Nanometric Oxide Research Articles

Hydroxyl terminated polybutadiene-based shape memory polyurethane nanocomposites containing nano metal-oxide fillers for microfluidic valve actuator applications

We report here a novel and unique thermo-responsive Shape Memory Polyurethane Nanocomposites (SMPUNCs) derived from Hydroxyl Terminated Polybutadiene (HTPB) and Poly Tetra Methylene Glycol (PTMG) blend encapsulated with nano metal oxides fillers such as CuO, NiO, Fe2O3, CuFe2O4, and Fe2NiO4 for possible use in polymer-based microvalve actuator systems. The synthesis methods adopted and the various characterization techniques employed are presented. The corresponding SMPUs are named PU−CuO, PU−Fe2O3, PU-NiO, PU−CuFe2O4, and PU-Fe2NiO4 respectively. HTPB and PTMG are used as the base polyols for reacting with isocyanates to form the polyurethane base matrix, named as PU-Neat for comparison. Different fillers were used to study the effect of these fillers on the enhancement of the shape memory properties of polyurethane. Morphological, thermal, mechanical, and shape-memory properties of the prepared SMPUs are fully characterized. Morphological studies confirm that all the nano-metal oxide fillers are uniformly dispersed within the SMPU matrix. The shape memory transition temperature (Ttrans), which plays an important role in the shape memory effect (SME), is obtained from DSC analysis. The results show that Ttrans is enhanced with the reinforcement of the nano-metal oxide fillers (resulting in about 10% enhancement in the shape recovery time). The metal oxide filler integrated samples show higher thermal stability as well as shape fixing and recovery performances than PU-Neat. The tensile test confirmed that the PU−Fe2O3 matrix possesses a high tensile modulus and is rigid when compared to other SMPUs. We also demonstrated a microvalve actuator system using PU−Fe2O3, as it possesses the optimum shape recovery and better shape fixing properties, compared to other prepared Shape Memory Polyurethane Nanocomposites. An improvement of 10% efficiency in the closing and opening of the valve for PU composite film was observed in the demonstrated actuator setup.

Photocatalytic Degradation of Metronidazole Using Zinc Oxide Nanoparticles Supported on Acha Waste

The presence of emerging pollutants like pharmaceutical compounds in the environment is currently an issue of concern. Pharmaceutical compounds often escape conventional treatment systems and are persistent in the receiving environment; thus, the advanced oxidation processes could complement existing treatment methods to completely remove pharmaceuticals from contaminated water bodies. This work investigated the removal of metronidazole by ultra-violet light catalyzed by zinc oxide nanoparticles supported on acha waste. The synthesized zinc oxide nanoparticles, acha waste, and zinc oxide nanoparticles/acha waste composite were characterized by electron microscopy (SEM and TEM), Fourier transforms infrared spectrometry (FTIR) and X-ray diffractometry (XRD). Experimental results revealed that the UV light combined with zinc oxide nanoparticles and/or acha waste was more effective for metronidazole removal in combination than UV alone. The degradation of the metronidazole by UV light only, UV/nano-ZnO, and UV/nano-ZnO/acha waste systems follow the pseudo-first-order kinetic model. The addition of a catalyst to the UV reactor enhanced the degradation of metronidazole (5 mg/L) from 41.0 up to 86.1%. The outcome of this research showed that UV light in the presence of nanometal oxides and composites is an efficient technique for the removal of pharmaceuticals from an aqueous solution.

Experimental study on the ignition and combustion of Mg particles enhanced by metal oxides in CO2

Due to the high cost and long lifecycle of manned Mars exploration missions, in-situ resource utilization technology, including Mg/CO 2 processes, has attracted increasing attention. At present, Mg/CO 2 engines face the challenges of long ignition delay, serious carbon deposition, and low combustion efficiency. The root of these challenges lies in the Mg/CO 2 combustion reaction. Therefore, based on an Mg-based powder prepared by mechanical mixing combined with ultrasonic dispersion, the effects of various nano-metal oxides (CuO, Fe 2 O 3 , MnO 2 , MoO 3 , and Bi 2 O 3 ) on the ignition and combustion of Mg particles in CO 2 were studied through constant volume combustion experiments. It was found that MoO 3 undergoes the optimal covered-type of binding with Mg particles. The other oxides achieved embedded-type binding, of which MnO 2 binding was the worst. The enhanced ignition and combustion effects of Bi 2 O 3 and CuO were best. Thermogravimetric analysis found that CuO and Bi 2 O 3 improve combustion efficiency by lower ignition temperatures, inhibiting low-temperature oxidation reaction and increasing reaction ratio. • The enhancement effects of metal oxides on ignition and combustion of Mg particles in CO 2 are firstly studied. • The binding abilities of different nano-metal oxides to micro-Mg particles are analyzed. • The enhancement effects of CuO and Bi 2 O 3 on ignition and combustion of Mg particles in CO 2 are analyzed. • The influences of metal oxide addition ratio on enhancement are analyzed.

Pyrolysis and characterization of poplar mixed nanometal oxide catalysts

Poplar is an important wood bioresource and is one of the most dominant plantations in the world with high content of cellulose (52.99%). However, the pyrolytic products produced from poplar pyrolysis are not well studied and applied. In this study, pyrolysis of poplar mixed with different types and the ratio of nanometal oxide catalyst (NiO: 0.50 g, NiO–Ag: 0.25 + 0.25 g, Ag: 0.50 g, Fe2O3: 0.50 g, and Fe2O3–Ag: 0.25 + 0.25 g) were performed to identify the catalyst showing desirable performance in poplar pyrolysis. The thermogravimetry (TG) analysis revealed that adding Fe2O3 in pyrolysis has enhanced the decomposition of poplar where most of the weight loss (71.61 wt%) was in the temperature range of 25–780 °C. The results of the gas chromatography/mass spectrometry (GC/MS) analysis showed that the primary components of the produced bio-oil are acetaldehyde, methyl glyoxal, furfural, d-allose, and acetic acid, which can be used as raw materials in pharmaceuticals, industrial processes, and agricultural endeavours.

In Silico Simulation of Impacts of Metal Nano-Oxides on Cell Viability in THP-1 Cells Based on the Correlation Weights of the Fragments of Molecular Structures and Codes of Experimental Conditions Represented by Means of Quasi-SMILES.

A simulation of the effect of metal nano-oxides at various concentrations (25, 50, 100, and 200 milligrams per millilitre) on cell viability in THP-1 cells (%) based on data on the molecular structure of the oxide and its concentration is proposed. We used a simplified molecular input-line entry system (SMILES) to represent the molecular structure. So-called quasi-SMILES extends usual SMILES with special codes for experimental conditions (concentration). The approach based on building up models using quasi-SMILES is self-consistent, i.e., the predictive potential of the model group obtained by random splits into training and validation sets is stable. The Monte Carlo method was used as a basis for building up the above groups of models. The CORAL software was applied to building the Monte Carlo calculations. The average determination coefficient for the five different validation sets was R2 = 0.806 ± 0.061.

Identification of Nano-Metal Oxides That Can Be Synthesized by Precipitation-Calcination Method Reacting Their Chloride Solutions with NaOH Solution and Their Application for Carbon Dioxide Capture from Air-A Thermodynamic Analysis.

Several metal oxide nanoparticles (NPs) were already obtained by mixing NaOH solution with chloride solution of the corresponding metal to form metal hydroxide or oxide precipitates and wash-dry-calcine the latter. However, the complete list of metal oxide NPs is missing with which this technology works well. The aim of this study was to fill this knowledge gap and to provide a full list of possible metals for which this technology probably works well. Our methodology was chemical thermodynamics, analyzing solubilities of metal chlorides, metal oxides and metal hydroxides in water and also standard molar Gibbs energy changes accompanying the following: (i) the reaction between metal chlorides and NaOH; (ii) the dissociation reaction of metal hydroxides into metal oxide and water vapor and (iii) the reaction between metal oxides and gaseous carbon dioxide to form metal carbonates. The major result of this paper is that the following metal-oxide NPs can be produced by the above technology from the corresponding metal chlorides: Al2O3, BeO, CaO, CdO, CoO, CuO, FeO, Fe2O3, In2O3, La2O3, MgO, MnO, Nd2O3, NiO, Pr2O3, Sb2O3, Sm2O3, SnO, Y2O3 and ZnO. From the analysis of the literature, the following nine nano-oxides have been already obtained experimentally with this technology: CaO, CdO, Co3O4, CuO, Fe2O3, NiO, MgO, SnO2 and ZnO (note: Co3O4 and SnO2 were obtained under oxidizing conditions during calcination in air). Thus, it is predicted here that the following nano-oxides can be potentially synthesized with this technology in the future: Al2O3, BeO, In2O3, La2O3, MnO, Nd2O3, Pr2O3, Sb2O3, Sm2O3 and Y2O3. The secondary result is that among the above 20 nano-oxides, the following five nano-oxides are able to capture carbon dioxide from air at least down to 42 ppm residual CO2-content, i.e., decreasing the current level of 420 ppm of CO2 in the Earth's atmosphere at least tenfold: CaO, MnO, MgO, CdO, CoO. The tertiary result is that by mixing the AuCl3 solution with NaOH solution, Au nano-particles will precipitate without forming Au-oxide NPs. The results are significant for the synthesis of metal nano-oxide particles and for capturing carbon dioxide from air.

Electroanalytical sensors-based biogenic synthesized metal oxide nanoparticles for potentiometric assay of pantoprazole sodium

ABSTRACT Two modified coated membrane sensors were designed and tested. Pantoprazole-phosphotungstate was prepared by a reaction of pantoprazole with phosphotungstic acid in the solvent mediator o-nitrophenyloctyl ether. Two metal oxide nanoparticles nickel oxide and iron oxide nanoparticles, were synthesized from green sources Matricaria recutita flowers and Salvia officinalis leaves extracts, respectively. These nanoparticles were used for the potentiometric assay of pantoprazole sodium in the authentic sample and commercial products. The results showed that the improved nickel oxide and iron oxide nanosensors exhibited linearity using the concentration range of 1.0 × 10−9–1.0 × 10−2 and 1.0 × 10−10–1.0 × 10−2 mol L−1, respectively compared with 1.0 × 10−6–1.0 × 10−2 mol L−1 for the normally coated sensor. The lower limits of detection (7.6 × 10−6, 2.3 × 10−10, 2.8 × 10−11 mol L−1) and quantification (1.0 × 10−6, 1.0 × 10−9, 1.0 × 10−10 mol L−1) were determined for each of the three proposed sensors. Least squares calculations gave EmV = (27.266 ± 0.5) log (pantoprazole) + 433.37, EmV = (30.967 ± 0.3) log (pantoprazole) + 432.24 for the enriched nano-metal oxides, and EmV = (26.642 ± 0.6) log (pantoprazole) + 443.69 for the conventional type, respectively with correlation coefficients around 0.999 for the proposed sensors. The accuracy and precision of the modified potentiometric systems were estimated and the results showed excellent validity and suitability for the determination of pantoprazole in an authentic sample.

Synthesis and characterization of PANI and PANI/nanometal oxides, photocatalytic and adsorbent applications.

In this study, polymeric nanocomposites of PANI and PANI/nanometal oxides (Fe2O3, NiO, SnO2, WO3, ZrO2) as photocatalysts were synthesized with a chemical polymerization method. Structural characterizations of synthesized polymeric nanocomposites were performed as follows: FT-IR, SEM, TEM and XRD, and TGA. The effect of pure nanometal oxides (Fe2O3, NiO, SnO2, WO3, ZrO2) and polymeric nanocomposites on the degradation of naproxen, the drug active ingredient, was studied under visible light (UV-A at 365 nm) and in the absence of light. In this study, photocatalytic and adsorbent efficiency of polymeric nanometal oxides were investigated. In order to determine the effect of pure nanometal oxide particles and polymeric nanometal oxide composites on naproxen removal in light and dark environments, the percent removal with time was measured, and the band gap energies of each photocatalyst were examined using Tauc curves. Furthermore, the degradation reaction rate kinetic measurements of naproxen in light and dark conditions were carried out. From the experimental results, it was determined that pure nanometal oxides were not effective in light and dark environments, but the synthesized PANI nanometal composites were effective in the removal of naproxen in wastewater in both light and dark environments.

Synthesis of strontium oxide nanoparticlesby probe sonication method: Its photocatalytic activity and electrochemical sensor studies

In this paper, we report on the synthesis of strontium oxide nanoparticles (SONPs) using a novel probe sonication method. Powder X-ray diffraction (PXRD) was used to characterize the physicochemical properties of the prepared materials, which confirmed that the average SrO crystallite size was 43 ​nm. The Kubelka-Monk function of diffuse reflectance spectroscopy (DRS) was used to confirm the average energy gap of SONPs (4.06 ​eV). SONPs have been successfully used in conjunction with inventive photocatalysts to remove dyes such as Methylene Blue (MB) and Acid Green (AG). MBand AG dyes were used as standard dyes to investigate the photocatalytic properties of NPs when exposed to UV light and sunlight.These nanometal oxides photodegrade methylene blue (87.70%) and acid green (71.20%) dyes with remarkable efficiency when exposed to UV light. These nanometal oxides demonstrated superior sensitivity when paracetamol was used as an analyte in cyclic voltammetry tests at various scan speeds (10 ​mV/s to 50 ​mV/s). As a result, SONPs may be useful in photocatalytic activity and electrochemical sensor applications.

Screening of Ni based catalysts supported on metal oxides for liquid-phase hydrogenation of furfural to furfuryl alcohol

Highly dispersed amorphous Ni on surface of MgO was prepared and served as a high-performance catalyst for furfural hydrogenation to furfuryl alcohol.

Soil activity and microbial community response to nanometal oxides were not due exclusively to a particle size effect

Metal oxide engineered nanomaterials (ENMs) in study influenced soil function and microbes, but we found no evidence that changes were caused exclusively by a nano-size effect.

Effect of nano-metal oxides types on oil sludge during microwave pyrolysis

Effect of nano-metal oxides types on oil sludge during microwave pyrolysis

Catalytic evaluation of cellulose pyrolysis by using nanosized metal oxide catalysts.

In this study, effects of TiO2 and ZnO nanometal oxides on cellulose pyrolysis have been investigated. Both catalysts have been synthesized via hydrothermal method and characterized by using different techniques. Catalytic and catalyst-free experiments were carried out so as to identify the catalytic abilities of synthesized nanoparticles. Catalyst-free experiments were carried out at 500, 600, and 700 °C in order to determine the optimal condition for pyrolysis and it was found as 700 °C. Optimum catalyst ratio for cellulose pyrolysis was found as 5% (w/w) for both TiO2 and ZnO catalysts. GC-MS and micro-GC analyses were conducted in order to examine the catalytic properties of synthesized nanoparticles and illuminate the content of pyrolytic oil and gaseous products. Results showed that maximum gas yield was observed at 700 °C in the presence of 5% TiO2. Maximum activity for both catalysts was observed at 700 °C and the char yield was significantly decreased in each catalytic experiment at specified temperatures, compared to catalyst-free experiments. Both nanoparticles catalyzed the dehydration and decarbonylation reactions and significantly increased the amount of furan derivatives, especially furanic aldehydes.

Preparation and characterization of Titanium oxide-composite polymers

Two types of monomers polyindole and poly m-aminophenol were used to prepare conducting copolymer with use FeCl3 as an initiator by using chemical polymerization. The prepared polymers were characterized using infrared spectroscopy, X-ray scattering, scanning electron microscope (SEM) and thermal analysis TGA. This study was included preparation of copolymers from both monomers in various ratios (1:1, 1:2, 2:1, 1:3, and 3:1) to study the effect of ratios on chemical and physical properties. Moreover, nano-metal oxide (TiO2) (10%) of the weight of the monomers was added to copolymers to synthesis composite polymers. Results of FTIR, SEM and EDX were proved the prepared compounds. TGA findings were showed that composites have remarkably increased of thermal stability. Finally, nano-composite polymers have applied as electrochemical sensor for (NH3) gas. Further, results display that the best sensitivity value is (24.12%) by using copolymer (1mA:3In) (without nano) with response time (7 seconds) and recovery time (3 seconds). Furthermore, results show that prepared nanocomposites have highly sensitive features with fast responses time even within a low concentration of ammonia gas at 25° C. The highest sensitivity value (79.14%), response time (3 seconds) and recovery time (3 seconds) was recorded when used nanocomposite titanium oxide (TiO2) at the ratio (1mA:3In).

Cellulose derivative as protection coating: Effect of nanoparticle additives on load capacity

The cellulose derivative hydroxypropyl methylcellulose (HPMC) has recently been extensively studied and used in mechanical applications. However, the softness and susceptibility to deformation of HPMC limited its further applications. In this study, metal nanoparticles (nano-aluminum and nano-copper) and nano-metal oxide particles (nano-alumina and nano-copper oxide) were used as additives to HPMC to form a composite film with improved mechanical properties, particularly load capacity. The addition of high levels of additives provided a higher load capacity. Among the nano-additives used in the study, Cu (2 wt.%) provided the composite with the highest load capacity, improving the load capacity of pure HPMC by 250%. The surface treatment of strengthening additives is an important step. Adding specific high-strength and high-modulus metal and metal oxide additives to the soft HPMC matrix can effectively improve the load-bearing capacity of the composite material. This study proposes a simple evaluation method for the load-bearing capability of the coating as well.

Performance relative study of metal oxide nanoparticles on mechanical, thermal, and optical characteristics of gamma‐irradiated poly (vinyl alcohol) nanocomposites

Nanocomposites based on poly (vinyl alcohol) (PVA) filled with different types of nanometal oxides named MgO, Al2O3, and CuO were attained from an aqueous solution of PVA. PVA/nanometal oxide films were achieved by the solution casting procedure. The prepared nanocomposites were subjected to a gamma radiation dose at 50 kGy to study the impact of ionizing radiation on the various properties of the prepared samples. In this context, this work was mainly concerned with the differences in the behavior of various metal oxides, as well as the effect of ionizing radiation on the tensile strength (TS), elongation at break (E%), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X‐ray diffraction, and optical characteristics of the fabricated specimens. Furthermore, Fourier transform infrared (FTIR), SEM, and thermodynamic factors (Ea, ΔH, ΔG, and ΔS) were considered. FTIR and the suggested reaction mechanism supported that the hydroxyl groups of PVA have a really strong affinity to form charge‐transfer complexes with different nanometal oxides done chelation. In general, the interference of 0.1% of all studied nanometal oxides improved TS, thermal stability, melting temperature, and optical properties of PVA, whereas PVA/0.1 CuO was the best. Moreover, gamma radiation exposure enhanced the different properties of native PVA and displayed anisotropic behavior toward its nanocomposites.

Biosorption of Congo Red dye from aqueous solutions using pristine biochar and ZnO biochar from green pea peels

To minimize the catastrophic influence of contaminated water, smart technology-based wastewater treatment processes are mandatory for safe water and sanitation. Nanometric metal oxides supported with biochar are green choices for futuristic adsorbents for water decontamination with versatility, simplicity, high surface reactivity, and efficacy. In this study, reactive Congo Red (CR) from an aqueous solution was decontaminated using prepared innovative green pea peels biochar (GPBC), and zinc oxide green pea peels biochar nanocomposite (ZnO/GPBC). The characterizations of GPBC and ZnO/GPBC were performed by EDX, TEM, XRD, BET, FTIR, and point of zero charge. The role of experimental conditions of initial concentration (50–250 mg/l), GPBC and ZnO/GPBC dosage pH (2−12), temperature (20–60 oC) and interaction time (0–90 min) were examined. The results revealed that ZnO/GPBC demonstrated better performance for anionic CR dye removal that recorded as 98% compared to 90% using GPPBC under optimized environment conditions. The examination of adsorption equilibrium isotherm displayed the validity of Freundlich and Langmuir model for description the dye decolorization onto ZnO/GPBC and GPBC, respectively, as best fitted models. Moreover, the kinetics studies disclosed pseudo-second-order (PSO) for both studied materials. The monolayer sorption capacities were 114.94 mg/g for ZnO/GPBC and 62.11 mg/g for GPBC, both exhibiting competitive performances with other carbon-based adsorbents available in the literature. The thermodynamic studies disclosed favorable, spontaneous, and endothermic processes. The synthesized ZnO/GPBC and GPBC are excellent adsorbents recommended for large-scale production in the removal of anionic dyes from wastewaters.

Fabrication of novel buckypaper metal oxide nano-catalysis glycerol carbonate/MWCNTs membrane for efficient removal of heavy metals

This study describes the fabrication of novel buckypaper membranes through the dispersion of multi-walled carbon nanotubes (MWCNTs) in the presence of surfactants metal oxide nano-catalysis Zinc oxide and magnesium oxide (ZnO and MgO) glycerol carbonate separately. Following vacuum filtration of the scattered solutions, self-supporting membranes known as buckypapers (BPs) were produced. The suggested membranes were employed for the efficient removal of heavy metals. The obtained data indicated that the incorporation of both glycerol carbonates prepared by two different nano metal oxides enhanced the permeability of MWCNTs membranes rejection efficiency. The characterization of the synthesized metal oxide nanoparticles, as well as the physicochemical and morphological properties of the membranes, were investigated. The rejection capabilities of membranes for the heavy metal ions were examined. Moreover, the suggested MWCNTs/ZnO nano-catalyst glycerol carbonate BP membrane displayed high rejection efficiency for heavy metals (Cd2+, Cu2+, Co2+, Ni2+, and Pb2+) than that prepared from the MgO nano-catalyst one.

Applications of Emerging Nanomaterials in Drilling Fluids

AbstractNanomaterials find several applications in the oilfield operations. In oilwell drilling, nanomaterials are being used for mitigating wellbore instability conditions, improving thermal stability of the fluid, minimizing formation damage by preventing fluid invasion into the reservoir, improving fluid rheology, and controlling fluid loss. A wide range of nanomaterials from organic as well as inorganic and composites are being developed to accomplish the mentioned functions. Significant nanomaterials being developed include nanocellulosic particles, nanoclay, nanosilica, nanometals, nanometal oxides and nanopolymers. Improving fluid properties to develop smart fluids by the incorporation of nanomaterials is an emerging research field which is yielding promising results. This review article presents the recent development made in the applications of the nanomaterials in drilling fluids especially the nanosilica particles surface modified by organic ligands. Surface modification of nanosilica with organic ligands namely 3‐Glycidoxypropyl‐triethoxy silane (GPTS), hyperbranched polyethyleneimine (HPEI) and Moringa oleifera cationic protein (MOCP) are discussed. Applications of nanomaterials in drilling fluids to minimize wellbore instability, prevent formation damage, improve thermal stability and conductivity, stabilize fluid rheology, improve hole cleaning, and minimize the chances of downhole string sticking have been reviewed.

Tribo-corrosive wear and mechanical properties of nanoparticles reinforced Mg-AZ91D composites

This study investigates the corrosion behaviour of magnesium (Mg-AZ91D) alloy reinforced with nano metal oxides (ZnO, MnO, and TiO2) using the tribocorrosion methodology. The mechanical characteristics of the materials were investigated using ASTM standards for AZ91D alloy, AZ91D/ZnO, AZ91D/MnO, and AZ91D/TiO2 composites. The AZ91D/TiO2 nanocomposite has higher hardness (122.71 HV) and tensile strength due to decreased porosity and smaller grain size (200.7 MPa). The corrosion behaviour of the fabricated alloys and composites was investigated using tribocorrosion test methods at various NaCl concentrations (2–3.5%). AZ91D/TiO2 nanocomposite evidenced least OCP drop (−0.7 to −1.0 V) with minimum COF (0.10) at 2.5% NaCl concentration as a result of the development of a thick oxide layer that protected the surface from wear and Cl- environment throughout the tribocorrosion test. Images of tribocorrosion test samples revealed corrosion pit and crack formation. The elemental mapping and EDAX results validate the formation of Mg2TiO3 precipitates on the AZ91D/TiO2 nanocomposite; at the same time, a tribo-corroded surface profile revealed an optimum wear depth of 55 µm at 2.5% NaCl concentration for the same composition.