nanoparticles resulted in a more than 7% increase in solar transmittance compared to the raw form. Nevertheless, grafting a thermoplastic shell onto the acrylic core reduced the average solar transmittance from 81.92% to 55.32%. Incorporating TiO2 nanoparticles (up to 6 wt%) into the polymer matrix led to an 18.44% further decrease in solar transmittance compared to the neat ASA. Heat build‐up tests showed enhanced cooling of 10.2, 12.7°C, 13.4°C, and 14.2°C for 0, 2, 4, and 6 wt% of used nanoparticles, respectively.Highlights In situ nanocomposites were synthesized through mini‐emulsion polymerization. Chemical bonding formed between functionalized TiO2 and polymeric matrix. ASA/TiO2 nanocomposite shields &gt;56% of NIR light and 63% of solar light. Nanocomposites reduced heat build‐up temperature by more than 14°C during indoor test.

Investigating the effects of TiO2 nanoparticles on the barrier inhomogeneity of brilliant-blue fruit dye-base solar cell

This study aims to investigate the effects of titanium dioxide nanoparticles on the barrier inhomogeneity of a brilliant-blue dye-based solar cell. The cell has been prepared by spin-coating technique. The barrier inhomogeneity was characterized by measuring the cell's current-voltage-temperature (I-V-T) characteristics. The results show that the incorporation of TiO2 nanoparticles leads to a significant reduction in the barrier inhomogeneity of the cell, which results from the improvement of charge injection at the junction. This improvement can be attributed to the role of TiO2 nanoparticles in reducing surface defects and improving the charge injection at the interface. Also, we have investigated the change in the Richardson constant. The homogeneous Richardson constant was found to be 81.63 × 10−7 Am−2K−2 for the dye and the value was modified to 22.85 × 10−7 Am−2K−2 by incorporation of nanoparticles. This illustrates that by the doping of nanoparticles modifies barrier inhomogeneity, resulting in enhanced conductivity.

Thermal Properties of TiO2 Nanoparticle-Treated Transformer Oil and Coconut Oil

This study investigates the impact of incorporating TiO2 nanoparticles into two types of oils at different temperatures and with varying volume fractions: transformer oil (NYTRO LIBRA) and virgin coconut oil (manufactured by Govi Aruna Pvt. Ltd., Gampaha, Sri Lanka). The nanofluids were prepared using a two-step method by adding CTAB (cetyltrimethylammonium bromide) surfactant. To minimize nanoparticle agglomeration, this study employed relatively low-volume fractions. Thermal properties by means of thermal conductivity, thermal diffusivity, and volumetric heat capacity were measured in accordance with ASTM (American Society for Testing and Materials) standard methods using a multifunctional thermal conductivity meter (LAMBDA thermal conductivity meter). The measured thermal conductivity values were compared with theoretical models and previous research findings. It was confirmed that the modification of thermal properties was enhanced by doping TiO2 nanoparticles with different volume fractions.

Enhancing the multifunctional properties of cellulose fabrics through in situ hydrothermal deposition of TiO2 nanoparticles at low temperature for antibacterial self-cleaning under UV–Vis illumination

This study aimed to improve the multifunctional properties (including photocatalysis, stability reusability, self-cleaning, antibacterial effects, and thermal radiation shielding) of cellulose fabrics through incorporation of TiO2 nanoparticles. To achieve this, anatase TiO2 nanoparticles were synthesized in situ and deposited onto cotton fabrics through hydrothermal method. The presence of TiO2 nanoparticles in cellulose fabrics greatly enhanced the photocatalytic efficiency and adsorption range and did not damage the fabric fibers. The TiO2-coated cotton exhibited an outstanding photocatalytic efficiency, with dye removal rates of 92.20 % ± 0.015 % and 99.68 % ± 0.002 % under UV-A and visible illumination, respectively. In addition, the material exhibited thermal radiation shielding properties, in which no heat absorption was observed within 60 min at 40 °C–70 °C. To further enhance the hydrophobicity, the TiO2-coated cotton was surface-modified with 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PFDTS). The resulting PFDTS/TiO2-coated cotton was superhydrophobic with a water contact angle of 156.50° ± 0.05° with a sliding angle of 4.33° ± 0.47° and roughness of 67.35 nm. The superhydrophobicity of the PFDTS/TiO2-coated cotton also facilitated self-cleaning through water injection to remove soil impurities. Furthermore, the PFDTS/TiO2-coated cotton exerted antibacterial effects against gram-negative (Escherichia coli) and gram-positive (Staphylococcus aureus) bacteria under UV-A or visible illumination. These nanocomposite fabrics with multifunctional properties have potential for industrial, military, and medical applications.

Development and evaluation of biodegradable starch-based films containing cellulose nanocrystals/titanium dioxide nanoparticles as an alternative for food packaging

Biodegradable starch-based films are an environmentally friendly solution to reduce the use of petroleum-derived polymers. Thus, this work aims to obtain corn starch films by incorporating 5% w/w of cellulose nanocrystals (CNC), different concentrations of titanium dioxide nanoparticles (TiO2) (0, 0.25, 0.5, 1, and 2% w/w), and 40% w/w of glycerol and sorbitol (plasticizers), in a 1:1 ratio. The films showed a high potential for UV-light barrier, with an increase of 307% incorporating only 2 wt% of TiO2 in relation to the film without incorporation of TiO2. The use of TiO2 increased the white pigmentation capacity of the samples and decreased the lower water solubility – a reduction of approximately 28% using 0.5 wt% TiO2 compared to the CNC control sample was observed. The incorporation of TiO2 nanoparticles increased the tensile strength by adding 1 wt% of TiO2 nanoparticles with 34% increase in the tensile strength of the film without incorporation of TiO2. The thermal stability of the films with 1 wt% TiO2 and 5 wt% CNC increased by 85°C. Thus, the addition of CNC and TiO2 enabled an improvement in the physical/thermal/chemical properties of the films, making them possible alternatives for use in food packaging.

3D printed denture base material: The effect of incorporating TiO2 nanoparticles and artificial ageing on the physical and mechanical properties

ObjectivesTo evaluate the physical and mechanical properties of three-dimensional (3D) printed denture base resin incorporating TiO2 nanoparticles (NPs), subjected to a physical ageing process. MethodsAcrylic denture base samples were prepared by a Stereolithography (SLA) 3D printing technique reinforced with different concentrations (0.10, 0.25, 0.50, and 0.75) of silanated TiO2 NPs. The resulting nanocomposite materials were characterized in terms of degree of conversion (DC), and sorption/solubility flexural strength, impact strength, Vickers hardness and Martens hardness and compared with unmodified resin and conventional heat-cured (HC) material. The nanocomposites were reassessed after subjecting them to ageing in artificial saliva. A fractured surface was studied under a scanning electron microscope (SEM). ResultsThe addition of TiO2 NPs into 3D-printed resin significantly improved flexural strength/modulus, impact strength, Vickers hardness, and DC, while also slightly enhancing Martens hardness compared to the unmodified resin. Sorption values did not show any improvements, while solubility was reduced significantly. The addition of 0.10 wt% NPs provided the highest performance amongst the other concentrations, and 0.75 wt% NPs showed the lowest. Although ageing degraded the materials’ performance to a certain extent, the trends remained the same. SEM images showed a homogenous distribution of the NPs at lower concentrations (0.10 and 0.25 wt%) but revealed agglomeration of the NPs with the higher concentrations (0.50 and 0.75 wt%). SignificanceThe outcomes of this study suggested that the incorporation of TiO2 NPs (0.10 wt%) into 3D-printed denture base material showed superior performance compared to the unmodified 3D-printed resin even after ageing in artificial saliva. The nanocomposite has the potential to extend service life of denture bases in future clinical use.

Fabrication and Characterization of Semi-refined Carrageenan Films Incorporated with TiO2 Nanoparticles

In this study, a packaging film was developed using semi-refined carrageenan, incorporating varying concentrations of TiO2 nanoparticles. The aim of this study was to investigate the effect of TiO2 nanoparticles on the properties of the SRC-based film. The films were prepared through a casting method, and the resulting samples were characterized in terms of their functional, mechanical, and physical properties. The SRC film containing 1 wt% of TiO2 nanoparticles demonstrated the highest tensile strength. However, with the addition of TiO2 nanoparticles at any concentrations (1, 3, 5, and 7 wt%), the elongation at break of the SRC film decreased in comparison to the SRC film without TiO2 nanoparticles. Moreover, as the concentration of TiO2 nanoparticles increased from 1 to 7 wt%, the moisture content, and water solubility of the SRC films decreased. The FTIR spectra analysis provided valuable information on the interaction between SRC and TiO2 nanoparticles. The results suggest that incorporating TiO2 nanoparticles into semi-refined carrageenan films shows promise for developing packaging materials with improved mechanical strength and physical performance.

Non-cytotoxic and bioactive nanocomposite film of natural Arabic gum incorporating TiO2 nanoparticles for bone tissue regeneration

Biomaterials with exceptional biocompatibility and bioactivity are now pushing the boundaries of bone tissue engineering. In this study, natural Arabic gum biopolymer incorporating titanium dioxide nanoparticles (NAG + TiO2NP) nanocomposite film was fabricated. The FTIR and XRD analysis show the presence of functional groups assigned to NAG biopolymers and highly crystalline anatase TiO2NP. Well dispersed TiO2NP can be seen from SEM micrograph suggesting good interaction between TiO2NP filler and NAG biopolymer matrix to enhance the mechanical characteristics of nanocomposite film. The NAG + TiO2NP nanocomposite film exhibited strong bioactivity to form bone-like apatite and promoted the proliferation of MG-63 cells attributed to their excellent biocompatibility and non-toxicity. The NAG + TiO2NP nanocomposite film also displays high antibacterial activity with (36.33 ± 1.53) mm and (27.00 ± 2.00) mm inhibition zone were recorded against Staphylococcus aureus and Escherichia coli. The findings indicate that the NAG + TiO2NP nanocomposite film, with its improved mechanical properties, high swelling capacity, biodegradability, and non-toxicity, shows promise as a viable option for bone tissue regeneration materials.

Characterization and photocatalytic performance of cement mortars with incorporation of TiO2 and mineral admixtures.

As the main components of the building envelope, construction materials have a straight relation with air contaminants from anthropogenic origins. Titanium dioxide has been recently applied in construction industry products since its photocatalytic properties can be used for pollutant degradation purposes. This study evaluated the performance of cement-based mortars with the incorporation of TiO2 nanoparticles and mineral admixtures. Six mortar compositions were defined by considering two reference mixes (with and without TiO2 incorporation), two mineral admixtures (bentonite and metakaolin) as partial cement replacement and one waste from ornamental stone processing in two levels of partial substitution of natural sand. Consistency index, density, and entrained air content of mixtures were investigated at fresh state. Compressive strength, water absorption, sorptivity, and micrographs from scanning electron microscopy were used to characterize mortars at hardened state. It was observed that incorporation of TiO2 does not considerably change mortar's properties at fresh and hardened state, despite a denser microstructure and improved interfacial transition zone. In general, the relation between the water-to-cement ratio and porosity on the performances of TiO2-added mortars was shown, which is strongly related to their photocatalytic efficiency. Metakaolin mixtures were more efficient to NO conversion, and high selectivity was observed for the bentonite mortars.

Effects of TiO2 nanoparticles on the physicochemical and biological properties of oxidized sodium alginate/polyacrylamide-gelatin composite hydrogels fabricated by interpenetrating network approach

To enhance the applicability of alginate hydrogel in tissue engineering, we attempted to fabricate oxidized sodium alginate/polyacrylamide-gelatin (OSA/PAM-GT) composite hydrogels by interpenetrating network approach with the hydroxyapatite/D-glucono-δ-lactone (HAP/GDL) as the endogenous ionic cross-linking agent for oxidized sodium alginate (OSA) and N, N′-methylenebisacrylamide (MBAA) as the chemical cross-linking agent for polyacrylamide (PAM), followed by their surface coverage with gelatin. Then TiO2 nanoparticles as the reinforcing agent were added to the OSA/PAM-GT hydrogel matrix to construct organic/inorganic hybrid OSA/TiO2/PAM-GT composite hydrogels. In particular, the effects of the amount of TiO2 nanoparticles on the microscopic morphology, mechanical properties, swellability, biodegradability, bio-mineralization and biocompatibility of the composite hydrogels were studied. Experimental results indicated that the addition of TiO2 nanoparticles into the matrix of OSA/TiO2/PAM-GT composite hydrogels could effectively regulate the porosity, mechanical properties, swelling ratio, in vitro biodegradability and bio-mineralization of OSA/TiO2/PAM-GT composite. Moreover, OSA/TiO2/PAM-GT composite hydrogels had the best biocompatibility when the content of TiO2 nanoparticles was 0.5% (w/v), indicating that an appropriate amount of TiO2 nanoparticles could effectively promote cell adhesion, proliferation and differentiation. Consequently, the combined method of the interpenetrating network technology, the incorporation of TiO2 nanoparticles with the surface coverage of gelatin could overcome the defects of alginate hydrogels to some extent, making OSA/TiO2/PAM-GT composite hydrogels suitable for tissue engineering applications.

Development of polyvinylpyrrolidone, inorganic nanoparticles, and lithium carbonate nanostructured systems

AbstractNanocomposites with inorganic nanofillers spread in a polymer matrix have been used for the development of pharmaceutical systems to treat mental illnesses such as bipolar disorder and Alzheimer's disease. In this study, nanostructured particles using a solution intercalation technique combined with a spray‐drying process using polyvinylpyrrolidone (PVP), montmorillonite, titanium dioxide, and lithium carbonate, with the aim of designing a new drug delivery system. XRD and low‐field nuclear magnetic resonance analyses showed that PVP/MMT 1% achieved an intercalated/exfoliated morphology. However, the incorporation of TiO2 nanoparticles into the PVP matrix did not affect its structure, indicating that there was not a strong interaction between the polymer and the TiO2 nanoparticles. Thermal analysis did not reveal any changes in the nanocomposites compared to the pure polymer. Scanning electron microscopy (SEM) analysis revealed a pseudo‐spherical shape, and SEM‐energy‐dispersive x‐ray spectrometry (EDS) confirmed the dispersion of MMT in the PVP matrix. The introduction of lithium carbonate into the PVP/MMT matrix created a new system with higher molecular mobility; the drug introduction increased the mean droplet size, and the zeta potential remained negative. Overall, the results indicate that the applied methodology can produce a new nanostructured particle as a drug delivery system.

Incorporation of TiO2 nanoparticles in CoWP coating for improved wear and corrosion resistance via electrodeposition

The CoWP/TiO2 composite coating is prepared by electrodeposition by adding TiO2 nanoparticles in the plating solution. The influence of TiO2 nanoparticles on the composition, thickness, roughness, surface morphology, mechanical performance and corrosion resistance of CoWP/TiO2 composite coating is investigated. It is found that adding proper amount of TiO2 nanoparticles in the plating solution can improve the deposition rate, increase the coating thickness, and enhance the wear resistance and corrosion resistance of composite coating. TiO2 nanoparticles in the plating solution can enter the crystal lattice of CoWP alloy and induce heterogeneous nucleation during electrodeposition, which plays the role of refining grain, so as to obtain compact surface morphology with smaller surface roughness. The CoWP/TiO2 composite coating electrodeposited from the plating solution with 15 g/L TiO2 nanoparticles has the best wear resistance and corrosion resistance with the smallest wear scar depth (17.04 µm) and minimum corrosion current density (12.92 μA/cm2). When the TiO2 nanoparticles in the solution are up to 20 g/L, the agglomeration phenomenon of TiO2 nanoparticles inhibits the electrodeposition, resulting in the decline of deposition rate, the increase of alloy surface roughness, and the decrease of wear and corrosion resistance performance.

Hybrid of Conjugated Polymers with Incorporation of Metal Oxide Nanocomposites for Improving Optoelectronic Properties

Herein, the incorporation of TiO2 nanoparticles (NPs), SiO2 NPs, and their nanocomposite (STNC) to enhance the optoelectronic properties of the hybrid of poly[9,9′‐di‐n‐octylfluorenyl‐2,7‐diyl] (F8), poly[2‐methoxy‐5(2‐ethylhexyl)‐1,4‐phenylenevinylene)] (MEH‐PPV), and poly[2‐methoxy‐5‐(3,7‐dimethyl‐octyloxy)‐1,4‐phenylenevinylene]‐end capped with dimethylphenyl (MDMO–PPV–DMP) are revealed. The tune of the donor (F8) conjugated length can be detected from the red shift in absorption spectra when TiO2 NPs and SiO2 NPs are added, as well as an increase in emission intensity of the donor. The addition of acceptors (MEH–PPV or MDMO–PPV–DMP) to the donor results in a new absorption peak at 510 nm, which increases when TiO2 NPs and SiO2 NPs or STNC are incorporated into the ternary hybrid. The incorporation of STNC into F8 is anticipated to reduce the donor energy bandgap and improve the energy transfer from F8 to both acceptors. Moreover, Förster resonance energy transfer (FRET) is improved in the ternary hybrid, as evidenced by enhanced emission spectra of the donor and both acceptors, increased broadness of photoluminescence excitation spectra, and shifting blue color toward white region. The ternary hybrid with STNC‐based organic light‐emitting diode shows superior current and turn‐on voltage compared to other devices, which is likely due to its superior FRET.

Flexible PET/(PET-TiO2) core/shell nanofibrous mats as potential photoanode layer for dye-sensitized solar cells, DSSCs

In this detailed study, high porous flexible structures composed of polyethylene terephthalate (PET) and a PET composite comprised of titanium dioxide (PET-TiO2) core/shell nanofibrous mats were developed using coaxial electrospinning technique. Two different TiO2 shapes (nanobars and nanorhombics) were developed, using the solvothermal synthesis method, then incorporated at various contents (0–20 wt%) in the shell layer of the nanofiber to improve the optical, thermal, and mechanical properties of their corresponding fibrous mats to use them as alternative porous structures to the brittle porous TiO2 based photoelectrode presently used. The surface morphology, porosity, specific surface area, thermal stability, dye adsorption, optical and mechanical properties of the so developed nanofibrous mats were investigated. Emphasis was to the effect of solvent miscibility and solvent composition on fibrous mats' morphology. The successful incorporation of TiO2 nanoparticles inside the nanofibers’ shell was confirmed by various characterizations techniques. It was observed that addition of up to 15 wt% TiO2 shifted the UV–Visible absorption of the of the so developed nanofibrous mats to larger wavelength. Moreover, PET/(PET-TiO2) core/shell nanofibrous mats obtained with nanobars TiO2 showed higher thermal stability due to a better TiO2/PET interfacial interaction. Photoluminescence results confirmed the efficient charge transfer between TiO2 nanoparticles and PET with a minimum recombination of the photogenerated charges.

Effect of Gamma Radiation on the Properties of Poly(Methyl Methacrylate)/Titanium Dioxide Nanocomposite Films

In this study, poly(methyl methacrylate)/titanium dioxide (PMMA/TiO2) nanocomposite films (NFs) were prepared by a solution casting method and afterward irradiated with gamma (γ)-rays at different doses. The structural and optical properties of the PMMA/TiO2NFs before and afterγ-irradiation at different doses were analyzed by X-ray diffraction (XRD) and ultraviolet-visible (UV-vis) spectroscopy, respectively. In addition, the impact ofγ-dose on the wetting properties of PMMA/TiO2was determined by measuring the water contact angle. The XRD patterns illustrated new sharp peaks after the incorporation of TiO2nanoparticles (NPs) into the PMMA matrix, which could be due to the interaction of TiO2with PMMA owing to the change in the crystallographic organization. Moreover, the degree of the disorder increases with increasingγ-dose. Optical property studies revealed that the optical gap-band energy of the PMMA/TiO2dropped to 3.92 eV at the highestγ-dose compared with pure PMMA, which was estimated to be 4.5 eV. A remarkable increase in the number of carbon atoms per cluster was observed with increasingγ-dose. The water contact angle was decreased with increasingγ-dose. The decrease in water contact angle is due to the formation of an oxidized layer and/or carbonaceous clusters on the surface of theγ-irradiated nanocomposite films. Therefore, it can be concluded that PMMA/TiO2NFs with controlled optical gap-band energy and controlled water contact angle can be prepared by theγ-irradiation technique to be used for the fabrication of optoelectronic products.