jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Homeira Faridnejad
Source: Biostatistics and Biometrics Open Access Journal (article, 2023-05-11)
Field: Materials Science — Biomaterials

Physicochemical Transformation Effect on the Relaxivity Enhancement of Iron Oxide Nanoparticles in Nuclear Medicine and MRI Imaging Iron Oxide Nanoparticles (IONPs), one of the contrast agents for MRI scanners, will be designed to have high relaxivity since they have distinct physical properties attributed to the quantum size effect.There are several techniques for synthesizing IONPs also for Superparamagnetic iron oxide nanoparticles (SPIONs) and Ultrasmall Superparamagnetic iron oxide nanoparticles (USPIONs) by using some physicochemical transformation effects which can affect relatxivity time by controlling the size and surface which is used respectively as a T 2 contrast agent and T 1 or T 2 contrast agent.Biomedical imaging like computed tomography (CT), positron emission tomography (PET), and single-photon emission computerized tomography (SPECT).Magnetite (Fe 3 O 4 ) and maghemite (γ-Fe 2 O 3 ) are both single crystalline structures.Nanoparticles that are non-spherical such as octopus's cubes and rods have more than their spherical counterparts.Size and shape must be controlled because they determine the phase, crystallization, size, and magnetism of the contrast agent of MR-CT are called GION gold oxide particles as a dual contrast.It can be provided from uneven structural nanocomposites of radiolabeled and MNP-labeled essential materials, while the intensity of contrast in the tumor area increases over time, indicating that FAuNC@Fe 3 O 4 is highly absorbed in the tumor.Radioactive elements that bind to IONP can be used in multimodal imaging and radiotherapy.The 99m Tc -labeled NOTA-IONPs were fabricated as shell microbeads and DTPA-IONPs to observe the clearance and distribution of nanoparticles in vivo (Figure 1). Nanoparticle ; Iron oxide nanoparticles ; Nuclear magnetic resonance ; Transformation (genetics) ; Iron oxide ; Materials science ; Nanotechnology ; Chemistry ; Metallurgy ; Biochemistry ; Physics Nanoparticle-Based Drug Delivery
Authors: Wenhua Shi | Liujun Pei | Xiaomin Gu | Jiping Wang
Source: Tenside Surfactants Detergents (article, 2023-03-16)
Field: Materials Science — Polymers and Plastics

Stain removal performance of moisture-wicking fabric during home laundry Abstract Moisture-wicking clothes are widely used in various sports or athletic activities due to their function of moisture absorption and perspiration. In this study, the washing and decontamination of moisture-wicking fabrics, especially the performance and decontamination effect of moisture-wicking fabrics after washing were investigated. The results showed that the physical morphology of moisture-wicking fabric is very different from that of an ordinary polyester fabric. The cross-section of the moisture-wicking fabric is hexagonal, and this fabric has good hydrophilicity. After the degreasing &amp; thermosetting process, the air permeability of the moisture-wicking fabric is increased from 1013 mm/s to 2911 mm/s. However, the air permeability is decreased after one washing, but it has little effect during the subsequent washing cycles. Moreover, the degreasing &amp; thermosetting process also improve the stains removal index. If the moisture-wicking fabric was washed before the preparation of stained fabric, the stain removal index of carbon black soil and sebum stains is increased. Although most of the aggregated particles on the surface of the fibers are removed after washing, a small amount of sebum still remains in the spaces between the fibers. These results indicate that most of the carbon black in the stained area is removed after washing, while oil components are hardly removed from the moisture-wicking fabric during home laundry. Compared to other surfactants, C 18 fatty acid methyl ester ethoxylates and nonionic surfactants with long carbon chains can effectively reduce the surface tension of water and improve the wettability of moisture-wicking fabric, so that water molecules can diffuse well between fibers and stains, the binding force between stains and fabric is weakened, and the decontamination of the fabric is improved. Degreasing ; Moisture ; Air permeability specific surface ; Chemistry ; Composite material ; Laundry ; Wetting ; Polyester ; Pulmonary surfactant ; Pulp and paper industry ; Materials science ; Chemical engineering ; Waste management Textile materials and evaluations ; Dyeing and Modifying Textile Fibers ; Material Properties and Processing
Authors: Qiaoxi Yu | Runxin Bei | Jiahui Liu | Yan‐Wei He | Siwei Liu | Zhenguo Chi | Jiarui Xu | Yi Zhang
Source:  (preprint, 2023-05-26)
Field: Materials Science — Polymers and Plastics

Bioinspired polyimide film with fire retardant and gas barrier properties by gravity-induced deposition of montmorillonite Flame retardants play a crucial role in improving the flame retardant properties of polymer materials. In recent years, environmental problems caused by flame retardants have attracted widespread attention. It is urgent to use green and effective methods to prepare flame retardant polymers. Bioinspired nanocomposites with layered structures seem to provide an effective idea, but in general, the hydrophilic properties of their raw materials limit their applications in certain fields. Here, we prepared biomimetic composites with a layered “brick-and-mortar” structure by gravity-induced deposition using polyimide as the polymer matrix and montmorillonite (MMT) as the filler. The well-arranged structures of the composite material could isolate oxygen and prevent combustible gases from escaping. The gas barrier performance has been greatly improved, in which the water vapor transmission rate (WVTR) and the oxygen transmission rate (OTR) decreased by 99.18% and three orders of magnitude, respectively. The flame retardant performance has also been improved, and its limiting oxygen index can reach 67.9%. More importantly, the polyimide matrix can be converted to water-insoluble by thermal imidization of water-soluble poly (amic acid) salt precursors, which endows the composites with low hygroscopicity. Such coating containing MMT can protect against polyurethane (PU) foam from fire. During the conical calorimetric test, the coated sample self-extinguished, and the peak heat release rate, total heat release, total smoke production is significantly decreased by 53.39%, 40.69%, and 53.03%, respectively. Taking advantage of these properties, this work utilizes a facile method to prepare biomimetic composites with low moisture absorption, excellent gas barrier properties, and flame retardancy, which have great application potential. Fire retardant ; Materials science ; Limiting oxygen index ; Composite material ; Montmorillonite ; Polyimide ; Polymer ; Nanocomposite ; Composite number ; Moisture ; Polymer clay ; Chemical engineering ; Char ; Pyrolysis ; Layer (electronics) Flame retardant materials and properties ; Synthesis and properties of polymers ; Silicone and Siloxane Chemistry
Authors: Lassi Hällström | Ilkka Tittonen
Source: Physical Review Applied (article, 2023-11-01)
Field: Materials Science — Materials Chemistry

Nonequilibrium Green’s function simulation of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><mml:msub><mml:mtext>Cu</mml:mtext><mml:mn>2</mml:mn></mml:msub><mml:mrow><mml:mi mathvariant="normal">O</mml:mi></mml:mrow></mml:math> photocathodes for photoelectrochemical hydrogen production In this work we present a simulation of the semiconductor electrodes of photoelectrochemical (PEC) water-splitting cells based on the nonequilibrium Green's function (NEGF) formalism. While the performance of simple PEC cells can be adequately explained with semiclassical drift-diffusion theory, the increasing interest towards thin-film cells and nanostructures, in general, requires theoretical treatment that can capture the quantum phenomena influencing the charge carrier dynamics in these devices. Specifically, we study a $p$-type ${\mathrm{Cu}}_{2}\mathrm{O}$ electrode and examine the influence of the bias voltage, reaction kinetics, and the thickness of the ${\mathrm{Cu}}_{2}\mathrm{O}$ layer on the generated photocurrent. The NEGF equations are solved in a self-consistent manner with the electrostatic potential from Poisson's equation, sunlight-induced photon scattering and the chemical overpotential required to drive the water-splitting reaction. We show that the NEGF simulation accurately reproduces experimental results from both voltammetry and impedance spectroscopy measurements, while providing an energy-resolved solution of the charge carrier densities and corresponding currents inside the semiconductor electrode at nanoscale. Physics ; Non-equilibrium thermodynamics ; Photocurrent ; Semiconductor ; Materials science ; Charge carrier ; Quantum mechanics Copper-based nanomaterials and applications ; Electronic and Structural Properties of Oxides ; ZnO doping and properties
Authors: Hyunsu Jeon | Runyao Zhu | Gaeun Kim | Yichun Wang
Source: bioRxiv (Cold Spring Harbor Laboratory) (preprint, 2023-06-29)
Field: Materials Science — Materials Chemistry

Chirality-Enhanced Transport and Drug Delivery of Graphene Nanocarriers to Tumor-like Cellular Spheroid Chirality, defined as “a mirror image,” is a universal geometry of biological and nonbiological forms of matter. This geometry of molecules determines how they interact during their assembly and transport. With the development of nanotechnology, many nanoparticles with chiral geometry or chiroptical activity have emerged for biomedical research. The mechanisms by which chirality originates and the corresponding synthesis methods have been discussed and developed in the past decade. Inspired by the chiral selectivity in life, a comprehensive and in-depth study of interactions between chiral nanomaterials and biological systems has far-reaching significance in biomedicine. Here, we investigated the effect of the chirality of nanoscale drug carriers, graphene quantum dots (GQDs), on their transport in tumor-like cellular spheroids. Chirality of GQDs ( L/D -GQDs) was achieved by the surface modification of GQDs with L/D -cysteines. As an in-vitro tissue model for drug testing, cellular spheroids were derived from a human hepatoma cell line ( i . e ., HepG2 cells) using the Hanging-drop method. Our results reveal that the L -GQDs had a 1.7-fold higher apparent diffusion coefficient than the D -GQDs, indicating that the left-handed chirality of GQDs can enhance their transport into tumor-like cellular spheroids. Moreover, when loaded with a common chemotherapy drug, Doxorubicin (DOX), via π-π stacking, L -GQDs are more effective as nanocarriers for drug delivery, resulting in 25% higher efficacy for cancerous cellular spheroids than free DOX. Overall, our studies indicated that the chirality of nanocarriers is essential for the design of drug delivery vehicles to enhance the transport of drugs in a cancerous tumor. Nanocarriers ; Chirality (physics) ; Drug delivery ; Nanotechnology ; Spheroid ; Nanomaterials ; Nanomedicine ; Graphene ; Biophysics ; Materials science ; Nanoparticle ; Chemistry ; In vitro ; Physics ; Biology Carbon and Quantum Dots Applications ; Nanocluster Synthesis and Applications ; Graphene and Nanomaterials Applications
Authors: Isaac J. Gresham | Seamus G. Lilley | Andrew Nelson | Kaloian Koynov | Chiara Neto
Source: Angewandte Chemie (article, 2023-08-08)
Field: Materials Science — Surfaces, Coatings and Films

Nanostructure Explains the Behavior of Slippery Covalently Attached Liquid Surfaces Abstract Slippery covalently‐attached liquid surfaces (SCALS) with low contact angle hysteresis (CAH, &lt;5°) and nanoscale thickness display impressive anti‐adhesive properties, similar to lubricant‐infused surfaces. Their efficacy is generally attributed to the liquid‐like mobility of the constituent tethered chains. However, the precise physico‐chemical properties that facilitate this mobility are unknown, hindering rational design. This work quantifies the chain length, grafting density, and microviscosity of a range of polydimethylsiloxane (PDMS) SCALS, elucidating the nanostructure responsible for their properties. Three prominent methods are used to produce SCALS, with characterization carried out via single‐molecule force measurements, neutron reflectometry, and fluorescence correlation spectroscopy. CO 2 snow‐jet cleaning was also shown to reduce the CAH of SCALS via a modification of their grafting density. SCALS behavior can be predicted by reduced grafting density, Σ, with the lowest water CAH achieved at Σ≈2. This study provides the first direct examination of SCALS grafting density, chain length, and microviscosity and supports the hypothesis that SCALS properties stem from a balance of layer uniformity and mobility. Microviscosity ; Nanostructure ; Materials science ; Chemical engineering ; Grafting ; Contact angle ; Neutron reflectometry ; Nanotechnology ; Covalent bond ; Polydimethylsiloxane ; Polymer chemistry ; Chemical physics ; Chemistry ; Small-angle neutron scattering ; Neutron scattering ; Polymer ; Composite material ; Organic chemistry ; Optics ; Scattering Surface Modification and Superhydrophobicity ; Adhesion, Friction, and Surface Interactions ; Polymer Surface Interaction Studies
Authors: Letizia Ferbel | Stefano Veronesi | Ylea Vlamidis | Antonio Rossi | Leonardo Sabattini | Camilla Coletti | Stefan Heun
Source: arXiv (Cornell University) (preprint, 2023-09-27)
Field: Materials Science — Materials Chemistry

Platinum-Decorated Graphene: Experimental Insight into Growth Mechanisms and Hydrogen Adsorption Properties The potential of graphene for hydrogen storage, coupled with the established role of Platinum as a catalyst for the hydrogen evolution reaction and the spillover effect, makes Pt-functionalized graphene a promising candidate for near-ambient hydrogen storage. This paper focuses on examining the process of Pt cluster formation on epitaxial graphene and assesses the suitability of the system as hydrogen storage material. Scanning tunneling microscopy unveils two primary pathways for Pt cluster growth. In the initial phase, up to ~1 ML of Pt coverage, Pt tends to randomly disperse and cover the graphene surface, while the cluster height remains essentially unchanged. Beyond a coverage of 3 ML, the nucleation of new layers on existing clusters becomes predominant. Then, the clusters mainly grow in height. Thermal desorption spectroscopy on hydrogenated Pt-decorated graphene reveals the presence of multiple hydrogen adsorption mechanisms, manifested as two Gaussian peaks superimposed on a linearly increasing background. We attribute the first peak at 150°C to hydrogen physisorbed on the surface of Pt clusters. The second peak at 430°C is attributed to chemisorption of hydrogen on the surface of the clusters, while the linearly increasing background is assigned to hydrogen bonded in the bulk of the Pt clusters. These measurements demonstrate the ability of Pt-functionalized graphene to store molecular hydrogen at temperatures that are high enough for stable hydrogen binding at room temperature. Graphene ; Hydrogen ; Platinum ; Materials science ; Hydrogen spillover ; Nucleation ; Chemisorption ; Hydrogen storage ; Chemical physics ; Adsorption ; Catalysis ; Cluster (spacecraft) ; Nanotechnology ; Chemical engineering ; Physical chemistry ; Chemistry ; Organic chemistry Graphene research and applications ; Hydrogen Storage and Materials ; Advancements in Battery Materials
Authors: Debela Jufar Turunesh | Gashaw Tadele Zewudie | Dereba Workineh Dereba Workineh Seboka
Source: Applied Chemical Engineering (article, 2023-11-08)
Field: Materials Science — Biomaterials

Extraction and modification of cellulose from Artocarpus heterophyllus for biosorption of lead ion from aqueous solution as cost effective biosorbent The heavy metals found in contaminated waters are dangerous for the environment and human health, so it is necessary to seek and apply techniques to remove these pollutants, using adsorption techniques with natural biopolymers as cost effective biosorbent. Since large amounts of Jackfruit (Artocarpus heterophyllus fruit) waste part are abandoned after the pulp used around Tepi areas, the possibility of developing value-added products from them is interesting innovation. In this work, cellulose fiber was extracted from Artocarpus heterophyllus fruit waste part and modified with Isopropyl alcohol groups to produce which were then used as Lead metal ion adsorbents. The modified cellulose was characterized by several techniques including Fourier transform infrared spectra (FTIR), scanning electron microscope (SEM), and thermogravimetric analysis (TGA). This modified cellulose was used as adsorbents for adsorption studies of heavy metal ions (Pb2+) within batch adsorption systems. A solution of lead ion (Pb2+) was used as artificial wastewater for the purpose of studying biosorption efficiencies. The biosorption efficiencies of modified cellulose were studied by using four adsorption parameters. The optimum biosorption of modified cellulose at 25 °C, were found to be 94.2%, 76.12%, 82.54%, and 90.13%, of Pb2+ for the adsorption parameter; biosorbent dosage, contact time, Pb (II) concentration, and pH respectively. The biosorption kinetics behaviour of modified cellulose for Pb2+ fitted well with a pseudo-second-order model with correlation coefficient of 0.9975. The biosorption isotherm behaviour was well described using the Langmuir biosorption isotherm model with higher correlation coefficient of 0.9935. The reusability and desorption study of modified cellulose shows that it can be reused 2 to 4 times and after 5th cycles the desorption was significantly decreased. This study showed that the modified cellulosic adsorbents made from (Artocarpus heterophyllus fruit) were able to efficiently adsorb metal ions from aqueous solution. Biosorption ; Adsorption ; Chemistry ; Cellulose ; Thermogravimetric analysis ; Langmuir adsorption model ; Artocarpus ; Nuclear chemistry ; Desorption ; Aqueous solution ; Regenerated cellulose ; Freundlich equation ; Metal ions in aqueous solution ; Fourier transform infrared spectroscopy ; Langmuir ; Chemical engineering ; Metal ; Sorption ; Organic chemistry ; Botany Advanced Cellulose Research Studies
Authors: Hongmei Xie | Na Liu | Haoyu Wang | Shuang Chen | Jia Zeng | Guilin Zhou
Source: Research Square (preprint, 2023-03-20)
Field: Materials Science — Materials Chemistry

Activated carbon with high mesopore ratio derived from waste Zanthoxylum bungeanum branches by KNO3 assisted H3PO4 staged activation for toluene adsorption Adsorption ; Activated carbon ; Toluene ; Mesoporous material ; Specific surface area ; Chemistry ; Chemical engineering ; Desorption ; Carbon fibers ; Nuclear chemistry ; Organic chemistry ; Materials science ; Catalysis ; Composite material Mesoporous Materials and Catalysis ; Adsorption and biosorption for pollutant removal ; Supercapacitor Materials and Fabrication
Authors: Michael Wenzel | Roland Mitrić
Source: arXiv (Cornell University) (preprint, 2023-09-26)
Field: Chemistry — Physical and Theoretical Chemistry

Prediction of Fluorescence Quantum Yields using the Extended Thawed Gaussian Approximation Spontaneous emission and internal conversion rates are calculated within harmonic approximations and compared to results obtained within the semi-classical extended thawed Gaussian approximation. This is the first application of the ETGA in the calculation of internal conversion and emission rates for real molecular systems, namely formaldehyde, fluorobenzene, azulene and a dicyano-squaraine dye. The viability of the models as black-box tools for prediction of spontaneous emission and internal conversion rates is assessed. All calculations were done using a consistent protocol in order to investigate how different methods perform without previous experimental knowledge. Contrasting the results with experimental data shows that there are further improvements required before theoretical predictions of emission and internal conversion rates can be used as reliable indicator for the photo-luminescence properties of molecules. We find that the extended thawed Gaussian approximation performs rather similar to the vertical harmonical model. Including anharmonicities in the calculation of internal conversion rates has a moderate effect on the quantitative results in the studied systems. The electronic structure calculations were done using the B3LYP, PBE0, $ω$B97XD and CAM-B3LYP functionals. The choice of the functional does not appear to be a major limiting factor for a black-box approach, when it comes to the prediction of radiative and nonradiative rates for organic molecules. The emission rates are fairly stable with respect to computational parameters, but the internal conversion rate reveals itself to be highly dependent on the choice of the spectral lineshape function, particularly the width of the Lorentzian function, associated with homogeneous broadening. Internal conversion ; Azulene ; Gaussian ; Radiative transfer ; Computational physics ; Function (biology) ; Chemistry ; Molecular physics ; Physics ; Materials science ; Computational chemistry ; Optics ; Quantum mechanics ; Spectral line Photochemistry and Electron Transfer Studies ; Atmospheric chemistry and aerosols ; Atmospheric Ozone and Climate
Authors: Ken Kato | Hiroki Takahashi | H Tamaki | Toshimichi Fujiwara | Yoh Matsuki
Source: ChemRxiv (preprint, 2023-08-30)
Field: Materials Science — Materials Chemistry

Nanodiamond-based hyperpolarization for in-situ magic-angle-spinning nuclear magnetic resonance spectroscopy of proteins Diamond-based hyperpolarization of external molecular spins has a significant impact on the modality of the nuclear magnetic resonance (NMR) spectroscopy and its sensitivity. The current nitrogen-vacancy (NV) center-based hyperpolarization and optical detection technique however faces a challenge in its implementation at high external field conditions required for the analysis of complex chemical entities such as proteins. In this work, we demonstrate that the surface electrons of nanodiamonds can be an attractive alternative with a number of practical benefits to this end. We first show at a very high external field condition (16.4 T) and low temperature (30 K) that the 13C spin polarization 200-fold higher than the conventional NMR can be achieved for the external bio-molecules within ~3 nm from the diamond surface with no laser illumination and no lattice orientation dependence. This latter property enabled us to record sensitivity-enhanced high-resolution multi-dimensional NMR data on protein sample under continuous sample spinning. We also show that the smallness of the nanodiamond (~5 nm), stability to bio-reduction and richness in surface chemistry enables a molecular-specific delivery of the diamond particle to targeted protein amyloid fibers within crowded cellular environment for a selective hyperpolarization. Overall, this work opens up new avenues to highly sensitive and targeted in-situ MAS NMR spectroscopy, relevant to biology and other fields. Hyperpolarization (physics) ; Nanodiamond ; Diamond ; Spins ; Nuclear magnetic resonance spectroscopy ; Materials science ; Spectroscopy ; Magic angle spinning ; Solid-state nuclear magnetic resonance ; Nanotechnology ; Nuclear magnetic resonance ; Chemistry ; Chemical physics ; Physics ; Condensed matter physics Diamond and Carbon-based Materials Research ; Atomic and Subatomic Physics Research ; Advanced NMR Techniques and Applications