Comparative electrochemical property of solvent-free ceramic/polymer hybrid electrolytes incorporating sol-gel prepared Li-phosphates, Li(Al,Ge)(PO4)3 and Li(Al,Ti)(PO4)3

2020 ◽  
Vol 843 ◽  
pp. 155878
Author(s):  
Hyemin Park ◽  
Seul ki Choi ◽  
Eun Gyu Lee ◽  
Mihye Wu ◽  
Ha Tran Huu ◽  
...  
Keyword(s):  
Electrochemical Property ◽  
Sol Gel ◽  
Solvent Free ◽  
Polymer Hybrid

scholarly journals Design of a New Gemini Lipoaminoacid with Immobilized Lipases Based on an Eco-Friendly Biosynthetic Process

Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 164
Author(s):  
Patrícia M. Carvalho ◽  
Rita C. Guedes ◽  
Maria R. Bronze ◽  
Célia M. C. Faustino ◽  
Maria H. L. Ribeiro
Keyword(s):  
High Performance ◽  
Transfection Efficiency ◽  
Sol Gel ◽  
Reaction Rates ◽  
Solvent Free ◽  
Bioactive Molecules ◽  
Thermomyces Lanuginosus ◽  
Chemical Production ◽  
Immobilized Lipases ◽  
Free Media

Lipoaminoacids (LAA) are an important group of biosurfactants, formed by a polar hydrophilic part (amino acid) and a hydrophobic tail (lipid). The gemini LAA structures allow the formation of a supramolecular complex with bioactive molecules, like DNA, which provides them with good transfection efficiency. Since lipases are naturally involved in lipid and protein metabolism, they are an alternative to the chemical production of LAA, offering an eco-friendly biosynthetic process option. This work aimed to design the production of novel cystine derived gemini through a bioconversion system using immobilized lipases. Three lipases were used: porcine pancreatic lipase (PPL); lipase from Thermomyces lanuginosus (TLL); and lipase from Rizhomucor miehei (RML). PPL was immobilized in sol-gel lenses. L-cystine dihydrochloride and dodecylamine were used as substrates for the bioreaction. The production of LAA was evaluated by thin layer chromatography (TLC), and colorimetric reaction with eosin. The identification and quantification was carried out by High Performance Liquid Chromatographer-Mass Spectrometry (HPLC-MS/MS). The optimization of media design included co-solvent (methanol, dimethylsulfoxide), biphasic (n-hexane and 2-propanol) or solvent-free media, in order to improve the biocatalytic reaction rates and yields. Moreover, a new medium was tested where dodecylamine was melted and added to the cystine and to the biocatalyst, building a system of mainly undissolved substrates, leading to 5 mg/mL of LAA. Most of the volume turned into foam, which indicated the production of the biosurfactant. For the first time, the gemini derived cystine lipoaminoacid was produced, identified, and quantified in both co-solvent and solvent-free media, with the lipases PPL, RML, and TLL.

scholarly journals The Improvement of Moisture Resistance and Organic Compatibility of SrAl2O4: Eu2+, Dy3+ Persistent Phosphors Coated with Silica–Polymer Hybrid Shell

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 426 ◽  
Author(s):  
Lei Lyu ◽  
Yuxian Chen ◽  
Liting Yu ◽  
Rui Li ◽  
Liu Zhang ◽  
...  
Keyword(s):  
Traffic Safety ◽  
Sol Gel ◽  
Chemical Precipitation ◽  
Road Surface ◽  
Moisture Resistance ◽  
Safety Hazards ◽  
Polymer Shell ◽  
Polymer Hybrid ◽  
Surface Marking ◽  
Luminescent Coatings

The existing road surface marking with poor visibility at night results in traffic safety hazards in insufficient lighting roads. This study aims to prepare the dedicated aluminate-based persistent phosphors considering the integrated pavement environment, as the first step to achieve the durable luminescent road surface marking. SrAl2O4: Eu2+, Dy3+ persistent phosphors coated with silica–polymer hybrid shell were prepared by chemical precipitation and sol-gel method to improve moisture resistance and organic compatibility. The optimum silane coupling agent type and dosage, the surfactant dosage, the optimum sodium silicate dosage, and the coating reaction time in silica shell and polymer shell coating were studied based on the moisture resistance test. The silica–polymer hybrid shell coating balances the organic compatibility and thermal stability as compared to the silica or polymer shell coating in the oil absorption test and thermogravimetric analysis. Ex-Em Spectra, XRD, and SEM method were used to characterize the persistent phosphors, indicating the preparation does not destroy the persistent phosphors. The outstanding durable properties of SrAl2O4: Eu2+, Dy3+ persistent phosphors coated with silica–polymer hybrid shell as shown in this research is crucial for its potential application in waterborne luminescent coatings of road surface marking.

scholarly journals Solvent-Free Process for the Development of Photocatalytic Membranes

Molecules ◽  
2019 ◽  
Vol 24 (24) ◽  
pp. 4481 ◽  
Author(s):  
Rosa M. Huertas ◽  
Maria C. Fraga ◽  
João G. Crespo ◽  
Vanessa J. Pereira
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Sol Gel ◽  
Ceramic Membranes ◽  
High Photocatalytic Activity ◽  
Solvent Free ◽  
Narrow Pore Size Distribution ◽  
Free Process ◽  
Solvent Free Conditions ◽  
Bacteria And Fungi

This work described a new sustainable method for the fabrication of ceramic membranes with high photocatalytic activity, through a simple sol-gel route. The photocatalytic surfaces, prepared at low temperature and under solvent-free conditions, exhibited a narrow pore size distribution and homogeneity without cracks. These surfaces have shown a highly efficient and reproducible behavior for the degradation of methylene blue. Given their characterization results, the microfiltration photocatalytic membranes produced in this study using solvent-free conditions are expected to effectively retain microorganisms, such as bacteria and fungi that could then be inactivated by photocatalysis.

Zirconium oxide nanoparticles coated on sepiolite by sol–gel process — Their application as a solvent-free catalyst for condensation reactions

2011 ◽  
Vol 89 (3) ◽  
pp. 280-288 ◽  
Author(s):  
Sadok Letaief ◽  
Yun Liu ◽  
Christian Detellier
Keyword(s):  
Clay Mineral ◽  
Zirconium Oxide ◽  
Condensation Reaction ◽  
Sol Gel ◽  
Magic Angle Spinning ◽  
Solvent Free ◽  
Cubic Phase ◽  
Magic Angle ◽  
Solvent Free Conditions ◽  
Sol Gel Process

An inorganic nanocomposite made of zirconia nanoparticles coated on the external surfaces of the fibrous clay mineral sepiolite was prepared by using the sol–gel process under soft conditions using zirconium(IV) propoxide in 1-propanol as the precursor. The resulting materials were characterized by X-ray diffraction (XRD), thermal gravimetric analyses (TGA) and differential thermal analyses (DTA), microporosimetry, 29Si magic-angle spinning (MAS) nuclear magnetic resonance (NMR), and high-resolution transmission electron microscopy (HR-TEM). The organic material from the precursor was fully removed after calcination at 450 °C, concurrently with the crystallization of the cubic phase of zirconium oxide. The coordinated water molecules of sepiolite were fully removed and its symmetrical layered structure was folded after calcination at 650 °C, as observed by XRD and 29Si cross-polarization (CP) / MAS NMR. The arrangement of the nanoparticles of zirconium oxide on the sepiolite external surfaces maintains a fibrous morphology for the nanocomposite. This material was applied as a catalyst for the Knoevenagel condensation reaction of benzaldehyde and malononitrile under solvent-free conditions. Strongly improved yields of reaction, attributed to larger catalytically active surfaces, were obtained compared with either the sepiolite clay mineral or the zirconium oxide tested individually.

Synthesis of chalcones catalyzed by aminopropylated silica sol–gel under solvent-free conditions

2011 ◽  
Vol 340 (1-2) ◽  
pp. 24-32 ◽  
Author(s):  
Gustavo Romanelli ◽  
Gustavo Pasquale ◽  
Ángel Sathicq ◽  
Horacio Thomas ◽  
Juan Autino ◽  
...  
Keyword(s):  
Sol Gel ◽  
Silica Sol ◽  
Solvent Free ◽  
Solvent Free Conditions

scholarly journals Synthesis and Characterization of PVA-Assisted Metal Oxide Nanomaterials: Surface Area, Porosity, and Electrochemical Property Improvement

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Buzuayehu Abebe ◽  
H. C. Ananda Murthy ◽  
Enyew Amare Zereffa ◽  
You Qiang
Keyword(s):  
Charge Transfer ◽  
Metal Oxide ◽  
Surface Area ◽  
Electrochemical Property ◽  
Sol Gel ◽  
Volume Ratio ◽  
Poly Vinyl Alcohol ◽  
Tem Analysis ◽  
Transfer Resistance ◽  
Transfer Capability

The poly(vinyl alcohol)-assisted sol-gel-self-propagation route has been used for the synthesis of porous binary metal oxide nanocomposites (BMONCs) and ternary metal oxide nanocomposites (TMONCs). The effects of synthesis techniques, precursor’s type, amount of PVA loading, and precursor’s percentage were studied. The optical, chemical bonding, crystallinity, morphological, textural, and electrochemical properties of the synthesized materials were characterized by UV-vis-DRS/UV-vis, FT-IR, XRD, SEM/EDX and TEM/HRTEM/SAED, BET, and CV/EIS techniques, respectively. The porous nature of the materials was confirmed by SEM, BET, and SAED analytical techniques. Using XRD and TEM analysis, the approximate particle size of the materials was confirmed to be in the nanometer range (~7-70 nm). The EDX and HRTEM analysis was confirming the presence of predictable composition and actuality of the composites, respectively. Moving from bare ZnO to ternary nanocomposites, the great morphological, surface area, and electrochemical property enhancement was confirmed. The charge transfer capability order was obtained to be ZnO/Fe2O3/Mn2O3 > ZnO/Fe2O3 > ZnO/Mn2O3 > ZnO. The respective approximate electron transfer resistance value is 7, 25, 61, and 65 Ω. Therefore, this work can improve the toxicity towards solvent used, surface area to volume ratio, and aggregation/agglomeration problem and also enhance the charge transfer capability due to the heterojunction.

scholarly journals The alkylation of indole with benzaldehyde derivatives catalyzed by 1-(4- sulfobutyl)-3-methylimidazolium hydrogene sulfate ion gel

2019 ◽  
Vol 2 (1) ◽  
pp. 59-64
Author(s):  
Nguyen Thi Xuan Trang ◽  
Tran Hoang Phuong
Keyword(s):  
Ionic Liquid ◽  
Ultrasonic Irradiation ◽  
Sol Gel ◽  
Catalytic Performance ◽  
Solvent Free ◽  
High Yield ◽  
Sulfate Ion ◽  
Gel Method ◽  
Ion Gel ◽  
Benzaldehyde Derivatives

The alkylation of indole with benzaldehyde and derivatives catalyzed by 1-(4- sulfobutyl)-3-methylimidazolium hydrogene sulfate ion gel has been developed. The reaction was taken place under solvent-free ultrasonic irradiation afforded the corresponding product in high yield. Ion gel catalysis was formed by sol-gel method. The recovered ionic liquid gel in each reaction which is quite simply achieved by filtration could be reused up to 5 times without any detectable loss of catalytic performance.

scholarly journals An Ecofriendly Synthesis of 2-oxazolidinone From 2-aminoethanol and Urea Under Solvent-free Condition Using CeO2 Nanoparticles

2021 ◽  
Author(s):  
ALI NEMATI KHARAT ◽  
Mehrnaz Aliahmadi
Keyword(s):  
Gas Adsorption ◽  
Sol Gel ◽  
Solvent Free ◽  
X Ray Diffraction ◽  
Nitrogen Gas ◽  
X Ray ◽  
Solvent Free Condition ◽  
Solvent Free Conditions ◽  
Adsorption Desorption ◽  
Desorption Method

Abstract Cerium dioxide nanoparticles were prepared by the sol-gel method using cellulose as a template and used in the synthesis of 2-oxazolidinone from urea and 2-aminoethanol under solvent-free conditions. All the reaction parameters were optimized to obtain the best selectivity and conversion. The selectivity of 100 % to 2-oxazolidinone with a pretty complete conversion of about 98.4 % was achieved. The prepared catalyst was characterized by Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), and volumetric isothermal nitrogen gas adsorption-desorption method (BET).

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