Addition Of TiO2 Nanoparticles Research Articles

Surface smoothening and formation of nano-channels improved mono-selectivity and antifouling property in TiO2 incorporated cation exchange membrane

Green liquor solution (GLS) is waste pollutant from pulp and paper mills. Causticization process is a common treatment method for GLS, which is energy intensive and environmentally unsafe, because of high operating cost, and solid waste generation. We reported synergetic effect of titanium dioxide nanoparticle (TiO2) incorporated sulfonated PEEK, on the performance cation exchange membrane (CEM), for producing NaOH from industrial GLS by electro-electroldiaysis (EED). Reported composite CEM was studied for morphology, physicochemical, electrochemical properties. The counter-ion transport number, stability and antifouling properties of CEM were significantly improved after the addition of TiO2 nanoparticles in the sulfonated PEEK membrane matrix. Two compartment EED cell (active membrane area: 66 cm2) was used to perform the experiments for producing NaOH using industrial GLS at 60 mA·cm−2 constant current density. The reported results shed light on production of NaOH along with prevention of sulfur scaling in treatment of wood based pulp and paper mills GLS stream. The modified membrane named SPK-T-5 (5 wt% of TiO2) by utilizing containing sulfonated polymer matrix outperforms an increasing trend of NaOH production along with notable sulfur antifouling. The obtained research outcomes are expected to be a valuable source for NaOH production with the aim of zero solid discharge practice for pulp and paper mills.

Visible Light-Induced Photocatalyst with Au/TiO2 Nanocomposites Fabricated through Pulsed Laser-Induced Photolysis

Gold–titanium oxide nanocomposites (Au–TiO2 NCPs) were fabricated through pulsed laser-induced photolysis (PIPS) and verified to be usable for the visible light catalytic degradation of methylene blue (MB). The PIPS method can produce a sufficient amount of NCPs quickly and has potential to be commercialized. In contrast to other studies, we clarified the optical spectrum of the light sources, including peak power, bandwidth, and total intensity used for photodegradation reactions and discovered that the photodegradation efficiency of the produced Au–TiO2 NCPs in the wavelength range of 405 nm could reach 37% in 30 min due to the charge transfer between Au and TiO2. The control experiment shows that the addition of individual Au and TiO2 nanoparticles (NPs) to an MB solution has no enhancement of degradation ability under visible light illumination. The photodegradation of Au–TiO2 NCPs can be further improved by increasing the concentrations of auric acid and TiO2 NPs in a precursor under PIPS fabrication.

Study of mechanical properties and wear resistance of nanostructured Al 1100/TiO2 nanocomposite processed by accumulative roll bonding

Aluminum (Al) composites have been extensively developed for automotive applications due to their high specific strength. Therefore, in this study, an Al-titanium dioxide (TiO2) nanocomposite was processed using the accumulative roll bonding (ARB) process. The mechanical characteristics of monolithic and nanocomposites specimens made with 0, 1, 2, and 3 wt% TiO2 nanoparticles as reinforcement were studied at several ARB passes. According to the microstructure of the composites, rolling after five passes achieves a homogenous distribution of reinforcement particles, ultrafine and elongated grains of the matrix. After five ARB passes, the TiO2 particles were uniformly dispersed. Finally, scanning electron microscopy and energy dispersive spectroscopy revealed that the Al-TiO2 nanocomposite had an appropriate dispersion of TiO2 nanoparticles. Vickers microhardness improves as the number of accumulative roll bonding passes increases. Furthermore, after five passes, Vickers microhardness testing revealed that the sample with 3%TiO2 has the greatest hardness value of 112 HV, which is significantly greater than the 44 HV hardness value of the ARB-processed aluminum. The mechanical properties of the specimens, yield and ultimate strengths, improved with the addition of TiO2 nanoparticles. Due to good bonding among the components, mechanical parameters such as microhardness and tensile strength were more than three times better than the Al matrix.

The effect of TiO2 nanoparticles size on Cd (II) removal by the paddy crusts from waterbody

The influence of nanoparticles (NP) on the accumulation of heavy metals in the paddy crust (PC) was unclear. This experiment explored the potential effects and mechanism of TiO2 NP with different particle sizes on Cd removal by PC from waterbody. All the TiO2 with size of 25 nm (T25), 100 nm (T100) and 2000 nm (T2000) can promote the Cd uptake by the PC, and with the sequence: T100 > T25 > T1000. Especially, 0.1 mg/L T100 can enhanced ~45% Cd removal comparing with pristine PC, and the Cd uptake capacity reached as high as 92 mg/g. After treatment of 72 h, the PC+T100 can reduce Cd in the acidic coal drainage from 0.48 mg/L to 0.009 mg/L, with removal efficiency of 98%. The total concentration of surface adsorptive site number of PC+T100, PC+T25 and PC was 0.87 ± 0.03, 0.78 ± 0.07 and 0.67 ± 0.04, respectively. The TiO2 stimulation to PCs secreted the extracellular substance and then increased the content of amino/hydroxyl adsorptive sites by 30–70%. T100 can stimulate high EPS-producing algae and bacteria, whereas most T25 can only penetrate the cell walls of low EPS-producing microorganisms. T100 can stimulate not only the thick sheath layer of Oedogonium, the main component of PC, but also the thin layer of algae and bacterium. And induce it to produce a large amount of protein, phospholipids, etc. T25 can only stimulate the Microcystics, Chlorococcum, Scenedesmius and bacteria with thin cell membranes to produce low extracellular substance. However, T25 would easily enter the cell trough thin cell membranes, result in that the Cd attached to T25 to penetrate the intracell. Therefore, the non-EDTA-exchangeable Cd fraction in PC+T25 was 55.48%, higher than 36.82% of PC+T100, and 21.52% of PC. Our investigation demonstrated that the addition of TiO2 NP with appropriated size in PC was a potential efficient method to remove the heavy metal from waterbody.

Effect of Solvent on Optical Properties and Surface Topography of Nanocomposite Conjugated Polymer Thin Film

The addition of TiO2 nanoparticles (NPs) to a white-emission conjugated polymer (CP) blend of poly(9,9-dioctylfluorene-2,7-diyl) (PFO) and poly(2-methoxy-5(2-ethylhexyl)−1,4-phenylenevinylene (MEH-PPV) enhanced the optical properties. However, the agglomeration of the nanoparticles restricted enhancement. This drawback was successfully overcome in this study. The highly polar solvent chloroform was mixed with toluene and used to prepare thin films of the blends. Solution blending and spin-coating techniques were used to prepare thin films with different TiO2 nanoparticle contents. In addition, pure toluene and chloroform were investigated as solvents for the nanocomposite blend. These three cases were compared by studying the emission spectra, absorption spectra, Commission Internationale d’Eclairage coordinates (CIE), field emission scanning electron microscopy (FE-SEM) images and scanning probe microscope (SPM) images. The average roughness, quenching constant, and energy transfer probability were calculated. The optimum physical properties of the thin film were achieved using nanoparticles at 15wt% and applied to the binary blend with a mixture of equal amounts of toluene and chloroform. Although chloroform is better for nanoparticle distribution, toluene is mandatory for obtaining the highest yield of PFO.

Characterization and performance evaluation of Cu-based/TiO2 nano composites

Copper and copper alloys are used in industrial applications and food contact surfaces due to their desirable properties; copper metal matrix composites have been exciting researchers' attention in recent years since they can offer many valuable characteristics. The present study investigated the effects of the TiO2 nanoparticles addition with different weight percent on the hardness and corrosion behavior of copper nanocomposites. The powder metallurgy method was used to fabricate the Cu/TiO2 reinforced with different weight fractions of TiO2 nano particles up to 12 wt.%. The corrosion behavior of fabricated specimens is evaluated using potentiodynamic polarization curves and electrochemical impedance spectroscopy in different solutions. These solutions were 3.5wt.% NaCl, 0.5 NaOH and 0.5 M H2SO4 reflected different pH. The results showed that the addition of TiO2 nano particles improves pure copper's hardness. The hardness of pure copper increased from 53 to 91 HV by adding 12 wt.% TiO2. The corrosion current density (Icorr) of copper nanocomposites test specimens was higher than Icorr of pure copper in all test solutions. As TiO2 nano particles increase, the corrosion resistance of Cu nano composites decreased. All test specimens exhibited little corrosion current density in 3.5 wt.% NaCl solution as compared with other test solutions.

Physical properties and DFT calculations of the hybrid organic polymeric nanocomposite thin film [P(An+o-Aph)+Glycine/TiO2/]HNC with 7.42% power conversion efficiency

Copolymer of aniline and ortho aminophenol was prepared by using the oxidative polymerization method with ferric chloride as an oxidizing agent in the occurrence of polyethylene glycol (Mol. Wt. 200) as a soft template. The microporous structure thin films were fabricated from the hybrid material of titanium oxide/copolymer (2-aminophenol and aniline) + glycine [P(An+o-Aph)+Gl/TiO2]HNC via a physical vapor deposition (PVD) method. The effect of the addition of glycine and TiO2 nanoparticles (NPs) on the physical properties of copolymer [P(An+o-Aph)] was discussed in light of the study of the crystallinity and optical properties. The addition of glycine increases the crystallinity of the resulting blend with the copolymer. The average crystallite size of TiO2 is ≈ 25 nm. The interaction between the blend and TiO2 was physical. The copolymer showed an absorbance of 1.18 at the wavelength (λ) 374 nm, which increased to 1.26 at λ= 440 nm after glycine addition, also increased to 1.53 at λ= 486 nm after TiO2 loading. Due to glycine blending and TiO2 addition, significant changes in the absorption index and indirect/direct bandgap of the copolymer have been detected. The materials Studio 7.0 program on TDDFT/DMol3 was used to optimize the molecular structure and perform the frequency calculations for the crystal models and isolated molecules. The DFT-Gaussian09W-vibration values are quite similar to the experimental data either in the structure or in the optical properties. The power conversion efficiency (η) of the blend Au/[P(An+o-Aph)+Gl]B/p-Si/Al heterojunction is 5.30 %, which increased to η=7.42% by loading the [TiO2]NPs to blend. The improvements in optical illuminations properties suggest the use the hybrid nanocomposite films in the polymers solar cell application.

Novel 8%‐TiO2‐nanoparticle‐reinforced dense polycrystalline bovine hydroxyapatite bioceramic

AbstractThis study aimed to produce and characterize the microstructure and mechanical properties of dense polycrystalline bovine hydroxyapatite (DPBHA) bioceramics with 5% and 8% of TiO2 nanoparticles after final synthetization for future use in dental implants. Structural characterization was obtained from analyzes by Fourier transform infrared spectroscopy, X‐ray diffraction, scanning electron microscope, energy dispersive spectroscopy, and relative density and apparent porosity. The mechanical characterization was performed by measuring the fracture toughness after three‐point flexural strength (FS) test. The microstructural characterization results showed no secondary phase formation and nonhomogeneous nanoparticle dispersion in HA matrix. DPBHA/Np8% (2.9 ± 0.09 g/cm3) exhibited significantly greater density than DPBHA (2.7 ± 0.03 g/cm3) (p = 0.011) and DPBHA/Np5% (2.7 ± 0.05 g/cm3) (p = 0.041). DPBHA (0.9%) had the smallest porosity followed by DPBHA/Np8% (3.4%). DPBHA/Np5% (4.5%) exhibited the greatest proportion of pores. Pure HA (51.7 ± 10.3 MPa) and DPBHA/Np8% (47.4 ± 6.4 MPa) had significant greater FS (p < 0.001) than DPBHA/Np5% (28.8 ± 3.1 MPa). DPBHA (0.43 ± 0.01 MPa m1/2) and DPBHA/Np8% (0.40 ± 0.06 MPa m1/2) presented greater KIc than DPBHA/Np5% (0.23 ± 0.02 MPa m1/2) (p < 0.003; p < 0.007). In conclusion, 8% TiO2 nanoparticle addition to this synthesis would be a promising HA blend, as mechanical properties were similar, and the relative density/apparent porosity showed superior results than those of the DPBHA.

Preparation and characterization of polyvinyl alcohol/polylactic acid/titanium dioxide nanocomposite films enhanced by γ‐irradiation and its antibacterial activity

AbstractSynthesis of antimicrobial films for packaging applications is eminent fields of research. This study describes preparation of biodegradable Poly (PVA/PLA/TiO2) nanocomposite films was carried out by blending polyvinyl alcohol (PVA) and polylactic acid (PLA) doped with titanium dioxide (TiO2) nanoparticles using solution casting method and then irradiated by γ‐irradiation. The properties of the films were characterized by FT‐IR, XRD, FE‐SEM, TEM, TGA, and mechanical tests. The addition of TiO2 nanoparticles (0.8 wt%) explored considerable effects on thermal stability of the films. Results of FE‐SEM and TEM illustrated quite uniformly dispersion of TiO2 nanoparticles with average size of 17.5 nm. The effect of γ‐irradiation on nanocomposite films showed enhanced water resistance property and water vapor transmission rate. The water resistance property was achieved using PVA/PLA composition ratio (2/1). The antibacterial activity was evaluated against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) bacteria. Poly(PVA/PLA/TiO2) nanocomposite film irradiated at 20 kGy displayed improved antibacterial activity and was selected for soil burial biodegradation tests. The biodegradation rate increased rapidly in the initial 12 weeks with significant changed morphology. The enhanced antibacterial efficiency and biodegradation property of the nanocomposite films suggest their possible use for development of packaging materials with low environmental impact.

Performance, combustion and emission characteristics of the CI engine fueled with Botryococcus braunii microalgae with addition of TiO2 nanoparticle

Production of biofuels from the green synthesis considered to be the promising source of the energy to replace the conventional fuels. Further the usage of the biofuels in the optimized ratio will effectively reduce the environmental concerns and the reduce the greenhouse gas emission. In this study, the impact of the Botryococcus braunii microalgae along with the diesel was examined. From the previous work it is understood that, usage of the Botryococcus braunii in the diesel affects the combustion and performance characteristics. To avoid the shortcomings, the nanoparticles TiO2 (50 ppm) were dispersed in the biodiesel blends by sonication method. The test blends such as D100 (100% diesel), B100 (neat microalgae oil), B10 (20% microalgae + 80% diesel), B10T (20% microalgae + 80% diesel), B30 (30% microalgae + 70% diesel) and B30 (30% microalgae + 70% diesel) were tested at engine loads of 0%, 25%, 50%, 75% and 100%. Individual blends were tested for brake thermal efficiency, brake specific fuel consumption, indicated thermal efficient, cylinder pressure and emission of NO, HC, CO and CO2. Based on the findings, addition of the microalgae blends with the nanoparticles enhances the BTE by 5% and 3% for BT20 and BT30, respectively, compared to neat diesel. Further, the BSFC was precisely reduced for B30 compared to D100 and B20 due to the viscosity of the blends. The role of the mixed fuel addition along with nanoparticles increases the cylinder pressure and heat release rate. With regard to emission, the CO, HC and CO2 reported significant drop in the emissions. However, NOx emissions remain to be high despite the engine speed for the blends B30.

Experiments on compression ignition engine powered by nano-fuels

The use of nanoparticles in fuels provides new opportunities for modification of fuel properties, which may affect the operational parameters of engines, in particular the efficiency and fuel consumption. The paper presents comparison of compression ignition engine performance fuelled with neat diesel and nano-diesel. Alumina (Al2O3) was used as nanoparticles. Surface-active substances, including Span 80 surfactant, as well as water admixture were used to improve the stability of the produced fuel. Measurements of the thermal conductivity and dynamic viscosity of the produced mixtures were conducted. In this study was used naturally aspirated, water cooled, four-stroke diesel engine. Addition of Al2O3 nanoparticles result in 4% reduced fuel consumption, addition of TiO2 nanoparticles result in 10% reduced fuel consumption with respect to neat diesel fuel.

Microbiological evaluation for antifungal activity of some metal oxides nanofillers incorporated into cold cured soft lining materials: clinical based study

Objective: The aim of the current study was to evaluate the efficacy of addition of zirconium oxide (ZrO2), titanium oxide(TiO2), and silica oxide (SiO2) nanoparticles to cold-cured soft liner on adhesion of Candida albicans (CA). Material andMethods: Fifty-four patients had been selected and divided into three groups according to the modification of soft linerwith ZrO2, TiO2, and SiO2 nanoparticles (18 each of). Each patient received maxillary complete denture having threecavities, the cavities were lined using cold cured soft liner modified with different concentration (0%, 3%, and 7%) ofmetal oxide nanoparticles. On days 14 and 28, swaps were taken out from relining site and immediately cultured forfungal evaluation. The number of colonies were counted, data collected and explored for normality using Shapiro-Wilktest, logarithmic transformation of CA count was performed. Repeated and one-way ANOVA were used followed byTukey HSD. Independent-t test used to compare between CA counts at different periods. Results: The CA adhesionwas significantly decreased by the addition of ZrO2, TiO2 and SiO2 nanoparticles in comparison with control group, alsothe antifungal coverage increased with nanoparticles concentration increased (P<0.005). The highest CA count wasidentified in group SiO2 followed by ZrO2, while TiO2 showed the lowest CA count (P <0.001). Conclusion: Additionof different nanoparticles; ZrO2, TiO2 and SiO2 to cold-cured soft liner is an effective method for reducing CA adhesion.KEYWORDSAntifungal agent; Candida albicans; Denture liners; Nanoparticles.

Effects of TiO2 and Al2O3 nanoparticles addition on the thermal properties and wettability of Sn-3.0Ag-0.5Cu-xTiO2-xAl2O3

This study investigated the effects of adding titanium dioxide (TiO2) and aluminium oxide (Al2O3) nanoparticles into Sn3.0Ag0.5Cu (SAC) lead-free solder alloy on the thermal properties and wettability. In comparison with SAC lead-free solder without addition of nanoparticles, the melting temperature is very similar and comparable. The solidus temperature is in the range of 217.1 to 217.2 °C with the addition of TiO2 and Al2O3 nanoparticles. The results shows that the addition of 0.25-1.0 wt% of TiO2 and Al2O3 nanoparticles caused the liquidus temperature to decrease from 222.4 to 220.5 °C. The spreading area of SAC-xTiO2-xAl2O3 lead-free solder increases from 5.7 to 7.1mm at 0-0.5wt% of TiO2 and Al2O3 nanoparticles. The contact angle decreased from 66.09° to 46.84° when the composition of TiO2 and Al2O3 increases from 0-0.5wt%.

Effect of the Lubrication on the Friction Characteristics of EN AW-2024-T3 Aluminium Alloy Sheets

The article presents the results of friction tests conducted on EN AW-2024 Alclad aluminium alloy sheets. The lubrication efficiency of oleic acid, mineral and vegetable oils with the addition of SiO2 and TiO2 nanoparticles was determined using the strip drawing test to assess the friction conditions in the flange area in the deep drawing process. The samples in the form of sheet metal strips were pulled between countersamples with a rounded surface at a speed of 2.5 mm/s. Gear oil and oleic acid demonstrated the lowest value of the coefficient of friction (COF) in the whole range of nominal pressures investigated. The lowest efficiency in reducing the COF was shown by hydraulic oil, olive oil and machine oil. A high content of TiO2 nanoparticles (0.5-0.9%wt%) is beneficial in the friction process involving oleic acid.

Preparation and characterization of biodegradable electrospinning PHBV/PBAT/TiO2 antibacterial nanofiber membranes

To reduce the environmental pollution caused by medical protective materials, such as masks and protective clothing, biodegradable antibacterial materials have received more and more attention in recent years. In this study, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and poly(butylene-adipate-co-terephthalate) (PBAT) were electrospun together and then treated with nano-TiO2 to develop and evaluate a biodegradable, antibacterial nanofiber membrane for medical protective fabric. The SEM images displayed that the nanofiber membrane with a mass fraction of 13 and a mass ratio of 50:50 PHBV/PBAT had the smallest diameter and the best morphology of all samples. In addition, the mechanical properties test and water contact angle test results demonstrated that the PBAT/PHBV composite nanofiber membrane had better mechanical properties and hydrophobicity without compromising its fundamental structure than pure PHBV. The addition of TiO2 nanoparticles decreased the fiber diameter of this nanofiber membrane. When the TiO2 concentration was 1.0 wt%, the average fiber diameter was 367 nm, which might approach the sub-micron level. Meanwhile, the presence of TiO2 reduced adhesion between fibers of the PBAT/PHBV membrane, resulting in a more uniform fiber distribution. Additionally, the elongation at the break of the PHBV/PBAT/TiO2 nanofiber membrane with 1.0 wt% TiO2 was raised from (135 ± 5)% to (203 ± 2)%. The PHBV/PBAT/TiO2 nanofiber membrane containing 1.0 wt% TiO2 inhibited Escherichia coli and Staphylococcus aureus, and its antibacterial rate was over 98%. In this research, we successfully prepared composite materials that were both biodegradable and antibacterial, which can be applied in the field of medical protection. It can promote the development of protective textile materials in the direction of functionalization and degradation.

Tribological and mechanical properties of surface nanocomposite AlCoCrFeNi2.1 high-entropy alloy produced by FSP

In the present work, the nanocomposite AlCoCrFeNi2.1 high-entropy alloy was produced using friction stir processing (FSP) with the addition of TiO2 nanoparticles. The size and weight percent of added nanoparticles were 30 ± 5 nm and 3 wt%, respectively. The applied rotating and transvers speeds were 800 rpm and 50 mm/min, respectively. The microstructural evolutions, the hardness changes, the shear properties and the tribological behavior were evaluated after applying FSP. These studies were carried out using X-ray fluorescence (XRF), optical microscopy, scanning electron microscopy (SEM), energy dispersive X-Ray analysis (EDX), X-Ray diffraction (XRD), Rockwell C and Vickers hardness testing, shear punch testing (SPT) and pin-on-disk wear test. After the FSP, the hard B2 phases, which were formed during casting, were broken and along with the TiO2 nanoparticles distributed uniformly in the matrix. These changes resulted in increase in hardness and shear strength from 301 HV to 485 HV and 332–411 MPa amounts, respectively for initial and FSPed cases; however, the wear resistance of the FSPed specimen decreased by approximately 60% compared to the initial condition.

Evaluation Flexural Strength of PMMA Resins with the Addition of Nanoparticles

The flexural strength of heat cure acrylic resin was investigated by adding different concentrations of TiO2 and ZrO2 nanoparticles to increase its mechanical properties. ZrO2 and TiO2 nanoparticles were added at 1, 3, and 5% concentrations to the powder portion of heat polymerized acrylic resins. A total of 49 samples were prepared in 65 × 10 × 3 mm size. The structural characterisations of all experimental groups were determined by Fourier transform infrared spectroscopy. Flexural strength of the resin specimens was evaluated with a three-point bending test in a universal test machine and then examined under by scanning electron microscope to assess its topographic characteristics. The highest flexural strength value was obtained for 3% TiO2, while the lowest values were obtained for 1% and 5% TiO2. 1% ZrO2 and 3% TiO2 groups showed statistically higher flexural strength values than the control group. The addition of 3% and 5% ZrO2 and 1% and 5% TiO2 showed statistically lower flexural strength than the control group. The addition of ZrO2 and TiO2 nanoparticles for strengthening acrylic resin is directly related to the amount of concentration. The addition of 1% ZrO2 and 3% TiO2 is recommended to strengthen heat cure acrylic resin due to its high flexural strength values.

Physico-mechanical properties, structure, and phase composition of (BeO + TiO2)-ceramics containing TiO2nanoparticles (0.1–2.0 wt.%)

AbstractThis research studies the effects of addition of micro- and nanoparticles of TiO2and variations in the firing temperature on the physico-mechanical properties of oxide-beryllium ceramics, shows the evolution of the microstructure of such ceramics during sintering, and presents the data of X-ray phase analysis. It was shown that the addition of TiO2nanoparticles leads to a higher density of the ceramic material after sintering due to the interpenetration of TiO2and BeO phases, which is caused by an increase in the diffusion mobility of atoms that can in turn be attributed to an increase in the imperfection of the structure and the fraction of grain boundaries. It was found that the presence of nanoparticles contributes to an increase in the apparent density of the material, as well as a decrease in its total and closed porosity; and an increase in the sintering temperature contributes to the transformation of the crystalline structure of TiO2into a more conductive Ti3O5with an orthorhombic structure. The presence of nanoparticles also promotes self-healing of micropores, which can be explained by the blocking of a certain fraction of the interfaces between BeO particles by nanoparticles and the creation of a diffusion barrier.

The effects of TiO2 nanoparticles and polydopamine on the structure, separation, and antifouling properties of PPSU membrane

ABSTRACT One of the most efficient and cost-effective technologies for removing dye pollutants from industrial effluents is membrane separation. This study aims to investigate the effect of modified nanocomposite polyphenylsulfone (PPSU) membrane for removing Direct Orange102 (DO) dye from aqueous solutions. For this purpose, the PPSU membrane was surface modified by polydopamine (PPSU/PD) to improve its hydrophilic properties and separation performance. Then, a nanocomposite membrane, PPSU/PD/TiO2, was prepared by coating the surface of PPSU/PD with different dosages of TiO2 nanoparticles. The prepared PPSU/PD and PPSU/PD/TiO2 samples were characterized by employing attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), and contact angle measurements. The ATR-FTIR analysis and FESEM images indicated that polydopamine and TiO2 were successfully coated on the surface of the membranes. Also, the results showed an increment in the hydrophilicity and roughness of the membrane after the addition of TiO2 nanoparticles. The performances of the fabricated membranes were compared in the separation of DO dye, Na2SO4, and bovine serum albumin (BSA). The best flux and rejection were obtained at 2 mg/ml of dopamine and 0.03 wt% of TiO2 loading. The prepared PPSU/PD/TiO2 membrane with high water flux provided impressive salt and dye removal. The results revealed that dye rejection increased from 80.5% for the PPSU membrane to 90% for the PPSU/PD membrane with a flux of 36 Lm−2h−1. For the PPSU/PD/TiO2 membrane, dye rejection and flux improved to 96.8% and 82 Lm−2h−1, respectively. The incorporation of TiO2 nanoparticles and polydopamine on the PPSU membrane surface enhanced the flux recovery ratio (FRR%) from 60.2% to 87%. The results of this study confirmed that modification of PPSU membrane by polydopamine and TiO2 nanoparticles leads to the improvement of the antifouling behavior and separation performance of the fabricated membrane toward the DO dye removal from aqueous solutions.

Experimental investigation on the effect of TiO2 nanoparticles on the performance of NH3 – H2O - LiBr absorption refrigeration system

The newly NH3 – H2O – LiBr working fluid can decrease the power wasted in the generator, thus improves the COP of the ammonia absorption refrigeration system. But the applying of NH3 – H2O – LiBr working fluid decreases the ammonia absorption efficiency, so the COP of the system is still unsatisfactory. To further enhance the COP of the NH3 – H2O - LiBr absorption refrigeration system, TiO2 nanoparticles are added to the NH3 – H2O - LiBr working fluid in this study. And the effects of TiO2 nanoparticles concentration on the performances of the generator, absorber, evaporator, condenser, and solution heat exchanger are tested in an ARS experimental system. The experimental results indicate that the addition of TiO2 nanoparticles increases the Pg, Pe, Pa, and Pc, meaning that the value of ammonia produced in the generator increases. Therefore, the COP and iCOP of the system are improved by adding TiO2 nanoparticles, and the COP is maximum improved by 18.96% compared with the ammonia-water absorption refrigeration system. When the xTiO2 is increased from 0.3% to 0.5%, the increase rate of the COP decreases because the newly added nanoparticles do not disperse well. So 0.3% is a better choice for the TiO2 nanoparticles concentration when comprehensively considering the dispersion stability of nanoparticles and the COP.