Sequential subcritical water process applied to orange peel for the recovery flavanones and sugars
Publication date: Available online 14 February 2020Source: The Journal of Supercritical FluidsAuthor(s): Daniel Lachos-Perez, Andressa M. Baseggio, Paulo C. Torres-Mayanga, Patrícia F. Ávila, G.A. Tompsett, Mario Marostica, Rosana Goldbeck, Michael T. Timko, Mauricio Rostagno, Julian Martinez, Tânia Forster-CarneiroAbstractThe economically viable orange peel biorefinery can be based on a single process capable of extraction and hydrolysis. One of the major barriers in the OP biorefinery concept is the lack of an efficient separation technology for the complete removal of valuable components from the bio...
Source: The Journal of Supercritical Fluids - February 15, 2020 Category: Chemistry Source Type: research

Volumetric properties of carbon dioxide + acrylic acid binary in the context of supercritical precipitation polymerization
Publication date: Available online 14 February 2020Source: The Journal of Supercritical FluidsAuthor(s): Matías Menossi, Juan M. Milanesio, Séverine Camy, Simon Harrisson, Miriam Strumia, Mathias DestaracAbstractAcrylic acid can be polymerized by precipitation in different solvents. Carbon dioxide is an interesting solvent given its tunable density and solvent power depending on the pressure and temperature. These physicochemical characteristics make it possible to solubilize some polar compounds in CO 2 depending on temperature and pressure. In this work, we report pressure vs volume pseudo-continuous curves...
Source: The Journal of Supercritical Fluids - February 15, 2020 Category: Chemistry Source Type: research

Surface morphology and drug loading characterization of 3D-printed methacrylate-based polymer facilitated by supercritical carbon dioxide
This study proposes the utilization of 3D printing technology and supercritical carbon dioxide (scCO2) processing to deliver a drug-impregnated polymeric material system which can be engineered and tuned to suit a particular implantation procedure and dramatically improve patient outcomes. In this work, an acrylate-based polymer is 3D-printed using stereolithography, then impregnated with flurbiprofen drug using scCO2. Drug loading above 24% by mass is achievable under the tested conditions. The correlation of drug loading and material surface roughness with different process parameters, including 3D printing layer thickne...
Source: The Journal of Supercritical Fluids - February 14, 2020 Category: Chemistry Source Type: research

Comparison of Polymeric Particles Synthesised Using scCO2 as the Reaction Medium on the Millilitre and Litre Scale
We describe the first steps to scale-up the free radical dispersion polymerization of poly(methyl methacrylate) (PMMA) from the millilitre to the litre scale, utilising supercritical carbon dioxide (scCO2) as the reaction medium. Our key focus is to develop a reproducible and controlled reactor system that produces well-defined polymer particles with narrow size distribution. Two different approaches to monomer addition were investigated, along with variations of surfactant concentration to consistently achieve control of particle size on the large and small scale. Comparison of scanning electron microscopy images from the...
Source: The Journal of Supercritical Fluids - February 12, 2020 Category: Chemistry Source Type: research

Impact of pinewood nematode on naturally-emitted volatiles and scCO2 extracts from Pinus pinaster branches: a comparison with Pinus pinea
Publication date: Available online 7 February 2020Source: The Journal of Supercritical FluidsAuthor(s): M.C. Gaspar, B. Agostinho, L. Fonseca, I. Abrantes, H.C. de Sousa, M.E.M. BragaABSTRACTIn Portugal, the pinewood nematode (PWN), Bursaphelenchus xylophilus, has been affecting Pinus pinaster, leading to economic and ecological losses, while P. pinea is a less susceptible species. The main goal of this study was to assess volatile composition of PWN-infected P. pinaster, and both non-infected P. pinaster and P. pinea branches, by using supercritical carbon dioxide extraction compared with solid-phase microextraction (SPME...
Source: The Journal of Supercritical Fluids - February 8, 2020 Category: Chemistry Source Type: research

Solvation structure of supercritical CO2 and brine mixture for CO2 plume geothermal applications: A molecular dynamics study
This study can help reveal the solvation structures of scCO2/brine mixture under different temperatures (373.15 K to 473.15 K) and ion concentrations (1 wt% to 10 wt%). Results show that H2O molecules bind more tightly to Na+ ion than Cl- ion while scCO2 molecules seem have a uniform distribution in the scCO2/brine mixture. Both the interaction of Na+-H2O pairs and that of Cl--H2O pairs become stronger under higher temperature conditions. Besides, the increase of ion concentration not only reduces the number of H2O molecules in the solvation shell of Na+ ion, but also weakens the interaction of hydrogen bonds. Moreover, it...
Source: The Journal of Supercritical Fluids - February 7, 2020 Category: Chemistry Source Type: research

Rapid production of liposomes using high pressure carbon dioxide and direct ultrasonication
Publication date: Available online 4 February 2020Source: The Journal of Supercritical FluidsAuthor(s): Shinichi Tokunaga, Hiroyuki Tashiro, Kento Ono, Tanjina Sharmin, Takafumi Kato, Keiichi Irie, Kenichi Mishima, Tomomitsu Satho, Taku M. Aida, Kenji MishimaAbstractHerein, we introduce a protocol for preparing liposomes using high-pressure CO2, water and direct ultrasonication (HPC-D) allowing rapid formation of liposomes in a single-step. In the HPC-D method, phospholipid suspensions were treated at temperatures from 25 °C to 70 °C and pressures from 4 MPa to 6.8 MPa with direct ultras...
Source: The Journal of Supercritical Fluids - February 5, 2020 Category: Chemistry Source Type: research

Density, compressibility and phase equilibrium of high pressure-high temperature reservoir fluids up to 473 K and 140 MPa
Publication date: Available online 4 February 2020Source: The Journal of Supercritical FluidsAuthor(s): Teresa Regueira, Maria-Lito Glykioti, Nomiki Kottaki, Erling H. Stenby, Wei YanAbstractExperimental measurement of volumetric and phase equilibrium properties of two high pressure - high temperature reservoir fluids was performed in this work. One fluid is volatile oil and the other is gas condensate. The density, isothermal compressibility, saturation pressure, and liquid fraction below the saturation pressure were determined in the temperature range up to 473.15 K by using a high pressure vibrating tube densitom...
Source: The Journal of Supercritical Fluids - February 5, 2020 Category: Chemistry Source Type: research

Crambe seed oil: Extraction and reaction with dimethyl carbonate under pressurized conditions
In this study, the efficiency of dimethyl carbonate as a solvent in the pressurized liquid extraction (PLE) of crambe seed oil and also as the acyl acceptor in the transesterification reaction using the mixture obtained, simulating a sequential process, was investigated. In the PLE process, the effect of temperature (140 to 180 °C) on the yield and quality of the oil was evaluated, and the results were compared to data obtained applying Soxhlet extraction. The reaction of the PLE mixture was conducted from 250 to 350 °C. The results showed greater oil removal from the seeds under pressurized condition...
Source: The Journal of Supercritical Fluids - February 2, 2020 Category: Chemistry Source Type: research

Recovery and bio-potentialities of astaxanthin-rich oil from shrimp ((Peneanus monodon) waste and mackerel (Scomberomous niphonius) skin using concurrent supercritical CO2 extraction
Publication date: 1 May 2020Source: The Journal of Supercritical Fluids, Volume 159Author(s): Vikash Chandra Roy, Adane Tilahun Getachew, Yeon-Jin Cho, Jin-Seok Park, Byung-Soo ChunAbstractIn the present study, astaxanthin (ASX)-enriched oil extracted from Tiger shrimp waste, Peneaus monodon, and Japanese Spanish mackerel, Scomberomous niphonius, skin in concurrent extraction by supercritical carbon dioxide and quality properties of the oil was evaluated. The extraction condition was optimized by response surface methodology to obtain the highest ASX content. There was a close agreement between the ASX content predicted by...
Source: The Journal of Supercritical Fluids - January 30, 2020 Category: Chemistry Source Type: research

Hydrogen production by supercritical water gasification of black liquor: use of high temperatures and short residence times in a continuous reactor
Publication date: Available online 25 January 2020Source: The Journal of Supercritical FluidsAuthor(s): P. Casademont, J. Sánchez-Oneto, A.P.J. Scandelai, L. Cardozo-Filho, J.R. PortelaAbstractThe Supercritical Water Gasification (SCWG) of black liquor (BL) to obtain hydrogen and dispose of organic waste simultaneously has been studied in a continuous reactor employing short residence times. The experiments were conducted at 600–700 °C, with times between 24.5–29.1 s, at 23 MPa and feedstock was diluted to different concentration levels (0.81–2.43 wt.%). Furthermore,...
Source: The Journal of Supercritical Fluids - January 27, 2020 Category: Chemistry Source Type: research

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Publication date: 1 April 2020Source: The Journal of Supercritical Fluids, Volume 158Author(s): (Source: The Journal of Supercritical Fluids)
Source: The Journal of Supercritical Fluids - January 26, 2020 Category: Chemistry Source Type: research

Measurements and correlation of diffusion coefficients of ibuprofen in both liquid and supercritical fluids
Publication date: Available online 23 January 2020Source: The Journal of Supercritical FluidsAuthor(s): Chang Yi Kong, Kaito Sugiura, Shingo Natsume, Junichi Sakabe, Toshitaka Funazukuri, Koji Miyake, Izumi Okajima, Sushmee Badhulika, Takeshi SakoAbstractThe diffusion coefficients of ibuprofen in both liquid and supercritical fluids are presented for the first time. The diffusion values in liquid ethanol were measured by the Taylor dispersion method at temperatures from 298.15 K to 333.15 K and pressures from 0.10 MPa to 30.00 MPa. Those in supercritical CO2 were carried out by the chromatograph...
Source: The Journal of Supercritical Fluids - January 24, 2020 Category: Chemistry Source Type: research

One-step Sustainable Preparation of Superparamagnetic Iron Oxide Nanoparticles Supported on Mesoporous SiO2
Publication date: Available online 22 January 2020Source: The Journal of Supercritical FluidsAuthor(s): Elena Chamorro, M. José Tenorio, Lourdes Calvo, M. José Torralvo, Regino Sáez-Puche, Albertina CabañasAbstractSuperparamagnetic iron oxide nanoparticles (SPIONs) supported on high surface area mesoporous SiO2 are advanced materials of great interest in catalysis, adsorption and biomedicine. Here we present a new process to prepare SPION/SiO2 materials by the impregnation and insitu decomposition of Fe(NO3)3.9H2O on mesoporous SiO2 supports in a 25-50% mol ethanol + CO2 mixture at...
Source: The Journal of Supercritical Fluids - January 23, 2020 Category: Chemistry Source Type: research

Quantification of mixture composition, liquid-phase fraction and - temperature in transcritical sprays
Publication date: Available online 23 January 2020Source: The Journal of Supercritical FluidsAuthor(s): Tobias C. Klima, Andreas Peter, Sebastian Riess, Michael Wensing, Andreas S. BraeuerAbstractHow do fuel and air mix, if a liquid fuel is injected into an environment featuring pressure and temperature that exceed the critical pressure and the critical temperature of the fuel? It is subject of current discussion on whether and if so when, the fuel/air-mixture becomes supercritical or not. We here report experimental data comprising three mixture properties that are relevant for the current debate, all spatially and tempor...
Source: The Journal of Supercritical Fluids - January 23, 2020 Category: Chemistry Source Type: research

Recrystallization of fine-crystalline barium titanate in low-density water medium
Publication date: Available online 21 January 2020Source: The Journal of Supercritical FluidsAuthor(s): Yu.D. Ivakin, M.N. Danchevskaya, A.A. Kholodkova, G.P. Muravieva, V.V. RybalchenkoAbstractFine-crystalline barium titanate was synthesized from a mixture of barium hydroxide monohydrate and titanium dioxide in water vapor medium at 200 °C and 1.55 MPa and subsequently treated in subcritical vapor and supercritical water at 200-400 °C and 1.55-26.3 MPa. Recrystallization of synthesized powder led to an increase in average crystal size and to tetragonal distortion of BaTiO3 structure. Fo...
Source: The Journal of Supercritical Fluids - January 23, 2020 Category: Chemistry Source Type: research

Recovery and bio-potentialities of astaxanthin-rich oil from shrimp (Peneanus monodon) waste and Mackerel (Scomberomous niphonius) skin using concurrent supercritical CO2 extraction
Publication date: Available online 22 January 2020Source: The Journal of Supercritical FluidsAuthor(s): Vikash Chandra Roy, Ad ane Tilahun Getachew, Yeon-Jin Cho, Jin-Seok Park, Byung-Soo ChunAbstractIn the present study, astaxanthin (ASX)-enriched oil extracted from Tiger shrimp waste, Peneaus monodon, and Japanese Spanish mackerel, Scomberomous niphonius, skin in concurrent extraction by supercritical carbon dioxide and quality properties of the oil was evaluated. The extraction condition was optimized by response surface methodology to obtain the highest ASX content. There was a close agreement between the ASX content p...
Source: The Journal of Supercritical Fluids - January 23, 2020 Category: Chemistry Source Type: research

Supercritical ethanol deposition of Ni(OH)2 nanosheets on carbon cloth for flexible solid-state asymmetric supercapacitor electrode
Publication date: Available online 22 January 2020Source: The Journal of Supercritical FluidsAuthor(s): Qiang Zou, Diab Khalafallah, Zongxiao Wu, Jianhui Chen, Mingjia Zhi, Zhanglian HongABSTRACTNi(OH)2 nanosheets (NSs) were grown onto an electrochemically activated carbon cloth (ECC) with a self-supported microstructure by using efficient ethanol assisted supercritical deposition method. Benefited from the structural features of the well-developed porous architecture with effective channels for electrolyte ions diffusion and accessible redox sites, the nano-heterostructure brings a high utilization of electroactive materi...
Source: The Journal of Supercritical Fluids - January 23, 2020 Category: Chemistry Source Type: research

Loading of 5-fluorouracil onto Halloysite nanotubes for targeted drug delivery using a subcritical gas antisolvent process (GAS)
Publication date: Available online 21 January 2020Source: The Journal of Supercritical FluidsAuthor(s): Sekar Harikrishnan, Rossen Sedev, Chau Chun Beh, Craig Priest, Neil R. FosterAbstractHalloysite clay nanotubes are efficient biocompatible nanocarriers for pharmaceutical products. A gas antisolvent (GAS) process employing subcritical carbon dioxide delivers a product with high loading (43%) and free of residual solvent. An anticancer agent, 5-fluorouracil, was loaded on nanoclay particles. A quantitative distinction is made between tightly-bound (adsorbed) and loosely-bound (co-precipitated) drug. The physical stages of...
Source: The Journal of Supercritical Fluids - January 22, 2020 Category: Chemistry Source Type: research

Single-step coprecipitation and coating to prepare curcumin formulations by supercritical fluid technology
Publication date: Available online 18 January 2020Source: The Journal of Supercritical FluidsAuthor(s): Ravenna Lessa Matos, Tiejun Lu, Gary Leeke, Valentina Prosapio, Christopher McConville, Andrew IngramAbstractCommon strategies to improve the dissolution properties of hydrophobic drug compounds include the preparation of composites with hydrophilic excipients and/or size reduction. However, nanoparticles have poor flowability and difficult handling. Therefore, this work aims to demonstrate the single-step improvement of dissolution and flow properties of pharmaceutical formulations. Coprecipitates of curcumin and poly (...
Source: The Journal of Supercritical Fluids - January 20, 2020 Category: Chemistry Source Type: research

Recovery of valuable lipophilic and polyphenolic fractions from cranberry pomace by consecutive supercritical CO2 and pressurized liquid extraction
In this study, cranberry pomace was consecutively fractionated by supercritical carbon dioxide (SC-CO2) and pressurized liquid (PLE) extraction for the recovery of lipophilic and polyphenolic fractions. Process parameters were optimized by response surface methodology (RSM), ethanol (EtOH) and water were used in PLE. The highest yield (11.10 ± 0.15%) in supercritical fluid extraction (SFE) was obtained at 42.4 MPa pressure, 53 °C temperature and 158 min. Linoleic (36.58%), linolenic (32.44%), oleic (21.79%) and palmitic (4.36%) acids were the major fatty acids in the oil. PLE-E...
Source: The Journal of Supercritical Fluids - January 18, 2020 Category: Chemistry Source Type: research

Imaging method for mass transport measurements in a two-phase bubbly flow of supercritical CO2 and viscous liquids in a static mixer
Publication date: Available online 17 January 2020Source: The Journal of Supercritical FluidsAuthor(s): Marvin Meinecke, Andreas Kilzer, Eckhard WeidnerAbstractIn this work, a simple optical measurement method for two-phase bubbly flow investigations was developed using backlight imaging and particle image velocimetry techniques. Besides information about bubble sizes, surface area and volumes, the mean dispersed phase mass flow rate and the mean dissolution of the dispersed phase in the continuous phase at the end of a static mixer were accurately estimated. The method was validated with air-in-glycerol and water-in-oil s...
Source: The Journal of Supercritical Fluids - January 18, 2020 Category: Chemistry Source Type: research

Simultaneous determination of partition coefficients of three organic compounds distributed as mixtures between SF-CO2 and water using interfaced SFE-SFC apparatus
Publication date: Available online 18 January 2020Source: The Journal of Supercritical FluidsAuthor(s): Li Ben, Wei Guo, Edward D. RamseyAbstractA combined SFE-SFC system has enabled the simultaneous determination of the partition coefficient (K) values of three organic compounds distributed as mixtures between SF-CO2 and water phases. The system used a single valve SFE-SFC recirculation interface. The compounds were: o-toluidine, o-cresol and indole prepared as mixtures in aqueous solutions at concentration levels applicable to industrial process waters and of relevance to potential groundwater contamination that may aris...
Source: The Journal of Supercritical Fluids - January 18, 2020 Category: Chemistry Source Type: research

Sclareol Purification Using the Supercritical Fractionation Process: A Modeling Case Study
Publication date: Available online 14 January 2020Source: The Journal of Supercritical FluidsAuthor(s): C. Dufour, C. Crampon, C. Delbecque, P-P. Garry, E. BadensAbstractThe aim of this study was to model experimental results obtained for the supercritical CO2 fractionation of a liquid mixture containing 24% of sclareol in order to recover a raffinate with increased sclareol content. First, supercritical CO2 fractionation experiments were carried out at pressures (10 to 12) MPa, and temperatures (313 to 338) K. Secondly, the modeling of the raffinate and extract compositions for 12 selected compounds including sclareol was...
Source: The Journal of Supercritical Fluids - January 15, 2020 Category: Chemistry Source Type: research

Extraction of Morus alba leaves using supercritical CO2 and ultrasound-assisted solvent: evaluation of β-sitosterol content
In this study, extracts of Morus alba leaves were obtained by supercritical CO2 and ultrasound-assisted methods, and the results were compared to those of the conventional Soxhlet extraction. The supercritical extraction resulted in the highest yields of 1.08 and 1.11 wt%, when under the highest pressure conditions investigated (200 bar; 40 and 60 °C, respectively). The ultrasound-assisted n-hexane extraction yielded 0.83 wt% at a temperature of 60 °C, solvent-to-solid ratio of 20 mL g-1, and ultrasound intensity of 43.0 W cm-2. The major compounds identified in the ...
Source: The Journal of Supercritical Fluids - January 15, 2020 Category: Chemistry Source Type: research

Supercritical CO2 extraction of Aloysia gratissima leaves and evaluation of anti-inflammatory activity
Publication date: Available online 15 January 2020Source: The Journal of Supercritical FluidsAuthor(s): Maryelen A. Souza, João G.G. Guzatti, Rafael H. Martello, Monica S.Z. Schindler, Jean F.F. Calisto, Letícia V. Morgan, Gean P.S. Aguiar, Gelvani Locateli, Jaqueline Scapinello, Liz G. Müller, J. Vladimir Oliveira, Jacir Dal MagroAbstractThis work aims to evaluate the effects of temperature and pressure on the extraction yield and chemical composition of the supercritical CO2 (SCCO2) extracts of A. gratissima leaves (EAG) and then to investigate in vivo anti-inflammatory activity of the extracts. The le...
Source: The Journal of Supercritical Fluids - January 15, 2020 Category: Chemistry Source Type: research

Quality parameters of radish seed oil obtained using compressed propane as solvent
Publication date: Available online 15 January 2020Source: The Journal of Supercritical FluidsAuthor(s): Natália Stevanato, Isabela Julio Iwassa, Lucio Cardozo-Filho, Camila da SilvaAbstractThe extraction of radish seed oil (RSO) with subcritical propane (SP) was investigated. The effects of pressure (6 and 10 MPa) and temperature (303 and 333 K) on the oil yield and chemical composition of the RSO were determined and the results were compared with ultrasound-assisted extraction (UAE) and Soxhlet extractor (SE) using n-hexane. The operating conditions investigated with SP had little influence on the RSO yield; howeve...
Source: The Journal of Supercritical Fluids - January 15, 2020 Category: Chemistry Source Type: research

Paramagnetic Bioactives Encapsulated in Poly(D,L-lactide) Microparticules: Spatial Distribution and In Vitro Release Kinetics
Publication date: Available online 8 January 2020Source: The Journal of Supercritical FluidsAuthor(s): E.N. Golubeva, N.A. Chumakova, S.V. Kuzin, I.A. Grigoriev, T. Kalai, A.A. Korotkevich, S.E. Bogorodsky, L.I. Krotova, V.K. Popov, V.V. LuninAbstractPoly(D,L-lactide) microparticles impregnated with a number of bioactive paramagnetic compounds have been fabricated using two SCF techniques: 1). PGSS (Particles from Gas Saturated Solution) and 2). polymer plasticization and swelling by supercritical carbon dioxide followed by its cryomilling. Electron paramagnetic resonance (EPR) spectroscopy manifested homogeneous spatial d...
Source: The Journal of Supercritical Fluids - January 8, 2020 Category: Chemistry Source Type: research

Extraction of Muriella decolor lipids using conventional and pressurized solvents and characterization of their fatty acid profile for biodiesel applications
Publication date: Available online 7 January 2020Source: The Journal of Supercritical FluidsAuthor(s): Nyelson da Silva Nonato, Estephanie Laura Nottar Escobar, Débora M. Kochepka, Roberto Bianchini Derner, Marcelo G. Montes D’Oca, Marcos Lúcio Corazza, Luiz Pereira RamosAbstractMicroalgae have been described as a sustainable feedstock for biodiesel production. In this work, Muriella decolor lipids were extracted using pressurized (compressed propane, scCO2 and scCO2 followed by scCO2+ethanol) and conventional solvents (hexane, ethanol and chloroform:methanol). Total fatty acid methyl esters (FAMEs) in ...
Source: The Journal of Supercritical Fluids - January 8, 2020 Category: Chemistry Source Type: research

Subcritical water extraction of phenolic antioxidants with improved α-amylase and α-glucosidase inhibitory activities from exocarps of Castanea mollissima Blume
Publication date: Available online 2 January 2020Source: The Journal of Supercritical FluidsAuthor(s): Xuanchi Liu, Yanhui Wang, Jiachan Zhang, Linlin Yan, Shiqi Liu, Ahmed Aboueloyoun Taha, Jing Wang, Chao MaAbstractsHerein, subcritical water extraction (SWE) technology was applied for the recovery of phenolics from chestnut exocarps. Results showed that extracts obtained by SWE had significantly higher extraction yield (Ye), total phenolic contents (TPC), as well as stronger antioxidant (AAs), α-amylase and α-glucosidase inhibitory activities than conventional techniques. The optimal temperature of SWE for re...
Source: The Journal of Supercritical Fluids - January 3, 2020 Category: Chemistry Source Type: research

Core–shell structure formation strategy with hydrothermal synthesis: Importance of seeds, precursor concentration, and heterogeneous reaction
Publication date: Available online 31 December 2019Source: The Journal of Supercritical FluidsAuthor(s): Akira Yoko, Sho Okabe, Gimyeong Seong, Takaaki Tomai, Tadafumi AdschiriAbstractWhile using the titanium organic complex as a starting material under widely various seed concentrations and temperature conditions, this study examined the reaction kinetics of titanium oxide formation on nickel particles. Homogeneous and heterogeneous nucleation depending on temperature were studied from the perspective of reaction engineering for core–shell type particle design. Homogeneous nucleation and the growth rate were compara...
Source: The Journal of Supercritical Fluids - January 1, 2020 Category: Chemistry Source Type: research

Prediction of Solid Solute Solubility in Supercritical Carbon Dioxide with and without Organic Cosolvents from PSRK EOS
Publication date: Available online 26 December 2019Source: The Journal of Supercritical FluidsAuthor(s): Zong-Zhe Cai, Chieh-Ming HsiehAbstractSolid solute solubility in supercritical carbon dioxide (ScCO2) with and without organic cosolvents provides important information for design and optimization of processes involving ScCO2 in industry. The accuracy of PSRK EOS in predicting solid solute solubility in ScCO2 with and without organic cosolvents is systematically investigated in this study. The first-principles thermodynamic model PR + COSMOSAC EOS and four well-known group contribution models are used to e...
Source: The Journal of Supercritical Fluids - December 27, 2019 Category: Chemistry Source Type: research

A low-temperature supercritical nitridation technology for enhancing the performance of AlGaN/GaN HEMTs
Publication date: Available online 26 December 2019Source: The Journal of Supercritical FluidsAuthor(s): Hong Zhang, Guanjun Chen, Jincheng Zhang, Xuefeng Zheng, Hong Zhou, Shenglei Zhao, Yue HaoAbstractA non-destructive low-temperature supercritical nitridation (LTSCN) is proved to boost the performance of AlGaN/GaN HEMTs. The samples were treated at 120 ℃ in a supercritical CO2 fluid mixed with NH3 under 20.7 MPa for one hour. After the LTSCN, the gate leakage current decreases by 69.6% for an increase of the Schottky barrier height and the subthreshold swing is reduced by 19.9%. Furthermore, the on-resistance is reduc...
Source: The Journal of Supercritical Fluids - December 27, 2019 Category: Chemistry Source Type: research

Subcritical Water Extraction for Selective Recovery of Phenolic Bioactives from Kānuka Leaves
This study investigated the selective recovery of antioxidant compounds from kānuka leaves using subcritical water extraction (SWE) at different extraction temperatures (150 to 210) °C, time (0 to 40) min, and solid-to-solvent ratio, SSR (15 to 35) g/L. The maximum total phenolic and flavonoid content in the kānuka leaf extracts were (167.93 ± 2) mg GAE/g dw and (405.4 ± 8.47) mg QE/g dw, respectively. These amounts were obtained using SWE at 170 °C for 20 min with SSR of 15 g/L; the extracts also showed the highest antioxidant activity. Eight compoun...
Source: The Journal of Supercritical Fluids - December 26, 2019 Category: Chemistry Source Type: research

Cost-effective production of organosolv lignin from woody biomass using ethanol-water mixed solvent at mild conditions
Publication date: Available online 24 December 2019Source: The Journal of Supercritical FluidsAuthor(s): Hongwei Li, Xudong Cai, Zhicai Wang, Chunbao XuAbstractA cost-effective process has been developed for fractionating pine sawdust into lignin and cellulose fractions in an ethanol-water mixed solvent. The effects of temperature, different types of catalysts (i.e., strong acid, weak acid and alkali), and residence time, with respect to yields and purity of the crude lignin (degraded products) and crude cellulose (solid residue) were investigated. It is found that the purity of crude lignin was higher but with a lower pro...
Source: The Journal of Supercritical Fluids - December 26, 2019 Category: Chemistry Source Type: research

Supercritical CO2 as solvent for fatty acids esterification with ethanol catalyzed by Amberlyst-15
Publication date: Available online 23 December 2019Source: The Journal of Supercritical FluidsAuthor(s): Diego Trevisan Melfi, Kallynca Carvalho dos Santos, Luiz Pereira Ramos, Marcos Lúcio CorazzaAbstractThis work reports on the esterification of fatty acids with ethanol using Amberlyst-15 in a scCO2-assisted system. A factorial design was carried out for the following process variables: temperature (70 °C to 110 °C), ethanol to acid molar ratio (3:1 to 9:1) and catalyst to acid concentration (5 to 20 wt%), with a fixed amount of CO2 added to the reactor (28.62 g). The best react...
Source: The Journal of Supercritical Fluids - December 24, 2019 Category: Chemistry Source Type: research

Thermal oxidation of polypropylene catalyzed by manganese oxide aerogel in oxygen-enriched supercritical carbon dioxide
Publication date: Available online 24 December 2019Source: The Journal of Supercritical FluidsAuthor(s): Igor Elmanovich, Andrey Stakhanov, Vadim Zefirov, Alexander Pavlov, Boris Lokshin, Marat GallyamovAbstractA new approach to the thermal oxidation of polypropylene in oxygen-enriched supercritical carbon dioxide is presented. Several parameters are revealed to affect the oxidation process, namely, the presence of supercritical carbon dioxide, the presence of Mn2O3 nanoparticles and oxygen to polypropylene mass ratio. It is demonstrated that the use of carbon dioxide enhances the oxidative process at lower oxygen content....
Source: The Journal of Supercritical Fluids - December 24, 2019 Category: Chemistry Source Type: research

Measurement and modeling of solubilities and diffusion coefficients of carbon dioxide in poly(ethylene-co-acrylic acid)
Publication date: Available online 20 December 2019Source: The Journal of Supercritical FluidsAuthor(s): Ikuo Ushiki, Yuki Yoshino, Souta Hayashi, Shin-ichi Kihara, Shigeki TakishimaAbstractWe measured and modeled the solubilities and diffusion coefficients of carbon dioxide (CO2) in poly(ethylene-co-acrylic acid) (PEAA) over temperatures of 373―473 K and pressures of up to 20 MPa. The measured solubilities of CO2 in PEAA obeyed Henry’s law and decreased with an increase in the acrylic acid content of the copolymer. The Sanchez-Lacombe equation of state could be applied to correlate the measured solub...
Source: The Journal of Supercritical Fluids - December 21, 2019 Category: Chemistry Source Type: research

Desulfurization of hexyl sulfide and hexanethiol using supercritical water
This study is expected to clarify the decomposition reactions of alkyl sulfides and alkyl thiols in SCW.Graphical abstract (Source: The Journal of Supercritical Fluids)
Source: The Journal of Supercritical Fluids - December 21, 2019 Category: Chemistry Source Type: research

Phosphatidylcholine solubility in supercritical carbon dioxide: Experimental data, thermodynamic modeling, and application in bioactive-encapsulated liposome synthesis
Publication date: Available online 19 December 2019Source: The Journal of Supercritical FluidsAuthor(s): Apratim Jash, Tahmasb Hatami, Syed S.H. RizviAbstractThe solubility of phosphatidylcholine (PC) in supercritical-CO2 (SC-CO2) was measured experimentally using a dynamic system for the pressure and temperature range of 12.4-17.2 MPa and 313-353 K, respectively. The data were used to model the solubility using three cubic equations of state (EOS) combined with the conventional one parameter mixing rule: Soave–Redlich–Kwong (SRK); Peng–Robinson (PR); and van der Waals EOS, modified with Soa...
Source: The Journal of Supercritical Fluids - December 20, 2019 Category: Chemistry Source Type: research

Effect of Interfacial Properties on the Stability of Ultra-dry CO2-in-Water (C/W) Foams Stabilized with Zwitterionic Surfactants and Nonionic/Anionic Polymers: Experimental and DPD Simulation
Publication date: Available online 19 December 2019Source: The Journal of Supercritical FluidsAuthor(s): Liru Ma, Lei Bao, Dongdong Hu, Ling Zhao, Tao LiuAbstractCocamidopropyl betaine (CAPB) and poly(acrylamide) (PAM) were used for the formation of an ultra-dry CO2-in-water (C/W) foam in which the water volume fraction could be as low as 5%. At water contents between 10% and 5% v/v, the C/W foam formed with CAPB and nonionic PAM (NPAM) showed four times longer stabilization times than that formed with only CAPB. The synergistic effect of surfactants and polymers on the viscosity, interfacial density and thickness was also...
Source: The Journal of Supercritical Fluids - December 20, 2019 Category: Chemistry Source Type: research

Experimental solubility data of two solid derivatives of menadione in supercritical carbon dioxide: 2-((4-chlorobenzyl)amino)-3-methylnaphtalene-1,4-dione, and 2-((4-chlorophenethyl)amino)-3-methylnaphtalene-1,4-dione
Publication date: 1 March 2020Source: The Journal of Supercritical Fluids, Volume 157Author(s): Flavia C. Zacconi, Adolfo L. Cabrera, José Alejandro Lozada, José M. del Valle, Juan C. de la FuenteAbstractTwo solid derivatives of vitamin K3 or menadione, 2-((4-chlorobenzyl)amino)-3-methylnaphthalene-1,4-dione and 2-((4-chlorophenethyl)amino)-3-methylnaphthalene-1,4-dione, were synthesized and chemically characterized with a purity of 98 % mol∙mol−1. The solubility (molar fraction) of each derivative in high-pressure carbon dioxide was measured using an analytic-recirculation methodology at (313, 323 an...
Source: The Journal of Supercritical Fluids - December 17, 2019 Category: Chemistry Source Type: research

Systematic study of alcohols based co-blowing agents for polystyrene foaming in supercritical CO2: Toward the high efficiency of foaming process and foam structure optimization
Publication date: Available online 13 December 2019Source: The Journal of Supercritical FluidsAuthor(s): Wei Qiang, Ling Zhao, Tao Liu, Zhen Liu, Xiulu Gao, Dongdong HuAbstractA new method is presented to improve the efficiency of the supercritical CO2 foaming process and optimize the foam structure after evaluating the effect of alcohols as co-blowing agents on supercritical CO2 foaming polystyrene (PS). The simulations revealed that the solubility parameter of the blowing agents and the diffusion coefficient of CO2 for PS increased with the growth of chain length of alcohol. The addition of decanol decelerated the desorp...
Source: The Journal of Supercritical Fluids - December 14, 2019 Category: Chemistry Source Type: research

A potential co-current mixing reactor design for supercritical water oxidation
This article presents the use of both pseudo fluid and Computational Fluid Dynamics (CFD) modelling approaches to simulate the general flow patterns and mixing regimes inside an innovative tube-in-tube co-current mixing reactor design. Both modelling techniques show evidence that corrosion on the internal surface of the reactor can be mitigated. A laboratory-scale reactor system was designed and fabricated to validate the modelling studies for application to SCWO. Results of Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX) Spectroscopy, and X-Ray Diffraction (XRD) indicated that the 1 meter long co-current...
Source: The Journal of Supercritical Fluids - December 14, 2019 Category: Chemistry Source Type: research

Morphological evolution of PLA foam from microcellular to nanocellular induced by cold crystallization assisted by supercritical CO2
Publication date: Available online 14 December 2019Source: The Journal of Supercritical FluidsAuthor(s): Jingyue Ni, Kesong Yu, Hongfu Zhou, Jianguo Mi, Shihong Chen, Xiangdong WangAbstractThe use of physical foaming agents to form nanofoams in semicrystalline polymers is still a tremendous challenge. The change from microcellular to nanocellular bubbles (the micro/nano transition) in poly(lactic acid) (PLA) foam was investigated by adjusting the type of crystals induced in PLA during cold crystallization. The results showed that at saturation temperatures below the micro/nano transition temperature, α′ crystal...
Source: The Journal of Supercritical Fluids - December 14, 2019 Category: Chemistry Source Type: research

Corrosion characterization of ZrO2 and TiO2 ceramic coatings via air plasma spraying on 316 stainless steel in oxygenated sub- and supercritical water
Publication date: Available online 9 December 2019Source: The Journal of Supercritical FluidsAuthor(s): Shuwei Guo, Donghai Xu, Yu Liang, Yanmeng Gong, Yanhui Li, Jianqiao YangAbstractAlloy 316 stainless steel (SS) is an important candidate material for supercritical water oxidation facilities, but severe corrosion negatively affects its life-span and potential application. In this work, ZrO2 and TiO2 were coated on the 316 SS substrate by air plasma spraying and then exposed in oxygenated sub- and supercritical water. The results show that the coatings could greatly improve the corrosion resistance of 316 SS in oxygenated...
Source: The Journal of Supercritical Fluids - December 10, 2019 Category: Chemistry Source Type: research

Hydrothermal conversion of microalgae and its waste residue after biofuel extraction to acetic acid with CuO as solid oxidant
Publication date: Available online 9 December 2019Source: The Journal of Supercritical FluidsAuthor(s): Heng Zhong, Lin Ma, Yingying Zhu, Binbin Jin, Tianfu Wang, Yangang Wang, Fangming JinAbstractProduction of chemicals from microalgae is a substantial way to contribute to the economic viability of a biorefinery. In this research, we report a new and green method for producing acetic acid from microalgae directly or from its waste residue after biofuel extraction using copper (II) oxide (CuO) as a solid oxidant. Results show that the CuO can significantly facilitate the oxidation of microalgae and its waste residue into a...
Source: The Journal of Supercritical Fluids - December 10, 2019 Category: Chemistry Source Type: research

Pet depolimerization in supercritical ethanol conditions catalysed by nanoparticles of metal oxides
Publication date: Available online 6 December 2019Source: The Journal of Supercritical FluidsAuthor(s): Janaina Rodrigues Fernandes, Lídia Pereira Amaro, Edvani Curti Muniz, Silvia Luciana Fávaro, Eduardo RadovanovicAbstractThe depolymerization of the PET in supercritical conditions using ethanol and catalyzed by cobalt and nickel oxides was enough for the recovery of the DET monomer, allowing yields close to 100% depolymerization. The formation of DET in the depolymerization process was characterized by 1H-NMR, DSC, FTIR, SEM, and HPLC. Cobalt oxide and nickel oxide were obtained through the Pechini method a...
Source: The Journal of Supercritical Fluids - December 7, 2019 Category: Chemistry Source Type: research

Migration and Transformation of Nitrogen during Hydrothermal Liquefaction of Penicillin Sludge
In this study, hydrothermal liquefaction (HTL) was used to dispose the penicillin sludge (PS). The effects of different reaction conditions on the product and the redistribution and transformation pathway of nitrogen were investigated. The results showed that the highest yield of bio-oil was 37.5% when the temperature of HTL was 340 °C and the holding time was 30 minutes. About 20% of the nitrogen was present in the solid residue obtained by HTL of PS, and the remaining was converted into other phases. The most amino-N in the PS was present in the aqueous phase in the form of Org-N, and the remaining was ...
Source: The Journal of Supercritical Fluids - December 7, 2019 Category: Chemistry Source Type: research

Enzyme-assisted supercritical fluid extraction of antioxidant isorhamnetin conjugates from Opuntia ficus-indica (L.) Mill
Publication date: Available online 4 December 2019Source: The Journal of Supercritical FluidsAuthor(s): Marilena Antunes-Ricardo, José A. Mendiola, Tomás García-Cayuela, Elena Ibañez, Janet A. Gutiérrez-Uribe, M. Pilar Cano, Daniel Guajardo-FloresAbstractA one-pot enzymatic assisted supercritical carbon dioxide (SC-CO2) extraction was used to obtain isorhamnetin conjugates from Opuntia ficus-indica (L.) Mill (nopal). Box-Benhken design, discriminate analysis and principal component analysis were used to studt the influence of pressure, temperature, aqueous ethanol solution and time on the...
Source: The Journal of Supercritical Fluids - December 5, 2019 Category: Chemistry Source Type: research