Boehmite Nanoparticles Research Articles

Submicron mullite hollow spheres synthesized via UV polymerization of Pickering emulsions

AbstractWe here propose a simple, facile, and effective method to prepare submicron mullite hollow spheres templated from Pickering emulsions. Dual‐phase sol consisted of boehmite and silica nanoparticles decorated by pentanoate ion could assemble at water/oil interface irreversibly to form photosensitive Pickering emulsions. The droplets of emulsions could be separated by dilution and formed by photopolymerization to gain hybrid microspheres, which could completely transform to mullite hollow microspheres via binder removal and sintering. It is found that the prepared hollow microspheres possess intact morphology, favorable sphericity, large cavity volume, and bulk density of 0.356 g/cm3. Importantly, the average diameter of mullite hollow spheres obtained via this method could be as low as 0.33–2.31 μm. This steady method is efficient and suitable for various types of inorganic particles, providing an innovative perspective for preparing fine hollow spheres applicable for filtration, drug loading as well as energy storage areas.

Fabrication of a hydrophobic surface as a new supported liquid membrane for microfluidic based liquid phase microextraction device using modified boehmite nanoparticles (AlOO-NSPO)

For the first time, modified nanomaterials are introduced to the prepared polyethersulfone (PES) membrane to fabricate a hydrophobic membrane. The effectiveness of the prepared membrane in a microfluidic device based on liquid phase microextraction (LPME) was evaluated for the determination of mesalazine, an anti-inflammatory drug, in water. The PES membrane was constructed using the phase inversion method. Modified boehmite (AlOO-NSPO) nanoparticles were deposited on the surface of the PES membrane by a dip-coating method. The chemical composition and morphological study of the membrane surface and nanoparticles were characterized using field emission scanning electron microscope (FESEM), atomic force microscopy (AFM), attenuated total reflection-fourier transform infrared spectroscopy (ATR-FTIR), and static water contact angle (WCA). A significant switch from hydrophilicity to hydrophobicity was observed when the water contact angle of the membrane increased from 65.4° for PES to 97.3° for PES- (AlOO-NSPO) membrane. The performance of the new membrane and the effects of the operational parameters were evaluated in a microfluidic system based on LPME. Compared with the commercial membrane, the modified synthetic membrane with a larger pore size and porosity had a noticeable improvement under the optimum operating conditions (flow rate, 0.01 mL/min; donor phase pH, 4.5; acceptor phase pH, 12; and solvent, 1-Butanol). Furthermore, the modified membrane had an acceptable reusability, showing an extraction efficiency of 90 % after three repeated runs.

Tailoring the performance of boehmite nanoparticles reinforced carboxymethyl chitosan/cashew gum blend nanocomposites via green synthesis

The main motivation for this study stemmed from the demand for bio-friendly polymeric materials with enhanced properties in various fields of application. Biopolymer blend nanocomposite films based on carboxymethyl chitosan (CMCS) and cashew gum (CG) with different contents of boehmite nanoparticles were prepared via a purely green method using water as the solvent. The successful inclusion of boehmite nanoparticles in the CMCS/CG blend was verified by Fourier transform infrared (FTIR) analysis. Scanning electron microscopy (SEM) and optical microscopy were used to analyze the surface microstructure of prepared films. SEM and optical images revealed a uniform distribution of nanofillers in the blend because of the strong interactions between nanoparticles and the CMCS/CG blend segments. The thermogravimetric analysis demonstrates that the addition of boehmite nanoparticles increased the thermal stability of the biopolymer blend films. Differential scanning calorimetry (DSC) showed a small shift in the glass transition and melting temperature of pristine blend to higher values with the addition of boehmite. The correlation of AC conductivity with varying frequency and temperature was evaluated. The maximum conductivity was shown by CMCS/CG blend with 7 wt % boehmite, which was further supported by their lowest activation energy value. Nyquist plots were used to illustrate the complex impedance of prepared nanocomposite films. A decrease in the area under the semicircular arc with temperature suggested an increase in conductivity with temperature. The dielectric constant and dielectric loss factor of blend and its nanocomposite films were found to increase with temperature. Boehmite addition increased tensile strength and hardness while lowering elongation at break up to a specific concentration. The synthesized CMCS/CG/boehmite films can be used as environmentally friendly alternatives in the development of flexible organic electronics and charge harvesting devices.

Safety and performance enhanced boehmite-coupled polyethylene nanocomposite separator for lithium-ion batteries by synergetic effects of silane treatment and electron irradiation

Separators are among the key components affecting both the safety and performance of batteries. Herein, boehmite-coupled high-density polyethylene (HDPE) nanocomposite separators with enhanced safety and performance are prepared via silane treatments and electron irradiation. The silane treatment of boehmite nanoparticles (BNPs) leads to the homogeneous dispersion of the BNPs in HDPE owing to the spacer alkyl groups in silane. Electron irradiation induces chemical coupling between the silane-treated BNPs and HDPE, as well as the crosslinking of HDPE. Electron irradiation also oxidizes HDPE, improving the electrolyte affinity of the separators. Consequently, the safety and performance of the separators are significantly improved, and the degree of improvement depends on the type of silane. A nanocomposite separator comprising octadecyl-functionalized BNPs exhibits superior dimensional stability (puncture strength of 0.74 N μm−1 and thermal shrinkage of 3.2% at 140 °C for 30 min). In addition, a nanocomposite separator comprising aminopropyl-functionalized BNPs demonstrates excellent ionic conductivity (1.61 mS cm−1). A lithium-ion cell assembled with the nanocomposite separator has an exceptional rate capability (discharge capacity at 20 C maintains 72.9% of the capacity at 0.5 C) and cyclic stability (discharge capacity retention of 96.2% with a Coulombic efficiency of 99.5% after 100 charge/discharge cycles at 0.5 C).

Efficient and biocompatible new palladium-supported boehmite nanoparticles: synthesis, characterization and application in Suzuki-Miura and Mizoroki-Heck coupling reactions.

Palladium complex-supported on boehmite (Pd(0)-SMTU-boehmite) nanoparticles were synthesized and characterized by using XRD, SEM, EDS, TGA, BET, ICP and FT-IR techniques. When applied as a new catalyst for C-C coupling reactions of Suzuki-Miyaura and Mizoroki-Heck in PEG-400 solvent, the Pd(0)-SMTU-boehmite nanoparticles showed excellent activity and recyclability. The study of palladium leaching by the ICP-OES technique and hot filtration led to the catalyst exhibiting excellent stability and recyclability.

Synthesis of tetrazoles catalyzed by a new and recoverable nanocatalyst of cobalt on modified boehmite NPs with 1,3-bis(pyridin-3-ylmethyl)thiourea.

In the first part of this work, boehmite nanoparticles (BNPs) were synthesized from aqueous solutions of NaOH and Al(NO3)3·9H2O. Then, the BNPs surface was modified using 3-choloropropyltrimtoxysilane (CPTMS) and then 1,3-bis(pyridin-3-ylmethyl)thiourea ((PYT)2) was anchored on the surface of the modified BNPs (CPTMS@BNPs). In the final step, a complex of cobalt was stabilized on its surface (Co-(PYT)2@BNPs). The final obtained nanoparticles were characterized by FT-IR spectra, TGA analysis, SEM imaging, WDX analysis, EDS analysis, and XRD patterns. In the second part, Co-(PYT)2@BNPs were used as a highly efficient, retrievable, stable, and organic-inorganic hybrid nanocatalyst for the formation of organic heterocyclic compounds such as tetrazole derivatives. Co-(PYT)2@BNPs as a novel nanocatalyst are stable and have a heterogeneous nature; therefore, they can be recovered and reused again for several consecutive runs without any re-activation.

Application of boehmite as a fiber coating for headspace solid-phase microextraction of chlorophenols from aqueous samples.

In this paper, the extraction of chlorophenols from water samples was carried out using high surface area boehmite nanoparticles as a sorbent. The surfactant-free process employed to make the nano-boehmite used in this work was simple, green, and efficient. The proposed approach was based on headspace solid-phase microextraction, followed by GC-ECD for the determination of analytes. In situ derivatization of analytes was performed with acetic anhydride in a basic medium. Various effective parameters, including the amount of derivatization reagent, ionic strength, desorption temperature and time, extraction temperature, equilibrium time, and extraction time were studied. Under optimal conditions, the linear dynamic range was 0.05-5.0 μg L-1 for 2,4-dichlorophenol and 2,6-dichlorophenol and 0.003-0.1 μg L-1 for 2,4,6-trichlorophenol. A low limit of detection (0.75 × 10-3-15 × 10-3 μg L-1), and relative standard deviations for real samples (RSDs) <10% were obtained. The precision (as intra- and inter-day RSDs) was between 1.2 and 9.8%. In comparison to commercial fibers (CAR-PDMS, 85 μm), this fiber showed a greater extraction efficiency. Various water samples were subjected to extraction by the proposed method. The recoveries ranged from 90 to 110%.

Preparation and Characterization of Free-Standing Composite Cellulose-Based Carbon Molecular Sieve Membranes

Carbon membranes with excellent strength and mechanical stability were prepared using a cellulose precursor regenerated from an ionic liquid solution with a low loading of boehmite ceramic nanoparticles, ca. 0.1 wt. %. The precursor films show an asymmetrical structure while, after carbonization, the corresponding carbon molecular sieve membranes (c-CMSM) show a dense structure with a uniform thickness of ca. 22 µm. The c-CMSM exhibited excellent separation performance, well above the Robeson Upper Bound. The permeability of the c-CMSM to hydrogen increased from 300 to 530 barrer and the H2/CH4 permselectivity increased to 473, after adding boehmite nanoparticles. Boehmite nanoparticles act as a microporosity-forming agent without compromising the width of the ultramicropores. The prepared c-CMSM is extremely promising for several applications, namely for hydrogen recovery from methane – H2/CH4 (Robeson index:θ=13.5); biogas upgrading – CO2/CH4 (θ=6.5); CO2 removal from combustion flue gas – CO2/N2 (θ=1.7); and hydrogen recovery from ammonia processes – H2/N2 (θ=4.8).

Investigation of the interaction between adsorbed water and various morphologies of boehmite nanoparticles prepared by continuous supercritical hydrothermal synthesis

Boehmite applications are often subject to specific characteristics in terms of morphologies and surface properties. The versatile continuous supercritical hydrothermal method allows synthesizing various boehmite morphologies from rhombic to hexagonal platelet-like nanoparticles depending on the preferential adsorption of part of the precursor after transformation species on the (020) surface resulting in a preferential growth along [001] and mostly [100] directions. This adsorption on surface free sites plays the role of morphology stabilizer and results in the reduction of adsorbed water. The interaction between adsorbed water and the boehmite morphology depends on various parameters: 1) the structure order of boehmite as exhibited by XPS analysis associated with 1H Solid-State NMR spectroscopy and, 2) the number of available free sites, which tend to be filled by the adsorption of nitrates as observed by Raman spectroscopy.

Seed-assisted hydrothermal fabrication of nanostructured boehmite coating on carbon fiber

Novel approach to boehmite nanoparticles on the surface of carbon fiber (CF) fabrication has been developed. The AlOOH nanoplates were deposited using a seeded hydrothermal procedure at 160 °C for 5 h. As a result, a flower like coating was obtained with a predominantly perpendicular orientation to the CF surface. The structure analysis of the composite was performed by EDS, XRD, Raman, and ATR-IR methods. Surface roughness and interaction with ABS plastic were determined by SEM and contact angle equipment. It was shown that the contact angle decreased from 71.7 to 39.4o and the surface energy increased by 3.14 times through two-stage surface modification. Also, introduction of boehmite nanoparticles as a filler changed tensile strength by 1.5 times (from 12.17 MPa to 18.99 MPa) compared to the functionalized CF.

Development of high‐performance biopolymer nanocomposites derived from carboxymethyl chitosan/boehmite via green synthesis

AbstractIn this work, biopolymer nanocomposites derived from carboxymethyl chitosan (CMCS) and boehmite were prepared via an environmentally friendly technique and their structural, morphological, thermal, electrical, dielectric, and mechanical properties were investigated. The successful fabrication of carboxymethyl chitosan/boehmite nanocomposites was evident from the appearance of characteristic peaks of boehmite in FTIR and alteration in the morphology as revealed by optical and SEM micrographs. The glass transition temperature (Tg) and melting temperature (Tm) were increased as the filler content increased. The enhanced thermal stability of nanocomposites was clear from thermogravimetric results. The incorporation of boehmite nanoparticles into CMCS improved the conductivity to a semiconducting range. The dielectric constant of CMCS/boehmite nanocomposites was significantly higher compared to pure CMCS. The influence of temperature on AC conductivity, activation energy, dielectric constant and loss tangent were analyzed. Complex impedance analysis carried out by Nyquist plots and the bulk resistance showed a decreasing trend with temperature, which indicated enhanced conductivity with temperature. Tensile strength and hardness were observed to be increased with boehmite inclusion, whereas elongation at break is reduced. As a result, eco‐friendly CMCS/boehmite biopolymer nanocomposites with good thermal, mechanical, electric, and dielectric properties may be a potential green alternative for flexible electronic, charge storage, and other electrochemical devices.

Performance of Boehmite Nanoparticles Reinforced Carboxymethyl Chitosan/Polyvinyl Alcohol Blend Nanocomposites Tailored Through Green Synthesis

Performance of Boehmite Nanoparticles Reinforced Carboxymethyl Chitosan/Polyvinyl Alcohol Blend Nanocomposites Tailored Through Green Synthesis

Investigation of the Gas Separation Properties of Polyurethane Membranes in Presence of Boehmite Nanoparticles

In this study, the effect of boehmite nanoparticles on the CO2, CH4, O2, and N2 permeability in polyurethane membranes was investigated. Boehmite nanoparticles were synthesized by the hydrothermal method using the salt of aluminum nitrate Al (NO3)3 and diethanolamine as a precipitating agent. Different temperatures (110, 160, and 200) °C and times (18–24 h) in synthesizing boehmite nanoparticles are also investigated. The characteristics of the synthesized nanoparticles were analyzed with X-ray diffraction (XRD), Field-emission scanning electron microscopy (FESEM), and Transmission electron microscopy (TEM). The analysis results represented that increasing the temperature to 200 °C as well as high duration time at this temperature (24 h) result in nanoparticles with high purity and high crystallinity. Polyurethane was synthesized by bulk two-step polymerization using hexamethylene diisocyanate (HMDI) and 1,4-butanediol (BDO) as hard segments and poly(tetramethylene glycol) (PTMG, 2,000 g/mol) as the soft segment. The synthesized polymer was in a molar ratio: PTMG: HMDI: BDO = 1:3:2. PU membranes and PU-boehmite nanocomposite membranes were prepared using solution casting and solvent evaporation technique. The characteristics of the synthesized nanocomposite membranes were analyzed with Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Field-emission scanning electron microscopy (FESEM), and differential scanning calorimetry (DSC). The results of characterization analyses indicated that there is a strong interaction between boehmite nanoparticles and polymer and also the appropriate distribution of boehmite nanoparticles in the prepared samples. Gas permeation properties of polyurethane—boehmite nanocomposite at different boehmite loadings (0, 5, 10, 15, and 20 wt.%) were studied for pure CO2, CH4, O2, and N2 gases at 8 bar and 30 °C. The obtained results indicated that the reduction in permeability of all gases but enhancement in CO2/N2, CO2/CH4, and O2/N2 selectivities were observed as boehmite content increases. In the membrane with 20 wt.% boehmite content, enhancement of CO2/N2 (65.33%) and CO2/CH4 (55.37%) selectivities were observed in comparison with pure polyurethane, while the CO2 permeability reduction of polyurethane–boehmite membranes was 22.08%.

Solubility determination of boehmite nanoparticles and modeling of solution thermodynamics of blend polymeric membranes

AbstractThe solubility of boehmite nanoparticles was determined experimentally for 20 different solvents using Hansen solubility parameter method (HSP). The algorithm given by Gharagheizi was optimized using MATLAB. The solubility was found as, δ = 33.08 MPa1/2 with, δD = 16.50 MPa1/2, δP = 15.54 MPa1/2, and δH = 24.09 MPa1/2. Flory‐Huggin's theory was used to model the quarternary system of a blend polymeric membrane. The thermodynamic equations were solved and optimized using MATLAB and ternary phase diagrams were obtained for different filler compositions. Thermodynamic enhancement and kinetic hindrance parameters were obtained to predict the membrane morphologies. The porosity of the membrane was increased with the addition of nanoparticles. Contact angle of the membrane was decreased from 84.45° to 50.2°.

2-(Aminomethyl)phenols-Modified Boehmite Nanoparticles Based Catalysts for Carbon–Carbon Bond Formation Reactions

2-(Aminomethyl)phenols-Modified Boehmite Nanoparticles Based Catalysts for Carbon–Carbon Bond Formation Reactions

Tetradentate copper complex supported on boehmite nanoparticles as an efficient and heterogeneous reusable nanocatalyst for the synthesis of diaryl ethers

In this work boehmite nanoparticles (BNPs) were prepared through addition of aqueous solution of NaOH to solution of Al(NO3)3·9H2O. Then, the surface of BNPs was modified by (3-chloropropyl)trimethoxysilane (CPTMS) and further tetradentate ligand (MP-bis(AMP)) was anchored on its surface. At final step, a tetradentate organometallic complex of copper was stabilized on the surface of modified BNPs (Cu(II)-MP-bis(AMP)@boehmite). These obtained nanoparticles were characterized using SEM imaging, WDX, EDS, AAS and TGA analysis, BET method, FT-IR spectroscopy, and XRD pattern. In continue, the catalytic activity of Cu(II)-MP-bis(AMP)@boehmite has been used as a much efficient, reusable and hybrid of organic–inorganic nanocatalyst in the synthesis of ether derivatives through C–O coupling reaction under palladium-free and phosphine-free conditions. Cu(II)-MP-bis(AMP)@boehmite catalyst has been recovered and reused again for several times in the synthesis of ether derivatives.

Thermal conductivity performance in propylene glycol-based Darcy-Forchheimer nanofluid flow with entropy analysis

Background and objectiveEntropy generation is a novel prospective in many thermodynamic processes and presents dynamic applications in heat polymer processing optimization. The significance of entropy generation is observed in heat exchangers, combustion, thermal systems, nuclear reactions, turbine systems, porous media and many others. In view of such thermal applications, the main objective of recent analysis is to analyze the entropy optimized analysis for dissipative flow of Darcy-Forchheimer nanofluid over a permeable medium. Flow is generated by stretching of surface. Thermal radiation and viscous dissipation are incorporated in heat expression. Boehmite (AlOOH) and silica (SiO2) are considered as nanoparticles. Here propylene glycol (C3H8O2) is considered as continuous phase fluid. Entropy features is discussed through thermodynamics second law. MethodologyNonlinear ordinary dimensionless form is obtained through suitable dimensionless variables. The obtained dimensionless expressions are numerically solved by implementation of ND-solve method. ResultsGraphical feature of entropy rate, temperature, Bejan number and velocity profile against flow variables for both Boehmite (AlOOH) and silica (SiO2) nanoparticles are discussed. Computational results of thermal transport rate and drag force versus sundry variables for Boehmite and silica nanoparticles are studied. An increment in velocity profile is seen through volume fraction. ConclusionsA reverse trend hold for entropy rate and velocity with rising values of porosity variable. An amplification in radiation correspond to augments thermal field and Bejan number. A decrement occurs in Bejan number with increasing values of Brinkman number. An improvement in drag force is noticed through volume fraction. An improvement in radiation improves the thermal transport rate. Higher estimation of radiation boosts up entropy generation.

High-performance Electret and Antibacterial Polypropylene Meltblown Nonwoven Materials Doped with Boehmite and ZnO Nanoparticles for Air Filtration

The current pandemic caused by COVID-19 has intensively triggered the development of high-performance air filters. Polypropylene (PP) is widely used as the raw material of meltblown nonwoven materials and is the core layer in air filters, such as masks. In this study, an electret PP meltblown nonwoven with antibacterial activity was developed, and nano boehmite (AlOOH) and nano-ZnO were employed as electret and antibacterial agents, respectively. AlOOH (0.5–2.0 wt%) and ZnO (1.0 wt%) were doped into the PP matrix using a twin-screw extruder, and the resulting masterbatches were applied as raw materials to produce nonwoven materials via a meltblown process. The as-prepared nonwoven samples were characterized by means of SEM, IR and DSC/TG. After corona charging, the filtration efficiency was determined by a filtration tester, charge decay was measured by an infrared electrostatic tester, and the antibacterial properties were evaluated (evaluation method: AATCC 100–2012). A dosage of AlOOH greater than 1.0 wt% endowed the nonwoven material with high filtration efficiency, and 1.0 wt% ZnO brought about antibacterial activity. Corona charging was an effective means to charge the nonwoven electret, and the charges were quicker to decay in air than in a sealed bag. The as-prepared meltblown nonwoven filter is a remarkably promising filter for air filtration.Electronic Supplementary Material (ESM)The online version of this article (doi: 10.1007/s12221-022-4786-8) contains supplementary material, which is available to authorized users.

Boehmite nanoparticles for potential enhancement of tribological performance of lubricants

A set of nanolubricants was prepared by varying concentrations of Boehmite nanoparticles (0.25,0.5,0.75,1 wt%) in synthetic base oil (PAO-6) with a fixed concentration of dispersant (PIBSA). This is the first study exploring Boehmite mineral for its antiwear and extreme pressure performance. Nanolubricants showed excellent colloidal stability for over 30 days without any sedimentation and improved viscosity index by 4.35% at 1 wt% concentration. Four ball tribometer was used for exploring the tribological performance of Boehmite nanolubricants. A significant 24% wear reduction over base oil was observed for optimum NPs concentration of 0.5 wt% beyond that performance deteriorated. On the other hand, increased NPs concentration enhanced load-bearing capacity for EP test and the highest enhancement of 40% was observed for 0.75 and 1 wt% concentrations. Based on surface characterization techniques, we confirm dehydration of Boehmite NPs into Aluminium oxide (Al2O3) under tribostress. We further confirm regenerative, sacrificial protective tribofilm composed of tribosintered Al2O3 along with oxide film on the rubbing surfaces.

Frustrated Coulombic and Cation Size Effects on Nanoscale Boehmite Aggregation: A Tumbler Small- and Ultra-Small-Angle Neutron Scattering Study

To better understand the effects of solution chemistry on particle aggregation in the complex legacy tank wastes at the Hanford (WA) and Savannah River (SC) sites, we have performed a series of tumbler small- and ultra-small-angle neutron scattering experiments on 20 wt % solid slurries of nanoparticulate aluminum oxyhydroxide (boehmite) with M1+ nitrates of various concentrations and radii. The solutes consisted of H, Li, Na, K, and Rb nitrates at 10–5, 10–3, 10–1, 2, and 4 molal (m) concentrations, as well as in pure H2O. Synthetic boehmite nanoparticles were used with a size range from ∼20 to 30 nm. Tumbler cells were used to keep the solids from settling. Although particles initially form individual rhombohedral platelets, once placed in solution, they quickly form well-bonded stacks, primary aggregates, up to ∼1500 Å long, and a second level of aggregates whose concentration and structure vary as a function of cation type and concentration. Aggregation generally increases with increased solute concentration and with cation radius up to a concentration somewhat above 10–1 m, at which point the trend reverses. Primary aggregates become more rodlike and larger. The Kirkwood-like reversal probably reflects a change from Derjaguin–Landau–Verwey–Overbeek (DLVO)/Debye behavior controlled by surface chemistry to a frustrated Coulombic system controlled by the solution structure. These data suggest that an understanding of the effects of salt concentration and chemistry on nanoparticle aggregate structures provides useful physical insights into the microscopic origin of slurry rheology in the Hanford and Savannah River legacy wastes.