jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Rashi Kedia | Manisha Khatak | Manisha Balkhandia | Asit Patra
Source: RSC Advances (article, 2024-01-01)
Field: Materials Science — Polymers and Plastics

Electrochemical copolymerization of 3,4-ethylenedioxythiophene and dithienothiophene: influence of feed ratio on electrical, optical and electrochromic properties Designing a copolymer is an efficient and alternative method to generate new chemical and physical properties compared to parent homopolymers without complex synthesis and structural modification. We herein report the electrochemical deposition of copolymer using two monomers 3,4-ethylenedioxythiophene (EDOT) and dithieno[3,2-<i>b</i>:2',3'-<i>d</i>]thiophene (DTT). Three different copolymers P[EDOT-<i>co</i>-DTT] were synthesized by using different feed ratios of monomers (EDOT and DTT molar ratios in solution are 2 : 1, 1 : 1 and 1 : 2) in acetonitrile containing 0.1 M tetrabutylammonium perchlorate (TBAClO<sub>4</sub>) as a supporting electrolyte. Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and UV-vis-NIR spectroscopy were employed to characterize the obtained copolymers. Energy dispersive X-ray spectroscopy (EDX) analysis was used to estimate the composition of EDOT and DTT units in copolymers. The electrochemical and morphological properties were analyzed using cyclic voltammetry (CV) and field emission scanning electron microscopy (FESEM). <i>In situ</i> spectroelectrochemistry and electrochromic studies were performed to investigate the optical and switching properties of the resultant copolymers. The homopolymers poly(3,4-ethylenedioxythiophene) (PEDOT) and polydithieno[3,2-<i>b</i>:2',3'-<i>d</i>]thiophene (PDTT) were also prepared using similar electrochemical conditions and made comparisons where applicable. Computational calculations were done to understand the structure and energy levels of these polymers. It was found that these copolymers P[EDOT-<i>co</i>-DTT] show new properties as compared to homopolymers PEDOT and PDTT for organic electronic applications. Interesting to note that the resultant copolymers display the property of tunable electrochromism with improved transmittance and redox color change between the neutral and oxidized states. Electrochromism ; Poly(3,4-ethylenedioxythiophene) ; Electrochemistry ; Copolymer ; Materials science ; Chemical engineering ; Polymer chemistry ; Chemistry ; Physical chemistry ; Polymer ; Composite material ; Electrode Conducting polymers and applications ; Transition Metal Oxide Nanomaterials ; Organic Electronics and Photovoltaics
Authors: Zixun Xie | Le Yuan | Xiaolong Qing | Yaqing Wang | Xiaoyan Wu | Xiaolong Weng
Source: Scientific Reports (article, 2024-07-08)
Field: Materials Science — Materials Chemistry

Hygroscopic Mg–Al LDHs composite microspheres for highly efficient hyperspectral camouflage in the VIS and NIR wavebands In order to enhance the hyperspectral camouflage efficacy of stealth coatings against a natural vegetative backdrop, LiCl, known for its significant hygroscopic properties, was incorporated into green Mg-Al layered double hydroxide (Mg-Al LDHs) material. Micron-sized composite microspheres were subsequently synthesized via the spray-drying granulation technique. The structure, morphology, and chemical composition of these microspheres were thoroughly characterized by X-ray diffraction, scanning electron microscopy, laser particle size analysis, nitrogen adsorption-desorption isotherms, and Fourier-transform infrared spectroscopy. The effect of LiCl content on the moisture absorption capacity and near-infrared reflectance spectra of the microspheres was systematically evaluated. We found that incorporating an optimal amount of LiCl into the internal pores of the Mg-Al LDHs microspheres did not compromise their smooth surface morphology and uniform particulate distribution. Notably, when the LiCl content was 10%, the maximum saturation moisture uptake ratio of the coating increased to 0.75 g/g. This hygroscopicity significantly enhanced the absorption and scattering of near-infrared radiation by the coating while concurrently improving its ability to modulate the shape and reflectance of both the visible and near-infrared spectral curves. Spectral congruence between the synthetic coating and natural green foliage was quantified at 97.41%. Moreover, this performance was maintained over 10 cycles of programmed drying and re-humidification, and the coating consistently demonstrated stable hygroscopic properties and sustained over 95% spectral congruence. These optimized artificial coatings were found to effectively confuse hyperspectral classification algorithms, thus blending seamlessly into a natural foliage backdrop. This study provides a new method for regulating VIS and NIR spectral (visible-near infrared spectrum) features, which will be critical for applications in advanced hyperspectral camouflage materials. Materials science ; Fourier transform infrared spectroscopy ; Coating ; Hyperspectral imaging ; Composite number ; Adsorption ; Chemical engineering ; Absorption (acoustics) ; Scanning electron microscope ; Analytical Chemistry (journal) ; Composite material ; Chromatography ; Chemistry Layered Double Hydroxides Synthesis and Applications ; Aerogels and thermal insulation ; Luminescence Properties of Advanced Materials
Authors: Milad Ghezelsofloo | Abdulhamid Dehghani
Source: Qeios (preprint, 2024-03-27)
Field: Materials Science — Biomaterials

Application of Chitosan in Industry and Medicine: A Mini-Review Chitosan, a biopolymer derived from chitin, has attracted considerable attention due to its versatile applications in industry and medicine. In industry, chitosan is used due to its remarkable properties such as biodegradability, biocompatibility and antimicrobial activity. It is used in various sectors including wastewater treatment, food packaging and fabric production. In medicine, the unique properties of chitosan make it a valuable material for drug delivery systems, wound healing, tissue engineering, etc. Its biocompatibility and ability to enhance drug absorption make it a promising candidate for pharmaceutical applications. The multifaceted nature of chitosan offers a wide range of opportunities for innovative developments in industrial and medical fields. Chitosan ; Business ; Engineering ; Chemical engineering Nanocomposite Films for Food Packaging ; Electrospun Nanofibers in Biomedical Applications ; Advanced Drug Delivery Systems
Authors: Akhil Chandran P. | Govu Radha | P. Meenu | Sounak Roy | Himanshu Aggarwal
Source: Materials Advances (article, 2024-01-01)
Field: Chemistry — Inorganic Chemistry

Post-synthetic exchange in a zirconium metal–organic framework for efficient photoreduction of CO<sub>2</sub> to formate Post-synthetic modification of a water-stable Zr–NDI MOF to a Zr–Ti mixed-metal MOF results in an enhanced photocatalytic CO 2 conversion to formate. Formate ; Zirconium ; Metal-organic framework ; Materials science ; Photocatalysis ; Metal ; Inorganic chemistry ; Chemical engineering ; Catalysis ; Chemistry ; Metallurgy ; Organic chemistry ; Adsorption Metal-Organic Frameworks: Synthesis and Applications ; Advanced Photocatalysis Techniques ; Covalent Organic Framework Applications
Authors: Fabio Manna | Mariangela Oggianu | José Ramón Galán‐Mascarós | Flavia Pop | Boris Le Guennic | Maria Laura Mercuri | Narcis Avarvari
Source: Dalton Transactions (article, 2024-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Tuning the slow magnetic relaxation with the substituents in anilate bridged bis(dysprosium) complexes Dinuclear lanthanide complexes [((HB(pz)<sub>3</sub>)<sub>2</sub>Dy)<sub>2</sub>(μ-Th<sub>2</sub>An)] (1Dy) and [((HB(pz)<sub>3</sub>)<sub>2</sub>Dy)<sub>2</sub>(μ-ClCNAn)] (2Dy), based on the hydrotris(pyrazol-1-yl)borate (HBpz<sub>3</sub><sup>-</sup>) scorpionate capping ligand and anilate (An<sup>2-</sup>) bridging linkers, namely homosubstituted dithiophene- and heterosubstituted chlorocyanoanilate, bearing electron-donating and withdrawing substituents at the 3,6-positions of the benzoquinone core, are reported. 1Dy shows an octacoordinated {N<sub>6</sub>O<sub>2</sub>} Dy<sup>III</sup> ion within a <i>D</i><sub>4h</sub> distorted square antiprismatic coordination, an ideal geometry for Single-Molecule Magnet (SMM) behavior, given its oblate nature, whereas in 2Dy the octacoordinated Dy<sup>III</sup> ion adopts a <i>D</i><sub>2d</sub> triangular dodecahedron geometry, while maintaining the same {N<sub>6</sub>O<sub>2</sub>} coordination sphere. Both complexes show field-induced single molecule magnet (SMM) behaviour, with tuning of the slow magnetic relaxation as a function of the nature of the substituents at the 3,6-positions of the anilate moiety. A comparison of the Arrhenius fitting parameters for 1Dy and 2Dy supports the hypothesis that square antiprismatic Dy<sup>III</sup> complexes, as 1Dy, exhibit higher energy barriers. This interpretation is supported by <i>ab initio</i> calculations that also shed light on the crucial role of intermolecular dipolar interactions. Dysprosium ; Magnetic relaxation ; Relaxation (psychology) ; Ligand (biochemistry) ; Crystallography ; Materials science ; Chemistry ; Lanthanide ; Polymer chemistry ; Inorganic chemistry ; Organic chemistry ; Ion ; Magnetization ; Receptor ; Magnetic field ; Physics Magnetism in coordination complexes ; Lanthanide and Transition Metal Complexes ; Organic and Molecular Conductors Research
Authors: Darwin Kurniawan | Francesca Caielli | Karthik Thyagajaran | Kostya Ostrikov | Wei‐Hung Chiang | David Z Pai
Source: Nanoscale (article, 2024-01-01)
Field: Materials Science — Materials Chemistry

Operando time and space-resolved liquid-phase diagnostics reveal the plasma selective synthesis of nanographenes Coupling atmospheric-pressure low-temperature plasmas to electrochemical reactors enables the generation of highly reactive species at plasma-liquid interfaces. This type of plasma electrochemical reactor (PEC) has been used to synthesize fluorescent nitrogen-doped graphene quantum dots (NGQDs), which are usable for multifunctional applications in a facile, simple, and sustainable way. However, the synthesis mechanism remains poorly understood, as well as the location of synthesis. To research these issues, we present an <i>in situ</i> diagnostics study on liquid phase chemistry during the PEC synthesis of NGQDs from chitosan. Monitoring of the photoluminescence and UV-VIS absorption at different depths in the reaction medium during plasma treatment reveals that the NGQD production initiates at the plasma-liquid interface but its completion and/or accumulation occurs at a few millimetres depth below the interface, where the liquid ceases to flow convectively, as determined by particle image velocimetry. Our study provides insights into the plasma synthesis of fluorescent GQDs/NGQDs from carbon precursors that may prove useful for achieving the scalability of PEC processes up to continuous-flow or array reactors. Plasma ; Materials science ; Liquid phase ; Phase (matter) ; Nanotechnology ; Chemistry ; Physics ; Thermodynamics Carbon and Quantum Dots Applications ; Graphene research and applications ; Gold and Silver Nanoparticles Synthesis and Applications
Authors: Shuai Liu | Li Ma | Feixiang Hao | Wei Gao | Baoying Li | Siyuan Liu | Zunqi Liu | Yuehui Li | Jianbin Chen
Source: Advanced Synthesis & Catalysis (article, 2024-07-30)
Field: Chemistry — Organic Chemistry

Molecular Electro(Photo)Catalysis: Triarylamine and Triarylimidazole Derivatives Mediated Oxidation Systems in Organic Electrosynthesis Abstract Organic electrosynthesis has become a green, efficient and sustainable alternative to traditional organic transformation for the redox reactions. In this connection, indirect electrolysis employing redox mediators is attaining increasing significance as it offers a chance to improve reaction selectivity and avoids the over‐oxidation/reduction issues encountered in direct electrolysis. Triarylamines and triarylimidazoles, as representative organic molecular mediators, have attracted widespread attention in recent years due to the advantages of well‐defined easy structural modification and tunable redox ability. Hence, in this minireview, the recent growth of triarylamine and triarylimidazole derivatives mediated electrochemical oxidation reactions were presented, highlighting the structural optimization, electrochemical performance and reaction mechanism of these organic mediators. Moreover, the photocatalytic and photoelectrocatalytic cases with these molecular mediators were also highlighted. To conclude, the current challenges and future prospects of this field are also discussed. Electrosynthesis ; Chemistry ; Catalysis ; Electrochemistry ; Combinatorial chemistry ; Photochemistry ; Organic chemistry ; Electrode ; Physical chemistry Radical Photochemical Reactions ; Sulfur-Based Synthesis Techniques ; Oxidative Organic Chemistry Reactions
Authors: Susanna V. Kunz | Fredrik Barnå | Mauricio Posada Urrutia | Fredric J. L. Ingner | Andrea Martínez-Topete | Andreas Orthaber | Paul J. Gates | Lukasz T. Pilarski | Christine Dyrager
Source: The Journal of Organic Chemistry (article, 2024-04-22)
Field: Chemistry — Organic Chemistry

Derivatization of 2,1,3-Benzothiadiazole via Regioselective C–H Functionalization and Aryne Reactivity Despite growing interest in 2,1,3-benzothiadiazole (BTD) as an integral component of many functional molecules, methods for the functionalization of its benzenoid ring have remained limited, and many even simply decorated BTDs have required <i>de novo</i> synthesis. We show that regioselective Ir-catalyzed C-H borylation allows access to versatile 5-boryl or 4,6-diboryl BTD building blocks, which undergo functionalization at the C4, C5, C6, and C7 positions. The optimization and regioselectivity of C-H borylation are discussed. A broad reaction scope is presented, encompassing <i>ipso</i> substitution at the C-B bond, the first examples of <i>ortho</i>-directed C-H functionalization of BTD, ring closing reactions to generate fused ring systems, as well as the generation and capture reactions of novel BTD-based heteroarynes. The regioselectivity of the latter is discussed with reference to the Aryne Distortion Model. Chemistry ; Aryne ; Derivatization ; Regioselectivity ; Surface modification ; Reactivity (psychology) ; Combinatorial chemistry ; Organic chemistry ; Stereochemistry ; High-performance liquid chromatography Cyclization and Aryne Chemistry ; Chemical Reactions and Mechanisms ; Asymmetric Synthesis and Catalysis
Authors: Shotaro Nakamura | Koji Hirano | Norimitsu Tohnai
Source: ChemPlusChem (article, 2024-07-30)
Field: Materials Science — Materials Chemistry

Organic Mechanochromic Luminescent Materials with Self‐Recovering Characters Recently, applied research on stimuli-responsive materials with luminescence-switching characteristics has been conducted in various fields. A representative phenomenon of stimuli-responsive luminescent materials is mechanochromic luminescence (MCL), which exhibits luminescent color change induced by mechanical stimuli such as grinding. These materials are among the most prominent candidates for security and sensing applications. Interestingly, some mechanochromic luminescent materials have shown self-recovery character, in which their original luminescent color can be recovered by just standing under ambient conditions after grinding. Although there have been more and more reports of such materials in recent years, the fundamental principles of molecular design still remain elusive. In this concept, we summarize distinctive advances in mechanochromic luminescent materials with self-recovery according to the core structures of luminescent molecules. Controlling amorphous state by introducing substituents such as alkyl or polar groups is effective method to provide self-recovering properties. Luminescence ; Materials science ; Grinding ; Nanotechnology ; Alkyl ; Optoelectronics ; Chemistry ; Organic chemistry ; Composite material Luminescence and Fluorescent Materials ; Crystallography and molecular interactions ; Synthesis and Reactivity of Heterocycles
Authors: Yosuke Akae | Patrick Théato
Source: Macromolecular Rapid Communications (article, 2024-07-23)
Field: Chemistry — Organic Chemistry

Polyurethane‐Type Poly[3]rotaxanes Synthesized from Cyclodextrin‐Based [3]Rotaxane Diol and Diisocyanates Synthesis of polyurethane-type poly[3]rotaxanes is achieved by polyaddition between a cyclodextrin (CD)-based [3]rotaxane diol and various diisocyanate species, which provide a more defined structure compared to conventional polyrotaxane syntheses. In this study, hydroxyl groups on CDs of [3]rotaxane diol are initially acetylated, and deprotected after the polyaddition to introduce polyurethane backbone structure into polyrotaxane framework. Despite a relatively complicated chemical structure, [3]rotaxane diol monomer is successfully synthesized in a high yield (overall 67%) without any taxing purification process, which is beneficial for practical applications. The polymerization itself proceeds well under a standard polyaddition reaction condition to afford corresponding polyurethanes around 80% yield with M<sub>n</sub> > 30 kDa. The poly[3]rotaxanes show different aggregation behavior or optical properties, whether or not acetyl groups are present, and are analyzed by XRD, SEM, and fluorescence measurements. Rotaxane ; Diol ; Cyclodextrin ; Polyurethane ; Polymer chemistry ; Monomer ; Materials science ; Yield (engineering) ; Polymerization ; Molecule ; Chemistry ; Polymer ; Supramolecular chemistry ; Organic chemistry ; Composite material Supramolecular Chemistry and Complexes ; Advanced Polymer Synthesis and Characterization ; Synthetic Organic Chemistry Methods
Authors: Nneka Damola Ajayi | Samson Abidemi Ajayi | John Oizamsi Boyi | Oluwaseun Oladeji Olaniyi
Source: Asian Journal of Chemical Sciences (article, 2024-01-01)
Field: Chemistry — Organic Chemistry

Understanding the Chemistry of Nitrene and Highlighting its Remarkable Catalytic Capabilities as a Non-Heme Iron Enzyme Nitrogen is a crucial ingredient for biological processes and is necessary for several cellular activities, including metabolic processes, nucleic acid generation, and protein synthesis. Herein we looked at the intricate chemical properties of nitrene, a molecule that contains nitrogen at its core. Nitrene, akin to carbene, exhibits unique reactivity as an electrophile due to its unpaired octet. The electrical arrangement of nitrene, namely in its most basic form as imidogen (HN), is analyzed, with an emphasis on its sp hybridization and spin density characteristics. The formation of nitrene, which is known for its strong reactivity, occurs as an intermediate species through two primary mechanisms: the photolysis or thermolysis of azides, and the decomposition of isocyanates. This study offers a concise elucidation of significant chemical occurrences involving nitrenes, such as the incorporation of C-H bonds, cycloaddition reactions, the observed phenomena of ring contraction and ring expansion in aryl nitrenes and the catalytic reactions through Nitrene radical. The final section of the paper provides a summary focused on a specific study involving the transfer of nitrene, which is assisted by a non-heme iron enzyme. The research examines the catalytic prowess of PsEFE, a non-heme iron enzyme derived from Pseudomonas savastanoi, in nitrene transfer processes. Through the utilization of directed evolution and the introduction of non-native small-molecule ligands, PsEFE demonstrated an elevated level of aziridination activity. This emphasizes the capability to enhance catalysis by modifying the reliance on ligands. This study advances the understanding of nitrene chemistry and highlights the remarkable catalytic capabilities of a non-heme iron enzyme, opening possibilities for further exploration in the area of biocatalysis with transition metals. Nitrene ; Chemistry ; Carbene ; Combinatorial chemistry ; Catalysis ; Photochemistry ; Organic chemistry Synthesis and Catalytic Reactions ; CO2 Reduction Techniques and Catalysts ; Radical Photochemical Reactions
Authors: Chris Rader | Patrick W. Fritz | Timur Ashirov | Ali Coşkun | Christoph Weder
Source: Biomacromolecules (article, 2024-02-21)
Field: Materials Science — Biomaterials

One-Component Nanocomposites Made from Diblock Copolymer Grafted Cellulose Nanocrystals Cellulose nanocrystals (CNCs) are bio-based, rod-like, high-aspect-ratio nanoparticles with high stiffness and strength and are widely used as a reinforcing nanofiller in polymer nanocomposites. However, due to hydrogen-bond formation between the large number of hydroxyl groups on their surface, CNCs are prone to aggregate, especially in nonpolar polymer matrices. One possibility to overcome this problem is to graft polymers from the CNCs' surfaces and to process the resulting "hairy nanoparticles" (HNPs) into one-component nanocomposites (OCNs) in which the polymer matrix and CNC filler are covalently connected. Here, we report OCNs based on HNPs that were synthesized by grafting gradient diblock copolymers onto CNCs via surface-initiated atom transfer radical polymerization. The inner block (toward the CNCs) is composed of poly(methyl acrylate) (PMA), and the outer block comprises a gradient copolymer rich in poly(methyl methacrylate) (PMMA). The OCNs based on such HNPs microphase separate into a rubbery poly(methyl acrylate) phase that dissipates mechanical energy and imparts toughness, a glassy PMMA phase that provides strength and stiffness, and well-dispersed CNCs that further reinforce the materials. This design afforded OCNs that display a considerably higher stiffness and strength than reference diblock copolymers without the CNCs. At the same time, the extensibility remains high and the toughness is increased up to 5-fold relative to the reference materials. Materials science ; Copolymer ; Nanocomposite ; Polymer ; Atom-transfer radical-polymerization ; Methyl methacrylate ; Acrylate ; Butyl acrylate ; Methacrylate ; Nanoparticle ; Chemical engineering ; Toughness ; Polymer chemistry ; Methyl acrylate ; Composite material ; Nanotechnology Advanced Cellulose Research Studies ; biodegradable polymer synthesis and properties ; Nanocomposite Films for Food Packaging