jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: E. A. Smirnova | A. V. Ankudinov | I. A. Chepurnaya | A. M. Timonov | М. П. Карушев
Source: Inorganics (article, 2023-01-14)
Field: Materials Science — Polymers and Plastics

In-Situ EC-AFM Study of Electrochemical P-Doping of Polymeric Nickel(II) Complexes with Schiff base Ligands Conductive electrochemically active metallopolymers are outstanding materials for energy storage and conversion, electrocatalysis, electroanalysis, and other applications. The hybrid inorganic–organic nature of these materials ensures their rich chemistry and offers wide opportunities for fine-tuning their functional properties. The electrochemical modulation of the nanomechanical properties of metallopolymers is rarely investigated, and the correlations between the structure, stiffness, and capacitive properties of these materials have not yet been reported. We use electrochemical atomic force microscopy (EC-AFM) to perform in-situ quantitative nanomechanical measurements of two Schiff base metallopolymers, poly[NiSalphen] and its derivative that contains two methoxy substituents in the bridging phenylene diimine unit poly[NiSalphen(CH3O)2], during their polarization in the electrolyte solution to the undoped and fully doped states. We also get insight into the electrochemical p-doping of these polymers using electrochemical quartz crystal microgravimetry (EQCM) coupled with cyclic voltammetry (CV). Combined findings for the structurally similar polymers with different interchain interactions led us to propose a correlation between Young’s modulus of the material, its maximum doping level, and ion and solvent fluxes in the polymer films upon electrochemical oxidation. Materials science ; Electrochemistry ; Cyclic voltammetry ; Polymer ; Conductive polymer ; Electrolyte ; Chemical engineering ; Doping ; Nanotechnology ; Polymer chemistry ; Electrode ; Chemistry ; Composite material ; Physical chemistry ; Optoelectronics Conducting polymers and applications ; Electrochemical Analysis and Applications ; Force Microscopy Techniques and Applications
Authors: Walter W. Young | Reika Katsumata
Source: ACS Polymers Au (article, 2023-11-16)
Field: Materials Science — Materials Chemistry

Intermediate Polymer Relaxation Explains the Anomalous Rheology of Nanocomposites with Ultrasmall Attractive POSS Nanoparticles The rheological properties of entangled polymers loaded with very small, strongly attractive polyhedral oligomeric silsesquioxane (POSS) fillers differ from that of nanocomposites with larger fillers by (1) the shorter breadth of the entanglement plateau and (2) the relatively unchanged terminal viscosity with increasing POSS loading. Although such anomalous rheological properties can rewrite the property-processing map of materials (e.g., high glass transition temperature and low viscosity), their mechanism remains unclear. In this study, we report that polymer relaxations on intermediate time scales between α and entire-chain relaxation, so-called "slower processes", are responsible for this unusual rheological behavior of poly(2-vinylpyridine)/octa(aminophenyl)silsesquioxane (P2VP/OAPS) nanocomposites. To uncover the effects of entanglements on the nanocomposite dynamics, rheometry is used for variable matrix molecular weights. Results show a systematic change in the rheological response, which is independent of the molecular weight, and in turn, the presence of entanglements. This supports a physical interpretation that a slower process dominates the rheological response of the material at intermediate frequencies on length scales larger than the segment length or the OAPS diameter, while the underlying physical time scales associated with the entanglement relaxation remain unchanged. Such insights are anticipated to assist the future rational design of other highly attractive and ultrasmall nanoparticles that enable a fine-tuned rheological response of nanocomposites across multiple length scales. Rheology ; Silsesquioxane ; Nanocomposite ; Rheometry ; Materials science ; Relaxation (psychology) ; Polymer ; Viscosity ; Stress relaxation ; Quantum entanglement ; Polymer nanocomposite ; Chemical physics ; Glass transition ; Viscoelasticity ; Nanoparticle ; Composite material ; Chemical engineering ; Polymer chemistry ; Nanotechnology ; Chemistry ; Physics Silicone and Siloxane Chemistry ; Polymer Nanocomposites and Properties ; Polymer crystallization and properties
Authors: Thi Mien Trung Huynh | Duy Dien Nguyen | Nhat Hieu Hoang | Thanh Hai Phan
Source: Crystals (article, 2023-04-07)
Field: Materials Science — Materials Chemistry

Reversible Tuning of Surface Properties of Graphene-like Material via Covalently Functionalized Hydrophobic Layer Nanoscale tuning of the surface properties of graphene-like materials is essential to optimize their application in electronic devices and protective technologies. The covalent modification method has recently been established as the most effective approach for tailoring the interface structure and properties, which are key aspects for fine-tuning the processability and performance of graphene-like materials. In this work, we demonstrate systematic exploration of the reversible covalent functionalization of a highly oriented pyrolytic graphite (HOPG) surface, a model system of multi-layered graphene, at the molecular scale. This is achieved using 3,5-trifluoromethyl benzenediazonum (3,5-TFD) and experimental investigations via cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), scanning tunneling microscopy (STM), and Raman spectroscopy. The degree of functionalization could be tuned by varying the concentration of 3,5-TFD dissolved in the grafting electrolyte. The covalently functionalized layer of 3,5-TFD was either locally degrafted by the STM tip or globally detracted upon thermal treatment, leaving the defect-free graphitic surfaces behind. Our findings open a new pathway for reversibly and robustly functionalizing graphene and other 2D materials for multiple uses in high-end applications. Graphene ; Surface modification ; Materials science ; Highly oriented pyrolytic graphite ; Raman spectroscopy ; Cyclic voltammetry ; Covalent bond ; Nanotechnology ; Pyrolytic carbon ; Scanning tunneling microscope ; Dielectric spectroscopy ; Graphite ; Chemical engineering ; Electrode ; Electrochemistry ; Organic chemistry ; Chemistry ; Composite material Graphene research and applications ; Molecular Junctions and Nanostructures ; Quantum and electron transport phenomena
Authors: Ewa Chukwu | Ming Yang
Source: Chem Catalysis (article, 2023-09-01)
Field: Materials Science — Materials Chemistry

Uncertainties in the reactivity of atomically dispersed catalytic metal: Can any single-atom catalyst work like a charm? Catalysis ; Reactivity (psychology) ; Metal ; Atom (system on chip) ; Dispersion (optics) ; Chemical physics ; Work (physics) ; Materials science ; Nanotechnology ; Characterization (materials science) ; Chemistry ; Physics ; Organic chemistry ; Metallurgy ; Computer science ; Thermodynamics Catalytic Processes in Materials Science ; Electrocatalysts for Energy Conversion ; Nanomaterials for catalytic reactions
Authors: Ilya V. Chepkasov | I. S. Zamulin | Viktor S. Baidyshev | Alexander G. Kvashnin
Source: Physical Chemistry Chemical Physics (article, 2023-01-01)
Field: Materials Science — Materials Chemistry

Tuning the surface properties of AuPd nanoparticles for adsorption of O and CO Bimetallic nanoparticles are attracting increasing attention as effective catalysts because they can exhibit higher efficiencies than their monometallic counterparts. Recent studies show that PdAu nanoparticles can exhibit truly impressive catalytic activity, due to the synergistic effect of their properties. However, fine-tuning the catalytic activity requires an understanding of the full picture of the processes taking place in bimetallic particles of different compositions and structures. Here we study the influence of the structure and composition of PdAu nanoparticles on their electronic properties, charge distribution and adsorption properties (CO and O) using <i>ab initio</i> calculations. Two types of nanoparticles were considered: core-shell (Pd@Au and Au@Pd) and bimetallic alloy (Au-Pd) with an average diameter of 2 nm (321 atoms), having either fcc, icosahedral or amorphous structures. The results obtained on surface charges show the possibility of fine-tuning the surface properties of nanoparticles by modifying their atomic structure and composition. In addition, the adsorption of O and CO on the surface of PdAu nanoparticles with fcc structure has been studied. The obtained adsorption data correlate with the surface charge redistribution and the d-band center. The results of this study thus open up great prospects for tuning the catalytic properties of nanocatalysts by modifying their local atomic environment. Adsorption ; Nanoparticle ; Surface (topology) ; Nanotechnology ; Materials science ; Chemical engineering ; Chemistry ; Physical chemistry ; Engineering ; Geometry Catalytic Processes in Materials Science ; nanoparticles nucleation surface interactions ; Nanomaterials for catalytic reactions
Authors: David Seelinger | Markus Biesalski
Source: Gels (article, 2023-03-09)
Field: Materials Science — Biomaterials

Cross-Linking of Oxidized Hydroxypropyl Cellulose in Paper: Influence of Molecular Weight and Polymer Distribution on Paper Wet Strength Development With the overarching aim for the development of sustainable, nontoxic wet strength agents for paper, a novel polymer gel system based on oxidized hydroxypropyl cellulose (keto-HPC) cross-linked with polyamines was investigated in detail to gain a deeper insight into the wet strength mechanism. When applied to paper, this wet strength system significantly increases the relative wet strength by using only low amounts of polymer, and it is therefore comparable with established wet strength agents based on fossil resources, such as polyamidoamine epichlorohydrin resins. With the help of ultrasonic treatment, keto-HPC was degraded with respect to its molecular weight and further cross-linked in paper using polymeric amine-reactive counterparts. The resulting polymer-cross-linked paper mechanical properties were analyzed with respect to the dry and wet tensile strength, respectively. In addition, we analyzed the polymer distribution using fluorescence confocal laser scanning microscopy (CLSM). If high-molecular-weight samples are being used for cross-linking, we do find accumulation of the polymer mainly on the surface of the fibers and at fiber crossing points, accompanied with enhancing strong effects on paper's wet tensile strength. In contrast, if low-molecular-weight (i.e., degraded) keto-HPC is being applied, the macromolecules are capable of entering the inner porous structure of the paper fibers, and almost no accumulation at the fiber crossing points is observed, which also results in a lowered wet paper tensile strength, respectively. This insight into wet strength mechanisms of the keto-HPC/polyamine system can thus lead to new opportunities for the development of alternative biobased wet strength agents where molecular weight dependence of the wet tensile properties allows for a fine tuning of mechanical properties in the wet state. Wet strength ; Ultimate tensile strength ; Polymer ; Epichlorohydrin ; Materials science ; Composite material ; Chemical engineering ; Fiber ; Cellulose ; Cellulose fiber Advanced Cellulose Research Studies ; Surface Modification and Superhydrophobicity ; Material Properties and Processing
Authors: Junwei Wang | Suxiang Ma | Sang Young Jeong | Wanli Yang | Jianfeng Li | Han Young Woo | Kui Feng | Xugang Guo
Source: Faraday Discussions (article, 2023-08-23)
Field: Materials Science — Materials Chemistry

High-performance n-type organic thermoelectrics enabled by modulating cyano-functionalized polythiophene backbones The scarcity of n-type polymers with high electrical conductivity (<i>σ</i>) and power factor (PF) is the major challenge for organic thermoelectrics (OTEs). By integrating cyano functionalities and an intramolecular conformation lock, we herein synthesize a new electron-deficient building block, CNg4T2, bearing long 1,4,7,10-tetraoxahendecyl side chains, and then further develop two n-type polythiophene derivatives, CNg4T2-2FT and CNg4T2-CNT2, with 3,4-difluorothiophene and 3,3'-dicyano-2,2'-bithiophene as co-units, respectively. Compared with CNg4T2-2FT, CNg4T2-CNT2 features a deeper-positioned lowest unoccupied molecular orbital (LUMO) while maintaining a high degree of backbone coplanarity. As a consequence, the CNg4T2-CNT2 film with molecular dopant N-DMBI delivered an impressive <i>σ</i> of 13.2 S cm<sup>-1</sup> and a high PF of up to 10.84 μW m<sup>-1</sup> K<sup>-2</sup>, significantly outperforming CNg4T2-2FT and benchmark n-type polymer N2200 films. To the best of our knowledge, this PF of CNg4T2-CNT2 devices is the highest value for n-type polythiophenes in OTEs. Further characterizations indicate that the high performance of CNg4T2-CNT2-based devices is attributed to the high doping efficiency and ordered packing of polymer chains. Our study demonstrates that CNg4T2 is a highly appealing electron-deficient building block for n-type OTE polymers and also suggests that fine-tuning of the polymer backbone is a powerful approach to accessing high-performance n-type polymers for OTE devices. Polythiophene ; Thermoelectric materials ; Materials science ; Scarcity ; Polymer ; Conductive polymer ; Electrical resistivity and conductivity ; Nanotechnology ; Chemical engineering ; Thermal conductivity ; Composite material ; Electrical engineering ; Engineering Advanced Thermoelectric Materials and Devices ; Organic Electronics and Photovoltaics ; Conducting polymers and applications
Authors: Sabrina Grigoletto | Arthur Gomes dos Santos | Guilherme Ferreira de Lima | Heitor A. De Abreu
Source: Physical Chemistry Chemical Physics (article, 2023-01-01)
Field: Chemistry — Inorganic Chemistry

Dynamical and electronic properties of anion-pillared metal–organic frameworks for natural gas separation The increasing demand for natural gas as a clean energy source has emphasized the need for efficient gas separation technologies. Metal-organic frameworks (MOFs) have emerged as a promising class of materials for gas separation, with anion-pillared MOFs (APMOFs) gaining attention for their fine-tuned pore design and shape/size selectivity. In this study, we investigate the dynamical and electronic properties of three APMOFs, SIFSIX-3-Cu, SIFSIX-2-Cu-i, and SIFSIX-2-Cu, for the separation of methane from ethane, ethene, propane, propene, and N using computational simulations. Our simulations employ Grand Canonical Monte Carlo (GCMC) and Molecular Dynamics (MD) techniques combined with Density Functional Theory (DFT) calculations. We find that that all three APMOFs exhibit promising separation capabilities for methane from propane and propene based on both thermodynamics and kinetics parameters. In addition, we use Noncovalent Interaction (NCI) analysis to investigate intermolecular interactions and find that the fluorine atoms in the MOF can polarize gas molecules and establish electrostatic interactions with hydrogen atoms in the molecule. Finally, we show that SIFSIX-2-Cu-i is a potential candidate for separating N<sub>2</sub>/CH<sub>4</sub> due to its interpenetration. Propane ; Propene ; Intermolecular force ; Density functional theory ; Molecule ; Chemical physics ; Gas separation ; Chemistry ; Methane ; Molecular dynamics ; Metal-organic framework ; Computational chemistry ; Physical chemistry ; Adsorption ; Organic chemistry ; Catalysis Metal-Organic Frameworks: Synthesis and Applications ; Covalent Organic Framework Applications ; Inorganic Fluorides and Related Compounds
Authors: Adrian Sanchez-Fernandez | Jia‐Fei Poon
Source: Current Opinion in Colloid & Interface Science (article, 2023-11-18)
Field: Chemistry — Organic Chemistry

The underlying order: Isomerism as a blueprint to control the behavior of sugar-based (bio)surfactants Surfactants are ubiquitous in formulated products and technologies. As one of the most important commodity chemicals, their remarkable consumption leads to the necessity of finding sustainable alternatives. Although the use of renewable sources limits the available chemical space for a “Green” production, the great variety of naturally occurring precursors, i.a., fatty acids and sugars, opens a myriad of possibilities to create biosurfactants capable of replacing the fatigued fossil-derived amphiphiles. Here, we visit the concept of isomer-directed assembly applied to sugar-based surfactants, wherein amphiphile assembly and function are fine-tuned through changes in the stereochemical and regiochemical configuration of the molecule. As such, we show how isomerism define directional interactions and solvation, ultimately dictating the assembly of surfactants. However, a general framework to understand the structure-function relationship for these is still missing, which is key to realizing this divergent set of tools for the design of new surfactants. Amphiphile ; Biochemical engineering ; Blueprint ; Sugar ; Function (biology) ; Chemistry ; Chemical space ; Phenylpropanoid ; Nanotechnology ; Folding (DSP implementation) ; Organic chemistry ; Materials science ; Biology ; Biochemistry ; Drug discovery ; Engineering Carbohydrate Chemistry and Synthesis ; Supramolecular Self-Assembly in Materials ; Surfactants and Colloidal Systems
Authors: Fuwei Sun | Li Tian | Guokang He | Ning Gao | Hongwei Zhao | Weigang Liu | Chao Liu | Qi An | Chen Wang | Guangtao Li
Source: Advanced Optical Materials (article, 2023-01-19)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Creation of Assembled Plasmonic Network Architectures with Selective Capture of Guest Molecules in Hotspots Region Abstract Plasmonic networks attract increasing attention owing to their strong plasmon coupling effects at hotspot regions, where intriguing, collective optical behavior and field enhancement occur. Engineering network architectures with flexible control over density and intensity of hotspots, thus fine‐tuning electromagnetic field is the prerequisite for fully exploiting their potential use in diverse plasmon‐based applications, but it represents a great challenge. Herein, a cage‐assisted bottom‐up self‐assembly strategy is proposed to construct a series of cage‐bridged complex network architectures with a high degree of flexibility in hotspot modulation. Critical parameters associated with plasmonic networks, including interparticle distance, the density and intensity of hotspots, as well as molecule accessibility of hotspot can be simultaneously and flexibly adjusted at will. Importantly, the integration of host–guest chemistry of molecular cages into interparticle regions of networks endows selective molecule trapping capability in hotspots, offering tremendous opportunities for broader plasmon‐based applications. The present study not only develops efficient plasmonic networks with enhanced density of hotspots and intense electromagnetic fields, but also provides new avenues for artificially engineering network architectures with advanced functionalities and facilitates further applications in sensing and optoelectronics. Plasmon ; Hotspot (geology) ; Materials science ; Nanotechnology ; Computer science ; Optoelectronics ; Physics Gold and Silver Nanoparticles Synthesis and Applications ; Plasmonic and Surface Plasmon Research ; Advanced biosensing and bioanalysis techniques
Authors: Jing Guo | Shi‐Yong Zhang | Chenghui Zeng | Zhonggao Zhou | Miao Xie | Zi‐Yi Du | Chun‐Ting He | Wei‐Xiong Zhang | Xiao‐Ming Chen
Source: The Journal of Physical Chemistry Letters (article, 2023-08-31)
Field: Materials Science — Materials Chemistry

Temperature-Tuned Variable Confined Space for Modulating Dipolar Polarization of a Disc-Shaped Ammonium Ion Free accessible confined space and loose interaction are crucial for most solid-state ionic motions. Here, by using a near-spherical anion and a disc-shaped ammonium as two distinct but rigid building blocks, we report a new ionic crystal, (HMIm)<sub>3</sub>[La(NO<sub>3</sub>)<sub>6</sub>] (HMIm = 1-methyl-1<i>H</i>-imidazol-3-ium), in which the different confined spaces of three (HMIm)<sup>+</sup> ions are fine-tuned over a broad temperature range. This effect can be utilized to modulate the dipolar polarization across a wide temperature/frequency range. Additionally, small-scale substitution of (HMIm)<sup>+</sup> by its isomer of almost identical shape/size affords molecular solid solutions, which can further tune the dipolar polarization by varying the doping ratio. It is revealed that the differences in dipole moment and hydrogen bond rather than that of shape/size lead to a distorted crystalline environment for these solid solutions. Overall, we provide an exceptional model for understanding and regulating the dipole motion of polar aromatic molecules/ions in a crystalline environment. Dipole ; Ion ; Hydrogen bond ; Ionic bonding ; Polarization (electrochemistry) ; Chemical physics ; Chemistry ; Molecule ; Chemical polarity ; Doping ; Ammonium ; Polar ; Crystallography ; Materials science ; Physical chemistry ; Organic chemistry ; Physics ; Optoelectronics Luminescence and Fluorescent Materials ; Molecular Sensors and Ion Detection ; Solid-state spectroscopy and crystallography
Authors: Nuratiqah Asyiqin | Nur Aishah Sulaiman | Nurul Mohammad | Wan Nor Raihan Wan Jaafar | Falah Abu | Siti Norasmah Surip
Source: Journal of Materials Exploration and Findings (review, 2023-07-04)
Field: Materials Science — Polymers and Plastics

The Effect of Heat Treatment and Chemical Treatment on Natural Fibre to The Durability of Wood Plastic Composites – A Review The application of WPC is not only limited to indoor applications but has been extended to exterior applications where properties of WPC could compromise during service life. WPC was derived from wood fiber of various sizes to reinforce polymers. Wood fiber has the advantage of a cheaper price, being abundantly available, and ease of processing, however, the critical factor is its hydrophilic nature, where moisture absorption is likely to occur. Thus, treatments for reducing the hydrophilicity of wood fibers are applied. By treatment of wood fiber, the surface impurities were removed, leaving the roughened surface of fibers, thus providing a good surface for fiber-matrix interaction. The purpose of this study is to systematically review the effect of heat treatment and chemical treatment on wood fiber on the durability of WPC. The literature cited was searched in Scopus with related keywords – leading to 4292 articles. Article search was then limited from 2012 to 2021 and led to 443 articles to identify and analyze focusing on the durability of WPC. After fine-tuning, only 30 articles were considered to answer the research question in this study. The finding reveals that the treatment of wood fiber has a significant effect on the durability of WPC. Heat and chemical treatment were observed to improve the interfacial adhesion and resistance to fungal attack and the mechanical and physical properties of WPCs. Durability ; Composite material ; Materials science ; Fiber ; Natural fiber ; Adhesive ; Moisture ; Absorption of water ; Polymer Natural Fiber Reinforced Composites ; Additive Manufacturing and 3D Printing Technologies ; Innovative concrete reinforcement materials