jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Andre Chambers | Daniel J. McCloskey | Nikolai Dontschuk | Hassan N. Al Hashem | Billy J. Murdoch | Alastair Stacey | Steven Prawer | Arman Ahnood
Source: Applied Surface Science (article, 2024-02-17)
Field: Materials Science — Materials Chemistry

Impact of surface treatments on the electron affinity of nitrogen-doped ultrananocrystalline diamond In recent years, various forms of nanocrystalline diamond (NCD) have emerged as an attractive group of diamond/graphite mixed-phase materials for a range of applications from electron emission sources to electrodes for neural interfacing. To tailor their properties for different uses, NCD surfaces can be terminated with various chemical functionalities, in particular hydrogen and oxygen, which shift the band edge positions and electron affinity values. While the band edge positions of chemically terminated single crystal diamond are well understood, the same is not true for nanocrystalline diamond, which has uncontrolled crystallographic surfaces with a variety of chemical states as well as graphitic grain boundary regions. In this work, the relative band edge positions of as-grown, hydrogen terminated, and oxygen terminated nitrogen-doped ultrananocrystalline diamond (N-UNCD) are determined using ultraviolet photoelectron spectroscopy (UPS), while the band bending is investigated using photoelectrochemical measurements. In contrast to the widely reported negative electrode affinity of hydrogen terminated single crystal diamond, our work demonstrates that hydrogen terminated N-UNCD exhibits a positive electron affinity owing to the increased surface and bulk defect densities. These findings elucidate the marked differences in electrochemical properties of hydrogen and oxygen terminated N-UNCD, such as the dramatic changes in electrochemical capacitance. Diamond ; Materials science ; Work function ; Material properties of diamond ; Band bending ; Ultraviolet photoelectron spectroscopy ; Nanotechnology ; Hydrogen ; X-ray photoelectron spectroscopy ; Analytical Chemistry (journal) ; Chemical physics ; Chemical engineering ; Optoelectronics ; Chemistry ; Composite material ; Organic chemistry Diamond and Carbon-based Materials Research ; Semiconductor materials and devices ; Force Microscopy Techniques and Applications
Authors: Sara Catalini | Francesco Bagni | Stefano Cicchi | Mariangela Di Donato | Alessandro Iagatti | Andrea Lapini | Paolo Foggi | C. Petrillo | Alessandro Di Michele | Marco Paolantoni | Giorgio Schirò | Lucia Comez | Alessandro Paciaroni
Source: Materials Advances (article, 2024-01-01)
Field: Materials Science — Biomaterials

Multiple length-scale control of Boc-protected diphenylalanine aggregates through solvent composition Self-aggregation of Boc-protected diphenylalanine towards the formation of architectures with morphology and structure highly dependent on the acetonitrile-water percentage. Acetonitrile ; Chemistry ; Solvent ; Composition (language) ; Chemical engineering ; Organic chemistry Supramolecular Self-Assembly in Materials ; Polydiacetylene-based materials and applications ; Luminescence and Fluorescent Materials
Authors: Xuexin Zhang | Yao Dou | Liqun Liu | Meixue Song | Zhenhao Xi | Yisheng Xu | Weihua Shen | Jie Wang
Source: Polymers (article, 2024-03-25)
Field: Materials Science — Polymers and Plastics

Polyimide Films Based on β-Cyclodextrin Polyrotaxane with Low Dielectric and Excellent Comprehensive Performance In order to prepare polyimide (PI) films with a low dielectric constant and excellent comprehensive performance, a two-step method was employed in this study to integrate β-cyclodextrin into a semi-aromatic fluorine-containing polyimide ternary system. By introducing trifluoromethyl groups to reduce the dielectric constant, the dielectric constant was further reduced to 2.55 at 10 MHz. Simultaneously, the film exhibited noteworthy thermal stability (a glass transition temperature exceeding 300 °C) and a high coefficient of thermal expansion. The material also demonstrated outstanding mechanical properties, boasting a strength of 122 MPa and a modulus of 2.2 GPa, along with high optical transparency (transmittance reaching up to 89% at 450 nm). Moreover, the inherent high transparency of colorless polyimide (CPI) combined with good stretchability contributed to the attainment of a low dielectric constant. This strategic approach not only opens up new opportunities for novel electroactive polymers but also holds potential applications in flexible displays, circuit printing, and chip packaging. Polyimide ; Materials science ; Dielectric ; Glass transition ; Ternary operation ; Thermal stability ; Composite material ; Polymer ; Transmittance ; Thermal expansion ; Polymer chemistry ; Chemical engineering ; Optoelectronics ; Layer (electronics) Synthesis and properties of polymers ; Silicone and Siloxane Chemistry ; Epoxy Resin Curing Processes
Authors: Daiki Doiuchi | Nanako Shimoda | Koushi Okazaki | Tatsuya Uchida
Source: Advanced Synthesis & Catalysis (article, 2024-01-16)
Field: Chemistry — Organic Chemistry

Acid‐Cooperative Transition Metal‐Catalysed Oxygen‐Atom‐Transfer: Ruthenium‐Catalysed C−H Oxygenation Abstract The prospect of developing methods to control the reactivity of metal(oxo) holds appeal for both synthetic and bioinorganic chemistry. In this study, we observed that carboxylic acids enhance reactivity in C−H oxidation by forming hydrogen bonds with the oxo ligand, thereby increasing the basicity and electrophilicity of the oxo intermediate. Additionally, we discovered that H‐dicarboxylate ligands, such as oxalate, malonate, and maleate, significantly improve the catalyst turnover frequency (up to 760/h) in unactivated C( sp 3 )−H oxidation. Furthermore, the addition of maleic acid was also found to activate Fe and Mn(pdp)‐catalysed C−H oxygenation. Notably, Ru(bpga)(H‐maleate) 2 3 ‐catalyzed C−H functionalization exhibited a broad functional group tolerance, including bromine, hydroxyl, benzoate, nitro, nitryl, sulfonate, imide, sulfonylamide, and carbamate, yielding up to 98% in a site‐ and chemoselective manner with only 0.1–2.0 mmol% loading. Chemistry ; Ruthenium ; Oxygenation ; Transition metal ; Catalysis ; Oxygen ; Oxygen atom ; Photochemistry ; Metal ; Atom (system on chip) ; Organic chemistry ; Molecule Catalytic C–H Functionalization Methods ; Asymmetric Hydrogenation and Catalysis ; Metal-Catalyzed Oxygenation Mechanisms
Authors: Reham M. Abu Shmeis | Ibrahim N. Tarawneh | Amneh T. Issa
Source: Water Quality Research Journal (article, 2024-01-18)
Field: Chemistry — Organic Chemistry

Profiling and evaluation of phenolic compounds in olive mill wastewater in Jordan Abstract Phenolic compounds (PCs) are prevalent in olive mill wastewater (OMW), offering numerous health benefits but concurrently posing environmental challenges. This study aims to comprehensively characterize PCs in OMW, both qualitatively and quantitatively. An accurate, sensitive, and cost-effective method was successfully developed for extracting and quantifying seven PCs in OMW. The extraction procedure was optimized to achieve the maximum recovery using a liquid-liquid extraction method. Concentrations of the identified PCs were determined using a high-performance liquid chromatography-diode array detector (HPLC-DAD). The seven PCs peaks were successfully separated on an RP-C8 column within a 23-minute runtime using a gradient mobile phase. The method underwent thorough validation, producing satisfactory results. Subsequently, the developed method was applied to analyze OMW from four olive mills in Jordan, revealing PC concentrations ranging from 139 to 430 mg/L. Tyrosol and hydroxytyrosol were identified as the most abundant compounds. Additionally, gas chromatography-mass spectrometry (GC-MS) separated and identified forty PCs. The total phenolic content was quantified, reaching a value of 1839 mg/L. Moreover, the antioxidant activity was assessed, yielding a maximum value of 95.8%. These results underscore the substantial levels of PCs in OMW, highlighting the importance of economically utilizing this water. Tyrosol ; Hydroxytyrosol ; Chromatography ; Chromatography detector ; Wastewater ; Chemistry ; Extraction (chemistry) ; High-performance liquid chromatography ; Mass spectrometry ; Olive oil ; Antioxidant ; Environmental science ; Polyphenol ; Food science ; Environmental engineering Edible Oils Quality and Analysis ; Essential Oils and Antimicrobial Activity ; Spectroscopy and Chemometric Analyses
Authors: Rinu Elizabeth Roy | Nanda K S | Sajna Salim | Shiburaj Sugathan | ARUN JOHN
Source: Chemistry & Biodiversity (article, 2024-09-14)
Field: Materials Science — Materials Chemistry

Two in One Gram Negative Antibacterial Agent and Organic Dye Photocatalyst from Green Synthesized Ocimum Sanctum‐Based N and O Co‐Doped Carbon Dot Silver Nanocomposite This study reports, successful synthesis of Oxygen(O) and Nitrogen(N) co-doped Ocimum Sanctum plant-based or tulsi carbon dots-silver nanoparticle nanocomposites (TCD-AgNP) for the development of an efficient, highly active, low-cost fingerprint antibacterial agent against gram-negative organisms and a highly efficient photocatalyst for the degradation of methylene blue (MB). Green synthesized, high quantum yield (47 %), intensely blue fluorescent, highly stable N and O co-doped TCDs from carbonization technique of tulsi leaves is achieved without any chemical treatment or surface fascination which could act as an efficient green reducing agent for the development green TCD-AgNP nanocomposites. The novelty and advantage of this study is the development of highly stable, blue fluorescent, high quantum yield (40 %) environmental -friendly TCD-AgNP nanocomposite through reduction method by using green TCDs. TCD-AgNP nanocomposites were synthesized by varying the concentrations of AgNO<sub>3</sub> into a fixed amount of green TCDs. Spectrochemical characteristics of synthesized TCDs and TCD-AgNP nanocomposites were investigated through UV-Vis absorbance, Photoluminescence (PL) spectroscopy, Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS) and Zeta potential measurements confirming excellent fluorescence, unique stability and effective O and N doping. High-resolution transmission electron microscopy (HR-TEM) images confirms that the synthesized TCDs and TCD-AgNP nanocomposites were spherical in shape with an average size of 6.3 nm and 11.5 nm respectively. The antibacterial studies proved that TCD-AgNP nanocomposites ware highly effective against Gram-negative (Serratia marcescens, E. coli, and Pseudomonas aeruginosa) microbial organisms and showed zones of inhibition 12, 9 and 18 mm as compared to streptomycin sulphate. Besides, TCD-AgNP nanocomposite was used as a photocatalyst for the degradation of MB (10 ppm) under sunlight irradiation for regular intervals of time at room temperature with a photodegradation efficiency of 95.63 % and a photocatalytic rate constant of 0.0195 min<sup>-1</sup>. Nanocomposite ; Silver nanoparticle ; Nuclear chemistry ; Chemistry ; Fourier transform infrared spectroscopy ; Antibacterial activity ; Absorbance ; Photocatalysis ; Photodegradation ; X-ray photoelectron spectroscopy ; Materials science ; Nanoparticle ; Nanotechnology ; Chemical engineering ; Organic chemistry ; Chromatography ; Catalysis Carbon and Quantum Dots Applications ; Advanced Nanomaterials in Catalysis ; Quantum Dots Synthesis And Properties
Authors: Tongyue Wu | Peilong Liao | Weilin Qi | Huai‐Yu Song | Hongpeng Li | Jianbin Huang | Yun Yan
Source: Advanced Functional Materials (article, 2024-11-07)
Field: Materials Science — Materials Chemistry

Stable White Afterglow Along the Blackbody Radiation Line Enabled by Assisted Partial Phosphorescence Resonance Energy Transfer Abstract White afterglow is very appealing both in scenario‐specific luminescence and background‐free bio‐imaging, while it is challenging to obtain stable white afterglow due to the difficulty in matching the emission lifetimes of complementary colors. It is reported here that assisted partial phosphorescence resonance energy transfer (ap‐PRET) can be a very efficient way toward this goal. When a blue afterglow of energy donor with long lifetime is obtained in a polymeric network displaying phosphorescent clusterization‐triggered emission (CTE), the network assisted partial phosphorescence resonance energy transfer (ap‐PRET) between it and a yellow fluorescent acceptor would yields orange afterglow. Owing to the energy supply of the CTE network, the lifetime of the donors blue afterglow can be tuned close to that of the acceptors orange afterglow through ap‐PRET in a wide donor to accepter ratios, and emissions ranging from the cold to warm white afterglows can be obtained. Amazingly, these white afterglows are along the blackbody radiation line in the CIE plot, disclosing the powerful ability of ap‐PRET in generating desired white afterglows for applications in diversified luminescent scenarios. Afterglow ; Phosphorescence ; Black-body radiation ; Materials science ; Energy transfer ; Radiation ; Resonance (particle physics) ; Atomic physics ; Line (geometry) ; Optoelectronics ; Optics ; Physics ; Fluorescence ; Astrophysics Luminescence and Fluorescent Materials ; Photodynamic Therapy Research Studies ; Advanced Fluorescence Microscopy Techniques
Authors: Julika Schlosser | Оlga А. Fedorova | Yu. V. Fedorov | Heiko Ihmels
Source: Beilstein Journal of Organic Chemistry (article, 2024-01-18)
Field: Chemistry — Organic Chemistry

Photoinduced in situ generation of DNA-targeting ligands: DNA-binding and DNA-photodamaging properties of benzo[<i>c</i>]quinolizinium ions The photoreactions of selected styrylpyridine derivatives to the corresponding benzo[<i>c</i>]quinolizinium ions are described. It is shown that these reactions are more efficient in aqueous solution (97-44%) than in organic solvents (78-20% in MeCN). The quinolizinium derivatives bind to DNA by intercalation with binding constants of 6-11 × 10<sup>4</sup> M<sup>-1</sup>, as shown by photometric and fluorimetric titrations as well as by CD- and LD-spectroscopic analyses. These ligand-DNA complexes can also be established in situ upon irradiation of the styrylpyridines and formation of the intercalator directly in the presence of DNA. In addition to the DNA-binding properties, the tested benzo[<i>c</i>]quinolizinium derivatives also operate as photosensitizers, which induce DNA damage at relative low concentrations and short irradiation times, even under anaerobic conditions. Investigations of the mechanism of the DNA damage revealed the involvement of intermediate hydroxyl radicals and C-centered radicals. Under aerobic conditions, singlet oxygen only contributes to marginal extent to the DNA damage. Chemistry ; Intercalation (chemistry) ; DNA ; Singlet oxygen ; Radical ; Titration ; DNA damage ; Photochemistry ; Aqueous solution ; Ligand (biochemistry) ; Ion ; Combinatorial chemistry ; Stereochemistry ; Oxygen ; Inorganic chemistry ; Biochemistry ; Organic chemistry ; Receptor Synthesis and Biological Evaluation ; Bioactive Compounds and Antitumor Agents ; Radical Photochemical Reactions
Authors: Md. Sazedul Islam | Andrew H. Comstock | Zhenqi Hua | Puja Thapa | Yufang He | Azza Ben‐Akacha | He Liu | Tarannuma Ferdous Manny | Jarek Viera | Xinsong Lin | Bin Ouyang | Peng Xiong | Dali Sun | Biwu Ma
Source: Angewandte Chemie International Edition (article, 2024-07-30)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Antiferromagnetic Ordering in A One‐Dimensional Organic Copper Chloride Hybrid Insulator Low dimensional (LD) organic metal halide hybrids (OMHHs) have recently emerged as new generation functional materials with exceptional structural and property tunability. Despite the remarkable advances in the development of LD OMHHs, optical properties have been the major functionality extensively investigated for most of LD OMHHs developed to date, while other properties, such as magnetic and electronic properties, remain significantly under-explored. Here, we report for the first time the characterization of the magnetic and electronic properties of a 1D OMHH, organic-copper (II) chloride hybrid (C<sub>8</sub>H<sub>22</sub>N<sub>2</sub>)Cu<sub>2</sub>Cl<sub>6</sub>. Owing to the antiferromagnetic coupling between Cu atoms through chloride bridges in 1D [Cu<sub>2</sub>Cl<sub>6</sub> <sup>2-</sup>]<sub>∞</sub> chains, (C<sub>8</sub>H<sub>22</sub>N<sub>2</sub>)Cu<sub>2</sub>Cl<sub>6</sub> is found to exhibit antiferromagnetic ordering with a Néel temperature of 24 K. The two-terminal (2T) electrical measurement on a (C<sub>8</sub>H<sub>22</sub>N<sub>2</sub>)Cu<sub>2</sub>Cl<sub>6</sub> single crystal reveals its insulating nature. This work shows the potential of LD OMHHs as a highly tunable quantum material platform for spintronics. Antiferromagnetism ; Spintronics ; Copper ; Materials science ; Halide ; Chloride ; Crystal structure ; Ferromagnetism ; Crystallography ; Condensed matter physics ; Inorganic chemistry ; Chemistry ; Physics Organic and Molecular Conductors Research ; Perovskite Materials and Applications ; Magnetism in coordination complexes
Authors: Maria Cherevatskaya | Ilia Cherepanov | N. V. Kalganova | Natalia Erofeeva | E. V. Romanovskaya | Andrej Frolov | Tatiana Bilova | Sergey K. Moiseev | Ludger A. Wessjohann
Source: Stresses (article, 2024-01-16)
Field: Chemistry — Organic Chemistry

Sydnone Imines as a New Class of Promising Plant Growth and Stress Tolerance Modulators—A First Experimental Structure–Activity Overview Due to the oncoming climate changes, various environmental stresses (drought, salinity, heavy-metals, low or high temperatures, etc.) might dramatically affect crop yields and the quality of produced foods. Therefore, to meet the growing food demand of the human population, improvement of stress tolerance of the currently cultured crops is required. The knowledge of the molecular underlying mechanisms provides a versatile instrument to correct plant metabolism via chemical tools and to thereby increase their adaptive potential. This will preserve crop productivity and quality under abiotic stress conditions. Endogenously produced nitric oxide (NO) is one of the key signaling factors activating stress tolerance mechanisms in plants. Thus, the application of synthetic NO donors as stress-protective phytoeffectors might support maintaining plant growth and productivity under stressful conditions. Sydnone imines (sydnonimines) are a class of clinically established mesoionic heterocyclic NO donors which represent a promising candidate group for such phytoeffectors. Therefore, here, we provide an overview of the current progress in the application of sydnone imines as exogenous NO donors in plants, with a special emphasis on their potential as herbicides as well as herbicide antidotes, growth stimulants and stress protectors triggering plant tolerance mechanisms. We specifically address the structure–activity relationships in the context of the growth modulating activity of sydnone imines. Growth stimulating or antidote effects are typical for 4-α-hydroxybenzyl derivatives of sydnone imines containing an alkyl substituent in position N-3. The nature of the substituent of the N-6 atom has a significant influence on the activity profile and the intensity of the effect. Nevertheless, further investigations are necessary to establish reliable structure–activity relationships (SAR). Consequently, sydnone imines might be considered promising phytoeffector candidates, which are expected to exert either protective effects on plants growing under unfavorable conditions, or herbicidal ones, depending on the exact structure. Sydnone ; Context (archaeology) ; Population ; Substituent ; Chemistry ; Biotechnology ; Biology ; Medicine ; Stereochemistry ; Organic chemistry ; Environmental health Quinazolinone synthesis and applications ; Synthesis and Biological Evaluation ; N-Heterocyclic Carbenes in Organic and Inorganic Chemistry
Authors: Meng-Ting Tsai | Yi-Chen Lee | Yung-Mei Lin | Vincent K. S. Hsiao | Chih‐Chien Chu
Source: Materials (article, 2024-02-21)
Field: Materials Science — Materials Chemistry

Exploring the Influence of Solvents on Electrochemically Etched Porous Silicon Based on Photoluminescence and Surface Morphology Analysis Porous silicon (PSi) has promising applications in optoelectronic devices due to its efficient photoluminescence (PL). This study systematically investigates the effects of various organic solvents and their concentrations during electrochemical etching on the resulting PL and surface morphology of PSi. Ethanol, n-butanol, ethylene glycol (EG) and N,N-dimethylformamide (DMF) were employed as solvents in hydrofluoric acid (HF)-based silicon etching. The PL peak position exhibited progressive blue-shifting with increasing ethanol and EG concentrations, accompanied by reductions in the secondary peak intensity and emission linewidth. Comparatively, changes in n-butanol concentration only slightly impacted the main PL peak position. Additionally, distinct morphological transitions were observed for different solvents, with ethanol and n-butanol facilitating uniform single-layer porous structures at higher concentrations in contrast to the excessive etching caused by EG and DMF resulting in PL quenching. These results highlight the complex interdependencies between solvent parameters such as polarity, volatility and viscosity in modulating PSi properties through their influence on surface wetting, diffusion and etching kinetics. The findings provide meaningful guidelines for selecting suitable solvent conditions to tune PSi characteristics for optimized device performance. Porous silicon ; Photoluminescence ; Materials science ; Etching (microfabrication) ; Chemical engineering ; Ethylene glycol ; Silicon ; Solvent ; Analytical Chemistry (journal) ; Nanotechnology ; Layer (electronics) ; Organic chemistry ; Chemistry ; Optoelectronics Silicon Nanostructures and Photoluminescence ; Nanowire Synthesis and Applications ; Semiconductor materials and devices