jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Guilherme Macedo R. Lima | Ranjita K. Bose
Source: Advances in Polymer Technology (article, 2022-12-28)
Field: Materials Science — Polymers and Plastics

Production and Application of Polymer Foams Employing Supercritical Carbon Dioxide Polymeric foams have characteristics that make them attractive for different applications. However, some foaming methods rely on chemicals that are not environmentally friendly. One of the possibilities to tackle the environmental issue is to utilize supercritical carbon dioxide ScCO2 since it is a “green” solvent, thus facilitating a sustainable method of producing foams. ScCO2 is nontoxic, chemically inert, and soluble in molten plastic. It can act as a plasticizer, decreasing the viscosity of polymers according to temperature and pressure. Most foam processes can benefit from ScCO2 since the methods rely on nucleation, growth, and expansion mechanisms. Process considerations such as pretreatment, temperature, pressure, pressure drop, and diffusion time are relevant parameters for foaming. Other variables such as additives, fillers, and chain extenders also play a role in the foaming process. This review highlights the morphology, performance, and features of the foam produced with ScCO2, considering relevant aspects of replacing or introducing a novel foam. Recent findings related to foaming assisted by ScCO2 and how processing parameters influence the foam product are addressed. In addition, we discuss possible applications where foams have significant benefits. This review shows the recent progress and possibilities of ScCO2 in processing polymer foams. Materials science ; Supercritical carbon dioxide ; Blowing agent ; Polymer ; Supercritical fluid ; Plasticizer ; Inert ; Chemical engineering ; Solvent ; Process engineering ; Environmentally friendly ; Viscosity ; Nucleation ; Carbon dioxide ; Composite material ; Polyurethane ; Organic chemistry Polymer Foaming and Composites ; Carbon dioxide utilization in catalysis ; biodegradable polymer synthesis and properties
Authors: Marianna V. Kharlamova
Source: Nanomaterials (review, 2022-12-30)
Field: Materials Science — Materials Chemistry

Kinetics, Electronic Properties of Filled Carbon Nanotubes Investigated with Spectroscopy for Applications The paper is dedicated to the discussion of kinetics of growth, and electronic properties of filled carbon nanotubes investigated by spectroscopy for applications. The paper starts with discussion of growth of carbon nanotubes inside metallocene-filled carbon nanotubes. Nickelocene, cobaltocene are considered for growth of carbon nanotubes. Then, the investigations of filled carbon nanotubes by four spectroscopic techniques are discussed. Among them are Raman spectroscopy, near edge X-ray absorption fine-structure spectroscopy, photoemission spectroscopy, optical absorption spectroscopy. It is discussed that metal halogenides, metal chalcogenides, metals lead to changes in electronic structure of nanotubes with n- or p-doping. The filling of carbon nanotubes with different organic and inorganic substances results in many promising applications. This review adds significant contribution to understanding of the kinetics and electronic properties of filled SWCNTs with considering new results of recent investigations. Challenges in various fields are analyzed and summarized, which shows the author's viewpoint of progress in the spectroscopy of filled SWCNTs. This is a valuable step toward applications of filled SWCNTs and transfer of existing ideas from lab to industrial scale. Carbon nanotube ; Materials science ; Cobaltocene ; Raman spectroscopy ; Selective chemistry of single-walled nanotubes ; Spectroscopy ; Absorption spectroscopy ; Nanotechnology ; Optical properties of carbon nanotubes ; Carbon fibers ; Absorption (acoustics) ; Carbon nanobud ; X-ray absorption spectroscopy ; Chemical engineering ; Nanotube ; Composite material ; Composite number ; Metallocene ; Polymerization Carbon Nanotubes in Composites ; Fullerene Chemistry and Applications ; Graphene research and applications
Authors: Maren Krause | Joshua Friedel | Stefan Buss | Dana Brünink | Annemarie Berger | Cristian A. Strassert | Nikos L. Doltsinis | Axel Klein
Source: Dalton Transactions (article, 2022-01-01)
Field: Chemistry — Organic Chemistry

Isoelectronic Pt(<scp>ii</scp>) complexes of cyclometalating C^N^N ligands with phenyl/(benzo)thiophenyl and pyridyl/(benzo)thiazolyl moieties A series of cyclometalated Pt(II) complexes [Pt(C^N^N)X] (X = Cl, CCPh, CCC<sub>6</sub>F<sub>5</sub>) was synthesised from the protoligands HC^N^N containing either phenyl (ph), naphthyl (na) or (benzo)thiophenyl (b(th)) <b><i>C</i> aryl</b> functions and either pyridyl (py) or (benzo)thiazolyl ((b)tz) <b>peripheral <i>N</i></b> units, alongside the central 4-phenyl-pyridyl (ppy) or <i>t</i>Bu<sub>2</sub>-phenyl-pyridyl (tbppy) <b><i>N</i></b> group. Depending on the combination of the <b>peripheral <i>N</i></b> or <b><i>C</i> aryl</b> building blocks, these square planar complexes reveal very different electrochemical, UV-vis absorption and emission behaviour. The reversible reductions shift anodically along the series th/py < ph/tz ≈ th/tz < ph/btz while the irreversible oxidations shift cathodically along the series Cl ≈ CCC<sub>6</sub>F<sub>5</sub> < CCPh. Similar trends were observed for the long-wavelength UV-vis absorption and photoluminescence properties. The emission maxima range from 605 to 675 nm at 298 K in CH<sub>2</sub>Cl<sub>2</sub> solution and from 555 to 655 nm at 77 K in glassy frozen CH<sub>2</sub>Cl<sub>2</sub>/MeOH matrices. Large differences in amplitude-weighted average lifetimes <i>τ</i><sub>av</sub> (up to 0.9 μs at 298 K, up to 12 μs at 77 K) and photoluminescence quantum yields <i>Φ</i><sub>L</sub> (up to 0.15 at 298 K and up to 0.82 at 77 K) were found. TD-DFT calculations showed that the decomposition of the triplet excited states into LC (π-π*, centred in the individual parts of the C^N^N ligand) and LLCT (π-π*, between the individual parts of the C^N^N ligand + X-π* from coligand to C^N^N) contributions for the ligand-centred states as well as MLCT (d<sub>Pt</sub>-to-π*<sub>C^N^N</sub>) and LMCT (p<sub>Cl</sub> or π<sub>CCR</sub>-to-d<sub>Pt</sub>) character for the charge-transfer states involving the metal is beneficial to assess the participation of the individual heteroaryl groups of the C^N^N ligands. In view of the modular synthesis of these ligands, this will allow the realisation of tailor-made Pt(II) triplet emitters in future work. Chemistry ; Medicinal chemistry ; Stereochemistry Organometallic Complex Synthesis and Catalysis ; Organic Light-Emitting Diodes Research ; N-Heterocyclic Carbenes in Organic and Inorganic Chemistry
Authors: Olga Pantić | M. Spasojević | Enis S. Džunuzović | Marija S. Nikolić | Sanja I. Savić | Maja D. Marković | Pavle Spasojević
Source: Polymers (article, 2022-07-22)
Field: Materials Science — Biomaterials

The Effect of Glycol Derivatives on the Properties of Bio-Based Unsaturated Polyesters The scope of the present study was to prepare fully bio-based unsaturated polyester resins (UPRs) with comparable properties to the commercial formulations. The focus was set on the determination of the optimal prepolymer formulation using the same set of diacids (itaconic and succinic acid) and different diols (propylene glycol, isosorbide and neopentyl glycol) or its equimolar mixtures, keeping the fixed molar ratio of 1:1:2.1 in all feed compositions. Instead of commonly used styrene, bio-based dimethyl itaconate was used as a reactive diluent (RD). The rheology of the obtained resins was studied in detail. The effect of the used diol on structural (FTIR), thermal (DSC), thermomechanical (DMA), and mechanical (tensile) properties was explained. The properties of UPRs were found to be highly dependent on the diol used in the prepolymer formulation. The UPR with an equimolar ratio of propylene glycol and neopentyl glycol was shown to be the most promising candidate to compete with the commercial petroleum-based resins. Prepolymer ; Diethylene glycol ; Isosorbide ; Diol ; Polyurethane ; Materials science ; Polyester ; Polyol ; Polyvinyl alcohol ; Dibasic acid ; Phthalic anhydride ; Succinic acid ; Adipic acid ; Organic chemistry ; Ethylene glycol ; Polymer chemistry ; Chemistry ; Composite material biodegradable polymer synthesis and properties ; Catalysis for Biomass Conversion ; Lignin and Wood Chemistry
Authors: Perrine Weber | Sébastien Hoyas | Émilie Halin | Olivier Coulembier | Julien De Winter | Jérôme Cornil | Pascal Gerbaux
Source: Biomacromolecules (article, 2022-01-18)
Field: Chemistry — Spectroscopy

On the Conformation of Anionic Peptoids in the Gas Phase Although <i>N</i>-(<i>S</i>)-phenylethyl peptoids are known to adopt helical structures in solutions, the corresponding positively charged ions lose their helical structure during the transfer from the solution to the gas phase due to the so-called charge solvation effect. We, here, considered negatively charged peptoids to investigate by ion mobility spectrometry-mass spectrometry whether the structural changes described in the positive ionization mode can be circumvented in the negative mode by a fine-tuning of the peptoid sequence, that is, by positioning the negative charge at the positive side of the helical peptoid macrodipole. <i>N</i>-(<i>S</i>)-(1-carboxy-2-phenylethyl) (<i>N</i>scp) and <i>N</i>-(<i>S</i>)-phenylethyl (<i>N</i>spe) were selected as the negative charge carrier and as the helix inductor, respectively. We, here, report the results of a joint theoretical and experimental study demonstrating that the structures adopted by the <i>N</i>spe<sub><i>n</i></sub><i>N</i>scp anions remain compactly folded in the gas phase for chains containing up to 10 residues, whereas no evidence of the presence of a helical structure was obtained, even if, for selected sequences and lengths, different gas phase conformations are detected. Peptoid ; Chemistry ; Gas phase ; Mass spectrometry ; Solvation ; Ion ; Helix (gastropod) ; Phase (matter) ; Side chain ; Protein secondary structure ; Crystallography ; Ionization ; Peptide ; Polymer ; Physical chemistry ; Chromatography ; Organic chemistry Mass Spectrometry Techniques and Applications ; Chemical Synthesis and Analysis ; Analytical Chemistry and Chromatography
Authors: Jean-Baptiste Lena | Balamurugan Ramalingam | Wendy Rusli | Lohitha Rao Chennamaneni | Praveen Thoniyot | Alex M. van Herk
Source: European Polymer Journal (article, 2022-10-14)
Field: Chemistry — Organic Chemistry

Insertion of ester bonds in three terpolymerization systems Methacrylamide ; Polymer chemistry ; Polymerization ; Methyl methacrylate ; Monomer ; Butyl acrylate ; Chemistry ; Polymer ; Radical polymerization ; Copolymer ; Methacrylate ; Radical initiator ; Acrylate ; Organic chemistry Advanced Polymer Synthesis and Characterization ; biodegradable polymer synthesis and properties ; Synthetic Organic Chemistry Methods
Authors: Giulio Ferrando | Matteo Gardella | Giorgio Zambito | Matteo Barelli | Debasree Chowdhury | Maria Caterina Giordano | F. Buatier de Mongeot
Source: Nanoscale (article, 2022-12-29)
Field: Materials Science — Materials Chemistry

Flat-optics hybrid MoS<sub>2</sub>/polymer films for photochemical conversion Novel light harvesting platforms and strategies are crucial to develop renewable photon to energy conversion technologies that overcome the current global energy and environmental challenges. Two-dimensional (2D) transition metal dichalcogenide (TMD) semiconductor layers are particularly attractive for photoconversion applications but new ultra-compact photon harvesting schemes are urgently required to mitigate their poor photon absorption properties. Here, we propose a flat-optics scheme based on nanogrooved ultra-thin MoS<sub>2</sub> layers conformally grown onto large area (cm<sup>2</sup> scale) nanopatterned templates. The subwavelength re-shaping of the 2D-TMD layers promotes the excitation of photonic Rayleigh anomaly (RA) modes, uniquely boosting a strong in-plane electromagnetic confinement. By tailoring the illumination conditions, we demonstrate effective tuning of the photonic anomalies over a broadband visible spectrum across the absorption band of relevant polluting dye molecules. Thanks to the strong photonic in-plane confinement, we achieve a resonant enhancement of the photodissociation rate of methylene blue (MB) molecules, well above a factor of 2. These results highlight the potential of flat-optics photon harvesting schemes for boosting photoconversion efficiency in large-scale hybrid 2D-TMD/polymer layers, with a strong impact in various applications ranging from new-generation photonics to waste water remediation and renewable energy storage. Materials science ; Polymer ; Optoelectronics ; Optics ; Photochemistry ; Nanotechnology ; Chemistry ; Physics ; Composite material 2D Materials and Applications ; Advanced Photocatalysis Techniques ; Conducting polymers and applications
Authors: Paolo Stufano | Alberto Perrotta | Rossella Labarile | Massimo Trotta
Source: MRS Energy & Sustainability (article, 2022-07-25)
Field: Materials Science — Electronic, Optical and Magnetic Materials

The second life of coffee can be even more energizing: Circularity of materials for bio-based electrochemical energy storage devices Abstract Coffee is among the most drunk beverages in the world and its consumption produces massive amounts of waste. Valorization strategies of coffee wastes include production of carbon materials for electrochemical energy storage devices such as batteries, supercapacitors, and fuel cells. Coffee is one of the most consumed beverages in the world. In the linear model adopted so far, its consumption is associated with huge amounts of waste and spent coffee grounds. These wastes, instead, are very interesting secondary raw materials for several circular economy concepts. Nano-structured porous carbon materials obtained by coffee waste are emerging as active materials for electrochemical energy storage devices like supercapacitors and batteries. The major results achieved in the last decade in this high-value exploitation strategy of coffee wastes are summarized to suggest a new sustainable use of coffee waste in the empowerment of the ongoing transition toward a green, electrified, and happier coffee-drinking society. Graphical abstract Supercapacitor ; Raw material ; Electrochemical energy storage ; Waste management ; Circular economy ; Environmental science ; Business ; Engineering ; Electrochemistry ; Chemistry Supercapacitor Materials and Fabrication ; Advancements in Battery Materials ; Advanced battery technologies research
Authors: Oksana Yanshyna | Liat Avram | Linda J. W. Shimon | Rafał Klajn
Source: Chemical Communications (article, 2022-01-01)
Field: Chemistry — Organic Chemistry

Coexistence of 1 : 1 and 2 : 1 inclusion complexes of indigo carmine We show that the optical properties of indigo carmine can be modulated by encapsulation within a coordination cage. Depending on the host/guest molar ratio, the cage can predominantly encapsulate either one or two dye molecules. The 1 : 1 complex is fluorescent, unique for an indigo dye in an aqueous solution. We have also found that binding two dye molecules stabilizes a previously unknown conformation of the cage. Indigo carmine ; Indigo ; Fluorescence ; Molecule ; Chemistry ; Aqueous solution ; Molar ratio ; Cage ; Photochemistry ; Crystallography ; Nuclear chemistry ; Organic chemistry ; Catalysis ; Optics Supramolecular Chemistry and Complexes ; Porphyrin and Phthalocyanine Chemistry ; Luminescence and Fluorescent Materials
Authors: Anna Lucia Pellegrino | Francesca Lo Presti | Graziella Malandrino
Source: Discover Materials (article, 2022-05-21)
Field: Chemistry — Inorganic Chemistry

A molecular route to fluoro-perovskite materials: synthesis of CsCaF3 films through a sol–gel/spin-coating process Abstract Fluoride perovskites have recently attracted great attention due to their unique optical properties. The present study reports for the first time the fabrication of fluoride-based perovskite, CsCaF 3 , in form of thin films through a combined sol–gel/spin-coating approach using β-diketonate fluorinated precursors. The entire sol–gel process has been carried out in ethanol solution under acid-catalyzed conditions starting from the β-diketonate complexes, Cs(hfa) and Ca(hfa) 2 •diglyme•H 2 O (Hhfa = 1,1,1,5,5,5-hexafluoro-2,4-pentanedione; diglyme = 2–Methoxyethylether), which act as single sources for metal ions and fluorine . A careful optimization of the process parameters, such as molar ratio of the starting mixture, aging time and annealing temperature, has allowed to produce for the first time, selectively and reproducibly, transparent and pure CsCaF 3 films. Field-emission scanning electron microscopy and energy dispersive X-ray analyses highlight the formation of films with compact morphologies having a 1:1 stoichiometric ratio of Cs:Ca, uniform throughout the film and compatible with the CsCaF 3 phase identified through X-ray diffraction analysis. Sol-gel ; Spin coating ; Materials science ; Fluorine ; Diglyme ; Thin film ; Chemical engineering ; Fluoride ; Perovskite (structure) ; Annealing (glass) ; Coating ; Stoichiometry ; Scanning electron microscope ; Fabrication ; Inorganic chemistry ; Nanotechnology ; Physical chemistry ; Organic chemistry ; Chemistry ; Composite material ; Metallurgy Inorganic Fluorides and Related Compounds ; Perovskite Materials and Applications ; Luminescence Properties of Advanced Materials
Authors: Luigi Musciacchio | Mario Mardirossian | Benedetta Guagnini | Alessandra Raffini | Michele Rizzo | Carlo Trombetta | Giovanni Liguori | Gianluca Turco | Davide Porrelli
Source: Materials & Design (article, 2022-10-21)
Field: Materials Science — Biomaterials

Rifampicin-loaded electrospun polycaprolactone membranes: Characterization of stability, antibacterial effects and urotheliocytes proliferation Pathological conditions such as infections, cancer, inflammation, or iatrogenic lesions, can hinder the correct functionality of the ureter and its structural integrity. Several strategies for the regeneration of the ureter and the restoration of its functionality are available but the best strategy has not been reached yet. Among the proposed strategies, a promising one is the development of tubular scaffolds, in particular exploiting electrospinning technique. In this work, antibacterial electrospun polycaprolactone/rifampicin (PCL/Rif) membranes were prepared and characterized. The membranes are characterized by randomly oriented nanofibers with a homogeneous diameter, as determined by scanning electron microscopy. The mechanical characterization, performed with uniaxial tensile tests, showed a suitable stability over time and a proper deformability. The rifampicin release, investigated by UV spectrophotometry, showed a burst release in the first part of the experiment and a sustained release over time. The membranes are biocompatible and able to support the adhesion and proliferation of urotheliocytes. Moreover, PCL/Rif membranes showed an antibacterial activity against Escherichia coli and other bacterial strains belonging to the “ESKAPE” group. Considering the possibility to use the electrospinning for the production of tubular scaffolds, the described membranes represent a promising starting point for the preparation of ureteral scaffolds with antibacterial properties. Polycaprolactone ; Membrane ; Electrospinning ; Materials science ; Nanofiber ; Adhesion ; Chemical engineering ; Biomedical engineering ; Composite material ; Chemistry ; Polymer ; Medicine ; Biochemistry Electrospun Nanofibers in Biomedical Applications ; Tissue Engineering and Regenerative Medicine ; Infectious Aortic and Vascular Conditions
Authors: Victoria Samanidou | Abuzar Kabir
Source: Analytica—A Journal of Analytical Chemistry and Chemical Analysis (article, 2022-12-02)
Field: Chemistry — Analytical Chemistry

Magnet Integrated Fabric Phase Sorptive Extraction (MI-FPSE): A Powerful Green(er) Alternative for Sample Preparation Green(er) sample preparation technologies still dominate as the anticipated improvement in all analytical protocols. Separation scientists all over the world continuously strive to comply with the Green Analytical Chemistry (GAC) demands. To follow this trend, microextraction techniques are constantly evolving to bridge the gap between Green Analytical Chemistry and sample pretreatment. A research group from Florida International University, Miami, Florida has introduced fabric phase sorptive extraction (FPSE) in 2014 that was considered as a new milestone in microextraction technologies at that time. Two years later, the same research group introduced an advantageous innovative configuration that combines the stirring and extraction mechanism into a single sample preparation device, keeping all the benefits originally offered by classical FPSE. Magnet integrated fabric phase sorptive extraction (MI-FPSE) was eventually introduced as a new, advantageous implementation of FPSE. This device exhibits the advantageous role of the increase in extraction kinetics through sample diffusion, resulting in improved extraction efficiency of the microextraction device and supports the need for combining processes for better promotion and implementation of the principles of Green Analytical Chemistry. The applications of MI-FPSE are presented herein, showing the essential role that this technique can play in analytical and bioanalytical sample preparation. Extraction (chemistry) ; Sample (material) ; Sample preparation ; Process engineering ; Computer science ; Solid-phase microextraction ; Green chemistry ; Nanotechnology ; Chemistry ; Materials science ; Chromatography ; Engineering ; Reaction mechanism ; Organic chemistry Analytical chemistry methods development ; Radioactive element chemistry and processing ; Electrochemical Analysis and Applications
Authors: Michael Czieborowski | A.J.B. Kemperman | Erik Rolevink | Janieke Blom | Tymen Visser | Bodo Philipp
Source: Journal of Microbiological Methods (article, 2022-03-24)
Field: Materials Science — Surfaces, Coatings and Films

A two-step bioluminescence assay for optimizing antibacterial coating of hollow-fiber membranes with polydopamine in an integrative approach Membrane ; Biofilm ; Coating ; Chemistry ; Leaching (pedology) ; Biofouling ; Ultrafiltration (renal) ; Bioluminescence ; Chromatography ; Chemical engineering ; Bacteria ; Biochemistry ; Organic chemistry ; Biology Polymer Surface Interaction Studies ; Antimicrobial agents and applications ; Bacterial biofilms and quorum sensing