jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Beyzanur Erdivan | Eylul Calikyilmaz | Suay Bilgin | Ayşe Dilay Erdali | Damla Nur Gul | Kerem Emre Ercan | Yunus E. Türkmen | Emrah Özensoy
Source: ACS Applied Materials & Interfaces (article, 2024-10-25)
Field: Chemistry — Organic Chemistry

Na-Promoted Bimetallic Hydroxide Nanoparticles for Aerobic C–H Activation: Catalyst Design Principles and Insights into Reaction Mechanism A precious metal-free bimetallic Fe<sub><i>x</i></sub>Mn<sub>1-<i>x</i></sub>(OH)<sub><i>y</i></sub> hydroxide catalyst was developed that is capable of catalyzing aerobic C-H oxidation reactions at low temperatures, without the need for an initiator, relying sustainably on molecular oxygen. Through a systematic synthetic effort, we scanned a wide nanoparticle synthesis parameter space to lay out a detailed set of catalyst design principles unraveling how the Fe/Mn cation ratio, NaOH(aq) concentration used in the synthesis, catalyst washing procedures, extent of residual Na<sup>+</sup> promoters on the catalyst surface, reaction temperature, and catalyst loading influence catalytic C-H activation performance as a function of the electronic, surface chemical, and crystal structure of Fe<sub><i>x</i></sub>Mn<sub>1-<i>x</i></sub>(OH)<sub><i>y</i></sub> bimetallic hydroxide nanostructures. Our comprehensive XRD, XPS, BET, ICP-MS, <sup>1</sup>H NMR, and XANES structural/product characterization results as well as mechanistic kinetic isotope effect (KIE) studies provided the following valuable insights into the molecular level origins of the catalytic performance of the bimetallic Fe<sub><i>x</i></sub>Mn<sub>1-<i>x</i></sub>(OH)<sub><i>y</i></sub> hydroxide nanostructures: (i) catalytic reactivity is due to the coexistence and synergistic operation of Fe<sup>3+</sup> and Mn<sup>3+</sup> cationic sites (with minor contributions from Fe<sup>2+</sup> and Mn<sup>2+</sup> sites) on the catalyst surface, where in the absence of one of these synergistic sites (i.e., in the presence of monometallic hydroxides), catalytic activity almost entirely vanishes, (ii) residual Na<sup>+</sup> species on the catalyst surface act as efficient electronic promoters by increasing the electron density on the Fe<sup>3+</sup> and Mn<sup>3+</sup> cationic sites, which in turn, presumably enhance the electrophilic adsorption of organic reactants and strengthen the interaction between molecular oxygen and the catalyst surface, (iii) in the fluorene oxidation reaction the step dictating the reaction rate likely involved the breaking of a C-H bond (<i>k</i><sub>H</sub><i>/k</i><sub>D</sub> = 2.4), (iv) reactivity patterns of a variety of alkylarene substrates indicate that the C-H bond cleavage follows a stepwise PT-ET (proton transfer-electron transfer) pathway. Bimetallic strip ; Catalysis ; Materials science ; Nanoparticle ; Hydroxide ; Mechanism (biology) ; Reaction mechanism ; Chemical engineering ; Nanotechnology ; Organic chemistry ; Chemistry Catalytic C–H Functionalization Methods ; Oxidative Organic Chemistry Reactions ; Catalytic Processes in Materials Science
Authors: Ionut‐Cristian Radu | Derniza‐Elena Cozorici | Erika Blânzeanu | Andreea Vadureanu | Cristina Stavarache | Eugenia Tanasă | Horia Iovu | Cătălin Zaharia
Source: Macromolecular Materials and Engineering (article, 2024-07-08)
Field: Materials Science — Biomaterials

Tailoring Silk Sericin Grafting: Comparing One‐Step and Two‐Step Approaches for PNIPAM/PAMPS Block Nanoparticles Abstract Structurally defined, protein‐grafted nanoparticles are widely used in various biomedical applications, particularly as intelligent nanocarriers for drug delivery. The integration of synthetic polymers with natural proteins such as silk sericin enhances the functionality and stability of these nanocarriers, making them suitable for targeted and controlled drug release. In this context, an optimized grafting procedure for silk sericin is presented, employing a protein macroinitiator and atom transfer radical polymerization (ATRP). This study aims to elucidate the significance of the grafting process in tailoring the structure of sericin through the chemistry of synthetic grafts. The grafting procedure uses block copolymers of N ‐isopropylacrylamide (NIPAM) and 2‐acrylamido‐2‐methylpropanesulfonic acid (AMPS), such as Poly‐(AMPS‐block‐NIPAM)/Poly‐(NIPAM‐block‐AMPS). The procedure employs both one‐step and two‐step synthesis methods to produce a well‐defined, biofunctionalized sericin. Subsequently, sericin‐based nanoparticles are prepared, demonstrating the significance of the optimized procedure. The synthesized products undergo structural analysis using H‐NMR, FTIR‐ATR, XPS, DLS, and zeta potential measurements. In addition, their thermal behavior is assessed using differential scanning calorimetry. To further investigate the prepared nanoparticles, SEM and DLS analyses are conducted. Through synthesis optimization, position and length of each synthetic block is precisely determined, significantly influencing properties of the grafted products and characteristics of the resulting nanoparticles. Materials science ; Sericin ; Grafting ; SILK ; Polymer science ; Nanoparticle ; Block (permutation group theory) ; Copolymer ; Chemical engineering ; Nanotechnology ; Composite material ; Polymer ; Engineering Silk-based biomaterials and applications ; Polymer Surface Interaction Studies ; Electrospun Nanofibers in Biomedical Applications
Authors: Michał Terlecki | Arkadiusz Kornowicz | Kornel Sacharczuk | Iwona Justyniak | Janusz Lewiński
Source: Dalton Transactions (article, 2024-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Synthesis, polymorphism, and shape complementarity-induced co-crystallization of hexanuclear Co(<scp>ii</scp>) clusters capped by a flexible heteroligand shell Polymorphism and co-crystallization have gradually gained attention as new tools in the development of modern crystalline functional materials. However, the study on the selective self-assembly of metal clusters into multicomponent crystals is still in its infancy. Herein, we present the synthesis and characterization of two new heteroleptic hydroxido-acetato and acetato Co(II) clusters [Co<sub>6</sub>(OH)<sub>2</sub>(OAc)<sub>4</sub>(<i>pyret</i>)<sub>6</sub>] (1) and [Co<sub>6</sub>(OAc)<sub>6</sub>(<i>pyret</i>)<sub>6</sub>] (2) incorporating auxiliary 2-pyrrolidinoethoxylate (<i>pyret</i>) ligands. On this occasion, we revealed that the commonly used thermal procedure for dehydration of cobalt(II) acetate leads to a reagent comprising substantial contamination by cobalt hydroxido moieties. Comprehensive structural analysis of new compounds demonstrated intriguing crystal structure diversity of hydroxido-acetato cluster 1, which represents a rare example of both conformational and packing polymorphism in one compound, originating from the flexibility of organic <i>O</i>,<i>N</i>-ligands in the secondary coordination sphere. Furthermore, both clusters exhibit an interesting propensity for the selective formation of co-crystals 1·2 driven mainly by van der Waals forces and specific shape complementarity between co-formers. Crystallization ; Complementarity (molecular biology) ; Polymorphism (computer science) ; Chemistry ; Crystallography ; Stereochemistry ; Organic chemistry ; Biochemistry ; Biology ; Gene ; Genetics Magnetism in coordination complexes ; Metal-Organic Frameworks: Synthesis and Applications ; Nanocluster Synthesis and Applications
Authors: Neny Rasnyanti M Aras | Adinda Irwana | Ameliana Utami
Source: al-Kimiya (article, 2024-08-01)
Field: Materials Science — Biomaterials

FABRICATION OF CU MODIFIED NANO CHITOSAN WITH BROMOCRESOL GREEN AS INTELLIGENT PACKAGING In recent advancements, the development of smart packaging systems for food has focused on utilizing composite materials to enhance functionality and sustainability. In this study, the composite film from chitosan and PVA was combined at various concentrations (ranging from 0.1% to 0.5%) with the addition of Cu(500mM) and 1% STPP at a 5:1 ratio. An additional indicator was included to detect fish spoilage. The synthesized chitosan material was then blended with PVA to form a composite film. The film was characterized using FTIR, which confirmed the presence of fingerprint vibrations indicating the cross-linking between TPP, chitosan, and Cu. These bonds were observed at wave numbers 1118 cm-1, 879 cm-1, and 603 cm-1. SEM analysis revealed that the film had particle sizes ranging from 865 nm to 1.49 μm. XRD analysis showed distinctive features of pure chitosan and chitosan composite. The composite film K-05 produced an amorphous structure, indicating decreased crystallinity due to the addition of STPP and Cu. The water uptake test demonstrated that an increased concentration of chitosan in the composite led to higher absorption and solubility effects. Conversely, the addition of chitosan in the film decreased water vapor permeability as determined by the water vapor permeability test. The antibacterial test conducted on all films (concentration of 0.1% to 0.5%) indicated that the films K-01 and K-02 exhibited the best zone of inhibition against Escherichia coli. This study sucessfully synthesized and characterized a smart packaging film composed of polyvinyl alcohol (PVA), chitosan, copper (Cu), and bromocresol green (BCG) indicator, designed to monitor food freshness through visual pH changes and inhibition of microbial growth. Bromocresol green ; Chitosan ; Bromocresol purple ; Fabrication ; Nano- ; Materials science ; Nanotechnology ; Chemical engineering ; Chemistry ; Composite material ; Chromatography ; Engineering Nanocomposite Films for Food Packaging
Authors: Fawad Ahmad | Qurat ul Ain | Shafaq Zahid | Takashiro Akitsu
Source: Preprints.org (preprint, 2024-01-31)
Field: Materials Science — Materials Chemistry

Nanoframes as a Resilient Candidate for the Solution of Broader Spectra of Catalysis Challenges Metal nanoframes have gained tremendous attention in the domain of modern research and development due to their distinctive 3D spatial structure, efficient physiochemical properties, and comparatively good activity. Different strategies have been implicated by the researchers to design nano frame of varying chemical nature and shapes. Most of the synthetic protocols being adopted to design a nano framee, mainly consist of two main steps, nucleation and growth of solid particles and secondly excavation of the interiors. In this context, many synthetic methods are overviewed. To show their unprecedented performance or activity, a few applications in catalytic, biomedical, theranostic, SERS, sensing of different materials, reduction of CO2, etc are also discussed. Spectral line ; Catalysis ; Nanotechnology ; Materials science ; Chemistry ; Physics ; Organic chemistry ; Quantum mechanics Machine Learning in Materials Science
Authors: Hao‐Yi Huang | Bai‐Hao Ren | Min Xie | Yu‐Ting Huang | Kun Li | Zhongzheng Cai | Xiao‐Bing Lu | Jian‐Bo Zhu
Source: Angewandte Chemie (article, 2024-12-23)
Field: Materials Science — Biomaterials

Access to Polyhydroxyalkanoates with Diverse Syndiotacticity via Polymerization by Spiro‐Salen Complexes and Insights into the Stereocontrol Mechanism Abstract Polyhydroxyalkanoates (PHAs) have attracted broad interest as promising sustainable materials to address plastic pollution and resource scarcity. However, the chemical synthesis of stereoregular PHAs via ring‐opening polymerization (ROP) has long been an elusive endeavor. In this contribution, we exploited a robust spiro‐salen yttrium complex ( Y3 ) as the catalyst to successfully prepare syndiotactic PHAs with diverse pendent groups. Simply altering the ratio of enantiomeric catalysts allowed to access of PHAs with diverse syndiotacticity ( P r =0.5–0.99, from sticky oil to tough materials), delivering tunable thermal properties (glass transition temperature, T g from −52 to 70 °C and melting transition temperature, T m from 38 to 223 °C). A combined experimental and computational study suggested a polymeric exchange mechanism could boost the polymerization activity and control the syndioselectivity. Polyhydroxyalkanoates ; Mechanism (biology) ; Polymerization ; Chemistry ; Polymer chemistry ; Combinatorial chemistry ; Organic chemistry ; Polymer ; Philosophy ; Biology biodegradable polymer synthesis and properties ; Carbon dioxide utilization in catalysis ; Advanced Polymer Synthesis and Characterization
Authors: Zulema Fernández | Luis Sánchez | Sukumaran Santhosh Babu | Gustavo Fernández
Source: Angewandte Chemie (article, 2024-02-29)
Field: Materials Science — Materials Chemistry

Oligo(phenyleneethynylene)s: Shape‐Tunable Building Blocks for Supramolecular Self‐Assembly Abstract Oligo(phenyleneethynylene)s (OPEs) have attracted widespread attention due to their remarkable (opto)electronic and photophysical properties, which have enabled numerous applications. The versatile functionalization possibilities of OPEs make them unique candidates to form various shape‐persistent geometries, including linear, triangular, rectangular, hexagonal and macrocyclic. However, as a result of this structural variety, it is oftentimes challenging to correlate molecular design with self‐assembly properties. In this minireview, we have classified OPEs based on their molecular shapes and correlated them with their self‐assembly behavior in solution. Particularly, we provide important insights into the aggregation propensity of the different molecular shapes and how to tune the association strength using various non‐covalent interactions. Our classification will enable a better understanding of the structure‐property correlation in OPEs, which is key to develop supramolecular functional materials. Supramolecular chemistry ; Self-assembly ; Chemistry ; Materials science ; Nanotechnology ; Crystallography ; Crystal structure Luminescence and Fluorescent Materials ; Supramolecular Self-Assembly in Materials ; Polydiacetylene-based materials and applications
Authors: David King | Matthew Cameron Le | Yan Pablo Arnaiz | Seonghyeok L. Cox | J. L. Smith | Haesook Han | Pradip K. Bhowmik
Source: Journal of Ionic Liquids (article, 2024-11-09)
Field: Materials Science — Materials Chemistry

Designing dicationic organic salts and ionic liquids exhibiting high fluorescence in the solid state Dicationic ionic liquids (DILs) are emerging as a powerful, next-generation approach to designing applied ILs because of their superior physicochemical properties as well as their diverse complexity and tunability for task specific applications. DILs are scarce in the literature compared to monocationic ILs (MILs), and one of their main issues is their expected tendency to possess higher melting temperatures. A series of 1,4-bis[2-(4-pyridyl)ethenyl] benzene and 1,4-bis[2-(2-pyridyl)ethenyl]benzene quaternary salts (Q-BPEBs) with different counterions (bromide, tosylate, and triflimide) and carbon chain lengths (C<sub>6</sub>, C<sub>9</sub>, and C<sub>12</sub>) have been synthesized for their potential as DILs with strong photoluminescent properties in the solid state. All Q-BPEB salts demonstrated robust thermal stabilities as determined by thermogravimetric analysis (TGA). The differential scanning calorimetry (DSC) thermograms for Q-BPEB tosylates and triflimides displayed crystalline polymorphisms before melting transitions as verified by polarizing optical microscopy (POM). The Q-BPEB bromide and tosylate salts all showed high melting points of above >170 °C because of their dicationic rigid structures and strong ionic interactions of their anions. Once the Q-BPEB tosylates were exchanged with triflimide ions, <i>para</i>- isomers <b>1aTf</b> <sub><b>2</b></sub> <b>N, 1bTf</b> <sub><b>2</b></sub> <b>N</b>, and <b>1cTf</b> <sub><b>2</b></sub> <b>N</b> still possessed very high melting points (>225 °C), however, the <i>ortho</i>- isomers <b>2aTf</b> <sub><b>2</b></sub> <b>N, 2bTf</b> <sub><b>2</b></sub> <b>N</b>, and <b>2cTf</b> <sub><b>2</b></sub> <b>N</b> exhibited melting points lower than 100 °C, classifying them as DILs. Their photoluminescent properties were also studied in methanol with the emission values of λ<sub>em</sub> = 476-482 nm for the <i>para</i>- isomers and those of λ<sub>em</sub> = 448-453 nm for the <i>ortho</i>- isomers. In the solid state, the Q-BPEB salts exhibited strong fluorescence with quantum yields of up to 50 %. The relatively simple synthesis of these fluorescent dicationic organic salts and ILs are pertinent towards the scarcity of these materials in the literature and provide a deeper insight on the design of fluorescent ILs containing more than one charge center. Ionic liquid ; Solid-state ; Fluorescence ; Chemistry ; Ionic bonding ; Organic chemistry ; Materials science ; Chemical engineering ; Inorganic chemistry ; Ion ; Physical chemistry Luminescence and Fluorescent Materials ; Molecular Sensors and Ion Detection ; Ionic liquids properties and applications
Authors: Fátima S. Aguilera | M. Cota–Leal | P.A. Luque | A. Olivas
Source: Journal of Ovonic Research (article, 2024-01-01)
Field: Materials Science — Polymers and Plastics

Tungsten oxide nanomaterial interactions below monolayer coverage A tungsten oxide load at submonolayer coverage of alumina renders highly dispersed dimeric polytungstate (octahedral and distorted octahedral coordination) and isolated monotungstate (tetrahedral) species. The polytungstate/monotungstate proportion increases when approaching monolayer. Crystalline WO3 nanoparticles emerge at higher loads. All components display hexavalent oxidation; yet, tungsten‐ oxide (W–O–W) and tungsten‐ oxide‐ alumina (W–O–Al) interactions were discerned by X‐ ray photoelectron spectroscopy of the WOx/Al2O3 materials herein prepared with 1, 3, and 5 weight percentages. The 5 wt % sample displayed the highest intensity percentage of W–O–Al species correlated to the highest methanol conversion (45 %), ascribed to the appearance of the weak acidity disclosed by temperature‐ programmed desorption of ammonia. Tungsten oxide ; Nanomaterials ; Monolayer ; Tungsten ; Materials science ; Oxide ; Nanotechnology ; Metallurgy Transition Metal Oxide Nanomaterials ; Catalytic Processes in Materials Science ; Catalysis and Oxidation Reactions
Authors: Achilleas Pipertzis | Angeliki Chroni | Stergios Pispas | Jan Swenson
Source: The Journal of Physical Chemistry B (article, 2024-11-05)
Field: Chemistry — Organic Chemistry

Molecular Dynamics and Self-Assembly in Double Hydrophilic Block and Random Copolymers We investigate the self-assembly and dynamics of double hydrophilic block copolymers (DHBCs) composed of densely grafted poly[oligo(ethylene glycol) methacrylate] (POEGMA) and poly(vinyl benzyl trimethylammonium chloride) (PVBTMAC) parent blocks by means of calorimetry, small- and wide-angle X-ray scattering (SAXS/WAXS), and dielectric spectroscopy. A weak segregation strength is evident from X-ray measurements, implying a disordered state and reflecting the inherent miscibility between the host homopolymers. The presence of intermixed POEGMA/PVBTMAC nanodomains results in homogeneous molecular dynamics, as evidenced through isothermal dielectric and temperature-modulated DSC measurements. The intermixed process undergoes a glass transition at a temperature approximately 40 K higher than the vitrification of bulk POEGMA segments, and it shifts to an even higher temperature by increasing the content of the hard block. At temperatures below the intermixed glass transition temperature, the confined POEGMA segments between the glassy intermixed regions contribute to a segmental process featuring (i) reduced glass transition temperature (<i>T</i><sub>g</sub>), (ii) reduced dielectric strength, (iii) broader distribution of relaxation times, and (iv) reduced fragility compared to the POEGMA homopolymer. We also observe two glass transition temperatures of dry PVBTMAC, which we attribute to the backbone and side chain segmental relaxation. To the best of our knowledge, this is the first time in the literature that these glass transitions of dry PVBTMAC have been reported. Finally, this study shows that excellent mixing of the two homopolymers is obtained, and this implies that different properties of this copolymer system can be tailored by adjusting the concentration of each homopolymer. Copolymer ; Molecular dynamics ; Block (permutation group theory) ; Self-assembly ; Dynamics (music) ; Materials science ; Nanotechnology ; Chemistry ; Chemical physics ; Polymer ; Mathematics ; Physics ; Computational chemistry ; Combinatorics ; Composite material Advanced Polymer Synthesis and Characterization ; Material Dynamics and Properties ; Surfactants and Colloidal Systems
Source: International Research Journal of Modernization in Engineering Technology and Science (article, 2024-06-26)
Field: Materials Science — Biomaterials

Advanced Drug Delivery with PLGA Copolymers Poly (lactic-co-glycolic acid) (PLGA) has emerged as a leading biodegradable and biocompatible polymer for controlled and targeted drug delivery.Its "smart" properties allow for stimuli-responsive release, making it a versatile platform for treating a wide range of diseases.This review delves into the recent advancements in PLGA-based drug delivery systems.We explore the latest findings on PLGA's chemistry, physicochemical characteristics, and biodegradation mechanisms.Furthermore, we discuss critical evaluation parameters for PLGA systems and showcase innovative drug-polymer combinations for targeted therapy.This review emphasizes PLGA's potential to revolutionize modern medicine by providing a comprehensive overview of its capabilities and future directions in drug delivery. Copolymer ; PLGA ; Drug delivery ; Drug ; Materials science ; Computer science ; Nanotechnology ; Pharmacology ; Medicine ; Nanoparticle ; Polymer ; Composite material biodegradable polymer synthesis and properties ; Nanoparticle-Based Drug Delivery ; Supramolecular Self-Assembly in Materials
Authors: Dongping Chen | Yun‐Shu Cui | Bo‐Han He | Feng Liu | Dan‐Dan Zhai | Zhang‐Jie Shi
Source: Chinese Journal of Chemistry (article, 2024-09-16)
Field: Chemistry — Inorganic Chemistry

A Dinitrogen Divanadium Complex Supported by a Trisamidophosphine Ligand Comprehensive Summary The reaction between tripodal trisamidophosphine ligand H 3 PN 3 Ar and V(Mes) 3 (THF) (Mes = mesityl) yields the vanadium(III) complex (PN 3 Ar )V ( 1 ) with an open site in the axial position, which could coordinate with THF, pyridine, and NH 3 to form the corresponding adducts ( 2 — 4 ). The vanadium(III) center is redox‐active, as demonstrated by cyclic voltammetry methods and chemical oxidation or reduction. Notably, a novel dinitrogen divanadium complex with a bridging N 2 ligand, {K(THF)} 2 {[PN 3 Ar ]V} 2 ( μ ‐N 2 ) ( 6 ), was synthesized via treatment of 1 with 1 equivalent of potassium naphthalenide in THF under a N 2 atmosphere. The electronic structures and binding properties of 6 are evaluated and discussed based on its DFT calculations. Additionally, these vanadium complexes ( 1 , 5 , 6 ) can serve as catalysts for the conversion of N 2 into N(SiMe 3 ) 3 in the presence of reductants and Me 3 SiCl. Chemistry ; Ligand (biochemistry) ; Computational chemistry ; Biochemistry ; Receptor Asymmetric Hydrogenation and Catalysis ; Organometallic Complex Synthesis and Catalysis ; Metal complexes synthesis and properties