Journal articles: 'Heating; Chemical syntheses'

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Whittaker, A. G., and D. M. P. Mingos. "The Application of Microwave Heating to Chemical Syntheses." Journal of Microwave Power and Electromagnetic Energy 29, no. 4 (January 1994): 195–219. http://dx.doi.org/10.1080/08327823.1994.11688249.

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Auwal, Ismail Alhassan, Fitri Khoerunnisa, Florent Dubray, Svetlana Mintova, Tau Chuan Ling, Ka-Lun Wong, and Eng-Poh Ng. "Effects of Synthesis Parameters on the Crystallization Profile and Morphological Properties of SAPO-5 Templated by 1-Benzyl-2,3-Dimethylimidazolium Hydroxide." Crystals 11, no. 3 (March 12, 2021): 279. http://dx.doi.org/10.3390/cryst11030279.

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The formation of SAPO-5 molecular sieves is studied under hydrothermal conditions in the presence of a new templating agent, 1-benzyl-2,3-dimethylimidazolium hydroxide ([bzmIm]OH). The syntheses were carried out by varying the synthesis parameters, viz. crystallization temperature, heating time and reactants molar composition (SiO2, Al2O3, P2O5, [bzmIm]+, H2O) in order to investigate the role of each synthesis parameter on the formation of SAPO-5. The results showed that these synthesis parameters had significant influences on the entire crystallization process (induction, nucleation, crystal growth, and Ostwald ripening) and physicochemical properties of SAPO-5 (morphology and crystal size). Moreover, this study also demonstrated a fast hydrothermal synthesis approach where a SAPO-5 molecular sieve with hexagonal prism morphology could be crystallized within 10 h instead of days using a novel [bzmIm]OH heterocyclic template, thus offering an alternative route for synthesizing zeolite-like materials for advanced applications.

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Chen, Chu Yang, Xu Chuan Jiang, Shi Xian Xiong, and Ai Bing Yu. "Shape-Controlled Syntheses of Silver Nanoparticles: Role of the Seeds." Materials Science Forum 654-656 (June 2010): 2402–5. http://dx.doi.org/10.4028/www.scientific.net/msf.654-656.2402.

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Precious metallic nanoparticles have attracted considerable attention because of their unique properties (optical, electronic, and chemical properties) and potential applications in many areas such as optical probes, biochemical sensors, and surface enhanced Raman Spectrum. Despite many successes in synthesis of anisotropic nanoparticles (rods, plates), some limitations still exist in generating monodispersed silver nanoparticles. This study intends to elucidate the influence of crystalline seeds on the shape, size, and size distribution of nanoparticles through a seed-mediated method. The crystalline seeds can be modified by using different ways, such as heating treatment and oxidative etching. The shape and size of the generated particles will be characterized by TEM, and the particle formation and growth is tracked by UV-vis spectrometry. The findings would be useful for the shape-controlled synthesis of metal nanoparticles for desired functional properties.

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Rodríguez-Padrón, Daily, Alina M. Balu, Antonio A. Romero, and Rafael Luque. "New bio-nanocomposites based on iron oxides and polysaccharides applied to oxidation and alkylation reactions." Beilstein Journal of Organic Chemistry 13 (September 21, 2017): 1982–93. http://dx.doi.org/10.3762/bjoc.13.194.

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Polysaccharides from natural sources and iron precursors were applied to develop new bio-nanocomposites by mechanochemical milling processes. The proposed methodology was demonstrated to be advantageous in comparison with other protocols for the synthesis of iron oxide based nanostructures. Additionally, mechanochemistry has enormous potential from an environmental point-of-view since it is able to reduce solvent issues in chemical syntheses. The catalytic activity of the obtained nanocatalysts was investigated in both the oxidation of benzyl alcohol to benzaldehyde and in the alkylation of toluene with benzyl chloride. The microwave-assisted oxidation of benzyl alcohol reached 45% conversion after 10 min. The conversion of the alkylation of toluene in both microwave-assisted and conventional heating methods was higher than 99% after 3 min and 30 min, respectively. The transformation of benzyl alcohol and toluene into valuable product in both the oxidation and alkylation reaction reveals a potential method for the valorization of lignocellulosic biomass.

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Keglevich, György, Nóra Zs Kiss, and Zoltán Mucsi. "Milestones in microwave-assisted organophosphorus chemistry." Pure and Applied Chemistry 88, no. 10-11 (November 1, 2016): 931–39. http://dx.doi.org/10.1515/pac-2016-0604.

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AbstractOur recent results in the field of microwave (MW)-assisted organophosphorus syntheses, especially regarding esterifications, condensations, substitutions and additions are surveyed. Beside making organic chemical reactions more efficient, it was possible to perform transformations that are reluctant on conventional heating. Another option is to substitute catalysts, or to simplify catalyst systems under MW conditions. It is also the purpose of this paper to elucidate the scope and limitations of the MW tool, to interpret the MW effects, and to model the distribution of the local overheatings and their beneficial effect. All these considerations are possible on the basis of the enthalpy of activations determined by us utilizing the Arrhenius equation and the pseudo first order kinetic equation.

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Ivanovich, Zvegintsev Valery, Nalivaichenko Denis Gennadievich, and Chirkashenko Vladimir Fedorovich. "Investigation of the Pulsed Annular Gas Jet for Chemical Reactor Cleaning." International Journal of Chemical Engineering 2012 (2012): 1–9. http://dx.doi.org/10.1155/2012/517465.

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The most economical technology for production of titanium dioxide pigment is plasma-chemical syntheses with the heating of the oxygen. The highlight of the given reaction is formation of a solid phase as a result of interactions between two gases, thus brings the formation of particle deposits on the reactor walls, and to disturbing the normal operation of the technological process. For the solving of the task of reactor internal walls cleaning the pulsed gaseous system was suggested and investigated, which throws circular oxygen jet along surfaces through regular intervals. Study of aerodynamic efficiency of the impulse system was carried by numerical modeling and experimentally with the help of a specially created experimental facility. The distribution of the pulsed flow velocity at the exit of cylindrical reactor was measured. The experimental results have shown that used impulse device creates a pulsed jet with high value of the specified flow rate. It allows to get high velocities that are sufficient for the particle deposits destruction and their removal away. Designed pulsed peelings system has shown high efficiency and reliability in functioning that allows us to recommend it for wide spreading in chemical industry.

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Andraos, John. "Aiming for a standardized protocol for preparing a process green synthesis report and for ranking multiple synthesis plans to a common target product." Green Processing and Synthesis 8, no. 1 (January 28, 2019): 787–801. http://dx.doi.org/10.1515/gps-2019-0048.

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Abstract This paper proposes a standardized format for the preparation of process green synthesis reports that can be applied to chemical syntheses of active pharmaceutical ingredients (APIs) of importance to the pharmaceutical industry. Such a report is comprised of the following eight sections: a synthesis scheme, a synthesis tree, radial pentagons and step E-factor breakdowns for each reaction step, a tabular summary of key material efficiency step and overall metrics for a synthesis plan, a mass process block diagram, an energy consumption audit based on heating and cooling reaction and auxiliary solvents, a summary of environmental and safety-hazard impacts based on organic solvent consumption using the Rowan solvent greenness index, and a cycle time process schedule. Illustrative examples of process green synthesis reports are given for the following pharmaceuticals: 5-HT2B and 5-HT7 receptors antagonist (Astellas Pharma), brivanib (Bristol-Myers Squibb), and orexin receptor agonist (Merck). Methods of ranking synthesis plans to a common target product are also discussed using 6 industrial synthesis plans of apixaban (Bristol-Myers Squibb) as a working example. The Borda count method is suggested as a facile and reliable computational method for ranking multiple synthesis plans to a common target product using the following 4 attributes obtained from a process green synthesis report: process mass intensity, mass of sacrificial reagents used per kg of product, input enthalpic energy for solvents, and Rowan solvent greenness index for organic solvents.

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Popova, Larisa Mikhaylovna, Varvara Alekseyevna Ivanova, and Sergey Vyacheslavovich Vershilov. "SYNTHESES OF POLYFLUOROALKYL ESTERS OF MALEOPIMARIC ACID N-PHENYLIMIDE." chemistry of plant raw material, no. 2 (January 12, 2019): 205–11. http://dx.doi.org/10.14258/jcprm.2019023999.

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To meet the challenge of complex processing of plant material, in particular, tall oil rosin, research has been conducted on the synthesis of new polyfluroalkyl maleimides. As is well known, maleopimaric acid’s imides constitute a forward-looking class of organic compounds for pharmacology, agriculture, polymer chemistry and so on. The introduction of a fluorocarbon unit often gives high surface activity, chemical and heat resistance, hydrophobic and oleophobic properties. This paper presents the results of experiments on the synthesis of new N-phenylimides of maleopimaric acid’s polyfluoroalkyl esters by the interaction of the corresponding monosubstituted polyfluorinated maleopimarates with aniline during boiling for 10–16 h in toluene (40–52%). The starting N-phenylimide of maleopimaric acid has been obtained by two methods: by the Diels-Alder reaction from abietic acid and N-phenyl maleimide using sulfuric acid as a catalyst in the melt (40%) and by heating (MPA) with aniline in toluene (80%). 2,2,3,3,4,4,5,5-octafluoroamyl and 2,2,3,3,4,4,5,5,6,6,7,7,7- dodecaftaforpetyl ethers have been obtained by esterification of MPA with fluorinated alcohols under conditions of acid catalysis (70%). It have been identified the ester bonds are quite stable by TLC during long-term treatment of the stock (over 11 hours). The synthesized substances were analyzed with UV-, IR-, 1H NMR and 19F.

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Charvot, Jaroslav, Daniel Pokorný, Milan Klikar, Veronika Jelínková, and Filip Bureš. "Towards Volatile Organoselenium Compounds with Cost-Effective Synthesis." Molecules 25, no. 21 (November 9, 2020): 5212. http://dx.doi.org/10.3390/molecules25215212.

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The current portfolio of organoselenium compounds applicable as volatile precursors for atomic layer deposition can be denoted as very limited. Hence, we report herein facile and cost-effective preparation of two bis(trialkylstannyl)selenides as well as one selenole and three bis(trialkylsilyl)selenides. Their syntheses have been optimized to: (i) use readily available and inexpensive starting materials, (ii) involve operationally simple methodology (heating in a pressure vessel), (iii) use a minimum amount of additives and catalysts, and (iv) either exclude additional purification or involve only simple distillation. The chemical structure of prepared Se derivatives was confirmed by multinuclear NMR and GC/MS. Their fundamental thermal properties were investigated by differential scanning calorimetry (DSC) and TGA methods that revealed thermal stability within the range of 160–300 °C.

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Dudina, Dina V., and Amiya K. Mukherjee. "Reactive Spark Plasma Sintering: Successes and Challenges of Nanomaterial Synthesis." Journal of Nanomaterials 2013 (2013): 1–12. http://dx.doi.org/10.1155/2013/625218.

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Spark plasma sintering (SPS), initially developed as an advanced sintering technique for consolidating nanopowders into nanostructured bulk materials, has been recently looked at in much broader perspective and gained a strong reputation of a versatile method of solid state processing of metals, ceramics, and composites. The powders in the SPS-dies experience the action of pulsed electric current and uniaxial pressure; they are heated at very high rates unachievable in furnace heating and sintered within shorter times and at lower temperatures than in conventional methods. The principle of SPS and convenient design of the facilities make it attractive for conducting solid state synthesis. In this paper, based on our own results and the literature data, we analyze the microstructure formation of the products of chemical reactions occurring in the SPS in an attempt to formulate the requirements to the microstructure parameters of reactant mixtures and SPS conditions that should be fulfilled in order to produce a nanostructured material. We present successful syntheses of nanostructured ceramics and metal matrix composite with nanosized reinforcements in terms of microstructure stability and attractive properties of the materials and discuss the challenges of making a dense nanostructured material when reaction and densification do not coincide during the SPS. In the final part of the paper, we provide an outlook on the further uses of reactive SPS in the synthesis of nanostructured materials.

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Samfaß, Julia, Timo D. Stark, and Thomas F. Hofmann. "Sensory-Directed Identification of Creaminess-Enhancing Semi-Volatile Lactones in Crumb Chocolate." Foods 10, no. 7 (June 25, 2021): 1483. http://dx.doi.org/10.3390/foods10071483.

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In order to gain a more comprehensive knowledge of the chemical nature of creaminess-related flavor compounds in milk chocolates on a molecular level, crumb chocolate was analyzed by means of activity guided screening techniques. Sensory studies of a triglyceride-free lipid emulsion indicated that the n-pentane extract showed the highest impact regarding creaminess sensation. Enhancement of creaminess by adding anhydrous milk fat fractions to chocolate was demonstrated by fractionated high-vacuum distillation of different fats associated with the chocolate production combined with sensory experiments. Syntheses of various δ-lactones and the quantification of these sensory active semi-volatiles led to the conclusion that the anhydrous milk fat contains a series of γ- and δ-lactones. Cocoa butter revealed a high concentration of δ-hexadecalactone, too. Experiments suggested that lactones are generated from the potential precursors monohydroxyalkanoic acid(s) esterified (mono-tri)glyceride(s) during heating. Sensory studies exhibited recognition thresholds of 29–40 µmol/kg for the long-chain δ-lactones in crumb chocolate. Furthermore, significant enhancement of the retro-nasal creamy flavor was found for δ-tetradecalactone.

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Dołżyńska, Magdalena, Sławomir Obidziński, Jolanta Piekut, and Güray Yildiz. "The Utilization of Plum Stones for Pellet Production and Investigation of Post-Combustion Flue Gas Emissions." Energies 13, no. 19 (October 1, 2020): 5107. http://dx.doi.org/10.3390/en13195107.

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Agri-food waste is generated at various food cycle stages and is considered to be a valuable feedstock in energy systems and chemical syntheses. This research identifies the potential and suitability of a representative agri-food waste sample (i.e., plum stones) as a solid fuel. Ground plum stones containing 10, 15, and 20 wt.% of rye bran were subjected to pelletization. The pelletizer was operated at 170, 220, and 270 rpm, and its power demand for the mixture containing 20 wt.% of rye bran was 1.81, 1.89, and 2.21 kW, respectively. Such pellets had the highest quality in terms of their density (814.6 kg·m−3), kinetic durability (87.8%), lower heating value (20.04 MJ·kg−1), and elemental composition (C: 54.1 wt.%; H: 6.4 wt.%; N: 0.73 wt.%; S: 0.103 wt.%; Cl: 0.002 wt.%; O: 38.2 wt.%). Whole plum stones and pellets were subjected to combustion in a 25 kW retort grate boiler in order to determine the changes in the concentrations of NO, SO2, CO, CO2, HCl, and O2 in the post-combustion flue gas. Collected results indicate that plum stone–rye bran pellets can serve as effective substitutes for wood pellets in prosumer installations, meeting the Ecodesign Directive requirements for CO and NO.

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Timar, Maria Cristina, Kevin Maher, Mark Irle, and Maria Daniela Mihai. "Preparation of Wood with Thermoplastic Properties, Part 2. Simplified Technologies." Holzforschung 54, no. 1 (January 28, 2000): 77–82. http://dx.doi.org/10.1515/hf.2000.012.

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Summary Aspen wood (Populus tremula) as sawdust was chemically modified through a two-step procedure: esterification with maleic anhydride and subsequent oligoesterification with glycidyl methacrylate and maleic anhydride. Simplified techniques consisting of impregnation by immersion followed by thermal treatment using conventional or microwave heating were employed. Chemical analyses and infra-red spectroscopy showed some differences in the chemical composition and structure of the resulting oligoesterified wood depending on the synthesis technique. However, the thermoplastic properties, clearly revealed by thermomechanical analysis, were quite similar and comparable to those exhibited by the oligoesterified wood resulting via classical synthesis. Moreover, similar degrees of chemical modification were obtained for a significantly shorter duration of the process when microwave heating was employed instead of conventional heating.

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Hassan, Hani Mutlak A., Steve Harakeh, Kaltoom A. Sakkaf, and Iuliana Denetiu. "Progress in Microwave-Aided Chemical Synthesis." Australian Journal of Chemistry 65, no. 12 (2012): 1647. http://dx.doi.org/10.1071/ch12366.

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The continuing use of microwave (µwave) energy in chemical synthesis has been impressive over the past decade, with many reports incorporating µwave-based reactions. Two of the major benefits of using µwave heating are the remarkable decrease in reaction times and often high yield of products in comparison with classical heating, an ideal technology for synthetic chemists. Herein, we highlight some exciting examples of its recent utility in organic, medicinal, and natural product synthetic endeavours.

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Kunal, Pranaw, and Todd J. Toops. "A Review of Microwave-Assisted Synthesis-Based Approaches to Reduce Pd-Content in Catalysts." Catalysts 10, no. 9 (September 1, 2020): 991. http://dx.doi.org/10.3390/catal10090991.

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This review article focuses on the latest advances in the synthesis of inorganic nano-catalysts using microwave heating, which has progressed significantly since its initial implementation in the mid-1980s. Over the years, nanoparticles (NPs), which inherently offer better surface accessibility for heterogeneous catalysis, have been synthesized using a wide array of heating methods. Microwave heating is one such method and employs a unique heating mechanism that can have several benefits for catalysis. When compared to conventional form of heating which relies on inter-layer mixing via convection, microwave heating operates through the chemical polarity in the target chemicals leading to an “inside-out” mode of heating. This heating mechanism is more targeted and therefore results in rapid synthesis of catalytically active NPs. Platinum group metals (PGM) have classically been the focus of nano-catalysis; however, recent efforts have also applied non-PGM group metals with the goals of lower costs, and ideally, improved catalytic reactivity and durability. This is especially of interest with respect to Pd because of its current historically high cost. Investigations into these new materials have primarily focused on new/improved synthetic methods and catalytic compositions, but it is important to note that these approaches must also be economic and scalable to attain practical relevance. With this overarching goal in mind, this review summarizes notable recent findings with a focus on Pd-dilution and microwave heating in a chronological fashion.

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Sorokova, Svetlana N. "Mathematical Modeling of the Solid Phase Sintering of Ti and Cu Powders in the Controlled Heating Conditions." Advanced Materials Research 1040 (September 2014): 500–503. http://dx.doi.org/10.4028/www.scientific.net/amr.1040.500.

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Two-dimensional model of sintering Ti and Cu powders substrate under controlled heating, taking into account the kinetic and thermal phenomena are proposed and studied. The base is ceramic. The system of chemical reactions is written according to the phase diagram of Ti-Cu. The model takes into account that the chemical reactions are slowed layer product. The problem is solved numerically. The temperature distribution and concentration of elements or compounds at different times for different synthesis conditions are determined. It is shown that at any process organization the synthesized material becomes chemically heterogeneous.

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Yang, Yu, Yu Cheng Wang, Zheng Yi Fu, Wei Min Wang, Hao Wang, and Jin Yong Zhang. "Preparation of Fine Mullite Powder in a SHS Chemical Furnace System." Advanced Materials Research 66 (April 2009): 115–18. http://dx.doi.org/10.4028/www.scientific.net/amr.66.115.

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Within a very short heating period, fine mullite powder with practicle size below 1µm was obtained in a novel synthesis system, a self-propagating high-temperature synthesis (SHS) chemical furnace, from which the tremendous heating derived. The combustion reactants consisting of Ni, Al and TiC were chosen as a chemical furnace in this system to supply the heat, calcining temperature was increased at a heating rate of 1350K/min in the heating process, till the maximum temperature (1350°C). The rapid mullitization process was performed within 1 min, microstructure analysis indicated that small mullite grains (<50nm) were crystallized, fine mullite particles (<1µm) with narrow particle size distribution, favorable activity for sintering were derived. And significant grain growth was observed in mullite powder, when the combustion reactants consisting of Ni, Al and <30 mol.% TiC.

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Jiang, Hong Zhou, Qiang Hao, Jian Zhou, and Juan Juan Li. "Microwave Synthesis of Dicalcium Silicate: — Comparison with Conventional Synthesis." Advanced Materials Research 306-307 (August 2011): 1060–65. http://dx.doi.org/10.4028/www.scientific.net/amr.306-307.1060.

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Dicalcium silicate, whose chemical formula is Ca2SiO4= 2CaO·SiO2, is a typical cementitious mineral phase, especially in Portland cement clinker. In the past, to study this mineral, it was common to use some conventional heating methods, e.g. flame heating, radiation heating etc. Whereas, in our study, the microwave (or MW in brief) heating method is used to synthesize this mineral, because MW heating method has several advantages in fabricating materials. In order to seek the characteristics of MW heating method in synthesizing this mineral, a conventional synthesizing method (i. e. electric radiation heating) is also used in our parallel experiments, so as to compare the results between experimental samples with both methods. All related samples are measured with XRD (X-ray diffraction) and SEM (scanning electron microscopy), then their results are discussed.

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Gyergyek, Sašo, Darja Lisjak, Miloš Beković, Miha Grilc, Blaž Likozar, Marijan Nečemer, and Darko Makovec. "Magnetic Heating of Nanoparticles Applied in the Synthesis of a Magnetically Recyclable Hydrogenation Nanocatalyst." Nanomaterials 10, no. 6 (June 10, 2020): 1142. http://dx.doi.org/10.3390/nano10061142.

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Utilization of magnetic nanoparticle-mediated conversion of electromagnetic energy into heat is gaining attention in catalysis as a source of heat needed for a substrate’s chemical reaction (electrification of chemical conversions). We demonstrate that rapid and selective heating of magnetic nanoparticles opens a way to the rapid synthesis of a nanocatalyst. Magnetic heating caused rapid reduction of Ru3+ cations in the vicinity of the support material and enabled preparation of a Ru nanoparticle-bearing nanocatalyst. Comparative synthesis conducted under conventional heating revealed significantly faster Ru3+ reduction under magnetic heating. The faster kinetic was ascribed to the higher surface temperature of the support material caused by rapid magnetic heating. The nanocatalyst was rigorously tested in the hydrotreatment of furfural. The activity, selectivity and stability for furfural hydrogenation to furfuryl alcohol, a valuable biobased monomer, remained high even after four magnetic recycles.

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Kadja, Grandprix T. M., Rino R. Mukti, I. Nyoman Marsih, and Ismunandar. "A Comparative Study of the Synthesis of MFI Zeolite by Using High- and Low-Temperature Heating." Advanced Materials Research 1112 (July 2015): 201–4. http://dx.doi.org/10.4028/www.scientific.net/amr.1112.201.

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Zeolites are among the main catalysts in the petroleoum and fine-chemical industry. The well-defined channel framework with the acid sites have empowered this kind of material to catalyze many chemical reactions, such as alkylation, isomerization, and hydrocarbon cracking. Controlling the energy consumption towards efficient process in the synthesis of zeolite has been a great interest. In this light, we succesfully show that synthesis of MFI zeolite can be tailored by using high or low temperature heating. Synthesis via high-temperature heating (HTH) at 150 °C, resulted in conventional coffin-type morphology whereas low-temperature heating (LTH) at 90 °C, resulted in a spherical-type morphology. This phenomenon indicates that energy consumption for synthesizing MFI zeolite can be decreased. Moreover, the tetrapropylammonion ion (TPA+) amount as structure-directing agents (SDA) can be lowered, hence reducing the synthesis cost. The obtained samples were charaterized by advanced techniques to compare interesting properties between samples synthesized by HTH and LTH. This concerns on the resulting morphology, textural properties, and Si/Al framework ratio.

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Baxendale, Ian R., Christian Hornung, Steven V. Ley, Juan de Mata Muñoz Molina, and Anders Wikström. "Flow Microwave Technology and Microreactors in Synthesis." Australian Journal of Chemistry 66, no. 2 (2013): 131. http://dx.doi.org/10.1071/ch12365.

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A bespoke microwave reactor with a glass containment cell has been developed for performing continuous flow reactions under microwave heating. The prototype unit has been evaluated using a series of standard organic chemical transformations enabling scale-up of these chemical processes. As part of the development, a carbon-doped PTFE reactor insert was utilized to allow the heating of poorly absorbing reaction media, increasing the range of solvents and scope of reactions that can be performed in the device.

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Gupta, Subodh. "Technology Focus: EOR Modeling (January 2021)." Journal of Petroleum Technology 73, no. 01 (January 1, 2021): 43. http://dx.doi.org/10.2118/0121-0043-jpt.

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The enhanced-oil-recovery (EOR) literature produced in the past several months was dominated by reservoir modeling and characterization; flood enhancements; machine learning; and, more notably, relative permeability estimation. This last one needs to be under-stood further. Relative permeability characterizes flow in porous media, the understanding and manipulating of which is key to the success of EOR. Our fascination with the topic during the last 75 years, therefore, is understandable. Starting with a seminal paper from W.R. Purcell in 1949, we have more than 12,000 articles in the SPE collection alone on relative permeability estimation, of which more than 400 were published in the last year. Mechanics of motion is also important to mankind, but we do not have literature piling up on Newton’s laws of motion. Is it that we haven’t understood flow in porous media yet, or is it because the subject matter is so complex? The truth, perhaps, lies somewhere in between. Flow in pores that are randomly sized, randomly connected, and have variable chemical makeup is, by nature, complex and mathematically unmanageable. Relative permeability has been our attempt to lend its aggregate behavior some sense of manageability. This has always been done in a fit-for-purpose manner. What is fit for one context, however, may not be so for the others, and this uncertainty continues to churn out theses, antitheses, and syntheses. Expectedly, even more such activity arises with every improvement in computing capabilities, as is once again evident with advances in machine learning—new tools to handle old problems. That is where my first pick is for you, with some additional suggested readings in references that follow. Data analytics does much more than estimate relative permeability, and the second paper abridged here uses it to predict a flood performance. To allow a break from data science, the third paper chosen deals with the important topic of electromagnetics as applied to reservoir characterization and heating. I hope you find these to be useful and interesting reads.

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Chehadi, Zeinab, Cédric Boissière, Corinne Chanéac, and Marco Faustini. "Nanoconfined water vapour as a probe to evaluate plasmonic heating." Nanoscale 12, no. 25 (2020): 13368–76. http://dx.doi.org/10.1039/d0nr01678k.

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MICHAEL, D., P. MINGOS, and A. G. WHITTAKER. "ChemInform Abstract: Microwave Dielectric Heating Effects in Chemical Synthesis." ChemInform 28, no. 27 (August 3, 2010): no. http://dx.doi.org/10.1002/chin.199727315.

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Gomes, Josileido, Alysson Israel Oliveira Rocha, Romualdo Rodrigues Menezes, Gelmires Araújo Neves, Maria Isabel Brasileiro, and Lisiane Navarro de Lima Santana. "Obtaining of Mullite by Rapid Sintering from Bentonite Clay." Materials Science Forum 660-661 (October 2010): 936–42. http://dx.doi.org/10.4028/www.scientific.net/msf.660-661.936.

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Bentonite clays are aluminium–silicates that when heated turn into mullite. The sintering of mullite obtained from these mineral clays by quick microwaves heating comes up as an alternative process for mullite powders synthesis. The use of quick heating on ceramics nano-powders synthesis is a recent technology that is being successfully used on synthesis with microwaves and synthesis process by combustion. The quick microwaves heating enable adding heat quickly and equally, accelerating the nucleation kinetics and the development of the mullite stage. Thus, the purpose of this work is to analyze the effect of the microwaves heating process variables, analyzing the influence of the applied power and of the heating rate on the mullite powders obtaining from bentonite clays. The clays have been favored and submitted to the following characterizations: chemical granulometric and mineralogically. Subsequently, the clays have been delamined aiming disagglomeration and separation of the thinner fractions and submitted to granulometric and mineralogical characterization. The synthesis has been realized on a domestic microwaves oven. The obtained powders have been characterized by X-ray diffraction. The results showed that the applied power variation and the sintering time are fundamental on the obtaining of mullite powders.

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Gönenli, I. Erkin, and A. Cüneyt Tas. "Chemical preparation of aluminum borate whiskers." Powder Diffraction 15, no. 2 (June 2000): 104–7. http://dx.doi.org/10.1017/s0885715600010927.

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Aluminum borate (9Al2O3·2B2O3) whiskers were chemically synthesized in potassium sulphate flux by using the starting chemicals of aluminum sulphate and boric acid. The synthesis temperature of 1075 °C was found to be the optimum with respect to whisker morphology. A tentative X-ray diffraction (XRD) pattern was suggested for the whiskers produced after heating at 1150 °C. The product purity, phase composition, and whisker morphology were investigated by XRD, energy dispersive X-ray spectroscopy, and scanning electron microscopy, respectively.

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Cundy, Colin S. "Microwave Techniques in the Synthesis and Modification of Zeolite Catalysts. A Review." Collection of Czechoslovak Chemical Communications 63, no. 11 (1998): 1699–723. http://dx.doi.org/10.1135/cccc19981699.

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Microwave dielectric heating is a convenient and effective way of bringing about chemical reactions in suitable (usually polar) media. Microwave-mediated organic synthesis has been the subject of considerable research and microwave heating is being increasingly applied to the synthesis and modification of zeolites and related microporous and mesoporous catalysts. The observed rate enhancements are caused by a variety of thermal effects, including very high rates of temperature rise, bulk superheating and (in non-homogeneous systems) differential heating. Specific, non-thermal activation is unlikely and can usually be excluded. The microwave synthesis of zeolites, zeotypes and mesoporous materials is reviewed, with emphasis on those aspects which differ from conventional thermal methods. Such standard methods are not displaced by microwave techniques and may in some instances be preferable. However, microwave synthesis does offer a high probability of rapid (and in some cases selective) reaction to give a pure product of good crystal quality. Non-synthetic applications of microwave heating in zeolite catalysis are also briefly described. A review with 118 references.

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Sriwong, Chaval, Kittisak Choojun, and Samart Kongtaweelert. "Investigation of the Influences of Reaction Temperature and Time on the Chemical Reduction of Graphene Oxide by Conventional Method Using Vitamin C as a Reducing Agent." Materials Science Forum 909 (November 2017): 225–30. http://dx.doi.org/10.4028/www.scientific.net/msf.909.225.

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The aim of this work is to investigate the synthesis of reduced graphene oxide (rGO) aqueous suspension by a conventional heating method using vitamin C as a reducing agent. The influences of reaction temperatures (70, 90 and 100 °C) and heating times (30, 45 and 60 min) on the chemical reduction of graphene oxide (GO) were studied. Then, the obtained rGO samples were characterized by FT-IR, Raman and UV-Vis spectroscopy. The FT-IR and Raman results showed that the reduction degree of GO to rGO was increased with the rising of the reaction temperature and time. Moreover, the UV-Vis spectra demonstrated that the absorption band at around 230 nm (π-π*) of pristine GO had shift to the longer wavelength upon the chemical reduction, indicating that GO is reduced to rGO. The optimal condition of the chemical reduction of GO to achievable rGO was the temperature of 90 °C with the 45 min of heating time. This condition yielded the rGO black aqueous suspension with the high quality and stability. Thus, this method of synthesis has an advantage of the rGO dispersion which led to many potential applications.

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Zhang, Ming-Jian, Yandong Duan, Chong Yin, Maofan Li, Hui Zhong, Eric Dooryhee, Kang Xu, Feng Pan, Feng Wang, and Jianming Bai. "Ultrafast solid-liquid intercalation enabled by targeted microwave energy delivery." Science Advances 6, no. 51 (December 2020): eabd9472. http://dx.doi.org/10.1126/sciadv.abd9472.

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In chemical reactions, the breaking and formation of chemical bonds usually need external energy to overcome the activation barriers. Conventional energy delivery transfers energy from heating sources via various media, hence losing efficiency and inducing side reactions. In contrast, microwave (MW) heating is known to be highly energy efficient through dipole interaction with polar media, but how exactly it transmits energy to initiate chemical reactions has been unknown. Here, we report a rigorous determination of energy delivery mechanisms underlying MW-enabled rapid hydrothermal synthesis, by monitoring the structure and temperature of all the involved components as solid-liquid intercalation reaction occurs using in situ synchrotron techniques. We reveal a hitherto unknown direct energy transmission between MW irradiation source and the targeted reactants, leading to greatly reduced energy waste, and so the ultrafast kinetics at low temperature. These findings open up new horizons for designing material synthesis reactions of high efficiency and precision.

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Desbrières, Jacques, Charlotte Petit, and Stéphanie Reynaud. "Microwave-assisted modifications of polysaccharides." Pure and Applied Chemistry 86, no. 11 (November 1, 2014): 1695–706. http://dx.doi.org/10.1515/pac-2014-0711.

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Abstract Polysaccharides are a natural and renewable feed stock for synthesizing high performance macromolecular materials. However, their structure does not allow reaching all properties required for specific applications and chemical modifications are necessary to reach such objectives. Despite the use of natural polymers, the chemistry and processes employed are not environment-friendly due to the nature of chemicals, solvents or because the conventional chemical process are energy-consuming. On the other hand, microwave assisted processes were developed in organic chemistry since the 1980s and more recently for polymer chemistry (polymer formation and modification). Within the chemistry of natural polymers, the use of microwave irradiation has been exploited in the past two decades to alleviate limitations in the synthesis of graft modified polysaccharide materials. Microwave heating is described as more homogeneous, selective and efficient as compared to conventional heating resulting in faster reactions with fewer or no side products as example. Different results reported within the recent literature will be discussed considering the role of microwave irradiation and its consequence on the reaction parameters and properties of final materials. Grafting of polysaccharides, specific modification of polysaccharides or fibers particularly for preparing smart textiles or medical products as well as reactions of polysaccharides to valuable bio-platform molecule will be discussed.

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Hamzah, Dzikri, Taufik Rinaldi, Marwan Marwan, and Wahyu Rinaldi. "Synthesis of Triacetin Catalyzed by Activated Natural Zeolite Under Microwave Irradiation." Jurnal Bahan Alam Terbarukan 8, no. 1 (July 24, 2019): 01–07. http://dx.doi.org/10.15294/jbat.v8i1.14028.

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Esterification of glycerol with acetic acid under microwave irradiation in the presence of activated natural zeolite was investigated. Natural zeolite was collected from Ujung Pancu (Aceh Besar) and chemically activated with hydrochloric acid. The reaction was carried out in a stirred glass flask reactor placed inside microwave oven. Experimental variables include microwave transmission time, molar ratio of glycerol to acetic acid, and catalyst loading. XRD profile of activated zeolite showed an increase of Si/Al ratio to 6.042 and the crystallinity decreased slightly by 12.23%, mainly due to dealumination during chemical treatment. Qualitative analysis by FTIR shows that the reaction product obtained by microwave heating contains ester group (triacetin) at wavelength 1706.669 cm-1, while the quantitative analysis by acidi-alkalimetry titration indicates the highest glycerol conversion of 93.033% at the reaction condition of the molar ratio of 1:9, catalyst loading of 3%, and microwave transmission of 10 minutes. The present work suggests that microwave can be utilized as efficient heating technique in esterification of glycerol to triacetin.

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Henini, Ghania, Fatiha Souahi, and Ykhlef Laidani. "Development of a Simulation Model for Controlling and Improving the Productivity of Batch Reactors." Polish Journal of Chemical Technology 15, no. 1 (March 1, 2013): 78–87. http://dx.doi.org/10.2478/pjct-2013-0014.

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This paper describes the development of a dynamic simulator model for a jacketed batch reactor equipped with a mono-fluid heating/cooling system. The Mono-fluid flows at constant flow-rate through the jacketed reactor. The heating and cooling are assured respectively by electrical resistance and two plate heat exchangers. A detailed description of the equations leading to the development of simulation model is presented. The model is based on writing the equations of the mass balance and the heat balance for the reactor and the thermal loop in unsteady state. To validate the simulation model, we first studied the thermal behavior of the reaction mixture during heating and cooling, using water as the reaction mixture. We then considered the consecutive chemical reaction of the synthesis of cyclopentanediol from cyclopentadiene by studying the yield of this reaction. The results show that heating the reaction mixture increases significantly the yield of this synthesis reaction.

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Mishra, A. D. "Microwave-Induced Synthesis of Some Novel Fungicidal Pyrazole Derivatives." Journal of Nepal Chemical Society 30 (December 19, 2013): 138–42. http://dx.doi.org/10.3126/jncs.v30i0.9385.

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A series of novel pyrazole derivatives have been synthesized from propanoyl hydrazine and aromatic aldehydes under microwave irradiations. The reaction leads to condensation in ethanolic solution to give corresponding hydrazones which undergo subsequent cyclisation to furnish pyrazole derivatives in presence of formic acid. The reaction rate is enhanced considerably by using microwaves with excellent yield as compared to conventional heating method. The reactions took 4-7 minutes for completion with 78-92% yield. All the synthesized pyrazole derivatives showed promising antifungal activities against Aspergillus niger and Aspergillus Flavus. Microwave-induced organic synthesis has been proved quite beneficial and eco-friendly method in terms of limited use of chemicals, short reaction time and good yield with higher degree of purity.DOI: http://dx.doi.org/10.3126/jncs.v30i0.9385Journal of Nepal Chemical Society Vol. 30, 2012 Page: 138-142 Uploaded date: 12/20/2013

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Minic, Dragica. "Synthesis, characterization and stability of amorphous alloys." Science of Sintering 38, no. 1 (2006): 83–92. http://dx.doi.org/10.2298/sos0601083m.

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In this paper the results of chemical and electrochemical synthesis of Fe-P, Fe-W and Fe-Ni amorphous powders, investigations of their structural characteristics, stability and processes of their relaxation and stabilization during heating in the temperature range of 20-1000oC are presented. .

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Botez, Cristian E., Masoud Mollaee, Andres J. Encerrado Manriquez, and Michael P. Eastman. "Monoclinic RbD2PO4: Room temperature synthesis, chemical and structural stability upon heating." Materials Chemistry and Physics 143, no. 2 (January 2014): 605–10. http://dx.doi.org/10.1016/j.matchemphys.2013.09.039.

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Sosnowchik, Brian D., Liwei Lin, and Ongi Englander. "Localized heating induced chemical vapor deposition for one-dimensional nanostructure synthesis." Journal of Applied Physics 107, no. 5 (March 2010): 051101. http://dx.doi.org/10.1063/1.3304835.

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Hortigüela, María J., Denise Machado, Igor Bdikin, Victor Neto, and Gonzalo Otero-Irurueta. "Chemical Changes of Graphene Oxide Thin Films Induced by Thermal Treatment under Vacuum Conditions." Coatings 10, no. 2 (January 29, 2020): 113. http://dx.doi.org/10.3390/coatings10020113.

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Reduction of graphene oxide is one of the most promising strategies for obtaining bulk quantities of graphene-like materials. In this study, graphene oxide was deposited on SiO2 and reduced by annealing at 500 K under vacuum conditions (5 × 10−1 Pa). Here, graphene oxide films as well as their chemical changes upon heating were characterized in depth by X-ray photoelectron spectroscopy, Raman spectroscopy, and scanning electron and atomic force microscopies. From the chemical point of view, the as prepared graphene oxide films presented a large quantity of oxidized functional groups that were reduced to a large extent upon heating. Moreover, residual oxidized sulfur species that originated during the synthesis of graphene oxide (GO) were almost completely removed by heating while nitrogen traces were integrated into the carbon framework. On the other hand, regarding structural considerations, reduced graphene oxide films showed more homogeneity and lower roughness than graphene oxide films.

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Chen, Jui Ho, Wen Tsai Sung, and Hsi Chun Wang. "MOF Synthesis Heating Process Control System Research." Applied Mechanics and Materials 418 (September 2013): 112–15. http://dx.doi.org/10.4028/www.scientific.net/amm.418.112.

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In the chemical engineering territory, the important parameters regarding reaction are fundamentally temperature, pressure, and concentration, among which the setting and monitoring of reaction temperature are crucial to complete the reaction efficiently, safely, and quickly. MOF Synthesis, due to the different heating pattern or unstable heating, usually affects the rate of nucleation and crystallization, causing the difference of crystalline. For the temperature sensing module made in this system, to ensure the reliability, this project implements the monitoring with wireless ZigBee chip and wire DAQ data acquisition card. The terminal interface sends the control package to infrared emission module through RS-232, and the signals are sent to infrared receiving module through infrared emission module to implement the automatic control of heating oven. The practical results are: (1) complete the temperature sensing module made by J type thermal couple, (2) ZigBee wireless and DAQ Data Acquisition Card wire transmission technology, (3) completing the development of infrared receiving and emitting control module, (4) the interface designed for this system covers the functions, such as monitoring, controlling, and recording, (5) Remote monitoring and control implemented with internet, (6) MOF synthesis heating experience.

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Motshekga, Sarah C., Sreejarani K. Pillai, Suprakas Sinha Ray, Kalala Jalama, and Rui W. M. Krause. "Recent Trends in the Microwave-Assisted Synthesis of Metal Oxide Nanoparticles Supported on Carbon Nanotubes and Their Applications." Journal of Nanomaterials 2012 (2012): 1–15. http://dx.doi.org/10.1155/2012/691503.

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The study of coating carbon nanotubes with metal/oxides nanoparticles is now becoming a promising and challenging area of research. To optimize the use of carbon nanotubes in various applications, it is necessary to attach functional groups or other nanostructures to their surface. The combination of the distinctive properties of carbon nanotubes and metal/oxides is expected to be applied in field emission displays, nanoelectronic devices, novel catalysts, and polymer or ceramic reinforcement. The synthesis of these composites is still largely based on conventional techniques, such as wet impregnation followed by chemical reduction of the metal nanoparticle precursors. These techniques based on thermal heating can be time consuming and often lack control of particle size and morphology. Hence, there is interest in microwave technology recently, where using microwaves represents an alternative way of power input into chemical reactions through dielectric heating. This paper covers the synthesis and applications of carbon-nanotube-coated metal/oxides nanoparticles prepared by a microwave-assisted method. The reviewed studies show that the microwave-assisted synthesis of the composites allows processes to be completed within a shorter reaction time with uniform and well-dispersed nanoparticle formation.

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Alni, Anita, and Alyssa Pratiwi Putri. "Microwave Assisted Amidation of 5-Aminoisophtalic Acid Dimethyl Ester Catalyzed by Imidazolium Ionic Liquids." Key Engineering Materials 874 (January 2021): 75–80. http://dx.doi.org/10.4028/www.scientific.net/kem.874.75.

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Amide functionalities present in living system as peptides and possess various biological role. Many synthetic amides also possess biological activities due to the possibility of interaction with cellular liquids such as those compounds useful as a contrast agent in radiographic method. Synthesis of amides from the carboxylic acid or derivatives normally require heating and catalyst. In this report, an environmentally benign synthesis of amide was carried out utilizing microwave radiation and catalyzed by imidazolium ionic liquids (BMIMCl). Microwave radiation provided efficient heating through activation of chemical bonds instead of conventional conductivity methods hence increasing the rate of reactions. Ionic liquids were suitable material in this synthesis due to non-volatile nature as well as stability under high temperature and microwave heating. Furthermore, ionic liquids are tunable material that can be designed for the specific synthesis and functioned as a catalyst. The optimum condition for coupling of 5-Amino-isophthalic acid dimethyl ester with an amino diol was found at 80 °C, 90 minutes, under radiation of microwave at the power of 300 Watt. The product was obtained at 38.46% yield. Furthermore, the methodology was applied to synthesis radiographic material and was successful to obtain product with 48.78% yield. The products were characterized by NMR spectroscopy.

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Wang, Jigang, Ji Zhou, Wenhua Zhou, Jilong Shi, Lun Ma, Wei Chen, Yongsheng Wang, Dawei He, Ming Fu, and Yongna Zhang. "Synthesis, Photoluminescence and Bio-Targeting Applications of Blue Graphene Quantum Dots." Journal of Nanoscience and Nanotechnology 16, no. 4 (April 1, 2016): 3457–67. http://dx.doi.org/10.1166/jnn.2016.11817.

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Chemical derived graphene oxide, an atomically thin sheet of graphite with two-dimensional construction, offers interesting physical, electronic, thermal, chemical, and mechanical properties that are currently being explored for advanced physics electronics, membranes, and composites. Herein, we study graphene quantum dots (GQD) with the blue photoluminescence under various parameters. The GQD samples were prepared at different temperatures, and the blue photoluminescence intensity of the solution improved radically as the heating temperatures increased. Concerning PL peak and intensity of the quantum dots, the results demonstrated dependence on time under heating, temperature of heating, and pH adjusted by the addition of sodium hydroxide. After hydrothermal synthesis routes, the functional groups of graphene oxide were altered the morphology showed the stacking configuration, and self-assembled structure of the graphene sheets with obvious wrinkles appeared at the edge structures. In addition, absorption, PL, and PLE spectra of the graphene quantum dots increase with different quantities of sodium hydroxide added. Finally, using GQD to target PNTIA cells was carried out successfully. High uptake efficiency and no cytotoxic effects indicate graphene quantum dots can be suitable for bio-targeting.

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42

Huang, Xin, Daiki Mitsuyama, Shinji Kudo, and Jun-ichiro Hayashi. "Fast Synthesis of Hydroxymethylfurfural from Levoglucosenone by Mixing with Sulphuric Acid and Heating in a Microtube Reactor." MATEC Web of Conferences 333 (2021): 05005. http://dx.doi.org/10.1051/matecconf/202133305005.

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Hydroxymethylfurfural (HMF) is a promising platform chemical in future bio-based chemical industry for synthesis of a variety of furan derivatives. Studies on the HMF synthesis have focused mainly on saccharides as the feedstock. Recently, levoglucosenone (LGO), anhydrosugar available from cellulose pyrolysis, has been identified as an alternative feedstock, which can be converted to HMF under milder conditions only with acid and water as catalyst and solvent, respectively. To further explore the potential of this reaction, in this study, we demonstrated the HMF synthesis below 100°C within a few minutes at high yields. The employment of microtube reactor and high concentration sulfuric acid as catalyst was effective, leading to the highest HMF yield of 61.5%-C with the reaction selectivity over 80%. Kinetic analysis revealed that rapid heating after mixing LGO with the catalytic aqueous solution was essential to supress side reaction that generates degradation products from LGO. The reaction with glucose or fructose as feedstock under same conditions resulted in poor HMF yield.

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43

Huang, Xin, Daiki Mitsuyama, Shinji Kudo, and Jun-ichiro Hayashi. "Fast Synthesis of Hydroxymethylfurfural from Levoglucosenone by Mixing with Sulphuric Acid and Heating in a Microtube Reactor." MATEC Web of Conferences 333 (2021): 05005. http://dx.doi.org/10.1051/matecconf/202133305005.

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Hydroxymethylfurfural (HMF) is a promising platform chemical in future bio-based chemical industry for synthesis of a variety of furan derivatives. Studies on the HMF synthesis have focused mainly on saccharides as the feedstock. Recently, levoglucosenone (LGO), anhydrosugar available from cellulose pyrolysis, has been identified as an alternative feedstock, which can be converted to HMF under milder conditions only with acid and water as catalyst and solvent, respectively. To further explore the potential of this reaction, in this study, we demonstrated the HMF synthesis below 100°C within a few minutes at high yields. The employment of microtube reactor and high concentration sulfuric acid as catalyst was effective, leading to the highest HMF yield of 61.5%-C with the reaction selectivity over 80%. Kinetic analysis revealed that rapid heating after mixing LGO with the catalytic aqueous solution was essential to supress side reaction that generates degradation products from LGO. The reaction with glucose or fructose as feedstock under same conditions resulted in poor HMF yield.

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Aruna-Devi, R., M. Latha, S. Velumani, J. Santos-Cruz, Banavoth Murali, J. Á. Chávez-Carvayar, F. A. Pulgarín-Agudelo, and O. Vigil-Galán. "Cu2ZnSn(S,Se)4 thin-films prepared from selenized nanocrystals ink." RSC Advances 9, no. 32 (2019): 18420–28. http://dx.doi.org/10.1039/c9ra02669j.

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Silva, Vera L. M., Raquel G. Soengas, and Artur M. S. Silva. "Ionic Liquids and Ohmic Heating in Combination for Pd-Catalyzed Cross-Coupling Reactions: Sustainable Synthesis of Flavonoids." Molecules 25, no. 7 (March 29, 2020): 1564. http://dx.doi.org/10.3390/molecules25071564.

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In order to meet the increasing demand for environmentally benign chemical processes, we developed a Suzuki–Miyaura reaction protocol based on the combination of ohmic heating (ΩH) and supported ionic liquid phase catalysis (SILPC) in aqueous media. This methodology was applied to the synthesis of a series of flavonoid derivatives, including isoflavones, styrylisoflavones, and diarylalkenylisoflavones.

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Sun, Weian, Wen Liu, and Junqin Li. "Effects of chloride ions on hydrothermal synthesis of tetragonal BaTiO3 by microwave heating and conventional heating." Powder Technology 166, no. 2 (August 2006): 55–59. http://dx.doi.org/10.1016/j.powtec.2006.05.007.

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47

Ha, Jong Keun, and Kwon Koo Cho. "Preparation of Amorphous Silicon Oxide Nanowires by the Thermal Heating of Ni or Au-Coated Si Substrates." Applied Mechanics and Materials 110-116 (October 2011): 1087–93. http://dx.doi.org/10.4028/www.scientific.net/amm.110-116.1087.

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Silicon oxide (SiOx) nanowires may have many applications due to their electrical, mechanical and optical properties. Many methods have been reported for the synthesis of SiOx nanowires, including laser ablation, sol–gel, thermal evaporation, carbothermal reduction, physical evaporation, rapid thermal annealing, chemical vapor deposition and thermal oxidation route, oxide assisted growth and thermal sublimation. In this paper, we reported SiOx nanowires fabricated by simple thermal heating process of catalyst thin film-coated Si substrates with various parameters, such as synthesis temperature, synthesis gases, catalysts, and buffer layer (SiO2layer). Synthesized silicon oxide nanowires were amorphous crystalline. The best synthesis condition of prepared SiOx nanowire is slightly varied with catalysts and buffer layer. The flow rate of synthesis gas affected diameter of silicon oxide nanowires.

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48

Galaguz, Vadym, Eduard Panov, and Sergiy Malovanyi. "SYNTHESIS OF LiFePO4 NANOCRYSTALS IN THE ION-LIQUID MEDIUM USING MICROWAVE HEATING." Ukrainian Chemistry Journal 85, no. 10 (October 16, 2019): 78–82. http://dx.doi.org/10.33609/0041-6045.85.10.2019.78-82.

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The liquid-phase method of synthesis of lithium iron(II) phosphate (LiFePO4) in the medium of choline chloride and diethylene glycol under the action of microwave heating is proposed. With a power of microwave radiation of 920 and 1150 W, a nanocrystalline LiFePO4 without impurities was obtained. Obtained samples of microwave processes contain amorphous phase and require long annealing resulting in nanocrystalline LiFePO4/C composites with small impurities Li3PO4, Li3Fe2(PO4)3, Fe2O3. For samples obtained in the choline chloride with diethylene glycol microwave heating characteristic is lamellar morphology – the same as for LiFePO4 obtained by thermal heating, but in the case of using microwave irradiation plates are smaller. This indicates that the reaction mechanism of LiFePO4 synthesis does not change in the microwave synthesis, but the reaction rate is significantly increased (up to 6 times faster than thermal synthesis). Using the Raman spectroscopy, the nature of the carbon coating on the crystal of LiFePO4 was studied. The Raman spectra of the LiFePO4/C composites obtained from an annealed powder with glucose and malic acid have pronounced D (~ 1340 cm-1) and G (~ 1600 cm-1) peaks, as well as two additional bands at ~ 1200 and ~ 1520 cm-1 obtained after the expansion of main peaks. The ratio of peak intensities of lines D and G (ID/IG) has a value of 1.06 for the material obtained after glucose carbonation and 1.01 for LiFePO4/C composites annealed with malic acid, which correlates with the results of other investigations of the carbon coating LiFePO4 (ID/IG ~ 1-3) That means the choice of an organic precursor does not affect the nature of the carbon coating (ID/IG ~ 1). Capacity of cathode material based on LiFePO4/C composites is ~ 130 mAh/g for a current of 0.1C.

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Tripathi, Prashant, Ch Ravi Prakash Patel, Abhishek Dixit, Avanish Pratap Singh, Pawan Kumar, M. A. Shaz, Ritu Srivastava, et al. "High yield synthesis of electrolyte heating assisted electrochemically exfoliated graphene for electromagnetic interference shielding applications." RSC Advances 5, no. 25 (2015): 19074–81. http://dx.doi.org/10.1039/c4ra17230b.

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Romanova, Svetlana Marsel'yevna, Dinara Ilnurovna Sabirova, and Maksim Vyacheslavovich Shulaev. "SYNTHESIS OF AZIDOCELLULOSE NITRATES." chemistry of plant raw material, no. 3 (October 22, 2020): 25–33. http://dx.doi.org/10.14258/jcprm.2020037294.

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A synthesis method of azidocellulose nitrate by chemical interaction between cellulose nitrates or chlorocellulose nitrates with various degree of chlorination with sodium azide in a medium of dimethylsulfoxide and with heating in the temperature range 40–70 °C is proposed. The chemical composition, structure and properties of the obtained compounds are determined on the basis of combination of physico-chemical methods of analysis: IR, 1H NMR and 13C NMR spectroscopy; elemental analysis; gel permeation chromatography; viscometry; thermogravimetric analysis; differential scanning calorimetry; thermal polarization microscopy. The main directions of the chemical interaction between polymers and sodium azide were predicted by quantum-chemical methods using the Gaussian 09 software. The reaction mechanism was confirmed by a mathematical model of kinetics. The scheme of the preferred simultaneously going reaction directions has been composed, which includes substitution of nitrate groups by the azide fragment; rupture of polymer chains by β-glycosidic bond leading to depolymerization; opening of the glucopyranose cycle with addition of the azidogroup to the formed free bonds. Use of the chlorocellulose nitrate for the azidation allows to get products with a higher degree of substitution by azidogroups, and the rate of azidation of chlorocellulose nitrate depends on halogen content directly.

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Journal articles on the topic 'Heating; Chemical syntheses'

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