Ultrasonic-assisted Technique Research Articles

Optimization of sonication-assisted synthesis of magnetic Moringa oleifera as an efficient coagulant for palm oil wastewater treatment

Optimization of the sonication-assisted synthesis of magnetic Moringa oleifera (MMO) was carried out, to produce an efficient coagulant for palm oil mill effluent treatment. Response surface methodology (RSM) was used to analyse the effect of magnetic nanoparticles (MNPs) composition, sonication time and sonication temperature on coagulation performances to remove total suspended solid (TSS), colour, chemical oxygen demand (COD) and sludge volume index (SVI)). The RSM analyses indicate 1.0 wt% of MNPs, 2.35 min and 50 °C as the optimal MNPs mass fraction, sonication time and sonication temperature, respectively in order to fabricate an efficient MMO coagulant. The analysis of variance (ANOVA), indicate that mass fraction of MNPs and sonication temperature are the most significant parameters. From the statistical analysis, the sonication time did not exert any influence on the fabrication of MMO as well as its coagulation performance. At the optimum conditions, 83.3%, 28.1%, 85.2% removal of TSS, colour, COD as well as 485 mL/g of SVI were respectively achieved. This paper also present the characterization studies on the synthesized MMO using Fourier transform infrared spectroscopy, X-ray diffractometry, scanning electron microscopy and vibrating sample magnetometer analysis. • Magnetic Moringa Oleifera (MMO) coagulant was synthesized via ultrasonic-assisted technique. • Optimization study on synthesis conditions was carried out by response surface methodology. • Magnetic composition and sonication temperature were the significant synthesis factors. • The developed MMO coagulant exhibited ferromagnetic properties.

Ultrasonic-assisted Dunlop method for natural rubber latex foam production: Effects of irradiation time on morphology and physico-mechanical properties of the foam

An ultrasonic-assisted technique was first introduced for the production of natural rubber latex foam (NRLF). The flexible elastomeric foam was formed by a liquid–solid state transformation in an aqueous media. The aim of the current research was to provide a novel strategy for fabricating NRLF using ultrasonication and the Dunlop method, as well as to simultaneously utilize irradiation events to achieve the desired foam properties. NRLFs were exposed to ultrasonication at 25 kHz at the beginning of the gelling process. The effects of irradiation times of 0, 1, 3, 5 and 7 min on the morphology, foaming behaviors, physical properties and mechanical performance of NRLFs were investigated. The results revealed that using ultrasonic irradiation, unfoamed regions and a bimodal structure, which seem to be microstructural defects in conventional NRLF, could be completely eliminated. However, excessive irradiation times of 5 min and longer appeared to affect the physico-mechanical properties of the foams in terms of transient cavitation and the unfavorable physicochemical effects of ultrasonic vibrations. As a result, the optimal ultrasonic irradiation time was found to be 3 min. Using this irradiation duration, a foam with the suitable microcellular structure achieved the most desirable properties, such as its expansion ratio (7-fold increase), foam porosity (85.7%), compression recoverability (98.7%), and tensile strength (307.3 kPa). Moreover, the foam still maintained its characteristic soft nature (hardness less than 100 N) with an indentation hardness of 71.9 N. Therefore, ultrasonic treatment introduced to the conventional Dunlop method is a potentially feasible technique since it improves the morphology and the physico-mechanical properties of NRLFs.

An innovative ultrasonic-assisted extraction process for enhancing the patchoulol from Pogostemon cablin essential oil using hydrotropes

Pogostemon cablin (Patchouli) is an aromatic herb cultivated for its high-value essential oil. It is majorly used as a base oil in fragrance formulation due to its characteristics sesquiterpenoid alcohols. Patchoulol is an imperative and bioactive sesquiterpenoid in the patchouli essential oil, which is primarily isolated from the aerial part of the plant. The patchoulol was enriched in this essential oil by ultrasonic-assisted extraction techniques using different hydrotropes viz., sodium p-toluene sulphonate, resorcinol, sodium cumene sulphonate and sodium salicylate. The effect of various parameters such as extraction time (min), ultrasonic amplitude (%) and pulse interval (s) with 2 M concentration of hydrotropes was studied. Ultrasonic assisted-techniques has improved the percentage of patchoulol in patchouli essential oil. The highest composition of patchoulol i.e., 70.06 % was obtained for 5 min extraction time, 40 % ultrasonic amplitude, 30:30 s pulse interval for sodium salicylate at 2 M concentration.

Characterisation of the variation of total saponin content in the Medicago species using an optimised extraction technique

ABSTRACT Medicago sativa is an important worldwide forage species containing characteristic secondary metabolites such as saponin which are reported to be biologically active. The objective of this study was to determine the dynamics of total saponin content in M. sativa among different cuttings throughout a year and the variation of total saponin content in 28 accessions in genera Medicago using an optimised ultrasonic-assisted technique. Under field conditions, seasonal changes of total saponin content in M. sativa showed an increase from March (spring) (4.0 mg g−1 dry matter [DM]) towards a peak in late June (early summer) (9.5 mg g−1 DM), and subsequent a decrease in September (fall) (7.0 mg g−1 DM). The maximum total saponin content in M. sativa (range: 6.5−9.4 mg g−1 DM) was obtained at the 3rd harvest. A significant variation of total saponin content was observed both among different annual (range: 6.3–8.8 mg g−1 DM) and perennial (range: 6.1–11.2 mg g−1 DM) Medicago species. Flower of Medicago species showed the highest saponin content compared to other plant parts. The present study would serve a valuable reference for the selection of germplasm with different levels of saponin compounds for various application purposes and thus contribute to Medicago breeding programmes.

Ultrasonic-Assisted Removal of Undesirable Submicron-Sized Particulates To Realize Sustainable and Eco-Friendly Circulation of Drilling Fluid

SummaryRemoval of useless and submicrometer-sized solids from drilling fluid, which exert significant effects on drilling performance, is a crucial part of sustainable and eco-friendly circulation in drilling operations. However, current solid-control methods for drilling-fluid reuse and recirculation, such as electronic-adsorption and chemical-flocculation methods, are associated with high cost and low efficiency and/or pollution of drilling fluid. In this study, a novel method using ultrasonic waves has been proposed to remove unwanted submicrometer-sized solids from polysulfonate drilling fluids. The results show that the suspension stability, viscosity, and particle size can all be significantly reduced, while the solid-separation ratio of the drilling fluid can be greatly enhanced by ultrasonic-wave treatment. The parameters of ultrasonic waves are optimized to be power of 3 kW, treating time of 30 minutes, treating frequency of 20 kHz, and ventilation (i.e., air) for 5 minutes in a laboratory scale. The scanning electron microscope (SEM) analysis shows that solid particles exhibit more obvious crystal morphology after ultrasonic-wave treatment, indicating that the breaking of gel-structure of drilling fluid due to the cavitation, mechanical, and heat effects of ultrasonic waves is the main mechanism for decreasing the suspension stability. Thus, the proposed ultrasonic-assisted technique has a high potential for removing undesirable solids from drilling fluid and fulfilling its recirculation in a cost-effective and environmentally friendly manner. This new technology has been successively applied to 12 wells, and good results were obtained.

Ultrasonic-Assisted Technique as a Novel Method for Removal of Naphthenic Acid from Model Oil Using Piperidinium-Based Ionic Liquids.

In this study, piperidinium-based ionic liquids (IL) containing trifluoromethanesulfonate, phenolate, and dicyanamide anions were synthesized. Using the ILs, extraction of naphthenic acid from highly acidic oil with a total acid number (TAN) of 1.44 was studied. Two agitation techniques have been implemented for the extraction process, which were mechanical stirring and ultrasonic-assisted irradiation. 1-Butyl-1-methylpiperidinium phenolate [BMPi][Phe] showed the best potential in extracting naphthenic acid from oil, with complete removal of naphthenic acid with IL-to-oil ratios of 0.010 and 0.0025 for the mechanical stirring method and the ultrasonic-assisted method, respectively. Ultrasonic-assisted extraction process shows very good potential in enhancing the extraction efficiency of naphthenic acid. Optimization and study on the effects of ultrasonic parameters, namely, IL-to-oil ratio, ultrasonic amplitude, and time, were studied through response surface methodology (RSM). Using [BMPi][Phe], the optimum conditions obtained are IL-to-oil ratio of 0.03, 53.91% of amplitude, and 4.29 min of extraction time. Under these optimum conditions, 100% removal of naphthenic acid was achieved.

Fast and practical synthesis of carboxymethyl cellulose from office paper waste by ultrasonic-assisted technique at ambient temperature

This report demonstrates the fastest technique to successfully achieve carboxymethyl cellulose (CMC) from office paper waste, within 30 min at ambient temperature using ultrasonic-assisted method as a source of energy. The obtained CMC was characterized using FTIR, TGA, and NMR techniques to confirm its structure. The FTIR spectrum showed characteristic peaks of carboxymethyl groups and its salt at the wavenumbers of 1585 (C=O) and 1412 (C-O) cm−1. The TGA results of CMC exhibited the loss of carbon dioxide at ca. 260 – 300 °C. Moreover, a higher ash yield of the obtained CMC indicated the substitution of carboxymethyl in the structure. The CMC product structure was confirmed using 13C- and HMBC 2D-NMR. The HMBC 2D-NMR results indicated a correlation between carbonyl and methylene carbons of carboxymethyl groups and protons of pyranose ring, implying that pyranose ring was substituted successfully by monocholoroacetic acid (MCA). The optimal conditions were obtained by using 4.11 ml of 30%w/v NaOH and 1.4 g of MCA in 40 ml of isopropanol at ambient temperature. The resulting CMC showed 0.75 degree of substitution at 18.75 W/ml ultrasonic intensity.

Physicochemical, antioxidant and sensory characteristics of cookies supplemented with different levels of spent coffee ground extract

Spent coffee grounds (SCG) are the primary by-product of coffee production which still contains functional properties with high natural antioxidant components. It can be extracted using ultrasonic-assisted techniques and then integrated into baking products such as cookies. This research is aimed to measure the physicochemical and sensory acceptability of cookies incorporated with SCG extract. Extraction of SCG was done using water through ultrasonic extraction following incorporated SCG water extract into cookies. Six different formulations were developed using different amount of SCG extract (A-control 0%, B-0.27%, C-0.52%, D-0.80%, E-1.07% and F-1.33%). Physicochemical properties (antioxidant properties, colour profile, texture, moisture, sugar, fat, protein, ash, calorie and texture profile) and the sensory acceptability of SCG extract cookies was observed. Total phenolic content (TPC) was used to quantify the antioxidant content while the antioxidant activity was measured using 2,2-diphenyl-2-picrylydrazyl radical scavenging activity assay (DPPH) and ferric reducing antioxidant power (FRAP) assays. Results show that decreasing in lightness (L*) and yellowness (b*) with the increasing percentage of SCG extract were observed. In contrast with L* and a* value, the b* value of cookies was increased with the increasing percentage of SCG extract. Formulation E (1.07% SCG extract) showed the highest percentage in almost all proximate analysis such as 6.49±0.39 moisture, 2.11±0.22 ash, 20.42±0.74 crude fat, 8.13±0.05 crude protein and 4.37±0.04 crude fibre content. The highest amount of antioxidant content was depicted by the formulation D cookie (1.72±0.04 mg GAE/g). The best antioxidative activity was found in formulation E (7.80±0.27 DPPH inhibition and 0.02 abs by FRAP analysis). Sensory acceptance revealed that formulation E (1.33%) cookies were more accepted by the panellists. It is interesting to note that SCG can serve as one of the ingredients for cookie production that showed significant effects on the physicochemical and organoleptic properties of the final products.

Ultrasonication-aided synthesis of nanoplates-like iron molybdate: Fabricated over glassy carbon electrode as an modified electrode for the selective determination of first generation antihistamine drug promethazine hydrochloride.

The innovation of novel and proficient nanostructured materials for the precise level determination of pharmaceuticals in biological fluids is quite crucial to the researchers. With this in mind, we synthesized iron molybdate nanoplates (Fe2(MoO4)3; FeMo NPs) via simple ultrasonic-assisted technique (70kHz with a power of 100W). The FeMo NPs were used as the efficient electrocatalyst for electrochemical oxidation of first-generation antihistamine drug- Promethazine hydrochloride (PMH). The as-synthesized FeMo NPs were characterized and confirmed by various characterization techniques such as XRD, Raman, FT-IR, FE-SEM, EDX and Elemental mapping analysis and electron impedance spectroscopy (EIS). In addition, the electrochemical characteristic features of FeMo NPs were scrutinized by electrochemical techniques like cyclic voltammetry (CV) and differential pulse voltammetry technique (DPV). Interestingly, the developed FeMo NPs modified glassy carbon electrode (FeMo NPs/GCE) discloses higher peak current with lesser anodic potential on comparing to bare GCE including wider linear range (0.01-68.65µM), lower detection limit (0.01µM) and greater sensitivity (0.97 µAµM-1cm-2). Moreover, the as-synthesized FeMo NPs applied for selectivity, reproducibility, repeatability and storage ability to investigate the practical viability. In the presence of interfering species like cationic, anionic and biological samples, the oxidation peak current response doesn't cause any variation results disclose good selectivity towards the detection of PMH. Additionally, the practical feasibility of the FeMo NPs/GCE was tested by real samples like, commercial tablet (Phenergan 25mg Tablets) and lake water samples which give satisfactory recovery results. All the above consequences made clear that the proposed sensor FeMo NPs/GCE exhibits excellent electrochemical behavior for electrochemical determination towards oxidation of antihistamine drug PMH.

Micropropagation, myristicin production enhancement, and comparative GC-MS analysis of the n-hexane extracts of different organs of Daucus pumilus (Gouan), family Apiaceae.

ABSTRACTAim:This work aimed to study the somatic embryogenesis and organogenesis of endangered Daucus pumilus (Gouan) for the conservation of this plant and improving the production of secondary metabolites of medicinal value.Materials and Methods:The callus formation and in vitro propagation of D. pumilus (Gouan) by using a different combination of naphthalene acetic acid and benzylaminopurine were established. Various embryogenic stages were tracked using scanning electron microscopy and light microscopy. The volatile constituents of the n-hexane extracts of D. pumilus (Gouan) that extracted by ultrasonic-assisted technique were analyzed by gas chromatography–mass spectrometry.Results and Discussion:Somatic embryogenesis and organogenesis of endangered D. pumilus (Gouan) were established for the first time. Myristicin and elemicin were successfully increased during micropropagation to 70.89% and 2.19%, respectively. Furthermore, the induction of compounds such as 6-methoxymellein, eugenin, methyl behenate, and 1,6-dimethylnaphthalene was also detected.Conclusion:Commercially, this protocol decreases the dependence on wild medicinal plants, enhances the manufacturing of valuable phytochemicals to meet the great demands of the pharmaceutical industries, and acts as a mean for genetic transformation of this plant.

β-Cyclodextrin-chitosan biocomposites for synergistic removal of imazethapyr and imazamox from soils: Fabrication, performance and mechanisms

The present study delineates to develop and explore the possibility of using chitosan-β-cyclodextrin biocomposites as environmentally friendly decontamination agent for removal of imazethapyr and imazamox from soils. The biocomposites were synthesised using ultrasonic assisted technique and characterised by UV–Visible spectrophotometer. The quantification of imazethapyr and imazamox was done using liquid chromatography tandem mass spectrometry. The adsorption capacity for imazethapyr and imazamox ranged from 0.12 to 1.22 and 0.02 to 1.01 μg1−ng−1mLn, respectively in studied soils (p < .05) indicating strong influence of soil properties on adsorption. Desorption studies indicated that distilled water could desorb only 1.23 to 5.48 and 3.11 to 8.63% of adsorbed imazethapyr and imazamox, respectively at high concentrations (1.0 and 10 μg mL−1) whereas herbicides were not desorbed at low concentrations (0.01 and 0.1 μg mL−1). The removal of imazethapyr and imazamox from soils were carried out with β-cyclodextrin, chitosan and their biocomposites and the influence of various parameters such as type and concentration of extractant, contact time, liquid to soil ratio, temperature and sequential extraction cycle was investigated. Under optimum conditions, herbicides were successfully desorbed from studied soils using low molecular weight chitosan-β-cyclodextrin biocomposite (LCD) and removal rate varied from 59.42 to 99.44% at initial herbicide concentration of 0.01 to 10 μg mL−1. The highest removal rate of imazethapyr and imazamox was observed for inceptisol 3 followed by entisol, inceptisol 2, aridisol, inceptisol 1, vertisol and alfisol probably due to differential physico-chemical properties of soil which affected the herbicide-soil interactions. Based on these results, LCD can be regarded as effective and environmentally friendly in situ green extracting agent for remediating soils contaminated with imazethapyr and imazamox.

Microwave-assisted conversion of agro-industrial copra residue oil to diesel engine compatible fatty acid methyl esters

Due to the increasing concern towards fossil fuel reserve and its fluctuating price, many countries shifted towards producing biodiesel as an alternative green fuel. In this study, the main objective is to synthesis biodiesel from coconut copra, an agro-industrial residue, as potential feedstock using different transesterification techniques, namely stirring mechanical-assisted technique (SAT), ultrasonic-assisted technique (UAT), and microwave-assisted technique (MAT). The current study will show comparison between the biodiesel yields, fatty acid methyl ester (FAME) compositions and fuel properties of the transesterification techniques used. The result showed that the copra residue biodiesel (CRB) using SAT produced the highest yield of biodiesel compared to UAT and MAT, which are 96.85% (±0.69), 93.79% (±1.00), and 91.76% (±0.87), respectively. Furthermore, different volumes of solvent and catalyst amount were found to affect the biodiesel yields, relatively. On the other hand, for FAME compositions, insignificant results were observed. The fuel properties in CRB complied with the international standards, thus, showing high compatibility to be used in diesel engine.

Highly Crystalline WO3 Nanoparticles Are Nontoxic to Stem Cells and Cancer Cells

Tungsten oxide sol, containing highly crystalline nanoparticles of orthorhombic WO3 and having good sedimentation stability, was synthesized using a facile, ultrasonic-assisted technique. An additional steric stabilizer, dextran, was proposed to enhance the stability of WO3 nanoparticles in biological media and to reduce their in vivo toxicity. The cytotoxicity of dextran-stabilized and nonstabilized WO3 sols was studied in vitro using dental pulp stem (DPS) cell lines and breast cancer (MCF-7) cell lines. Both tungsten oxide sols demonstrated low cytotoxicity and low genotoxicity for both stem cells and malignant cells and only slightly reduced their metabolic activity in the concentration range studied (from 0.2 to 200 μg/ml). The data obtained support possible theranostic applications of tungsten oxide colloidal solutions.

Production of polyimide ceria nanocomposites by development of molecular hook technology in nano-sonochemistry

Poly(amic acid), the precursor of polyimide (PI), was used for the preparation of PI/CeO2 nanocomposites (NC)s by ultrasonic assisted technique via insertion of the surface modified CeO2 nanoparticles (NP)s into PI matrix. In the preparation stages, in the first, the modifications of CeO2 NPs by using hexadecyltrimethoxysilane (HDTMS) as a binder were targeted using ultrasonic waves. In the second step, newly designed PI structure was formed from the sonochemical imidization process as a molecular hook. In this step two different reactions were occurred. The acetic acid elimination reaction in the main chain of macromolecule, and the acetylation reaction in the side chains of poly(amic acid) were accomplished. By acetylation process the hook structure was created for trapping of the modified nanoparticles. In the final step the preparation of PI NCs were achieved by sonochemical process. The structural and thermal properties of pure PI and PI/CeO2 NCs were studied by several techniques such as fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance spectroscopy (NMR), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), X-ray diffraction (XRD), and thermal analyses. FT-IR and 1H NMR spectra confirmed the success in preparation of PI matrix. The FE-SEM, TEM, and AFM analyses showed the uniform distribution of CeO2 NPs in PI matrix. The XRD patterns of NCs show the presence of crystalline CeO2 NPs in amorphous PI matrix. The thermal analysis results reveal that, with increases in the content of CeO2 NPs in PI matrix, the thermally stability factors of samples were improved.

Patterning of silver nanowire for grid formation by using ultrasonic assisted clean chemical etching for the application of high transparent electrode

We propose a novel, fast, clean, and dimensionally very accurate ultrasonic assisted technique for silver nanowire (AgNW) etching by using Ni etchant for the purpose of fabricating a grid type structure under static and ultrasonic conditions. A photoactive material pattern on an AgNW network was prepared by using a photolithography process, followed by chemical etching of unwanted AgNWs under static and ultrasonic conditions. The ultrasonic assisted etching process facilitates complete etching of the AgNW pattern (initial condition was 22.4 Ω resistance with 94% light transmittance) within 20–25 s, with almost 35.4% dimensional accuracy relative to the longer static etching condition (7.5 min). A combined process was followed for accurate dimensions because the initial short static etching process weakened the unwanted nanowire structure, while the secondary ultrasonic chemical etching process helps to remove all the AgNW residue from pattern area with faster etching.

Ultrasound extraction optimization, structural features, and antioxidant activity of polysaccharides from Tricholoma matsutake.

An ultrasonic-assisted technique was employed to extract crude polysaccharide from Tricholoma matsutake fruiting bodies. Single-factor tests and orthogonal experimental design (L9(33)) were used to obtain the optimal extraction conditions. Results showed that the optimal parameters were as follows: ultrasonic temperature, 40 °C; ultrasonic time, 50 min; water to raw material ratio, 25 ml/g; ultrasonic frequency, 45 kHz; and ultrasonic power, 100 W. Three novel T. matsutake polysaccharide (TMP) fractions (TMP30, TMP60, and TMP80) were isolated and purified from TMP by stepwise alcohol precipitation. Their preliminary structural features were determined by high-performance anion-exchange chromatography with pulsed-amperometric detection (HPAEC-PAD) and Fourier transform infrared spectrophotometer (FT-IR) analyses. Furthermore, their in vitro antioxidant activity was investigated in terms of a reducing power assay and the scavenging rates of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radicals. The order of the various fractions based on their antioxidant activity was TMP80>TMP>TMP60>TMP30. These findings suggested that novel polysaccharide fractions from T. matsutake, especially TMP80, could be promising active macromolecules for biomedical use.

Inclusion complex of neohesperidin dihydrochalcone and glucosyl-β-cyclodextrin: Synthesis, characterization, and bitter masking properties in aqueous solutions

The objective of this study was to synthesize a new water-soluble bitterness inhibitor—neohesperidin dihydrochalcone (NHDC)/glucosyl-β-cyclodextrin (G-β-CD) inclusion complex via ultrasonic-assisted technique in the ethanol aqueous solution, and also assess its bitterness-masking effect on corn peptides (CPs) using descriptive sensory analysis. Under the optimal synthetic condition, the NHDC payload was 278mg/g and inclusion rate was 74.6%. The scanning electron microscopy (SEM) observation demonstrated that NHDC was inserted into the cavity of G-β-CD. The disposition of NHDC/G-β-CD inclusion complexes were affirmed by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). Furthermore, the molecular structures of the complexes were explored by Fourier transform infrared (FT-IR) and proton nuclear magnetic resonance (1H NMR). Results clearly indicated that the formation of a multicomponent complex was held together by hydrophobic interaction or hydrogen bond. The CP-debittering assessment showed that the prepared NHDC/G-β-CD inclusion complex possessed a more superior bitterness-masking effect on CP compared to single NHDC or G-β-CD, and other bitterness inhibitors, such as phosphatidic acid, protein-phosphatidic acid complexes, tannin, and neodiosmin. Therefore, this inclusion complex has a potential use for debittering of CP-based food and drugs.

Adsorption of fluoride from aqueous solution on supported Fe/γ-Al2O3 adsorbent prepared by ultrasonic-assisted technique

Adsorption of fluoride from aqueous solution on supported Fe/γ-Al2O3 adsorbent prepared by ultrasonic-assisted technique

Ethyl Levulinate Obtained from Lignocellulosic Waste Material with Previous Delignification by Ultrasonic-Assisted Technique

Ultrasound-assisted pretreatment under mild operating conditions has been investigated for intensification of delignification to facilitate the obtaining of ethyl levulinate from biomass. The effect of pH (2 - 12), temperature (30°C - 70°C) and pretreatment time (0 - 120 minutes) has been studied for different biomass samples. The most favorable conditions were basic pH, temperature of 70°C and pretreatment time of 2 h, obtaining values of delignification near 80 percent. The ethyl levulinate is obtained in microwave directly via from samples before and after delignification and analyzed for GC-MS. The results evidenced better yields for the delignified samples.

Fabrication and Characterization of Lu$lt;inf$gt;2$lt;/inf$gt;O$lt;inf$gt;3$lt;/inf$gt; Nanowire Arrays by Sol-Gel Template Method Assisted with Ultrasonic Treatment

Lu2O3 nanowire arrays were fabricated by a Sol-Gel anodic aluminum oxide (AAO) template method assisted with ultrasonic treatment. The structure and morphology of Lu2O3 nanowire arrays were characterized by X-ray diffractometer (XRD), scanning electron microscope (SEM), Energy disperse X-ray spectroscope (EDX), and transmission electron microscope (TEM). The results indicate that the as-prepared nanowire arrays consist of cubic structure of polycrystalline Lu2O3. The Lu2O3 nanowires are parallel to each other and quite uniform in diameter of about 200 nm. The formation mechanism of nanowires is also explored here. It is found that it is easy to evolve Lu2O3 into bamboo-like nanotubes without ultrasonic treatment. Compared with traditional Sol-Gel template method, a good filling of Lu2O3 nanowires embedded in the AAO template can be obtained by improved ultrasonicassisted technique. Ultrasonic treatment is useful to prepare for other nanowire arrays of different materials.