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16 pages, 5449 KiB

Open AccessArticle

Carbon Materials Prepared from Invading Pelagic Sargassum for Supercapacitors’ Electrodes

by Sandra Roche, Christelle Yacou, Corine Jean Marius, Ronald Ranguin, Marckens Francoeur, Pierre-Louis Taberna, Nady Passe-Coutrin and Sarra Gaspard

Molecules 2023, 28(15), 5882; https://doi.org/10.3390/molecules28155882 - 04 Aug 2023

Viewed by 862

Abstract

Since 2011, substantial amounts of pelagic Sargassum algae have washed up along the Caribbean beaches and the Gulf of Mexico, leading to negative impacts on the economy and the environment of those areas. Hence, it is now crucial to develop strategies to mitigate [...] Read more.

Since 2011, substantial amounts of pelagic Sargassum algae have washed up along the Caribbean beaches and the Gulf of Mexico, leading to negative impacts on the economy and the environment of those areas. Hence, it is now crucial to develop strategies to mitigate this problem while valorizing such invasive biomass. This work deals with the successful exploitation of this pelagic Sargassum seaweed for the fabrication of carbon materials that can be used as electrodes for supercapacitors. Pelagic Sargassum precursors were simply pyrolyzed at temperatures varying from 600 to 900 °C. The resultant carbonaceous materials were then extensively characterized using different techniques, such as nitrogen adsorption for textural characterization, as well as X-ray photoelectron (XPS), Fourier transform infrared spectroscopies (FT-IR) and scanning electron microscopy (SEM), to understand their structures and functionalities. The electrochemical properties of the carbon materials were also tested for their performance as supercapacitors using cyclic voltammetry (CV), the galvanostatic method and electrochemical impedance spectroscopy analyses (EIS). We managed to have a large specific surface, i.e., 1664 m² g⁻¹ for biochar prepared at 800 °C (CS800). Eventually, CS800 turned out to exhibit the highest capacitance (96 F g⁻¹) over the four samples, along with the highest specific surface (1664 m² g⁻¹), with specific resistance of about 0.07 Ω g ⁻¹. Full article

(This article belongs to the Special Issue Feature Papers in Applied Chemistry)

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18 pages, 3867 KiB

Open AccessArticle

Synthesis and Evaluation of Fluorine-18-Labeled L-Rhamnose Derivatives

by Xiang Zhang, Falguni Basuli, Zhen-Dan Shi, Swati Shah, Jianfeng Shi, Amelia Mitchell, Jianhao Lai, Zeping Wang, Dima A. Hammoud and Rolf E. Swenson

Molecules 2023, 28(9), 3773; https://doi.org/10.3390/molecules28093773 - 27 Apr 2023

Viewed by 1415

Abstract

The use of radiolabeled glucose for PET imaging resulted in the most commonly used tracer in the clinic, 2-deoxy-2-[¹⁸F]fluoroglucose (FDG). More recently, other radiolabeled sugars have been reported for various applications, including imaging tumors and infections. Therefore, in this study, we [...] Read more.

The use of radiolabeled glucose for PET imaging resulted in the most commonly used tracer in the clinic, 2-deoxy-2-[¹⁸F]fluoroglucose (FDG). More recently, other radiolabeled sugars have been reported for various applications, including imaging tumors and infections. Therefore, in this study, we developed a series of fluorine-18-labeled L-rhamnose derivatives as potential PET tracers of various fungal and bacterial strains. Acetyl-protected triflate precursors of rhamnose were prepared and radiolabeled with fluorine-18 followed by hydrolysis to produce L-deoxy [¹⁸F]fluororhamnose. The overall radiochemical yield was 7–27% in a 90 min synthesis time with a radiochemical purity of 95%. In vivo biodistribution of the ligands using PET imaging showed that 2-deoxy-2-[¹⁸F]fluoro-L-rhamnose is stable for at least up to 60 min in mice and eliminated via renal clearance. The tracer also exhibited minimal tissue or skeletal uptake in healthy mice resulting in a low background signal. Full article

(This article belongs to the Special Issue Feature Papers in Applied Chemistry)

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17 pages, 4474 KiB

Open AccessArticle

Passivation Effect of the Chlorinated Paraffin Added in the Cutting Fluid on the Surface Corrosion Resistance of the Stainless Steel

by Lan Yan, Xingguo Yao, Tian Zhang, Feng Jiang, Yan Shui, Hong Xie, Zhiyang Xiang, Yousheng Li and Liangliang Lin

Molecules 2023, 28(9), 3648; https://doi.org/10.3390/molecules28093648 - 22 Apr 2023

Cited by 3 | Viewed by 1115

Abstract

Cutting fluids are the most effective method to lower the cutting temperature and decrease the cutting tool wear. At the same time, the cutting fluids influence the corrosion resistance property of the machined surface. In this study, chlorinated paraffin (CP), which is a [...] Read more.

Cutting fluids are the most effective method to lower the cutting temperature and decrease the cutting tool wear. At the same time, the cutting fluids influence the corrosion resistance property of the machined surface. In this study, chlorinated paraffin (CP), which is a common additive in the cutting fluid, was selected as the research objective to study its corrosion resistance property. The passivation effect of CP with different concentrations on the machined surface of stainless steel was studied. Electrochemical measurements and surface morphology investigation were used to characterize the passivation effect of CP with different concentrations. The test results showed that the corrosion resistance of stainless steel in the cutting fluid was enhanced with the increase in CP additive. This reason is that the charge transfer resistance increases and the corrosion current density decreases with the increase in CP additive. The X-ray photoelectron spectroscopy (XPS) results show that the proportion of metal oxides on the processed surface of the stainless steel sample was increased from 20.4% to 22.0%, 32.9%, 26.6%, and 31.1% after adding 1 mL, 2 mL, 4 mL and 6 mL CP in the cutting fluid with a total volume of 500 mL, respectively. The oxidation reaction between CP and the stainless steel sample resulted in an increase in metal oxides proportion, which prevented the stainless steel sample from corrosion in cutting fluid. Full article

(This article belongs to the Special Issue Feature Papers in Applied Chemistry)

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13 pages, 4141 KiB

Open AccessArticle

Metalorganic Chemical Vapor Deposition Approach to the Synthesis of Perovskite BaCeO₃ and BaCe_0.8Y_0.2O₃ Thin Films

by Anna L. Pellegrino, Francesca Lo Presti and Graziella Malandrino

Molecules 2023, 28(8), 3303; https://doi.org/10.3390/molecules28083303 - 07 Apr 2023

Cited by 2 | Viewed by 1058

Abstract

In the present energetic scenario, the development of materials with high potentiality in the technological fields of energy conversion processes, production and storage of hydrogen, are of great interest in the scientific community. In particular, we report for the first time the fabrication [...] Read more.

In the present energetic scenario, the development of materials with high potentiality in the technological fields of energy conversion processes, production and storage of hydrogen, are of great interest in the scientific community. In particular, we report for the first time the fabrication of crystalline and homogeneous barium-cerate-based materials in the form of thin films on various substrates. Starting from the β-diketonate precursor sources Ce(hfa)₃diglyme, Ba(hfa)₂tetraglyme and Y(hfa)₃diglyme (Hhfa = 1,1,1,5,5,5-hexafluoroacetylacetone; diglyme = bis(2-methoxyethyl)ether; tetraglyme = 2,5,8,11,14-pentaoxapentadecane), a metalorganic chemical vapor deposition (MOCVD) approach has been successfully applied to the fabrication of BaCeO₃ and doped BaCe_0.8Y_0.2O₃ systems in the form of thin films. Structural, morphological and compositional analyses allowed for an accurate determination of the properties of deposited layers. The present approach represents a simple, easily scalable, and industrially appealing process for the production of compact and homogeneous barium cerate thin films. Full article

(This article belongs to the Special Issue Feature Papers in Applied Chemistry)

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21 pages, 7561 KiB

Open AccessArticle

Structure Features and Physicochemical Performances of Fe-Contained Clinoptilolites Obtained via the Aqueous Exchange of the Balanced Cations and Isomorphs Substitution of the Heulandite Skeletons for Electrocatalytic Activity of Oxygen Evolution Reaction and Adsorptive Performance of CO₂

by Chunlei Wan, Xueqing Cui, Ming Liu, Bang Xu, Jihong Sun and Shiyang Bai

Molecules 2023, 28(7), 2889; https://doi.org/10.3390/molecules28072889 - 23 Mar 2023

Cited by 1 | Viewed by 986

Abstract

Fe(III)-modified clinoptilolites (Fe-CPs) were prepared by hydrothermal treatment. The collapse of the heulandite skeletons was avoided by adjusting the pH value using HCl solution, showing the maximum relative crystallinity of the Fe-CPs at an optimal pH of 1.3. The competitive exchange performances between [...] Read more.

Fe(III)-modified clinoptilolites (Fe-CPs) were prepared by hydrothermal treatment. The collapse of the heulandite skeletons was avoided by adjusting the pH value using HCl solution, showing the maximum relative crystallinity of the Fe-CPs at an optimal pH of 1.3. The competitive exchange performances between Fe³⁺ ions and H⁺ with Na⁺ (and K⁺) suggested that the exchange sites were more easily occupied by H⁺. Various characterizations verified that the hydrothermal treatments had a strong influence on the dispersion and morphology of the isolated and clustered Fe species. The high catalytic activity of the oxygen evolution reaction indicated the insertion of Fe³⁺ into the skeletons and the occurrences of isomorphic substitution. The fractal evolutions revealed that hydrothermal treatments with the increase of Fe content strongly affected the morphologies of Fe species with rough and disordered surfaces. Meanwhile, the Fe(III)-modified performances of the CPs were systematically investigated, showing that the maximum Fe-exchange capacity was up to 10.6 mg/g. Their thermodynamic parameters and kinetic performances suggested that the Fe(III)-modified procedures belonged to spontaneous, endothermic, and entropy-increasing behaviors. Finally, their adsorption capacities of CO₂ at 273 and 298 K were preliminarily evaluated, showing high CO₂ adsorption capacity (up to 1.67 mmol/g at 273 K). Full article

(This article belongs to the Special Issue Feature Papers in Applied Chemistry)

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22 pages, 11279 KiB

Open AccessArticle

O,S-Acetals in a New Modification of oxo-Friedel–Crafts–Bradsher Cyclization—Synthesis of Fluorescent (Hetero)acenes and Mechanistic Considerations

by Krzysztof Owsianik, Ewa Różycka-Sokołowska and Piotr Bałczewski

Molecules 2023, 28(6), 2474; https://doi.org/10.3390/molecules28062474 - 08 Mar 2023

Cited by 1 | Viewed by 1285

Abstract

This paper presents the use of O,S-acetals in a new modification of the oxo-Friedel–Crafts–Bradsher cyclization. In this reaction, under mild reaction conditions (25 °C), three- and four-ring fused RO-acenes (major) and/or HO(CH₂)₂S-acenes (minor) are formed, [...] Read more.

This paper presents the use of O,S-acetals in a new modification of the oxo-Friedel–Crafts–Bradsher cyclization. In this reaction, under mild reaction conditions (25 °C), three- and four-ring fused RO-acenes (major) and/or HO(CH₂)₂S-acenes (minor) are formed, the latter products having never been observed before in this type of cyclization. In this way, two electronically different fluorophores could be obtained in a single cyclization reaction, one of them having strong electron donor properties (+M effect of alkoxy groups) and the other having donor-acceptor properties (+M and −I effects of the HO(CH₂)₂S-group, Hammett’s constants). Further increasing the reaction temperature, HCl concentration or prolonging reaction time, surprisingly, yielded a 2:1 mixture of cis and trans dimeric isomers, as the only products of this cyclization. The DFT calculations confirmed a greater stability of the cis isomer compared to the trans isomer. The formation of unexpected dimeric products and HO(CH₂)₂S-acenes sheds light on the mechanism of oxo-Friedel–Crafts–Bradsher cyclization, involving competitive O/S atom protonation in strained O,S-acetals and in strain-free side groups of intermediate species. Full article

(This article belongs to the Special Issue Feature Papers in Applied Chemistry)

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13 pages, 2921 KiB

Open AccessArticle

Antibacterial Properties of Polyurethane Foams Additivated with Terpenes from a Bio-Based Polyol

by Simona Tomaselli, Fabio Bertini, Angelica Cifarelli, Adriano Vignali, Laura Ragona and Simona Losio

Molecules 2023, 28(4), 1966; https://doi.org/10.3390/molecules28041966 - 18 Feb 2023

Cited by 4 | Viewed by 2156

Abstract

Water-blown polyurethane (PU) foams were prepared by bio-polyols from epoxidized linseed oils and caprylic acid in combination with toluene diisocianate (TDI). A series of terpenes (menthol, geraniol, terpineol, and borneol), natural compounds with recognized antibacterial properties, were included in the starting formulations to [...] Read more.

Water-blown polyurethane (PU) foams were prepared by bio-polyols from epoxidized linseed oils and caprylic acid in combination with toluene diisocianate (TDI). A series of terpenes (menthol, geraniol, terpineol, and borneol), natural compounds with recognized antibacterial properties, were included in the starting formulations to confer bactericidal properties to the final material. Foams additivated with Irgasan^®, a broad-spectrum antimicrobial molecule, were prepared as reference. The bactericidal activity of foams against planktonic and sessile E. coli (ATCC 11229) and S. aureus (ATCC 6538) was evaluated following a modified AATCC 100-2012 static method. Menthol-additivated foams showed broad-spectrum antibacterial activity, reducing Gram+ and Gram− viability by more than 60%. Foams prepared with borneol and terpineol showed selective antibacterial activity against E. coli and S. aureus, respectively. NMR analysis of foams leaking in water supported a bactericidal mechanism mediated by contact killing rather than molecule release. The results represent the proof of concept of the possibility to develop bio-based PU foams with intrinsic bactericidal properties through a simple and innovative synthetic approach. Full article

(This article belongs to the Special Issue Feature Papers in Applied Chemistry)

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11 pages, 925 KiB

Open AccessArticle

Structure and Vibrational Spectroscopy of C₈₂ Fullerenol Valent Isomers: An Experimental and Theoretical Joint Study

by Felix N. Tomilin, Polina V. Artyushenko, Irina A. Shchugoreva, Anastasia V. Rogova, Natalia G. Vnukova, Grigory N. Churilov, Nikolay P. Shestakov, Olga N. Tchaikovskaya, Sergei G. Ovchinnikov and Pavel V. Avramov

Molecules 2023, 28(4), 1569; https://doi.org/10.3390/molecules28041569 - 06 Feb 2023

Cited by 1 | Viewed by 1810

Abstract

Gd@C₈₂O_xH_y endohedral complexes for advanced biomedical applications (computer tomography, cancer treatment, etc.) were synthesized using high-frequency arc plasma discharge through a mixture of graphite and Gd₂O₃ oxide. The Gd@C₈₂ endohedral complex was isolated by [...] Read more.

Gd@C₈₂O_xH_y endohedral complexes for advanced biomedical applications (computer tomography, cancer treatment, etc.) were synthesized using high-frequency arc plasma discharge through a mixture of graphite and Gd₂O₃ oxide. The Gd@C₈₂ endohedral complex was isolated by high-efficiency liquid chromatography and consequently oxidized with the formation of a family of Gd endohedral fullerenols with gross formula Gd@C₈₂O₈(OH)₂₀. Fourier-transformed infrared (FTIR) spectroscopy was used to study the structure and spectroscopic properties of the complexes in combination with the DFTB3 electronic structure calculations and infrared spectra simulations. It was shown that the main IR spectral features are formed by a fullerenole C₈₂ cage that allows one to consider the force constants at the DFTB3 level of theory without consideration of gadolinium endohedral ions inside the carbon cage. Based on the comparison of experimental FTIR and theoretical DFTB3 IR spectra, it was found that oxidation of the C₈₂ cage causes the formation of Gd@C₈₂O₂₈H₂₀, with a breakdown of the integrity of the parent C₈₂ cage with the formation of pores between neighboring carbonyl and carboxyl groups. The Gd@C₈₂O₆(OOH)₂(OH)₁₈ endohedral complex with epoxy, carbonyl and carboxyl groups was considered the most reliable fullerenole structural model. Full article

(This article belongs to the Special Issue Feature Papers in Applied Chemistry)

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11 pages, 3457 KiB

Open AccessArticle

Synthesis of Triblock Polycarboxylate Superplasticizers with Well-Defined Structure and Its Dispersing Performance in β-Hemihydrate Gypsum

by Guangming Guo, Guohua Gao, Weiliang Jiang, Xianglong Wang, Meishan Pei and Luyan Wang

Molecules 2023, 28(2), 513; https://doi.org/10.3390/molecules28020513 - 04 Jan 2023

Cited by 1 | Viewed by 1478

Abstract

In this work, a novel A_aBA_b-type triblock polycarboxylate superplasticizers (PCEs) with well defined molecular structures were designed and synthesized, firstly, by reversible addition-fragmentation chain transfer (RAFT) polymerization, to explore the structure–property relationship PCEs in the β-hemihydrate gypsum (β-HH) system. [...] Read more.

In this work, a novel A_aBA_b-type triblock polycarboxylate superplasticizers (PCEs) with well defined molecular structures were designed and synthesized, firstly, by reversible addition-fragmentation chain transfer (RAFT) polymerization, to explore the structure–property relationship PCEs in the β-hemihydrate gypsum (β-HH) system. Three PCEs with the same molecular weight and different structure were obtained by changing the feed ratio of the RAFT agent, initiator, and monomer. The effect of the chemical structure of PCEs on their dispersing property and water reduction capacity were assessed in gypsum by measuring the flowability of pastes and the adsorption ability of PCEs on gypsum. Results showed that among three PCEs, when the monomer ratio is 5:1 and a:b = 1:1, PCE-1 exhibited a higher working efficiency, verifying the contribution of regulating structural parameters to the improvement in performances of gypsum paste, because PCE-1 showed the strongest binding capacity with calcium ions due to the relatively equal amount of carboxyl groups at both ends. The A_aBA_b-type PCEs provide a special advantage over the conventional comb polymer to understand the relation between the structure and property of PCEs, and a direction for further development of PCEs of high performance. Full article

(This article belongs to the Special Issue Feature Papers in Applied Chemistry)

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13 pages, 2778 KiB

Open AccessArticle

Polypyrrole-Coated Low-Crystallinity Iron Oxide Grown on Carbon Cloth Enabling Enhanced Electrochemical Supercapacitor Performance

by Chunhui Wu, Zifan Pei, Menglin Lv, Duchen Huang, Yuan Wang and Shaojun Yuan

Molecules 2023, 28(1), 434; https://doi.org/10.3390/molecules28010434 - 03 Jan 2023

Cited by 6 | Viewed by 1649

Abstract

It is highly attractive to design pseudocapacitive metal oxides as anodes for supercapacitors (SCs). However, as they have poor conductivity and lack active sites, they generally exhibit an unsatisfied capacitance under high current density. Herein, polypyrrole-coated low-crystallinity Fe₂O₃ supported on [...] Read more.

It is highly attractive to design pseudocapacitive metal oxides as anodes for supercapacitors (SCs). However, as they have poor conductivity and lack active sites, they generally exhibit an unsatisfied capacitance under high current density. Herein, polypyrrole-coated low-crystallinity Fe₂O₃ supported on carbon cloth (D-Fe₂O₃@PPy/CC) was prepared by chemical reduction and electrodeposition methods. The low-crystallinity Fe₂O₃ nanorod achieved using a NaBH₄ treatment offered more active sites and enhanced the Faradaic reaction in surface or near-surface regions. The construction of a PPy layer gave more charge storage at the Fe₂O₃/PPy interface, favoring the limitation of the volume effect derived from Na⁺ transfer in the bulk phase. Consequently, D-Fe₂O₃@PPy/CC displayed enhanced capacitance and stability. In 1 M Na₂SO₄, it showed a specific capacitance of 615 mF cm⁻² (640 F g⁻¹) at 1 mA cm⁻² and still retained 79.3% of its initial capacitance at 10 mA cm⁻² after 5000 cycles. The design of low-crystallinity metal oxides and polymer nanocomposites is expected to be widely applicable for the development of state-of-the-art electrodes, thus opening new avenues for energy storage. Full article

(This article belongs to the Special Issue Feature Papers in Applied Chemistry)

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13 pages, 11734 KiB

Open AccessArticle

In Situ Synthesis of C-N@NiFe₂O₄@MXene/Ni Nanocomposites for Efficient Electromagnetic Wave Absorption at an Ultralow Thickness Level

by Qing Sun, Xin Yang, Tie Shu, Xianfeng Yang, Min Qiao, Dashuang Wang, Zhaohui Liu, Xinghua Li, Jinsong Rao, Yuxin Zhang, Pingan Yang and Kexin Yao

Molecules 2023, 28(1), 233; https://doi.org/10.3390/molecules28010233 - 27 Dec 2022

Cited by 5 | Viewed by 1797

Abstract

Recently, the development of composite materials composed of magnetic materials and MXene has attracted significant attention. However, the thickness and microwave absorption performance of the composite is still barely satisfactory. In this work, the C-N@NiFe₂O₄@MXene/Ni nanocomposites were successfully synthesized [...] Read more.

Recently, the development of composite materials composed of magnetic materials and MXene has attracted significant attention. However, the thickness and microwave absorption performance of the composite is still barely satisfactory. In this work, the C-N@NiFe₂O₄@MXene/Ni nanocomposites were successfully synthesized in situ by hydrothermal and calcination methods. Benefiting from the introduction of the carbon-nitrogen(C-N) network structure, the overall dielectric properties are improved effectively, consequently reducing the thickness of the composite while maintaining excellent absorption performance. As a result, the minimum reflection loss of C-N@NiFe₂O₄@MXene/Ni can reach −50.51 dB at 17.3 GHz at an ultralow thickness of 1.5 mm, with an effective absorption bandwidth of 4.95 GHz (13.02–18 GHz). This research provides a novel strategy for materials to maintain good absorption performance at an ultralow thickness level. Full article

(This article belongs to the Special Issue Feature Papers in Applied Chemistry)

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17 pages, 12707 KiB

Open AccessArticle

Bridges and Vertices in Heteroboranes

by Stuart A. Macgregor and Alan J. Welch

Molecules 2023, 28(1), 190; https://doi.org/10.3390/molecules28010190 - 26 Dec 2022

Viewed by 1165

Abstract

A number of (hetero)boranes are known in which a main group atom X ‘bridges’ a B—B connectivity in the open face, and in such species X has previously been described as simply a bridge or, alternatively, as a vertex in a larger cluster. [...] Read more.

A number of (hetero)boranes are known in which a main group atom X ‘bridges’ a B—B connectivity in the open face, and in such species X has previously been described as simply a bridge or, alternatively, as a vertex in a larger cluster. In this study we describe an approach to distinguish between these options based on identifying the best fit of the experimental {B_x} cluster fragment with alternate exemplar {B_x} fragments derived from DFT-optimized [B_nH_n]²⁻ models. In most of the examples studied atom X is found to be better regarded as a vertex, having ‘a ‘verticity’ of ca. 60–65%. Consideration of our results leads to the suggestion that the radial electron contribution from X to the overall skeletal electron count is more significant than the tangential contribution. Full article

(This article belongs to the Special Issue Feature Papers in Applied Chemistry)

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13 pages, 2871 KiB

Open AccessArticle

From the Streets to the Judicial Evidence: Determination of Traditional Illicit Substances in Drug Seizures by a Rapid and Sensitive UHPLC-MS/MS-Based Platform

by Fabio Gosetti, Viviana Consonni, Davide Ballabio, Marco Emilio Orlandi, Angelo Amodio, Maria Valeria Picci, Marco Visentin and Veronica Termopoli

Molecules 2023, 28(1), 164; https://doi.org/10.3390/molecules28010164 - 25 Dec 2022

Cited by 1 | Viewed by 1958

Abstract

According to the 2021 World Drug Report, around 275 million people use drugs of abuse, and 36 million people suffer from addiction, fostering a thriving market for illicit substances. In Italy, 30,083 people were reported to the Judicial Authority for offenses in violation [...] Read more.

According to the 2021 World Drug Report, around 275 million people use drugs of abuse, and 36 million people suffer from addiction, fostering a thriving market for illicit substances. In Italy, 30,083 people were reported to the Judicial Authority for offenses in violation of the Italian Law D.P.R. 309/1990. These offences are sentenced after a qualitative–quantitative analysis of seized materials. Given the large quantity of seized drugs and the need to perform accurate analytical determinations, Italian forensic laboratories struggle to complete analyses in a short time, delaying the entire reporting process needed to achieve sentencing. For this purpose, an UHPLC-MS/MS-based platform was developed at the University of Milano-Bicocca to support law-enforcement authorities. Software was designed to easily manage street seizure acquisition, documentation registration, and sampling. A sensitive UHPLC-MS/MS method was fully validated for the quantification of the traditional illicit substances (cocaine, heroin, 6-MAM, morphine, amphetamine, methamphetamine, MDMA, ketamine, GHB, GBL, LSD, trans-∆9-THC, and THCA) at the ppb level. The final report is relayed to the Prefecture in 3–4 days, even within 24 h for urgent requests. The platform allows for semi-automatic data handling to minimize erroneous results for an accurate report generation by standardized procedures. Full article

(This article belongs to the Special Issue Feature Papers in Applied Chemistry)

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12 pages, 1573 KiB

Open AccessArticle

Nitrogen-Doped Carbon Quantum Dots for Biosensing Applications: The Effect of the Thermal Treatments on Electrochemical and Optical Properties

by Francesco Ghezzi, Riccardo Donnini, Antonio Sansonetti, Umberto Giovanella, Barbara La Ferla and Barbara Vercelli

Molecules 2023, 28(1), 72; https://doi.org/10.3390/molecules28010072 - 22 Dec 2022

Cited by 2 | Viewed by 1695

Abstract

The knowledge of the ways in which post-synthesis treatments may influence the properties of carbon quantum dots (CDs) is of paramount importance for their employment in biosensors. It enables the definition of the mechanism of sensing, which is essential for the application of [...] Read more.

The knowledge of the ways in which post-synthesis treatments may influence the properties of carbon quantum dots (CDs) is of paramount importance for their employment in biosensors. It enables the definition of the mechanism of sensing, which is essential for the application of the suited design strategy of the device. In the present work, we studied the ways in which post-synthesis thermal treatments influence the optical and electrochemical properties of Nitrogen-doped CDs (N-CDs). Blue-emitting, N-CDs for application in biosensors were synthesized through the hydrothermal route, starting from citric acid and urea as bio-synthesizable and low-cost precursors. The CDs samples were thermally post-treated and then characterized through a combination of spectroscopic, structural, and electrochemical techniques. We observed that the post-synthesis thermal treatments show an oxidative effect on CDs graphitic N-atoms. They cause their partially oxidation with the formation of mixed valence state systems, [CDs]⁰⁺, which could be further oxidized into the graphitic N-oxide forms. We also observed that thermal treatments cause the decomposition of the CDs external ammonium ions into ammonia and protons, which protonate their pyridinic N-atoms. Photoluminescence (PL) emission is quenched. Full article

(This article belongs to the Special Issue Feature Papers in Applied Chemistry)

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20 pages, 4080 KiB

Open AccessArticle

Polymeric Nanoparticles with Embedded Eu(III) Complexes as Molecular Probes for Temperature Sensing

by Kirill M. Kuznetsov, Vadim A. Baigildin, Anastasia I. Solomatina, Ekaterina E. Galenko, Alexander F. Khlebnikov, Victor V. Sokolov, Sergey P. Tunik and Julia R. Shakirova

Molecules 2022, 27(24), 8813; https://doi.org/10.3390/molecules27248813 - 12 Dec 2022

Cited by 2 | Viewed by 1567

Abstract

Three novel luminescent Eu(III) complexes, Eu1–Eu3, have been synthesized and characterized with CHN analysis, mass-spectrometry and ¹H NMR spectroscopy. The complexes display strong emission in dichloromethane solution upon excitation at 405 and 800 nm with a quantum yield from [...] Read more.

Three novel luminescent Eu(III) complexes, Eu1–Eu3, have been synthesized and characterized with CHN analysis, mass-spectrometry and ¹H NMR spectroscopy. The complexes display strong emission in dichloromethane solution upon excitation at 405 and 800 nm with a quantum yield from 18.3 to 31.6%, excited-state lifetimes in the range of 243–1016 ms at 20 °C, and lifetime temperature sensitivity of 0.9%/K (Eu1), 1.9%/K (Eu2), and 1.7%/K (Eu3). The chromophores were embedded into biocompatible latex nanoparticles (NPs_Eu1–NPs_Eu3) that prevented emission quenching and kept the photophysical characteristics of emitters unchanged with the highest temperature sensitivity of 1.3%/K (NPs_Eu2). For this probe cytotoxicity, internalization dynamics and localization in CHO-K1 cells were studied together with lifetime vs. temperature calibration in aqueous solution, phosphate buffer, and in a mixture of growth media and fetal bovine serum. The obtained data were then averaged to give the calibration curve, which was further used for temperature estimation in biological samples. The probe was stable in physiological media and displayed good reproducibility in cycling experiments between 20 and 40 °C. PLIM experiments with thermostated CHO-K1 cells incubated with NPs_Eu2 indicated that the probe could be used for temperature estimation in cells including the assessment of temperature variations upon chemical shock (sample treatment with mitochondrial uncoupling reagent). Full article

(This article belongs to the Special Issue Feature Papers in Applied Chemistry)

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13 pages, 1941 KiB

Open AccessArticle

Design of a New Chiral Deep Eutectic Solvent Based on 3-Amino-1,2-propanediol and Its Application in Organolithium Chemistry

by Achille Antenucci, Matteo Bonomo, Simone Ghinato, Marco Blangetti and Stefano Dughera

Molecules 2022, 27(23), 8566; https://doi.org/10.3390/molecules27238566 - 05 Dec 2022

Cited by 2 | Viewed by 2131

Abstract

A chiral glycerol derivative, namely 3-amino-1,2-propanediol, was employed for as the hydrogen bond donor (HBD) in the design of a new deep eutectic solvent (DES) with choline chloride acting as the hydrogen bond acceptor (HBA). The novel mixture was characterized and unambiguously classified [...] Read more.

A chiral glycerol derivative, namely 3-amino-1,2-propanediol, was employed for as the hydrogen bond donor (HBD) in the design of a new deep eutectic solvent (DES) with choline chloride acting as the hydrogen bond acceptor (HBA). The novel mixture was characterized and unambiguously classified as a DES. Furthermore, its synthetic usefulness was demonstrated in the room-temperature n-butyllithium-addition under air to carbonyl compounds and benzyl chloride. In some cases, pure products (100% conversion) were obtained by a simple extractive work-up in up to 72% isolated yield, thus suggesting the potential practical usefulness of this procedure as a green alternative to the classical Schenk procedure in volatile organic solvents for the synthesis of tertiary alcohols. The chirality of the HBD, bearing an interesting basic primary amino group, is an intriguing feature currently under investigation for further exploitation. Full article

(This article belongs to the Special Issue Feature Papers in Applied Chemistry)

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12 pages, 3001 KiB

Open AccessFeature PaperArticle

A Comparative Study of Cellulose Ethers as Thermotropic Materials for Self-Tracking Solar Concentrators

by Francesco Galeotti, Lorenzo Scatena, Franco Trespidi and Mariacecilia Pasini

Molecules 2022, 27(23), 8464; https://doi.org/10.3390/molecules27238464 - 02 Dec 2022

Viewed by 1107

Abstract

The continuous growth in energy demand requires researchers to find new solutions to enlarge and diversify the possible ways of exploiting renewable energy sources. Our idea is the development of a solar concentrator based on trapping the luminous radiation with a smart window. [...] Read more.

The continuous growth in energy demand requires researchers to find new solutions to enlarge and diversify the possible ways of exploiting renewable energy sources. Our idea is the development of a solar concentrator based on trapping the luminous radiation with a smart window. This system is able to direct light towards the photovoltaic cells placed on window borders and produce electricity, without any movable part and without changing its transparency. Herein, we report a detailed study of cellulose ethers, a class of materials of natural origin capable of changing their state, from transparent aqueous solution to scattering hydrogel, in response to a temperature change. Cellulose thermotropism can be used to produce a scattering spot in a window filled with the thermotropic fluid to create a new kind of self-tracking solar concentrator. We demonstrate that the properties of the thermotropic fluid can be finely tuned by selecting the cellulose functionalization, the co-dissolved salt, and by regulating their dosage. Lastly, the results of our investigation are tested in a proof-of-concept demonstration of solar concentration achieved by thermotropism-based light trapping. Full article

(This article belongs to the Special Issue Feature Papers in Applied Chemistry)

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11 pages, 1585 KiB

Open AccessArticle

Activity of Mono-, Bi-, and Trimetallic Catalysts Pt-Ni-Cr/C in the Bicyclohexyl Dehydrogenation Reaction

by Alexander N. Kalenchuk and Leonid M. Kustov

Molecules 2022, 27(23), 8416; https://doi.org/10.3390/molecules27238416 - 01 Dec 2022

Cited by 1 | Viewed by 1130

Abstract

The influence of metals with different redox properties and a carbon carrier on the activity of mono-, bi- and trimetallic Pt-Ni-Cr/C catalysts has been studied in the bicyclohexyl dehydrogenation reaction as the hydrogen release stage in hydrogen storage. An increase in the conversion [...] Read more.

The influence of metals with different redox properties and a carbon carrier on the activity of mono-, bi- and trimetallic Pt-Ni-Cr/C catalysts has been studied in the bicyclohexyl dehydrogenation reaction as the hydrogen release stage in hydrogen storage. An increase in the conversion (X > 62%) of bicyclohexyl and selectivity for biphenyl (S > 84%) was observed on trimetallic catalysts Pt-Ni-Cr/C compared with the monometallic catalyst Rt/C (X > 55%; S > 68%). It has been established that the increase in the conversion of bicyclohexyl and selectivity for biphenyl in the dehydrogenation reaction on trimetallic catalysts is due to an increase in the activity of Pt nanoparticles in the vicinity of local Cr-Ni clusters of solid substitution solutions. Full article

(This article belongs to the Special Issue Feature Papers in Applied Chemistry)

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19 pages, 2947 KiB

Open AccessArticle

Encapsulation of Vitamin C by Glycerol-Derived Dendrimers, Their Interaction with Biomimetic Models of Stratum corneum and Their Cytotoxicity

by Katia Bacha, Catherine Chemotti, Jean-Claude Monboisse, Anthony Robert, Aurélien L. Furlan, Willy Smeralda, Christian Damblon, Julien Estager, Sylvie Brassart-Pasco, Jean-Pierre Mbakidi, Jelena Pršić, Sandrine Bouquillon and Magali Deleu

Molecules 2022, 27(22), 8022; https://doi.org/10.3390/molecules27228022 - 18 Nov 2022

Cited by 1 | Viewed by 1714

Abstract

Vitamin C is one of the most sensitive cosmetic active ingredients. To avoid its degradation, its encapsulation into biobased carriers such as dendrimers is one alternative of interest. In this work, we wanted to evaluate the potential of two biobased glycerodendrimer families (GlyceroDendrimers-Poly(AmidoAmine) [...] Read more.

Vitamin C is one of the most sensitive cosmetic active ingredients. To avoid its degradation, its encapsulation into biobased carriers such as dendrimers is one alternative of interest. In this work, we wanted to evaluate the potential of two biobased glycerodendrimer families (GlyceroDendrimers-Poly(AmidoAmine) (GD-PAMAMs) or GlyceroDendrimers-Poly(Propylene Imine) (GD-PPIs)) as a vitamin C carrier for topical application. The higher encapsulation capacity of GD-PAMAM-3 compared to commercial PAMAM-3 and different GD-PPIs, and its absence of cytotoxicity towards dermal cells, make it a good candidate. Investigation of its mechanism of action was done by using two kinds of biomimetic models of stratum corneum (SC), lipid monolayers and liposomes. GD-PAMAM-3 and VitC@GD-PAMAM-3 (GD-PAMAM-3 with encapsulated vitamin C) can both interact with the lipid representatives of the SC lipid matrix, whichever pH is considered. However, only pH 5.0 is suggested to be favorable to release vitamin C into the SC matrix. Their binding to SC-biomimetic liposomes revealed only a slight effect on membrane permeability in accordance with the absence of cytotoxicity but an increase in membrane rigidity, suggesting a reinforcement of the SC barrier property. Globally, our results suggest that the dendrimer GD-PAMAM-3 could be an efficient carrier for cosmetic applications. Full article

(This article belongs to the Special Issue Feature Papers in Applied Chemistry)

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12 pages, 29834 KiB

Open AccessArticle

Au-TiO₂/Ti Hybrid Coating as a Liquid and Gas Diffusion Layer with Improved Performance and Stability in Proton Exchange Membrane Water Electrolyzer

by Gaoyang Liu, Shanlong Peng, Faguo Hou, Baizeng Fang and Xindong Wang

Molecules 2022, 27(19), 6644; https://doi.org/10.3390/molecules27196644 - 06 Oct 2022

Cited by 4 | Viewed by 1895

Abstract

The liquid and gas diffusion layer is a key component of proton exchange membrane water electrolyzer (PEMWE), and its interfacial contact resistance (ICR) and corrosion resistance have a great impact on the performance and durability of PEMWE. In this work, a novel hybrid [...] Read more.

The liquid and gas diffusion layer is a key component of proton exchange membrane water electrolyzer (PEMWE), and its interfacial contact resistance (ICR) and corrosion resistance have a great impact on the performance and durability of PEMWE. In this work, a novel hybrid coating with Au contacts discontinuously embedded in a titanium oxidized layer was constructed on a Ti felt via facile electrochemical metallizing and followed by a pre-oxidization process. The physicochemical characterizations, such as scanning electron microscopy, energy dispersive spectrometer, and X-ray diffraction results confirmed that the distribution and morphology of the Au contacts could be regulated with the electrical pulse time, and a hybrid coating (Au-TiO₂/Ti) was eventually achieved after the long-term stability test under anode environment. At the compaction force of 140 N cm⁻², the ICR was reduced from 19.7 mΩ cm² of the P-Ti to 4.2 mΩ cm² of the Au-TiO₂/Ti. The corrosion current density at 1.8 V (RHE) is 0.689 μA cm⁻². Both the ICR and corrosion resistance results showed that the prepared protective coating could provide comparable ICR and corrosion resistance to a dense Au coating. Full article

(This article belongs to the Special Issue Feature Papers in Applied Chemistry)

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20 pages, 28310 KiB

Open AccessFeature PaperArticle

Post-Functionalization of Organometallic Complexes via Click-Reaction

by Stanislav Petrovskii, Viktoria Khistiaeva, Aleksandra Paderina, Evgenia Abramova and Elena Grachova

Molecules 2022, 27(19), 6494; https://doi.org/10.3390/molecules27196494 - 01 Oct 2022

Cited by 2 | Viewed by 1930

Abstract

CuAAC (Cu catalyzed azide-alkyne cycloaddition) click-reaction is a simple and powerful method for the post-synthetic modification of organometallic complexes of transition metals. This approach allows the selective introduction of additional donor sites or functional groups to the periphery of the ligand environment. This [...] Read more.

CuAAC (Cu catalyzed azide-alkyne cycloaddition) click-reaction is a simple and powerful method for the post-synthetic modification of organometallic complexes of transition metals. This approach allows the selective introduction of additional donor sites or functional groups to the periphery of the ligand environment. This is especially important if a metalloligand with free donor sites, which are of the same nature as the primary site for the coordination of the primary metal, has to be created. The concept of post-synthetic modification of organometallic complexes by click-reaction is relatively recent and the currently available experimental material does not yet allow us to identify trends and formulate recommendations to address specific problems. In the present study, we have applied the CuAAC reaction for the post-synthetic modification of diimine mononuclear complexes Re(I), Pt(II) and Ir(III) with C≡C bonds at the periphery of the ligand environment and demonstrated that click-chemistry is a powerful tool for the tunable chemical post-synthetic modification of coordination compounds. Full article

(This article belongs to the Special Issue Feature Papers in Applied Chemistry)

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11 pages, 1628 KiB

Open AccessArticle

Controlled Thermal Release of L-Menthol with Cellulose-Acetate-Fiber-Shelled Metal-Organic Framework

by Xinjiao Cui, Donghao Ye, Jiankun Wei, Xiaodi Du, Pengzhao Wang and Junsheng Li

Molecules 2022, 27(18), 6013; https://doi.org/10.3390/molecules27186013 - 15 Sep 2022

Cited by 2 | Viewed by 1335

Abstract

Fragrances have been widely used in many customer products to improve the sensory quality and cover flavor defects. The key to the successful application of fragrance is to realize controlled fragrance release, which relies on the use of an appropriate carrier for fragrance. [...] Read more.

Fragrances have been widely used in many customer products to improve the sensory quality and cover flavor defects. The key to the successful application of fragrance is to realize controlled fragrance release, which relies on the use of an appropriate carrier for fragrance. An ideal fragrance carrier helps to achieve the stable storage and controlled release of fragrance. In this work, a novel composite fragrance carrier with MIL-101 (Cr) as the fragrance host and cellulose acetate fiber (CAF) as the protective shell was developed. The encapsulation effect of MIL-101 (Cr) and the protective function of the CAF shell significantly improved the storage stability of L-menthol (LM). Only 5 wt % of LM was lost after 40 days of storage at room temperature. Encapsulated LM could also be effectively released upon heating due to the thermal responsiveness of CAF. In addition, the composite carrier was highly stable with neglectable Cr leaching under different conditions. The results of this work showed that the developed composite carrier could be a promising carrier for the thermally triggered release of fragrance. Full article

(This article belongs to the Special Issue Feature Papers in Applied Chemistry)

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17 pages, 2264 KiB

Open AccessArticle

Developing a Chromatographic ^99mTc Generator Based on Mesoporous Alumina for Industrial Radiotracer Applications: A Potential New Generation Sorbent for Using Low-Specific-Activity ⁹⁹Mo

by Mohamed F. Nawar, Alaa F. El-Daoushy, Ahmed Ashry and Andreas Türler

Molecules 2022, 27(17), 5667; https://doi.org/10.3390/molecules27175667 - 02 Sep 2022

Cited by 2 | Viewed by 1338

Abstract

The commercial low-pressure column chromatographic ⁹⁹Mo/^99mTc generator represents a reliable source of onsite, ready-to-use ^99mTc for industrial applications. These generators use fission-produced ⁹⁹Mo of high specific activity, posing serious production challenges and raising proliferation concerns. Therefore, many concepts [...] Read more.

The commercial low-pressure column chromatographic ⁹⁹Mo/^99mTc generator represents a reliable source of onsite, ready-to-use ^99mTc for industrial applications. These generators use fission-produced ⁹⁹Mo of high specific activity, posing serious production challenges and raising proliferation concerns. Therefore, many concepts are aimed at using low-specific-activity (LSA) ⁹⁹Mo. Nonetheless, the main roadblock is the low sorption capacity of the used alumina (Al₂O₃). This study investigates the feasibility of using commercial alumina incorporated with LSA ⁹⁹Mo to develop a useful ⁹⁹Mo/^99mTc generator for industrial radiotracer applications. First, the adsorption profiles of some commercial alumina sorbents for LSA ⁹⁹Mo were tested under different experimental conditions. Then, the potential materials to develop a ⁹⁹Mo/^99mTc generator were selected and evaluated regarding elution yield of ^99mTc and purity. Among the sorbents investigated in this study, mesoporous alumina (SA-517747) presented a unique sorption-elution profile. It demonstrated a high equilibrium and dynamic sorption capacity of 148 ± 8 and 108 ± 6 mg Mo/g. Furthermore, ^99mTc was eluted with high yield and adequate chemical, radiochemical, and radionuclidic purity. Therefore, this approach provides an efficient and cost-effective way to supply onsite ^99mTc for radiotracer applications independent of fission-produced ⁹⁹Mo technology. Full article

(This article belongs to the Special Issue Feature Papers in Applied Chemistry)

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11 pages, 3356 KiB

Open AccessArticle

Novel Polycyclic Fused Amide Derivatives: Properties and Applications for Sky-blue Electroluminescent Devices

by Guo-Xi Yang, Deng-Hui Liu, Si-Min Jiang, Zhi-Hai Yang, Zi-Jian Chen, Wei-Dong Qiu, Yi-Yang Gan, Kun-Kun Liu, De-Li Li and Shi-Jian Su

Molecules 2022, 27(16), 5181; https://doi.org/10.3390/molecules27165181 - 14 Aug 2022

Cited by 2 | Viewed by 1474

Abstract

Aromatic imide derivatives play a critical role in boosting the electroluminescent (EL) performance of organic light-emitting diodes (OLEDs). However, the majority of aromatic imide-based materials are limited to long wavelength emission OLEDs rather than blue emissions due to their strong electron-withdrawing characteristics. Herein, [...] Read more.

Aromatic imide derivatives play a critical role in boosting the electroluminescent (EL) performance of organic light-emitting diodes (OLEDs). However, the majority of aromatic imide-based materials are limited to long wavelength emission OLEDs rather than blue emissions due to their strong electron-withdrawing characteristics. Herein, two novel polycyclic fused amide units were reported as electron acceptor to be combined with either a tetramethylcarbazole or acridine donor via a phenyl linker to generate four conventional fluorescence blue emitters of BBI-4MeCz, BBI-DMAC, BSQ-4MeCz and BSQ-DMAC for the first time. BSQ-4MeCz and BSQ-DMAC based on a BSQ unit exhibited higher thermal stability and photoluminescence quantum yields than BBI-4MeCz and BBI-DMAC based on a BBI unit due to their more planar acceptor structure. The intermolecular interactions that exist in the BSQ series materials effectively inhibit the molecular rotation and configuration relaxation, and thus allow for blue-shifted emissions. Blue OLED devices were constructed with the developed materials as emitters, and the effects of both the structure of the polycyclic fused amide acceptor and the electron donor on the EL performance were clarified. Consequently, a sky-blue OLED device based on BSQ-DMAC was created, with a high maximum external quantum efficiency of 4.94% and a maximum luminance of 7761 cd m⁻². Full article

(This article belongs to the Special Issue Feature Papers in Applied Chemistry)

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11 pages, 1549 KiB

Open AccessArticle

Evaluation of Acidic Ionic Liquids as Catalysts for Furfural Production from Eucalyptus nitens Wood

by Lucía Penín, Mar López, Valentín Santos and Juan Carlos Parajó

Molecules 2022, 27(13), 4258; https://doi.org/10.3390/molecules27134258 - 01 Jul 2022

Cited by 3 | Viewed by 1512

Abstract

Eucalyptus nitens wood samples were subjected to hydrothermal processing to obtain soluble saccharides from the hemicellulosic fraction. The hemicellulose-derived saccharides were employed as substrates for furfural production in biphasic media made up of water, methyl isobutyl ketone, and one acidic ionic liquid (1-butyl-3-methylimidazolium [...] Read more.

Eucalyptus nitens wood samples were subjected to hydrothermal processing to obtain soluble saccharides from the hemicellulosic fraction. The hemicellulose-derived saccharides were employed as substrates for furfural production in biphasic media made up of water, methyl isobutyl ketone, and one acidic ionic liquid (1-butyl-3-methylimidazolium hydrogen sulfate or 1-(3-sulfopropyl)-3-methylimidazolium hydrogen sulfate). The reactions were carried out in a microwave-heated reactor to assess the effects of the most influential variables. Under selected operational conditions, the molar conversions of the precursors into furfural were within the range of 77–86%. The catalysts conserved their activity after reutilization in five consecutive reaction cycles. Full article

(This article belongs to the Special Issue Feature Papers in Applied Chemistry)

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Review

Jump to: Research

28 pages, 13216 KiB

Open AccessReview

p-Xylene Oxidation to Terephthalic Acid: New Trends

by Hugo M. Lapa and Luísa M. D. R. S. Martins

Molecules 2023, 28(4), 1922; https://doi.org/10.3390/molecules28041922 - 17 Feb 2023

Cited by 9 | Viewed by 4886

Abstract

Large-scale terephthalic acid production from the oxidation of p-xylene is an especially important process in the polyester industry, as it is mainly used in polyethylene terephthalate (PET) manufacturing, a polymer that is widely used in fibers, films, and plastic products. This review [...] Read more.

Large-scale terephthalic acid production from the oxidation of p-xylene is an especially important process in the polyester industry, as it is mainly used in polyethylene terephthalate (PET) manufacturing, a polymer that is widely used in fibers, films, and plastic products. This review presents and discusses catalytic advances and new trends in terephthalic acid production (since 2014), innovations in terephthalic acid purification processes, and simulations of reactors and reaction mechanisms. Full article

(This article belongs to the Special Issue Feature Papers in Applied Chemistry)

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17 pages, 7519 KiB

Open AccessReview

The Gemstone Cyborg: How Diamond Films Are Creating New Platforms for Cell Regeneration and Biointerfacing

by Nádia E. Santos, Joana C. Mendes and Susana Santos Braga

Molecules 2023, 28(4), 1626; https://doi.org/10.3390/molecules28041626 - 08 Feb 2023

Cited by 1 | Viewed by 1470

Abstract

Diamond is a promising material for the biomedical field, mainly due to its set of characteristics such as biocompatibility, strength, and electrical conductivity. Diamond can be synthesised in the laboratory by different methods, is available in the form of plates or films deposited [...] Read more.

Diamond is a promising material for the biomedical field, mainly due to its set of characteristics such as biocompatibility, strength, and electrical conductivity. Diamond can be synthesised in the laboratory by different methods, is available in the form of plates or films deposited on foreign substrates, and its morphology varies from microcrystalline diamond to ultrananocrystalline diamond. In this review, we summarise some of the most relevant studies regarding the adhesion of cells onto diamond surfaces, the consequent cell growth, and, in some very interesting cases, the differentiation of cells into neurons and oligodendrocytes. We discuss how different morphologies can affect cell adhesion and how surface termination can influence the surface hydrophilicity and consequent attachment of adherent proteins. At the end of the review, we present a brief perspective on how the results from cell adhesion and biocompatibility can make way for the use of diamond as biointerface. Full article

(This article belongs to the Special Issue Feature Papers in Applied Chemistry)

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17 pages, 6541 KiB

Open AccessReview

Ionic Liquids as Organocatalysts for Nucleophilic Fluorination: Concepts and Perspectives

by Young-Ho Oh, Dong Wook Kim and Sungyul Lee

Molecules 2022, 27(17), 5702; https://doi.org/10.3390/molecules27175702 - 04 Sep 2022

Cited by 5 | Viewed by 1903

Abstract

Besides their extremely useful properties as solvent, ionic liquids (ILs) are now considered to be highly instructive tools for enhancing the rates of chemical reactions. The ionic nature of the IL anion and cation seems to be the origin of this fascinating function [...] Read more.

Besides their extremely useful properties as solvent, ionic liquids (ILs) are now considered to be highly instructive tools for enhancing the rates of chemical reactions. The ionic nature of the IL anion and cation seems to be the origin of this fascinating function of ILs as organocatalyst/promoter through their strong Coulombic forces on other ionic species in the reaction and also through the formation of hydrogen bonds with various functional groups in substrates. It is now possible to tailor-make ILs for specific purposes as solvent/promoters in a variety of situations by carefully monitoring these interactions. Despite the enormous potentiality, it seems that the application of ILs as organocatalysts/promoters for chemical reactions have not been fully achieved so far. Herein, we review recent developments of ILs for promoting the nucleophilic reactions, focusing on fluorination. Various aspects of the processes, such as organocatalytic capability, reaction mechanisms and salt effects, are discussed. Full article

(This article belongs to the Special Issue Feature Papers in Applied Chemistry)

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