Sonication In Ethanol Research Articles

Swellable hybrid silicas for the removal of rhodamine B dye from aqueous phase

This study is focused on the use of a hybrid organic-inorganic silica (Silica-SOM) for the removal of Rhodamine B dye (RhB) from water media. Because of its hybrid structure, Silica-SOM has the unique property of being swellable in the presence of an organic solvent, thus increasing the volume available for pollutants adsorption. The adsorption capacity of the Silica-SOM to adsorb RhB from water media has been determined. In particular, if the material is previously swollen with an organic solvent, it is able to sequester more than 99 % of dye molecules in a 1.0 × 10−5 M RhB solution in less than 1 h at ambient conditions. In addition, the ability of Silica-SOM to be re-generated by mild sonication in ethanol after one RhB adsorption cycle was tested for the first time: the material was easily regenerated and used for six consecutive adsorption cycles; in each of them there is no loss in adsorption performance, which remains quantitatively high and extremely fast.

Plasma Treatment of PDMS for Microcontact Printing (μCP) of Lectins Decreases Silicone Transfer and Increases the Adhesion of Bladder Cancer Cells.

The present study investigates silicone transfer occurring during microcontact printing (μCP) of lectins with polydimethylsiloxane (PDMS) stamps and its impact on the adhesion of cells. Static adhesion assays and single-cell force spectroscopy (SCFS) are used to compare adhesion of nonmalignant (HCV29) and cancer (HT1376) bladder cells, respectively, to high-affinity lectin layers (PHA-L and WGA, respectively) prepared by physical adsorption and μCP. The chemical composition of the μCP lectin patterns was monitored by time-of-flight secondary ion mass spectrometry (ToF-SIMS). We show that the amount of transferred silicone in the μCP process depends on the preprocessing of the PDMS stamps. It is revealed that silicone contamination within the patterned lectin layers inhibits the adhesion of bladder cells, and the work of adhesion is lower for μCP lectins than for drop-cast lectins. The binding capacity of microcontact printed lectins was larger when the PDMS stamps were treated with UV ozone plasma as compared to sonication in ethanol and deionized water. ToF-SIMS data show that ozone-based treatment of PDMS stamps used for μCP of lectin reduces the silicone contamination in the imprinting protocol regardless of stamp geometry (flat vs microstructured). The role of other possible contributors, such as the lectin conformation and organization of lectin layers, is also discussed.

Facile preparation of hydroxyl−functionalized mica nanosheets assisted by plasma treatment

The efficient exfoliation of mica, a naturally layered material, into two-dimensional (2D) nanosheets has received much attention due to its low price, good chemical stability, and better shielding function against UV light. However, fast and simple exfoliation of mica in a large-scale face a great challenge. In this work, we developed a simple and effective method for obtaining OH−functionalized mica nanosheets (MNs). The process involved calcination, plasma treatment, and ultrasonic exfoliation, resulting in a yield of 7.535%. Furthermore, the effects of sonication time, solvent type and particle sizes of mica were investigated. The conditions for the preparation of MNs were determined: mica calcination, plasma treatment, and sonication in ethanol for 5 h. XPS and FT−IR demonstrated that more hydroxyl groups were introduced to mica after the plasma treatment, which facilitated the exfoliation of mica.

Processing and characterization of Inconel 718/Al2O3 nanocomposite powder fabricated by different techniques

Inconel 718/Al2O3 nanocomposite powders produced by sonication-assisted high-energy ball milling (HEBM) and mechanofusion processes are presented and compared. Powders were pre-mixed via sonication in ethanol. Two pre-mixed batches were processed by HEBM using two different cooling temperatures and milling times. To investigate the influence of Al2O3 on the mechanical milling stages, Inconel 718 powder without alumina was also mechanically milled. Results show that the tested methods are able to produce Inconel 718/Al2O3 composite with suitable characteristics for further manufacturing or functionalization. A homogeneous dispersion of nanosized alumina throughout the metal matrix was only achieved by milling, showing a monomodal particle size distribution, with controlled both morphology and composition. Low cooling milling temperatures reduce Inconel 718/Al2O3 composite production time using less mechanical energy during milling. Sonication-assisted HEBM is an adequate method for the fabrication of non-commercial nanocomposites to be used as raw material in different manufacturing techniques.

GeTe Nanosheets as Theranostic Agents for Multimodal Imaging and Therapy of Inflammatory Bowel Disease

AbstractRecently, 2D nanomaterials have received considerable attention in nanomedicine due to their intrinsic optical properties, biocompatibility, and therapeutic effect. Here, 2D germanium telluride (GeTe) nanosheets coated with polyvinylpyrrolidone (PVP) (GeTe‐PVP NSs) developed as theranostic agents are reported that can be used for multispectral optoacoustic tomography (MSOT) and fluorescence imaging and therapy of inflammatory bowel disease (IBD). GeTe‐PVP NSs, fabricated by simple sonication in ethanol and PVP, show broad optical absorption in visible and near‐infrared (NIR) ranges (400–1200 nm) and have intrinsic fluorescence properties. Thus, they provide deeper ex vivo and in vivo MSOT tissue images than gold nanorods or indocyanine green with strong optical absorption in the first NIR window (700–900 nm). In addition, when orally administered to IBD mice, GeTe‐PVP NSs exhibit therapeutic efficacy similar to or higher than sulfasalazine, with strong accumulation at inflammatory colon sites. This demonstrates that oral administration of GeTe‐PVP NSs may be used to treat inflammatory diseases in the gastrointestinal tract.

Ultraviolet/blue light emitting high-quality graphene quantum dots and their biocompatibility

Fluorescent graphene quantum dots (GQDs) have a significant potential in the application to bio-fields. However, most of the GQDs synthesized by existing methods face limitations due to the harmful chemicals involved in their synthesis and the presence of various oxygen functional groups, both of which affect the biocompatibility of the GQDs. Here, we present a simple approach to fabricating fluorescent and biocompatible high-quality GQDs with low oxygen content without the involvement of harmful chemicals. High-quality GQDs are synthesized by hydrogen-assisted pyrolysis of silicon carbide and this dry synthesis process allows the GQDs to possess high crystallinity with no unwanted chemicals on the surface. Subsequently, the high-quality GQDs are slightly oxidized through sonication in ethanol, but the treated GQDs (t-GQDs) still retain their high crystallinity. The t-GQDs exhibit strong ultraviolet/blue light emission with a high yield of 30.9%, a phenomenon that can be attributed to intrinsic emission resulting from the low oxygen content of the t-GQDs. Furthermore, the t-GQDs show low cytotoxicity even at a high concentration of 200 μg/mL due to the absence of harmful chemicals during their synthesis and the low oxygen content of the t-GQDs. These results demonstrate the excellence of the t-GQDs and their applicability in bio-fields.

Coumaroyl Flavonol Glycosides and More in Marketed Green Teas: An Intrinsic Value beyond Much-Lauded Catechins.

Marketed green teas (GTs) can highly vary in their chemical composition, due to different origins, processing methods, and a lack of standardization of GT-based products. Consequently, biological activities become difficult to correlate to the presence/content of certain constituents. Herein, ultra-high-performance liquid chromatography (UHPLC) combined with high-resolution tandem mass spectrometry (HR MS/MS) was successfully applied to six commercial GT products, extracted by ethanol sonication, to disclose their polyphenol profile beyond the well-known catechins. The relative abundance of each class of metabolites was correlated to antiradical and antilipoperoxidant data through hierarchical clustering analysis, since it reasonably affects the beneficial properties of the product that reaches the consumer. The thiobarbituric acid reactive substances (TBARS) assay demonstrated that GT extracts effectively counteracted the UV-induced lipoperoxidation of hemp oil, which is highly rich in Polyunsaturated Fatty Acids (PUFAs), and therefore highly unstable. The Relative Antioxidant Capacity Index (RACI) comprehensively emphasized that gunpower and blend in filter GTs appeared to be the less active matrices, and except for a GT-based supplement, the Sencha GT, which was particularly rich in flavonol glycosides, was the most active, followed by Bancha GT.

Comparison of Inorganic and Organic Acid Etching Processes on Germanium(100)

Germanium is currently used in semiconductor devices alloyed with silicon and shows promise as an alternative material which could eventually replace silicon. One challenge associated with implementing germanium is rapid oxidation after cleaning, which results in degraded electrical performance because germanium oxides contain many defects. Optimization of cleaning and etching processes are critical to the development of devices based on Ge. This study compares the use of inorganic and organic acids to etch germanium oxides, such as Ge(+1)2O, Ge(+2)O and Ge(+4)O2. X-ray photoelectron spectroscopy (XPS) was used to characterize the Ge(100) surface composition after hydrochloric and citric acid treatments. Immersion in concentrated HCl (12 M) completely removed both GeO2 as well as sub-stoichiometric oxides. The surface remained oxide free when etched inside an Ar purged glovebox attached to an XPS chamber, but suboxides were detected within 3 minutes when samples were exposed to air. A short immersion (60 s) in 2.4 M citric acid in ambient conditions yielded a visible film on the surface even after drying. Two rinse strategies were employed to remove residual citric acid from the surface. After a short rinse (30 s) in ethanol peaks attributed to carboxylic acid were detected in the C 1s XPS region. Residual citrate species were minimized by sonication in ethanol, however citrate species were still detected. Germanium surfaces etched in HCl showed less oxide and adsorbed carbon than those etched in citric acid however both surfaces are unstable in air and suboxides form readily. We investigated the two different acid cleans before passivation of the surface with sulfur.

High-Performance Fluorinated Ethylene-Propylene/Graphite Composites Interconnected with Single-Walled Carbon Nanotubes

Herein, we report a novel method for the fabrication of highly conductive fluorinated ethylene-propylene (FEP)/graphite nanocomposites for high-temperature bipolar plates (BPs) by incorporating the well-dispersed single-walled carbon nanotube (SWCNT) as a secondary filler in the FEP matrix. The SWCNTs were pre-dispersed with FEP powder by sonication in ethanol and subsequently mixed with graphite powder by ball milling. The composite BPs were prepared from the mixed powder by compression molding. The resulting FEP/graphite/SWCNT nanocomposite containing 80 wt% graphite (500 µm particles) and 0.1 wt% SWCNT exhibited high electrical conductivity (210 S cm−1) superior to that of the composite devoid of SWCNTs (120 S cm−1) by modulating the electrical transportation pathways between graphite particles through the SWCNTs. A small amount of the incorporated SWCNTs (0.1 wt%) also improved chemical inertness to phosphoric acid. Hence, the prepared FEP/graphite nanocomposites with SWCNTs as a secondary filler exhibited a robust performance for application as high-temperature BPs for phosphoric acid fuel cells.

Ultrasonic-Assisted Preparation, Characterization, and Use of Novel Biocompatible Core/Shell Fe3O4@GA@Isinglass in the Synthesis of 1,4-Dihydropyridine and 4H-Pyran Derivatives.

This work focussed on the synthesis of a new catalytic material isinglass (IG)-based Fe3O4@GA@IG core/shell magnetic nanoparticles and the investigation of its catalytic activity in two important multicomponent reactions. Fe3O4 nanoparticles were prepared using a simple coprecipitation method and then coated with IG consisting predominantly of the protein collagen in the presence of glutaraldehyde as a cross-linking agent. The obtained hybrid material has been characterized by Fourier transform infrared analysis, scanning electron microscopy, transmission electron microscopy (TEM), vibrating sample magnetometry, energy-dispersive X-ray, X-ray diffraction (XRD), and Brunauer–Emmett–Teller analyses. The results of XRD analysis implied that the prepared nanocomposite consists of two compounds of crystalline magnetite and amorphous IG, and the formation of its core/shell structure had been confirmed by TEM images. The catalytic performance of the as-prepared core/shell bionanocatalyst was evaluated for the first time in the synthesis of 1,4-dihydropyridine and 4H-pyran derivatives under sonication in ethanol. This core/shell structure because of the superparamagnetic property of Fe3O4 and unique properties of IG as a bifunctional biocatalyst offers a high potential for many catalytic applications. Recycling study revealed that no significant decrease in the catalytic activity was observed even after six runs.

Cellulose nanosheets induced by mechanical impacts under hydrophobic environment

The nanoscale structural changes of crystalline cellulose by mechanical milling was studied by high-resolution microscopy (AFM, SEM, TEM). We examined influence of environment [dry, water, silicone oil (PDMS)] on cellulose milling, finding their characteristic effects on microscopic morphology of the products. Dry milling of cellulose gave aggregated globular particles with fast decrystallization. Milling with water or PDMS caused partial dispersion of nanofibers. Milling with PDMS formed micro-platelets <1 µm thick with slight decrystallization. Remarkably, nanoscale particles isolated from PDMS-milled cellulose by sonication in ethanol contained cellulose nanosheets, typically 0.1–10 µm wide and 4.2 nm thick, apparently formed by monolayer association of elementary fibrils. TEM and electron diffraction revealed crystalline nature of nanosheets, with specific orientation of (110) plane or (200) plane perpendicular to the sheet plane. A possible mechanism of the nanosheets formation is proposed, in which the elementary fibrils are aligned parallel by mechanical impacts.

Atom-Thin SnS2-xSex with Adjustable Compositions by Direct Liquid Exfoliation from Single Crystals.

Two-dimensional (2D) chalcogenide materials are fundamentally and technologically fascinating for their suitable band gap energy and carrier type relevant to their adjustable composition, structure, and dimensionality. Here, we demonstrate the exfoliation of single-crystal SnS2-xSex (SSS) with S/Se vacancies into an atom-thin layer by simple sonication in ethanol without additive. The introduction of vacancies at the S/Se site, the conflicting atomic radius of sulfur in selenium layers, and easy incorporation with an ethanol molecule lead to high ion accessibility; therefore, atom-thin SSS flakes can be effectively prepared by exfoliating the single crystal via sonication. The in situ pyrolysis of such materials can further adjust their compositions, representing tunable activation energy, band gap, and also tunable response to analytes of such materials. As the most basic and crucial step of the 2D material field, the successful synthesis of an uncontaminated and atom-thin sample will further push ahead the large-scale applications of 2D materials, including, but not limited to, electronics, sensing, catalysis, and energy storage fields.

Study on Dispersion and Characterization of Functionalized MWCNTs Prepared by Wet Oxidation

The MWCNTs was functionalized by refluxing commercial MWCNTs (a-MWCNTs) in concentrated HNO3/H2SO4 (3:1 v/v) at 100°C for 6 hours. The dispersion of a-MWCNTs and functionalized MWCNTs (f-MWCNTs) were observed after 1 hour sonication in ethanol. Both samples were characterized by UV-vis spectroscopy for dispersion behavior. The dried f-MWCNTs and a-MWCNTs were characterized by Raman spectroscopy to estimate the defect level. The morphology of the samples were analyzed by Transmission Electron Microscopy (TEM). The f-MWCNTs was well dispersed in ethanol within 2 weeks of observations period. The colloidal stability of a-MWCNTs was low as it was easily sediment after 24 hours. The UV-vis spectra of f-MWCNTs show maximum absorbance at 250 nm meanwhile no absorbance was observed for a-MWCNTs. Analysis from Raman spectrum shows that the f-MWCNTs have relative intensity of 1.101 which is higher than a-MWCNTs that have relative intensity of 0.935. The image from TEM revealed that the f-MWCNTs have structural defects and the absence of amorphous carbon on sidewall meanwhile the a-MWCNTs indicate otherwise.

Robust Organometallic Gold Nanoparticles

Robust gold–carbon nanoparticles were synthesized by the sodium borohydride reduction of the diazonium tetrachloroaurate(III) complex [C8F17-4-C6H4N≡N]AuCl4. FT-IR, 1H NMR, thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS) of the ruby red gold nanoparticles indicated the absence of the diazonium nitrogen and the presence of the organic shell C8F17-4-C6H4. Temperature-dependent X-ray powder diffraction (TD-XRD) measurements showed intense cubic gold nanoparticle diffraction patterns in the temperature range 300–500 °C. The effective hydrodynamic size measured by a nanoparticle track analyzer (NTA) in ethanol is 45 nm, and the average core size estimated by transmission electron microscopy (TEM) is 3.2 ± 0.2 nm. The core–shell bonding is strong and is able to withstand prolonged sonication in ethanol and acetonitrile and indefinite exposure to ambient conditions in the solid state.

A New Method for the Removal and Analysis of Small Particles Adhering to Carpet Fiber Surfaces,,

Fibers are a commonly encountered evidence type and fiber comparisons are routinely conducted. When the characteristics of questioned and known fibers correspond, the probative value is limited because the characteristics compared are determined by their manufacture. It would be valuable to test the hypothesis that questioned fibers originated from a specific carpet. One means of testing this is to analyze fine particles on the fibers. A procedure was developed for removing adhering particles from fibers and preparing them for scanning electron microscopy/ energy dispersive X-ray spectrometry (SEM/EDS) analysis. The efficacy of several fluids (acetone, ethanol, hexanes, aqueous ethanol, aqueous sodium hexametaphosphate) and agitation methods (sonication and vortexing) for removing particles from fibers was evaluated. The most effective method evaluated was sonication in ethanol for 10min. The recovered particles were filtered onto a polycarbonate filter and analyzed by automated SEM/EDS analysis to generate data on the particle assemblage. This method makes possible future research to test the within-item and between-item variability of particle assemblages on fibers.

Synthesis of tetrakis(carboxyphenyl)porphyrin coated paramagnetic iron oxide nanoparticles via amino acid for photodegradation of methylene blue

In this paper, synthesis of tetrakis(carboxyphenyl)porphyrin (TCPP) coated cadmium ferrite (CdFe_2O_4) nanoparticles by using L-lysine as an anchor is reported for the first time. The ferrimagnetic CdFe_2O_4 nanoparticles were prepared via the facile self-assembly method of reflux followed by a heating treatment. The obtained magnetic nanoparticles were coated with TCPP in the presence of the amino acid L-lysine by sonication in ethanol and then refluxing for 12 h. The structural characteristics of the products were determined using FT-IR and XRD pattern. Scanning electron microscopy (SEM) images indicated uniform morphologies of the magnetic nanoparticles with an average size of 43 nm. The magnetic properties of the prepared samples were characterized on a vibrant sample magnetometer (VSM) with maximum saturation magnetization values of 65.09 and 46.80 emu/g for nanoparticles and nanoparticle/TCPP. The synthesized products were successfully employed to remove the methylene blue (MB) dye from aqueous solutions by using visible light irradiation. The magnetic CdFe_2O_4 nanoparticles indicated an enhancement of 13% for photodegradation of MB dye after being sensitized by TCPP.

Growth and optical properties of silver nanostructures obtained on connected anodic aluminum oxide templates

Ag nanostructures are grown by AC electrodeposition on anodic alumina oxide (AAO) connected membranes acting as templates. Depending on the thickness of the template and on the voltage applied during the growth process, different Ag nanostructures with different optical properties are obtained. When AAO membranes about 1 μm thick are used, the Ag nanostructures consist in Ag nanorods, at the bottom of the pores, and Ag nanotubes departing from the nanorods and filling the pores almost for the whole length. When AAO membranes about 3 μm thick are used, the nanostructures are Ag spheroids, at the bottom of the pores, and Ag nanowires that do not reach the upper part of the alumina pores. The samples are characterized by angle resolved x-ray photoelectron spectroscopy, scanning electron microscopy and UV–vis and Raman spectroscopies. A simple NaOH etching procedure, followed by sonication in ethanol, allows one to obtain an exposed ordered array of Ag nanorods, suitable for surface-enhanced Raman spectroscopy, while in the other case (3 μm thick AAO membranes) the sample can be used in localized surface plasmon resonance sensing.

A Nanoscale Interface Improves Attachment of Cast Polymers to Glass

A novel interface was prepared on glass slides that stabilizes several cast polymers against delamination under conditions necessary for the study of cell surface interactions. This interface was synthesized by deposition of zirconium tetra(tert-butoxide) from the vapor phase onto the glass followed by mild thermolysis, which gives a surface-bound zirconium oxide coating. This oxide coating improved attachment of polymer coatings cast from formic acid or methylene chloride. Nylon, polyurethane, and polyhydroxybutyrate/polyhydroxyvalerate coatings were stable against delamination from the oxide-coated glass following sonication in ethanol for more than 30 min or immersion in water at pH 8 for at least 48 h.

Niobium pentoxide prepared by soft chemical routes: morphology, structure, defects and quantum size effect

Niobium pentoxide (Nb2O5) is prepared by soft chemical routes (digestion either in ammonia or in hydrazine solutions) and is compared to a commercial sample. According to various characterization methods (XRD, HRTEM, DTA-TG, UV-visible diffuse reflectance, Raman and EPR spectroscopies), Nb2O5 shows particular bulk and surface properties. The phase transformation temperatures (amorphous → pseudo-hexagonal, pseudo-hexagonal → orthorhombic and orthorhombic → monoclinic) for the synthetic Nb2O5 are about 100–150 °C higher than for the commercial sample. The textural properties depend strongly on the preparation method. After calcination at 400 °C, the sample prepared in ammonia has a larger pore volume (0.22 cm3 g−1) and a better resistance to sintering at 600 °C. The preparation in hydrazine gives the following advantages only if the gel is sonically redispersed in ethanol: low particle size, narrow size distribution, and higher resistance to sintering (140 m2 g−1 at 600 °C). Preparation in ammonia or in hydrazine favors the formation of defects, characterized by a significant absorption in the visible range adjacent to the interband transition (3.4 eV, 360 nm). These defects, which disappear upon heating in oxygen, are identified as Nb4+ species and ionized oxygen vacancies as confirmed by EPR measurements. Finally, the nanoparticles obtained by sonication in ethanol (average particle size 4.5 nm) shows a significant band gap increase (from 3.4 eV to 4.2 eV) which is assigned to a quantum size effect.

Amino-terminated self-assembled monolayer on a SiO2 surface formed by chemical vapor deposition

Well-ordered amino-terminated self-assembled monolayers (SAMs) were reproducibly prepared on Si substrates covered with native oxide in a vapor of 12.5 vol % solution of N-(6- aminohexyl)-3-aminopropyltrimethoxysilane (H2N(CH2)6NHCH2CH2CH2Si(OCH3)3,AHAPS) diluted with absolute toluene. Although aggregated AHAPS molecules were excessively adsorbed on the deposited AHAPS-SAM films, they were removed by sonication in ethanol, toluene, NaOH, and HNO3 aqueous solutions, conducted in that order. The thickness of the AHAPS-SAM as estimated by ellipsometry was 1.3±0.1 nm. The AHAPS-SAM surfaces observed by atomic force microscopy appeared very smooth with a root mean square roughness of about 0.15 nm in a several micron square area. This resulted in low hysteresis between the advancing and receding water-contact angles, which were determined to be 62±3° and 57±2°, respectively. Micropatterning of the SAM was also demonstrated on the basis of photolithography using an excimer lamp radiating vacuum ultraviolet light of 172 nm in wavelength. A microstructure composed of 5 μm×25 μm rectangular features was successfully fabricated on an AHAPS-SAM surface.