Subjects -> ENGINEERING (Total: 2677 journals)
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CHEMICAL ENGINEERING (235 journals)            First | 1 2     

Showing 201 - 236 of 236 Journals sorted alphabetically
Nanochemistry Research     Open Access   (Followers: 1)
Natural Volatiles & Essential Oils     Open Access  
Noise Control Engineering Journal     Full-text available via subscription   (Followers: 4)
npj Science of Food     Open Access  
Ochrona Srodowiska i Zasobów Naturalnych : Environmental Protection and Natural Resources     Open Access  
Open Chemical Engineering Journal     Open Access  
Periodica Polytechnica Chemical Engineering     Open Access  
Petroleum Chemistry     Full-text available via subscription   (Followers: 1)
Physics and Chemistry of Glasses - European Journal of Glass Science and Technology Part B     Full-text available via subscription  
Plasma     Open Access   (Followers: 3)
Plasma Processes and Polymers     Hybrid Journal   (Followers: 2)
Polymer     Hybrid Journal   (Followers: 86)
Polymer Bulletin     Hybrid Journal   (Followers: 6)
Polymer Composites     Hybrid Journal   (Followers: 18)
Polyolefins Journal     Open Access  
Powder Technology     Hybrid Journal   (Followers: 13)
Reaction Chemistry & Engineering     Hybrid Journal  
Reactions     Open Access  
Research on Chemical Intermediates     Hybrid Journal   (Followers: 3)
Revista Cubana de Química     Open Access  
Revista ION     Open Access  
Revista Mexicana de Ingeniería Química     Open Access  
Russian Chemical Bulletin     Hybrid Journal   (Followers: 3)
Russian Journal of Applied Chemistry     Hybrid Journal  
Solid Fuel Chemistry     Hybrid Journal  
South African Journal of Chemical Engineering     Open Access   (Followers: 3)
Surface Engineering and Applied Electrochemistry     Hybrid Journal   (Followers: 7)
Sustainable Chemical Processes     Open Access   (Followers: 3)
Synthesis Lectures on Chemical Engineering and Biochemical Engineering     Full-text available via subscription  
The Canadian Journal of Chemical Engineering     Hybrid Journal   (Followers: 5)
The Chemical Record     Hybrid Journal   (Followers: 1)
Theoretical Foundations of Chemical Engineering     Hybrid Journal   (Followers: 3)
Transition Metal Chemistry     Hybrid Journal   (Followers: 6)
Transylvanian Review of Systematical and Ecological Research     Open Access  
Upstream Oil and Gas Technology     Open Access   (Followers: 1)
Visegrad Journal on Bioeconomy and Sustainable Development     Open Access   (Followers: 1)

  First | 1 2     

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Research on Chemical Intermediates
Journal Prestige (SJR): 0.361
Citation Impact (citeScore): 2
Number of Followers: 3  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 0922-6168 - ISSN (Online) 1568-5675
Published by Springer-Verlag Homepage  [2469 journals]
  • Highly silver-selective fluorescent sensor based on functionalized
           nanoporous silica (SBA-Pr-NMP) in aqueous media

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      Abstract: A new chemosensor based on silica entitled SBA-Pr-NMP was prepared by modification of SBA-15 with (3-aminopropyl)triethoxysilane and 3-methyl-1-phenyl-5-oxo-1H-pyrazole-4-carbaldehyde. The functionalized structure was characterized and confirmed via various methods like FT-IR, XRD, EDX, SEM, TGA, and BET. The sensing properties of SBA-Pr-NMP were studied using fluorescence spectroscopy in the presence of various metal ions, and the intensity increased remarkably with Ag+ ion compared to other cations. Also, a good linear relationship was obtained between the fluorescence intensity of SBA-Pr-NMP and the concentration of Ag+ with a calculated detection limit of 2.85 × 10–7 M. Graphical abstract
      PubDate: 2022-09-01
       
  • Occurrence, analysis and removal of pesticides, hormones, pharmaceuticals,
           and other contaminants in soil and water streams for the past two decades:
           a review

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      Abstract: Chemical waste constitutes a group of environmental pollutants including pesticides, heavy metals, hormones, pharmaceuticals, and healthcare products that are widely distributed in our environment due to their wide use in various human activities. The presence of these compounds within local communities and ecosystems has drawn significant interest in improving the detection and bioremediation efforts of these compounds. Since these pollutants are highly mobile and stable under ambient conditions, there is a need to detect such pollutants in water and soil samples as an initial step that helps to eliminate their effect through adsorption or photocatalytic degradation processes. This review aims to highlight the origin of these pollutants and recent advancements in available analytical tools to detect such pollutants in environmental samples with a focus on pesticides, hormones, and pharmaceutical products. The environmental ecosystems of focus in this review involve soil, groundwater, and freshwater ecosystems. Various extraction and other pretreatment processes were also highlighted with a major focus on methods reported to decontaminate and help the environment through photocatalytic degradation of these pollutants under various conditions. Graphical abstract
      PubDate: 2022-09-01
       
  • Activity and durability of intermetallic PdZn electrocatalyst for ethanol
           oxidation reaction

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      Abstract: Abstract Intermetallic or substitutional solid-solution PdZn alloy nanoparticle (NP)-loaded carbon black (i-PdZn/C, s-PdZn/C) was prepared by reducing equimolar palladium acetate and zinc acetate in ethanol dispersion of carbon black with sodium tetrahydroborate with and without the following heat-treatment in an autoclave. The Pd 3d and Zn 2p core-level spectra exhibited that the binding energy of Pd and Zn for i-PdZn/C shifted positively and negatively compared to that for metallic Pd and Zn sheets, respectively, suggesting a strong electronic interaction between Pd and Zn. In contrast, for s-PdZn/C, the binding energy for Pd shifted positively, but only a peak for ZnO was observed. In 1 M KOH aqueous solution at 20 ºC, the Zn content of s-PdZn/C was almost zero in 30 min, while i-PdZn/C held the Zn component of 75% at 20 ºC and 70% at 60 ºC after 30 min, indicating that i-PdZn/C was much more tolerant to alkaline medium than s-PdZn/C. Consequently, s-PdZn NPs were changed to porous Pd NPs, whereas i-PdZn NPs were changed to core–shell NPs whose surface was porous Pd. In the (1 M KOH + 1 M ethanol) aqueous solution at 20 ºC, i-PdZn/C and s-PdZn/C significantly enhanced the activity for ethanol oxidation reaction (EOR) compared to Pd NP-loaded carbon black (Pd/C). In the potentiostatic electrolysis at 0.7 V for 10,000 s, the deterioration of i-PdZn/C was effectively delayed compared to Pd/C and s-PdZn/C due to the electronic effect of the intermetallic PdZn core.
      PubDate: 2022-09-01
       
  • Surface engineering of mesoporous TiO2 nanosheets for boosting lithium
           storage

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      Abstract: The delicate control over materials at the nanoscale needs well command over both structures and surface compositions, thereby imparting enhanced performance. Herein, we developed an effective and scalable way for the construction of 2D mesoporous TiO2 nanosheets by using graphene oxides as sacrifice templates. The combination of 2D morphologies and porous structures, can effectively increase the inaccessible surface areas, shorten the ion diffusion path and facilitating the lithium-ion mobility. Moreover, the surface composition of mesoporous TiO2 nanosheets can be rationally tuned through a facile second annealing method, resulting a stable interface between electrodes and electrolyte. Thus, benefiting from structural design and precise compositional modulation, the obtained mesoporous TiO2 nanosheets exhibit promising performance for lithium storage. Graphical abstract Here, we developed an effective and scalable way for the construction of 2D mesoporous TiO2 nanosheets. In addition, the mesoporous TiO2 nanosheets show an enhanced lithium storage after the removal of carbonates, demonstrating an effective way for surface engineering.
      PubDate: 2022-09-01
       
  • RSM optimization of biodiesel production by a novel composite of
           Fe(ΙΙΙ)-based MOF and phosphomolybdic acid

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      Abstract: The synthesis of MIL-53 samples and encapsulation process of phosphomolybdic acid were implemented using ultrasound at ambient temperature and atmospheric pressure. Analysis of the results showed that H3PMo salts have strong electrostatic interactions with the iron (III) lattice, which plays an important role in reducing leaching from the compound. Characterization of newly synthesized nanocomposite was carried out using various techniques such as XRD, FT-IR, SEM, EDS, BET, ICP and NH3-TPD. The catalytic activity of the prepared nanocomposites, PMA@MIL-53(Fe), was tested through the esterification reaction of oleic acid with methanol under ultrasonic irradiation. Biodiesel production process using certain molar ratio of oleic acid/methanol, PMA@MIL-53(Fe) as catalyst (50–200 mg) containing different amounts of PMA (0–40%), at different reaction times (5–25 min) and ambient temperature under ultrasound conditions was optimized using CCD tab of Design Expert software. The results indicated that the synthesized composites show excellent catalytic activity. Graphical abstract
      PubDate: 2022-09-01
       
  • Novel sulfonated mesoporous organic–inorganic SBA@Pr-3AP-SO3H for the
           synthesis of phenyl-[1,2,4]-triazolidines

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      Abstract: Novel SBA@Pr-3AP-SO3H is designed as a sulfonated mesoporous hybrid organic–inorganic catalyst, which is anchored to the pore walls of SBA-15. SBA@Pr-3AP-SO3H was fabricated through modification of SBA-15 with (3-chloropropyl)triethoxysilane to yield SBA-Pr-Cl, reacted with 2,4,6-triaminopyrimidine (3AP) to provide SBA-Pr-3AP, followed by the reaction with 1,4-,4-butane sultone (SO3H) to obtain SBA@Pr-3AP-SO3H as an efficient catalyst. It was used in the synthesis of various heterocyclic phenyl-[1,2,4]-triazolidines through the reaction of aldehydes, urazole, and dimedone. Graphical abstract
      PubDate: 2022-09-01
       
  • Phosphotungstic acid-supported melamine–terephthalaldehyde covalent
           organic framework as a novel and reusable nanostructured catalyst in
           three-component synthesis of 2H-indazolo[2,1-b]phthalazine-trione
           derivatives

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      Abstract: Abstract In this study, phosphotungstic acid (H3PW12O40)-supported melamine–terephthalaldehyde Covalent Organic Framework (COF-PTA) has been prepared as a novel solid acid catalyst for the synthesis of 2H-indazolo[2,1-b]phthalazine trions under solvent-free conditions. The catalyst was characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM) and Brunauer–Emmett–Teller (BET) surface area analysis. The advantages of using this ecofriendly protocol include: excellent yield in a shorter time period, inexpensive chemicals without any use of solvents, simple experimental and work-up procedure. The catalyst was readily separated and was recycled for several runs with no significant loss of catalytic property.
      PubDate: 2022-09-01
       
  • Metal-free g-C3N4/melem nanorods hybrids for photocatalytic degradation of
           methyl orange

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      Abstract: Abstract In this work, g-C3N4/melem nanorods hybrids were synthesized via a rapid cooling process with H2SO4-assisted treatments of bulk g-C3N4. The results show that post treatment of pristine g-C3N4 using concentrated H2SO4 can produce a hybrid crystal structure containing both melem and g-C3N4. The melem nanorods were formed based on H2SO4 exfoliation, regrowth process and nanoplates roll-up mechanism through a rapid cooling process. The g-C3N4/melem nanorods hybrids exhibited efficient degradation of methyl orange and the efficiency was nearly 100% in 80 min, which presented much better than bulk g-C3N4 (giving a degradation efficiency of 67% in 80 min). The enhanced photocatalytic performance of g-C3N4/melem nanorods hybrids mainly originates from the synergistic effect of g-C3N4 and melem, which the g-C3N4/melem hybrids can improving the efficiency of photogenerated charge separation of g-C3N4. This study contributes towards an effective strategy for optimizing the crystalline structure and nanostructure of g-C3N4/melem hybrids to enhanced g-C3N4 photodegradation activity.
      PubDate: 2022-09-01
       
  • Palladium@silica-coated magnetic nanoparticles as efficient and recyclable
           catalysts for ligand-free Suzuki–Miyaura coupling reaction under mild
           conditions

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      Abstract: Abstract Many efforts have been done to develop new catalysts for organic reactions. In this study, preparation and characterization of palladium immobilized on modified magnetic Fe3O4 nanocatalyst (Fe3O4@SiO2@DPA-Pd) have been reported; dipicolylamine (DPA) groups are used as linkers to fix palladium nanoparticles on silica-coated Fe3O4 nanoparticles without agglomeration. The structure of the nanocatalyst was investigated using scanning electron microscopy, X-ray powder diffraction, Fourier-transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, Brunauer–Emmett–Teller (BET) and thermogravimetry analysis. The data showed that the nanoparticles have spherical morphology with an average size of about 40 nm and 49.16 m2/g BET surface area. The inductively coupled plasma analysis confirmed that the Pd2+ had been successfully loaded on the Fe3O4@SiO2@DPA support with a high amount of 1.03 mmol g−1. The synthesized nanocatalyst was considered for synthesis of biaryls by the Suzuki–Miyaura coupling reaction in water/ethanol as the solvent system and in the absence of toxic phosphine ligand. The reaction conditions were mild, and coupling reaction yields were excellent (68–95%). The synthesis is compatible with the environment. The nanocatalyst can be easily recycled from the reaction mixture using an external magnet and was used at least five times without significant loss of catalytic activity.
      PubDate: 2022-09-01
       
  • Implanted mixed ligand Ni complex of phenolic Schiff base and 2, 2’
           bipyridine on MCM-41 as an efficient catalyst for Suzuki–Miyaura
           cross-coupling reactions: a greener approach

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      Abstract: Abstract A new mixed ligand Ni complex of phenolic Schiff base and 2,2’ bipyridine was implanted on MCM-41 to prepare a simple and reusable catalyst. The designed heterogeneous catalyst has been characterized by FT-IR, PXRD analysis, N2 adsorption and desorption, SEM–EDX, TEM, ICP-OES and TGA. The synthesized Ni-MCM-41 is utilized as a potential catalyst against the Suzuki cross-coupling reaction of a wide range of aryl/alkyl/allyl halides with aryl boronic acid in DMF: water/water under microwave irradiation with the yield up to 95 / 86% of the catalytic product. Moreover, short reaction time, easy workup, eco-friendly, low cost and reusability of catalyst up to four times without a noteworthy loss of its activity are some of the merits of this method. The hot filtration test has been ratified that there was no leaching of metal during the catalytic reaction, indicating the heterogeneous manner of the catalyst.
      PubDate: 2022-09-01
       
  • Adsorption of hexavalent chromium from aqueous solution by polyamidoamine
           dendrimer polycondensate

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      Abstract: Abstract Cr(VI) is a toxic heavy metal ion, which can cause serious hazards to human health. The present study explored that polyamidoamine (PAMAM) dendrimer polycondensate was a potential promising adsorbent for removal of Cr(VI) from aqueous solution. The surface morphology of PAMAM dendrimer polycondensate was characterized by SEM. The adsorption capacity of Cr(VI) onto PAMAM dendrimer polycondensate was found to be dependent on Cr(VI) initial concentration, pH value of aqueous solution, adsorbent dosage, adsorption time, and adsorption temperature. In addition, the adsorption equilibrium could be described by Langmuir isotherm, Freundlich isotherm, and Temkin isotherm. The kinetic of the adsorption process is fitted with pseudo-second-order model and intraparticle diffusion model. The thermodynamic study showed that a negative value of ΔGθ indicated that the adsorption process was spontaneous in nature, while positive value of ΔHθ indicate that the adsorption is endothermic and higher temperature makes the adsorption easier, and positive value of ΔSθ reflected good affinity of Cr(VI) toward PAMAM dendrimer polycondensate.
      PubDate: 2022-09-01
       
  • Formulation and therapeutic efficacy of PEG-liposomes of sorafenib for the
           production of NL-PEG-SOR FUM and NL-PEG-SOR TOS

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      Abstract: Liver cancer is characterized by abnormal cell growth in liver tissue and is one of the most common causes of cancer mortality. The synthesis of medicinal salts is of special importance in order to improve the dissolution of the drug in water and the optimal bioavailability of the drug. One of these common medicinal salts that are used in most medicinal compounds is fumarate salt. In this project, liposomes were used to deliver sorafenib-tosylate and sorafenib-fumarate due to their special and unique properties. In this study, NL-PEG-SOR FUM and NL-PEG-SOR TOS were synthesized using reverse phase evaporation method with dimensions of 80 and 90 nm and zeta potential of − 1.7 and − 1.5 mV, respectively. The results of FESEM and TEM of both nanoparticles showed that the nanoparticles have a smooth, uniform and integrated pattern and the vesicles are round. The NL-PEG-SOR FUM and NL-PEG-SOR TOS capsule efficiencies were 99.085 and 99.000%, respectively. After 24 h, the release rate of sorafenib-fumarate and sorafenib-tosylate from the drug carrier was 5.24 and 5.35%, respectively, which is much less than the release rate of the free form of sorafenib. The results of MTT test on liver cancer cell line showed that at the highest concentration of 0.25 g/ml, the survival rate of cancer cells in the presence of NL-PEG-SOR FUM and NL-PEG-SOR TOS was 43 and 45%, respectively. IC50 NL-PEG-SOR FUM and NL-PEG-SOR TOS were 35 and 33%, respectively. Graphical abstract
      PubDate: 2022-09-01
       
  • Three coordination polymers of manganese(II), cadmium(II) with a flexible
           ligand of cis, cis, cis-1,2,3,4-cyclopentanetetracarboxylic acid: crystal
           structures, thermal decomposition mechanisms and magnetic properties

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      Abstract: The synthesized condition by means of controlling pH values of the reaction mixtures has been explored. Three Mn2+, Cd2+ ion coordination polymers with the fully deprotonated cis, cis, cis-1,2,3,4-cyclopentanetetracarboxylic acid (H4L) ligand were synthesized and characterized, sometimes incorporating different auxiliary ligand: {[Mn(H2O)6][Mn3(L)2(H2O)2]}·3H2O (1), [Cd2L(H2O)4] (2) and [Cd2Lphen)2(H2O)2]·3H2O (3) (phen = 1,10-phenanthroline). With an initial of pH values of 6.0, 4.0 and 9.0 of the reaction mixtures, we get the compounds 1, 2 and 3, respectively. In crystal of 1, two crystallographic different Mn2+ ions (Mn1 and Mn2) form a negatively charged coordination polymeric chain, which contains a centrosymmetrically linear trinuclear Mn2+ cluster (Mn3L2) subunit; another crystallographically independent Mn2+ ions (Mn3) coordinated by six water molecules act as counter ions to link the neighboring coordination polymeric chains via intermolecular H-bond interactions. The Mn2+ ions in 1 were completely replaced by Cd2+ ions to give 2 and 3, respectively. Complex 2 shows 3D distributions of Cd2+ ions while Complex 3 displays 2D networks contributed by intermolecular H-bond interactions. Three complexes exhibit distinct thermal decomposition mechanisms, and the deprotonated cis, cis, cis-1,2,3,4-cyclopentan-etetracarboxylic acid ligands decompose in 420–700 °C to give the residue MnO + C in 1 and CdO in 2 and in 3. Complex 1 shows a complicated magnetic behavior of coexistence of antiferromagnetic exchange interactions between neighboring Mn2+ ions. Graphical abstract
      PubDate: 2022-09-01
       
  • Effects of partial substitution of Cu by Mn and Co in LaCu0.5Ni0.5O3
           catalyst synthesized by mechanochemical method in the total oxidation of
           methane

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      Abstract: Abstract This study pertains to the effects of Cu substitution by Mn and Co on the textural properties and catalytic activity of the LaCu0.5-xMnxNi0.5O3 (x= 0, 0.1, 0.3) and LaCu0.4Co0.1Ni0.5O3 catalysts for methane catalytic combustion. The perovskite catalysts were prepared by a solvent-free mechanochemical synthesis method. The catalytic results showed that adding Mn into the structure of LaCu0.5Ni0.5O3 improved the catalytic activity and thermal stability and also increased the specific surface area, whereas the addition of Co=0.1 led to a slight decrease in catalytic performance and specific surface area. The H2-TPR results illustrated that the substitution of Mn improved the reducibility feature of the catalysts. Among all the samples, LaCu0.2Mn0.3Ni0.5O3 catalyst exhibited the highest catalytic activity. The combustion of methane is a type of interfacial reaction, and considering the Mars–Van Krevelen mechanism, the increase in the catalytic activity can be related to the increment of lattice oxygen mobility and oxygen vacancy. Moreover, the decrease in calcination temperature of the LaCu0.2Mn0.3Ni0.5O3 improved the catalytic activity due to the increase in the BET area and the concentration of oxygen vacancy.
      PubDate: 2022-09-01
       
  • Controlled delivery of tetracycline with TiO2@Chitosan@ZIF-8 nanocomposite
           and evaluation of their antimicrobial activities

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      Abstract: In recent years, metal–organic frameworks (MOFs) have attracted the attention of scientists. The applications of these frameworks are gas storage and separation, electrochemical energy storage, drug delivery, catalyst, etc. In this research, a nanocarrier named TiO2@Chitosan@ZIF-8 was synthesized to deliver the antibiotic tetracycline (TC). Furthermore, the antimicrobial effect of TiO2@Chitosan@ZIF-8@TC was tested against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) bacteria with the best results. The structure of the nanocarrier, as well as the nanocarrier/drug, was validated by the X-ray crystallography (XRD), Fourier-transform infrared spectroscopy (FT-IR), Breuer–Emmett–Teller (BET), field emission scanning electron microscope (FE-SEM), Transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), and energy-dispersive X-ray spectroscopy (EDX/Mapping). This research indicated that 90% of the TC was encapsulated in the synthesized framework. Also, drug release was performed at pH: 5 and pH: 7.4, which revealed that 73% and 67% of TC were released in three days. It is considerable that this is the first report of the synthesizing and using a novel nanocarrier including TiO2@Chitosan@ZIF-8 with various advantages such as high surface area, high porosity, high loading percentage, and high stability. Graphical abstract
      PubDate: 2022-09-01
       
  • Epoxidation of vinyl cyanides by lithium hypochlorite in the presence of
           Fe3O4@Ag-CTAB as a new eco-friendly catalyst in aqueous medium

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      Abstract: To cater to the requirement of environmental protection, cetyltrimethylammonium bromide (CTAB)-coated Fe3O4@Ag Nanoparticles as a new hybrid magnetic catalyst was prepared for the one-pot multicomponent epoxidation of a wide range of alkenes by lithium hypochlorite (LiOCl) in aqueous medium. FT-IR, TEM, XRD, EDS and VSM techniques were employed to characterize the structure of the magnetic catalyst. The results obtained revealed that the CTAB modification effectively decreased the particle size and enhanced the dispersion of the particles in solution. Application of this catalyst was studied efficiently in one-pot multicomponent synthesis of epoxide derivatives. The structure of the synthesized epoxides was confirmed by FT-IR, 1H-NMR, 13C-NMR and elemental analysis. The main advantages of our work are reusability of the catalyst, easy work-up, Short reaction times and use of water as a green solvent. Graphical abstract
      PubDate: 2022-08-13
       
  • Efficient removal of Hg2+ by L-cysteine and polypyrrole-functionalized
           magnetic kaolin: condition optimization, model fitting and mechanism

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      Abstract: To enhance the adsorption capacity and improve agglomeration properties of kaolin during the adsorption process of Hg2+ from aqueous solution, kaolin was bi-functionally modified using L-cysteine and polypyrrole. The as-synthetized adsorbent of L-Ppy-Fe3O4/kaolin was characterized before and after modification. The removal conditions were optimized by response surface methodology, and the optimized results show that the optimal adsorption capacity of Hg2+ reaches 482.71 mg/g at pH of 7.9, temperature of 315 K, initial concentration of 40 mg/L and dosage of 0.05 g/L. And the effects of adsorption conditions on Hg2+ removal follow the order of solution pH > temperature > initial concentration > dosage. The adsorption process of Hg2+ in aqueous solution can be well described by pseudo-second-order kinetic model and Langmuir isothermal model. Moreover, the thermodynamic fitting indicates that the adsorption of Hg2+ is an endothermic and spontaneous process. The adsorption mechanism of Hg2+ onto L-Ppy-Fe3O4/kaolin is mainly the complexation between divalent Hg2+ and sulfhydryl/amino groups to form stable metal complexes, and electrostatic attraction is also a part of the reaction mechanism. In addition, L-Ppy-Fe3O4/kaolin is proved to have satisfactory dispersion ability and chemical stability and can be easily separated and recovered after adsorption in aqueous solution. Therefore, L-Ppy-Fe3O4/kaolin is a promising adsorbent for the efficient removal of mercury ions. Graphical abstract
      PubDate: 2022-08-12
       
  • Insight to an efficient and magnetic α-Fe2O3/γ-Fe2O3/Cu2O hybrid
           catalysis for peroxymonosulfate: preparation, performance, and mechanism

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      Abstract: Abstract The development of catalysts with high catalytic activity and convenient recycling property is the long-term goal of sulfate-based advanced oxidation processes for the degradation of organic pollutants. In this work, a kind of iron/copper oxide hybrid catalyst (α-Fe2O3/γ-Fe2O3/Cu2O, CuFe-13) with both higher catalytic performance and paramagnetism was synthesized using a modified method for conventional CuFeO2. Through X-ray diffraction and infrared spectra characterization, the catalyst was verified a hybrid of α-Fe2O3, γ-Fe2O3 and Cu2O, in which the exist of magnetic γ-Fe2O3 was the main cause for CuFe-13’s paramagnetism and convenient magnetic recycling property. The mechanism for CuFe-13’s excellent catalytic performance was primarily investigated. Through scanning electron microscope, X-ray photoelectron spectroscopy, N2 adsorption–desorption measurement, radical quenching experiments, and electron paramagnetic resonance characterization analysis, the CuFe-13 represented larger surface area, bigger porosity, more efficient synergistic effect among Cu, Fe, and O than CuFeO2. The generation of various of reactive oxygen species (ROS), including sulfate radical ( \({\text{SO}}_{4}^{\cdot - }\) ), hydroxyl radical (·OH), and singlet oxygen (1O2), especially 1O2 were more, which might lead to CuFe-13’s higher catalytic performance. The effects of PMS concentration, CuFe-13 dosage, initial pH, initial OG concentration were analyzed. The optimal removal efficiency of OG could be achieved 100% within 20 min with 1 mM PMS and 0.2 g L−1 CuFe-13 under neutral condition. This study provided an efficient PMS-activated catalyst for degradation of organic pollution.
      PubDate: 2022-08-10
       
  • Catalytic influence of mesoporous SBA-16 supported manganese molybdate on
           liquid phase selective oxidation of salicyl alcohol

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      Abstract: Selective oxidation of alcohol to the corresponding aldehyde plays a pivotal role in organic synthesis. In the present study, 3D cubic cage-like mesoporous SBA-16 was synthesized by a one-pot hydrothermal route. Then SBA-16 supported MnMoO4 catalysts, designated as MnMoO4 (1, 3, and 5wt.%)/SBA-16, were prepared by the wet impregnation method. The catalysts were thoroughly characterized by various analytical techniques to verify phase purity, mesoporous structure, morphology, and oxidation state of the catalytic active sites. Further, catalytic activity was performed for the liquid phase oxidation of salicyl alcohol and its family members to obtain the respective aldehydes between 50 and 90 °C. MnMoO4 (3 wt.%)/SBA-16 showed higher catalytic activity than other catalysts by giving 88% salicyl alcohol conversion with 81% salicylaldehyde selectivity. The recovered catalyst retained activity for five cycles, thus proving MnMoO4 (3 wt.%)/SBA-16 is a better choice for commercial production of salicylaldehyde. Graphical abstract
      PubDate: 2022-08-10
       
  • Optical, thermal and temperature dependent electrical properties of
           chlorinated natural rubber/copper alumina nanocomposites for flexible
           electrochemical devices

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      Abstract: Abstract The present investigation focuses on the optical, thermal, temperature-dependent alternating current (AC) and activation energy of chlorinated natural rubber (Cl-NR)/ copper alumina (Cu-Al2O3) nanocomposite systems. Temperature-dependent dielectric properties like dielectric permittivity, modulus and complex impedance were analyzed in the frequency region of 102 to 106 Hz. The effect of Cu-Al2O3 on the DC conductivities was correlated with various theoretical approaches like Scarisbrick, McCullough and Buche model. The surface behaviour of chlorinated NR with Cu-Al2O3 composites was analysed by contact angle measurements. The composite with 5 phr Cu-Al2O3 incorporated Cl-NR showed the least bandgap energy and maximum absorbance in the UV spectra. The TGA shows the thermal decomposition temperature of the rubber nanocomposite with an increase in the concentration of nanoparticles. The non-perfect linear plots obtained from AC conductivity showed the non-ohmic type of conduction in composite systems. The semiconducting nature was illustrated by the semi-circular Cole–Cole plot observed for Cl-NR/ Cu-Al2O3 composites. The lowest dielectric modulus was observed for the composite with 5 phr sample indicated the electron hopping conduction. Theoretical conductivity obtained from McCullough model was found to be best to explain the experimental DC conductivity. According to the results of this study, the Cl-NR/ Cu-Al2O3 nanocomposites can be a paramount alternative in the fabrication of important flexible dielectric materials like actuators, sensors, electromagnetic interference shielding and super-capacitors.
      PubDate: 2022-08-03
       
 
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