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A Themed Issue in Honor of Professor Ernesto Reverchon: The Top 20 in Chemical Engineering

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A special issue of Molecules (ISSN 1420-3049). This special issue belongs to the section "Molecular Liquids".

Deadline for manuscript submissions: closed (30 June 2021) | Viewed by 32837

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Special Issue Editors

Dr. Stefano Cardea

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Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II, Fisciano, SA, Italy
Interests: supercritical-fluids-assisted processes; membranes; aerogels; scaffolds; foams; micro- and nanoparticles
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Dr. Antonio Tabernero de Paz

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Chemical Engineering Department, University of Salamanca, Salamanca, Spain
Interests: supercritical fluids; exopolysaccharides; rheology; scaffolds; nanotechnology

Dr. Silvio A.B. Vieira de Melo

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Department of Chemical Engineering, Polytechnic School, Federal University of Bahia, Salvador, Brazil
Interests: supercritical carbon dioxide; natural products; biomaterials; drug delivery; nanoscience

Special Issue Information

Dear Colleagues,

Molecules is pleased to announce a Special Issue, dedicated to Professor Ernesto Reverchon, Full Professor at the University of Salerno (Italy), for being in the Top 20 of the World Ranking in Chemical Engineering, thanks to his outstanding contribution in the research field of supercritical fluid applications. Indeed, his scientific activities include more than 450 scientific publications in international journals, among which more than 320 are related to supercritical fluid processing with more than 18000 citations (h-index 66); furthermore, he is the inventor of 18 patents, of which 7 are international patents (WIPO released). He has also worked toward the development of some industrial plants related to the applications of supercritical fluids in nutraceutical and pharmaceutical field.

In recent years, the use of supercritical fluids in several industrial applications such as food industry, biomedical, pharmaceutical, textile industry, water treatment, etc. has been extensively studied. Indeed, supercritical fluids are characterized by specific peculiarities such as high solvent power (i.e., like a liquid solvent), high diffusivity (i.e., like a gaseous solvent), and low surface tension, which make them an ideal substitute of organic solvents in different traditional processes. Moreover, these peculiarities can be properly modified, adjusting operative parameters, such as pressure and temperature, making the processes versatile. In this way, it is possible to obtain new products with special characteristics or to design new processes, which are environmentally friendly and sustainable.

Therefore, this Special Issue of Molecules dedicated to Professor Ernesto Reverchon wants to attract original research and review articles that cover the latest findings about supercritical fluids applications. In particular, works about extraction and fractionation, generation of micro- and nanoparticles, microcapsules, fibers, foams, scaffolds, membranes and aerogels, liposomes and nanosomes will be welcome.

Prof. Stefano Cardea
Prof. Antonio Tabernero de Paz
Prof. Silvio A.B. Vieira de Melo
Guest Editors

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Keywords

Supercritical fluids
Extraction
Micro and nanoparticles
Microcapsules, Membranes and scaffolds
aerogels
Liposomes and nanosomes

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Published Papers (9 papers)

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Research

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21 pages, 10776 KiB

Open AccessArticle

Polymeric Microfiltration Membranes Modification by Supercritical Solvent Impregnation—Potential Application in Open Surgical Wound Ventilation

by Mariusz Nowak, Dusan Misic, Anna Trusek and Irena Zizovic

Molecules 2021, 26(15), 4572; https://doi.org/10.3390/molecules26154572 - 28 Jul 2021

Cited by 4 | Viewed by 2299

Abstract

This study investigated supercritical solvent impregnation of polyamide microfiltration membranes with carvacrol and the potential application of the modified membranes in ventilation of open surgical wounds. The impregnation process was conducted in batch mode at a temperature of 40 °C under pressures of 10, 15, and 20 MPa for contact times from 1 to 6 h. FTIR was applied to confirm the presence of carvacrol on the membrane surface. In the next step, the impact of the modification on the membrane structure was studied using scanning electron and ion beam microscopy and cross-filtration tests. Further, the release of carvacrol in carbon dioxide was determined, and finally, an open thoracic cavity model was applied to evaluate the efficiency of carvacrol-loaded membranes in contamination prevention. Carvacrol loadings of up to 43 wt.% were obtained under the selected operating conditions. The swelling effect was detectable. However, its impact on membrane functionality was minor. An average of 18.3 µg of carvacrol was released from membranes per liter of carbon dioxide for the flow of interest. Membranes with 30–34 wt.% carvacrol were efficient in the open thoracic cavity model applied, reducing the contamination levels by 27% compared to insufflation with standard membranes. Full article

(This article belongs to the Special Issue A Themed Issue in Honor of Professor Ernesto Reverchon: The Top 20 in Chemical Engineering)

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20 pages, 2829 KiB

Open AccessArticle

Simulation of Organic Liquid Products Deoxygenation by Multistage Countercurrent Absorber/Stripping Using CO₂ as Solvent with Aspen-HYSYS: Thermodynamic Data Basis and EOS Modeling

by Elinéia Castro Costa, Welisson de Araújo Silva, Eduardo Gama Ortiz Menezes, Marcilene Paiva da Silva, Vânia Maria Borges Cunha, Andréia de Andrade Mâncio, Marcelo Costa Santos, Sílvio Alex Pereira da Mota, Marilena Emmi Araújo and Nélio Teixeira Machado

Molecules 2021, 26(14), 4382; https://doi.org/10.3390/molecules26144382 - 20 Jul 2021

Cited by 1 | Viewed by 3149

Abstract

In this work, the thermodynamic data basis and equation of state (EOS) modeling necessary to simulate the fractionation of organic liquid products (OLP), a liquid reaction product obtained by thermal catalytic cracking of palm oil at 450 °C, 1.0 atmosphere, with 10% (wt.) Na₂CO₃ as catalyst, in multistage countercurrent absorber/stripping columns using supercritical carbon dioxide (SC-CO₂) as solvent, with Aspen-HYSYS was systematically investigated. The chemical composition of OLP was used to predict the density (ρ), boiling temperature (T_b), critical temperature (T_c), critical pressure (P_c), critical volume (V_c), and acentric factor (ω) of all the compounds present in OLP by applying the group contribution methods of Marrero-Gani, Han-Peng, Marrero-Pardillo, Constantinou-Gani, Joback and Reid, and Vetere. The RK-Aspen EOS used as thermodynamic fluid package, applied to correlate the experimental phase equilibrium data of binary systems OLP-_i/CO₂ available in the literature. The group contribution methods selected based on the lowest relative average deviation by computing T_b, T_c, P_c, V_c, and ω. For n-alkanes, the method of Marrero-Gani selected for the prediction of T_c, P_c and V_c, and that of Han-Peng for ω. For alkenes, the method of Marrero-Gani selected for the prediction of T_b and T_c, Marrero-Pardillo for P_c and V_c, and Han-Peng for ω. For unsubstituted cyclic hydrocarbons, the method of Constantinou-Gani selected for the prediction of T_b, Marrero-Gani for T_c, Joback for P_c and V_c, and the undirected method of Vetere for ω. For substituted cyclic hydrocarbons, the method of Constantinou-Gani selected for the prediction of T_b and P_c, Marrero-Gani for T_c and V_c, and the undirected method of Vetere for ω. For aromatic hydrocarbon, the method of Joback selected for the prediction of T_b, Constantinou-Gani for T_c and V_c, Marrero-Gani for P_c, and the undirected method of Vetere for ω. The regressions show that RK-Aspen EOS was able to describe the experimental phase equilibrium data for all the binary pairs undecane-CO₂, tetradecane-CO₂, pentadecane-CO₂, hexadecane-CO₂, octadecane-CO₂, palmitic acid-CO₂, and oleic acid-CO₂, showing average absolute deviation for the liquid phase (

A A D_{x}

) between 0.8% and 1.25% and average absolute deviation for the gaseous phase (

A A D_{y}

) between 0.01% to 0.66%. Full article

(This article belongs to the Special Issue A Themed Issue in Honor of Professor Ernesto Reverchon: The Top 20 in Chemical Engineering)

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20 pages, 25015 KiB

Open AccessArticle

Multidisciplinary Studies of Folk Medicine “Five Thieves’ Oil” (Olejek Pięciu Złodziei) Components

by Przemysław Siejak, Wojciech Smułek, Farahnaz Fathordobady, Anna Grygier, Hanna Maria Baranowska, Magdalena Rudzińska, Łukasz Masewicz, Małgorzata Jarzębska, Piotr T. Nowakowski, Aleksandra Makiej, Pardis Kazemian, Paweł Drobnik, Barbara Stachowiak, Maciej Jarzębski and Anubhav Pratap-Singh

Molecules 2021, 26(10), 2931; https://doi.org/10.3390/molecules26102931 - 14 May 2021

Cited by 7 | Viewed by 4511

Abstract

To meet the growing interest in natural antibacterial agents, we evaluated the physicochemical and biological properties of the folk medicine known as “five thieves’ oil” (Polish name: olejek pięciu złodziei). Five thieves’ oil consists of a mixture of five oils: rosemary, lemon, clove, eucalyptus, and cinnamon. In this study, we performed gas chromatography, FTIR, and UV–vis spectroscopic analysis, as well as L-a-b color tests, contact angle determination, and surface tension determination. To verify its antibacterial activity, the metabolic activity and changes in cell membrane permeability of bacteria of the genus Pseudomonas were studied. As a result, it was found that among the constituent oils, the oils of clove and cinnamon were the least volatile and, at the same time, had the strongest antibacterial activity. However, a mix of all the oils also showed comparable activity, which was even more pronounced for the oils after 4 weeks of aging. This effect can be linked to the high content of terpene derivatives such as eugenol and cinnamaldehyde, which can cause changes in bacterial membrane permeability, affecting cell activity and survival. This study is the first to characterize the constituents of the popular folk medicine five thieves’ oil, confirming and explaining its strong antibacterial activity, thus constituting a significant contribution to contemporary health education. Full article

(This article belongs to the Special Issue A Themed Issue in Honor of Professor Ernesto Reverchon: The Top 20 in Chemical Engineering)

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14 pages, 2108 KiB

Open AccessArticle

A Pilot-Scale Supercritical Carbon Dioxide Extraction to Valorize Colombian Mango Seed Kernel

by Leidy J. Cerón-Martínez, Andrés M. Hurtado-Benavides, Alfredo Ayala-Aponte, Liliana Serna-Cock and Diego F. Tirado

Molecules 2021, 26(8), 2279; https://doi.org/10.3390/molecules26082279 - 14 Apr 2021

Cited by 18 | Viewed by 3432

Abstract

Colombian mango production, which exceeded 261,000 t in 2020, generates about 40% of the whole fruit as solid waste, of which more than 50% are seed kernels (over 52,000 t solid by-product); though none is currently used for commercial purposes. This study reports the results of the supercritical carbon dioxide (scCO₂) extraction of an oil rich in essential fatty acids (EFAs) from revalorized mango seed kernels and the optimization of the process by the Response Surface Methodology (RSM). In pilot-scale scCO₂ experiments, pressure (23–37 MPa) and temperature (52–73 °C) were varied, using 4.5 kg of CO₂. The highest experimental oil extraction yield was 83 g/kg (37 MPa and 63 °C); while RSM predicted that 84 g/kg would be extracted at 35 MPa and 65 °C. Moreover, by fine-tuning pressure and temperature it was possible to obtain an EFA-rich lipid fraction in linoleic (37 g/kg) and α-linolenic (4 g/kg) acids, along with a high oleic acid content (155 g/kg), by using a relatively low extraction pressure (23 MPa), which makes the process a promising approach for the extraction of oil from mango waste on an industrial scale, based on a circular economy model. Full article

(This article belongs to the Special Issue A Themed Issue in Honor of Professor Ernesto Reverchon: The Top 20 in Chemical Engineering)

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13 pages, 2768 KiB

Open AccessArticle

The Influence of Supercritical Carbon Dioxide on Graham Flour Enzyme Polyphenol Oxidase Activity

by Gordana Hojnik Podrepšek, Željko Knez and Maja Leitgeb

Molecules 2020, 25(24), 5981; https://doi.org/10.3390/molecules25245981 - 17 Dec 2020

Cited by 12 | Viewed by 2760

Abstract

Graham flour is a form of whole wheat flour made by grinding the endosperm and is thus also the most nutritious. Generally, the enzyme polyphenol oxidase (PPO) catalyzes two different reactions in the presence of molecular oxygen: the hydroxylation of monophenols to ortho-diphenol and the oxidation of o-diphenol to o-quinone. The purpose of the work was to inactivate PPO activity to extend the shelf life of graham flour and at the same time preserve all the of its high-quality properties. The influence of supercritical CO₂ (scCO₂) treatment on PPO activity in graham flour was investigated. First, graham flour was exposed to scCO₂ conditions, then the proteins were extracted, and in the last step the concentration of total proteins and the specific activity of the PPO enzyme were determined by spectrophotometric assay. PPO activity decreased with an increase in treatment pressure. Furthermore, the flour quality characteristics that meet all needs for wheat end-use products after scCO₂ treatment have been preserved. No major changes in the structure of the granulate or shape of the flour particles were observed. A slightly reduced value of the moisture content in scCO₂-treated graham flour also implies an extension of the shelf life. Full article

(This article belongs to the Special Issue A Themed Issue in Honor of Professor Ernesto Reverchon: The Top 20 in Chemical Engineering)

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15 pages, 1197 KiB

Open AccessArticle

Co-Solvent Selection for Supercritical Fluid Extraction (SFE) of Phenolic Compounds from Labisia pumila

by Shazana Azfar Radzali, Masturah Markom and Noorashikin Md Saleh

Molecules 2020, 25(24), 5859; https://doi.org/10.3390/molecules25245859 - 11 Dec 2020

Cited by 37 | Viewed by 3986

Abstract

A preliminary study was conducted to study the effects of different types and concentrations of co-solvents based on yield, composition and antioxidants capacity of extract prior to optimization studies of supercritical fluid extraction (SFE) of Labisia pumila (locally referred to as ‘kacip fatimah’). The following co-solvents were studied prior to the optimization of supercritical carbon dioxide (SC–CO₂) technique: ethanol, water, methanol, as well as aqueous solutions of ethanol–water and methanol–water (50% and 70% v/v). By using the selected co-solvents, identification of phenolic acids (gallic acid, methyl gallate and caffeic acid) was determined by using High-Performance Liquid Chromatography (HPLC). Then, the antioxidant capacity was evaluated by using three different assays: total phenolic content (TPC), ferric reducing/antioxidant power (FRAP) and free radical-scavenging capacity of 2,2-diphenyl-1-picrylhydrazyl (DPPH). SC–CO₂ with 70% ethanol–water co-solvent was superior in terms of a higher combination of phenolic compounds extracted and antioxidants capacity. Overall, SC–CO₂ with co-solvent 70% ethanol–water technique was efficient in extracting phenolic compounds from L. pumila, and thus the usage of this solvent system should be considered for further optimization studies. Full article

(This article belongs to the Special Issue A Themed Issue in Honor of Professor Ernesto Reverchon: The Top 20 in Chemical Engineering)

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13 pages, 21526 KiB

Open AccessArticle

Nanoporous Crystalline Composite Aerogels with Reduced Graphene Oxide

by Christophe Daniel, Baku Nagendra, Maria Rosaria Acocella, Esther Cascone and Gaetano Guerra

Molecules 2020, 25(22), 5241; https://doi.org/10.3390/molecules25225241 - 10 Nov 2020

Cited by 3 | Viewed by 2392

Abstract

High-porosity monolithic composite aerogels of syndiotactic polystyrene (sPS) and poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) containing reduced graphene oxide (r-GO) were prepared and characterized. The composite aerogels obtained by supercritical carbon dioxide (scCO₂) extraction of sPS/r-GO and PPO/r-GO gels were characterized by a fibrillar morphology, which ensured good handling properties. The polymer nanoporous crystalline phases obtained within the aerogels led to high surface areas with values up to 440 m² g⁻¹. The role of r-GO in aerogels was studied in terms of catalytic activity by exploring the oxidation capacity of composite PPO and sPS aerogels toward benzyl alcohol in diluted aqueous solutions. The results showed that, unlike sPS/r-GO aerogels, PPO/r-GO aerogels were capable of absorbing benzyl alcohol from the diluted solutions, and that oxidation of c.a. 50% of the sorbed benzyl alcohol molecules into benzoic acid occurred. Full article

(This article belongs to the Special Issue A Themed Issue in Honor of Professor Ernesto Reverchon: The Top 20 in Chemical Engineering)

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14 pages, 1883 KiB

Open AccessArticle

Effect of Ethanol on the Textural Properties of Whey Protein and Egg White Protein Hydrogels during Water-Ethanol Solvent Exchange

by Christian Kleemann, Joël Zink, Ilka Selmer, Irina Smirnova and Ulrich Kulozik

Molecules 2020, 25(19), 4417; https://doi.org/10.3390/molecules25194417 - 25 Sep 2020

Cited by 12 | Viewed by 4392

Abstract

This study aims at investigating the effect of ethanol (EtOH) on the textural properties of whey protein and egg white protein hydrogels. The hydrogels were produced by thermally induced gel formation of aqueous protein solutions. The water contained in the gel network was subsequently exchanged by EtOH to assess structural changes upon exposure of hydrogels to ethanolic aqueous phases. The textural properties of the hydrogel and alcogel samples were analyzed by uniaxial compression tests. For both protein sources, the hardness increased exponentially when pH and EtOH concentration were increased. This increase correlated with a shrinkage of the gel samples. The gel texture was found to be elastic at low EtOH concentrations and became stiff and hard at higher EtOH concentrations. It was found that the solvent exchange influences the ion concentration within the gels and, therefore, the interactions between molecules in the gel structure. Non-covalent bonds were identified as substantially responsible for the gel structure. Full article

(This article belongs to the Special Issue A Themed Issue in Honor of Professor Ernesto Reverchon: The Top 20 in Chemical Engineering)

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Review

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19 pages, 1075 KiB

Open AccessReview

Biopesticide Encapsulation Using Supercritical CO₂: A Comprehensive Review and Potential Applications

by Dário Rodrigues do Nascimento Junior, Antonio Tabernero, Elaine Christine de Magalhães Cabral Albuquerque and Silvio Alexandre Beisl Vieira de Melo

Molecules 2021, 26(13), 4003; https://doi.org/10.3390/molecules26134003 - 30 Jun 2021

Cited by 15 | Viewed by 4017

Abstract

As an alternative to synthetic pesticides, natural chemistries from living organisms, are not harmful to nontarget organisms and the environment, can be used as biopesticides, nontarget. However, to reduce the reactivity of active ingredients, avoid undesired reactions, protect from physical stress, and control or lower the release rate, encapsulation processes can be applied to biopesticides. In this review, the advantages and disadvantages of the most common encapsulation processes for biopesticides are discussed. The use of supercritical fluid technology (SFT), mainly carbon dioxide (CO₂), to encapsulate biopesticides is highlighted, as they reduce the use of organic solvents, have simpler separation processes, and achieve high-purity particles. This review also presents challenges to be surpassed and the lack of application of SFT for biopesticides in the published literature is discussed to evaluate its potential and prospects. Full article

(This article belongs to the Special Issue A Themed Issue in Honor of Professor Ernesto Reverchon: The Top 20 in Chemical Engineering)

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A Themed Issue in Honor of Professor Ernesto Reverchon: The Top 20 in Chemical Engineering

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