jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Ayşe Bostancı | Nilay Aladag Tanik | Yakup Aykut
Source: TEKSTİL VE KONFEKSİYON (article, 2019-08-01)
Field: Materials Science — Polymers and Plastics

CELLULOSE MONOACETATE/NAFION (CMA/N) HYBRID NANOFIBERS AS INTERFACE FOR ELECTROCHEMICAL DNA BIOSENSORS Nafion/cellulose monoacetate (CMA/N) hybrid nanofibers were produced via a one-step electrospinning method. Nanofibers morphologies transformed from uniform to bead on a string defect morphology with increasing Nafion ratio in CMA/N hybrid nanofibers. The melting point of CMA was detectable at DSC measurement, but the addition of Nafion didn’t allow a proper crystallization of CMA and melting peak disappeared after the Nafion addition. Decomposition temperature decreased dramatically with the addition of Nafion into CMA/N nanofibers and decomposition took place at a broad temperature range. Differential pulse voltammetry (DPV) analyses were conducted to observe the guanine oxidation signal at neat and NH-modified DNA on the as-prepared nanofiber sensory system. Maximum oxidation signals were obtained from pure CMA nanofibers at neat ssDNA. Comparing neat DNA, signal intensity increased with the addition of Nafion into CMA/N nanofibers at NH-modified ssDNA sample. The examined CMA/N hybrid nanofibers could be a promising DNA biosensor devices. Nanofiber ; Nafion ; Biosensor ; Materials science ; Electrospinning ; Differential pulse voltammetry ; Electrochemistry ; Cellulose ; Chemical engineering ; Cyclic voltammetry ; Nuclear chemistry ; Polymer chemistry ; Electrode ; Chemistry ; Polymer ; Nanotechnology ; Organic chemistry ; Physical chemistry ; Composite material Conducting polymers and applications ; Advanced Sensor and Energy Harvesting Materials ; Biosensors and Analytical Detection
Authors: Liangyu Lu | Jian Li | Hongwei Li | Chengtao Gao | Haibo Xie | Yuzhu Xiong | Zhu Luo | Qi Sun | Fuping Dong
Source: Applied Surface Science (article, 2019-03-05)
Field: Materials Science — Materials Chemistry

Controllable synthesis of hierarchical polysilsesquioxane surfaces: from spheres-on-sphere to bowls-on-sphere structure SPHERES ; Polystyrene ; Silane ; Materials science ; Fabrication ; Pulmonary surfactant ; Chemical engineering ; Nanotechnology ; Composite material ; Polymer ; Physics Silicone and Siloxane Chemistry ; Surface Modification and Superhydrophobicity ; Catalytic Processes in Materials Science
Authors: Makoto Sakurai | Pradyot Koley | Masakazu Aono
Source: Scientific Reports (article, 2019-10-10)
Field: Materials Science — Materials Chemistry

Tunable Magnetism of Organometallic Nanoclusters by Graphene Oxide On-Surface Chemistry Assembly of interacting molecular spins is an attractive candidate for spintronic and quantum computing devices. Here, we report on-surface chemical assembly of aminoferrocene molecules on a graphene oxide (GO) sheet and their magnetic properties. On the GO surface, organometallic molecules having individual spins through charge transfer between the molecule and the sheet are arranged in nanoclusters having diameters of about 2 nm. The synthetic fine tuning of the reaction time enables to change the interspacing between the nanoclusters, keeping their size intact. Their magnetism changes from paramagnetic behavior to collective one gradually as the interspacing decreases. The creation of collective nature among weakly interacting molecular spins through their nanoscale arrangement on the GO surface opens a new avenue to molecular magnetism. Nanoclusters ; Magnetism ; Graphene ; Spintronics ; Spins ; Nanotechnology ; Oxide ; Chemical physics ; Paramagnetism ; Molecule ; Materials science ; Ferromagnetism ; Chemistry ; Condensed matter physics ; Physics ; Organic chemistry Graphene research and applications ; Surface Chemistry and Catalysis ; Molecular Junctions and Nanostructures
Authors: Yingge Zhou | Shahrima Mahurubin | Dilshan Sooriyaarachchi | George Z. Tan
Source: Procedia Manufacturing (article, 2019-01-01)
Field: Materials Science — Biomaterials

The Effect of Nanoclays on Nanofiber Density Gradient in 3D Scaffolds Fabricated By Divergence Electrospinning Tissue engineering generally requires the use of artificial scaffolds to recreating the in vivo milieu which coordinates complex spatiotemporal mechanisms to guide cell behavior. Studies showed that aligned nanofiber scaffolds provide biophysical stimuli to promote cell adhesion, proliferation, morphogenesis, and motility. This study presents a 3D assembly process of aligned polycaprolactone nanofibers directed by a symmetrically divergent electric field. Nanoclays (phyllosilicate) were added into the polymer solution to enhance the homogeneity of fiber distribution within the scaffold. The conductivity and viscosity of solutions were characterized. The nanofiber attributes including fiber diameter, fiber density, and fiber alignment were analyzed by scanning electron microscopy. The results showed that the homogeneity of nanofiber distribution with regard to density and alignment were positively correlated with the conductivity and viscosity of polymer solution. This study demonstrated the feasibility of fine-tuning the microstructure of 3D assembled nanofiber scaffolds by altering the material properties. Nanofiber ; Electrospinning ; Materials science ; Polycaprolactone ; Nanotechnology ; Polymer ; Fiber ; Composite material ; Scaffold ; Biomedical engineering Electrospun Nanofibers in Biomedical Applications ; Bone Tissue Engineering Materials ; Graphene and Nanomaterials Applications
Authors: Luis Seijo | S.P. Feofilov | Zoila Barandiarán
Source: The Journal of Physical Chemistry Letters (article, 2019-05-27)
Field: Chemistry — Electrochemistry

Fine-Tuning the Cr<sup>3+</sup> R<sub>1</sub>-Line by Controlling Pauli Antisymmetry Strength Fine-tuning of the Cr<sup>3+</sup> zero-phonon R<sub>1</sub>-line fluorescence (<sup>2</sup>E-<sup>4</sup>A<sub>2</sub>) has recently been achieved by varying the composition of Cr-doped solid solution garnets. Chemical substitutions of Y<sup>3+</sup> with Lu<sup>3+</sup> and Tb<sup>3+</sup> produce R<sub>1</sub>-line shifts and multiplets that cannot be associated with direct or indirect changes in the Cr-O covalency alone and raise important questions on the nature of the interactions between the CrO<sub>6</sub> active center and its environment, hence on the impact of local disorder. In this Letter we show that Pauli antisymmetry interactions with next-nearest neighbor ions, which are commonly omitted from theoretical analyses, induce a nephelauxetic effect on the CrO<sub>6</sub> active center that shifts the R<sub>1</sub>-line. The strength of these interactions increases with the ionic radius and number of codopant ions, all of it resulting in controlled shifts and multiplets of R<sub>1</sub>-lines. The Pauli antisymmetry induced nephelauxetic effect, combined with the R<sub>1</sub>-line shift with lattice constant, allows for a very fine-tuning of the Cr<sup>3+</sup> R<sub>1</sub>-line. Pauli exclusion principle ; Antisymmetry ; Ionic radius ; Ion ; Physics ; Bohr radius ; RADIUS ; Line (geometry) ; Atomic physics ; Chemistry ; Condensed matter physics ; Electron ; Quantum mechanics ; Mathematics Electrochemical Analysis and Applications ; Luminescence Properties of Advanced Materials ; Analytical Chemistry and Sensors
Authors: Rajul Ranjan Choudhury | R. Chitra | И. П. Макарова | В. Л. Маноменова | Е. Б. Руднева | А. Э. Волошин | М. В. Колдаева
Source: Journal of Applied Crystallography (article, 2019-11-14)
Field: Materials Science — Materials Chemistry

α-Nickel sulfate hexahydrate crystals: relationship of growth conditions, crystal structure and properties Studies on α-nickel sulfate hexahydrate (NSH) crystals grown under different conditions are undertaken to investigate how changes in growth conditions affect crystal properties and whether or not there is any modification of the average crystal structure due to changes in crystallization conditions. Thermogravimetric and microhardness studies were carried out on the crystals grown from two different aqueous solutions, one of them containing an excess of sulfuric acid. Raman spectra were recorded and a single-crystal neutron diffraction investigation was conducted on both crystals. A detailed comparison between the two crystal structures and their Raman spectra showed that, although the two crystal structures are very similar, there are slight differences, such as the change in unit-cell volume, differences in the ionic structure, particularly of the sulfate ions, and changes in the hydrogen-bonding network. During solution crystal growth of a salt like NSH, varying the ionic environment around the solute ions influences the interionic interactions between them. Hence it is suggested that the above-mentioned structural differences result from a fine-tuning of the interionic interaction between the cations and anions of NSH in the solution phase. This difference is finally carried over to the crystalline phase. The resulting small crystal structure differences are enough to produce measurable changes in the thermal stability and fragility of the crystals. These differences in crystal properties can be explained on the basis of the observed structural differences between the two crystals grown under different conditions. Raman spectroscopy ; Crystal (programming language) ; Crystal structure ; Crystallography ; Crystallization ; Nickel ; Ionic bonding ; Phase (matter) ; Materials science ; Neutron diffraction ; Chemistry ; Ion ; Organic chemistry Crystallization and Solubility Studies ; Crystallography and molecular interactions ; X-ray Diffraction in Crystallography
Authors: Lisha Xia | Ziliang Ma | Jiahui Tong | Yuliang Tang | Shanshan Li | Shanshan Qin | Ronghui Lou | Suwen Zhao | Xiaoguang Lei | Wenqing Shui
Source: Analytica Chimica Acta (article, 2019-12-19)
Field: Chemistry — Spectroscopy

Evaluation of chemical cross-linkers for in-depth structural analysis of G protein-coupled receptors through cross-linking mass spectrometry Chemistry ; G protein-coupled receptor ; Receptor ; Mass spectrometry ; Ligand (biochemistry) ; Biophysics ; Computational biology ; Biochemistry ; Chromatography Mass Spectrometry Techniques and Applications ; Receptor Mechanisms and Signaling ; Pharmacological Effects and Assays
Authors: Zhenqian Pang | Jiayu Wan | Aijiang Lu | Jiaqi Dai | Liangbing Hu | Teng Li
Source: Extreme Mechanics Letters (article, 2019-12-04)
Field: Materials Science — Materials Chemistry

Giant tunability of interlayer friction in graphite via ion intercalation Intercalation (chemistry) ; Graphite ; Graphene ; Materials science ; Nanotechnology ; Ion ; Layer (electronics) ; Chemical physics ; Composite material ; Chemistry ; Inorganic chemistry ; Organic chemistry Graphene research and applications ; 2D Materials and Applications ; MXene and MAX Phase Materials
Authors: К. Г. Абдулвахидов | Marina Sirota | Andriy P. Budnyk | T. A. Lastovina | Bashir Abdulvakhidov | S. A. Sadykov | Pavel Plyaka | А. В. Солдатов
Source: Journal of Physics Condensed Matter (article, 2019-01-15)
Field: Materials Science — Materials Chemistry

The role of defects in the physical properties of mechanically activated PbTiO <sub>3</sub> ferroelectrics In this work a multi-technique characterization was performed for the first time to trace the influence of structural defects on the physical properties of PbTiO<sub>3</sub> ferroelectrics. The structural defects were generated by the mechanical activation in the pressure range of 40-320 MPa, by combining a uniaxial strain with a shear deformation in the Bridgman anvils. The induced defectivity of PbTiO<sub>3</sub> was assessed via calculation of unit cell parameters, estimation of the regions of coherent scattering and analysis of micro-deformations. The Debye characteristic temperature, the static mean-square displacement, the Debye-Waller isotropic factor, the vibrational spectra and dielectric properties of the activated PbTiO<sub>3</sub> ceramics are presented. The high-quality PbTiO<sub>3</sub> ceramics was prepared without modifiers, hence, changing the concentration of structural defects via mechanical activation constitutes a chemically clean method for fine tuning of the dielectric properties of PbTiO<sub>3</sub>. Materials science ; Dielectric ; Isotropy ; Debye ; Ceramic ; Piezoelectricity ; Composite material ; Characterization (materials science) ; Debye model ; Condensed matter physics ; Optics ; Nanotechnology ; Optoelectronics Ferroelectric and Piezoelectric Materials ; Ultrasonics and Acoustic Wave Propagation ; Acoustic Wave Resonator Technologies
Authors: Yanda Ji | Qiang Yang | Xiyuan Zhang | Ruixing Xu | Weizheng Liang | Run Zhao | Weiwei Li | Xin Ou | Hao Yang
Source: Applied Physics Letters (article, 2019-11-11)
Field: Materials Science — Polymers and Plastics

Tuning critical phase transition in VO2 via interfacial control of normal and shear strain Interface strain plays a key role in creating the emergent functional properties of heteroepitaxially correlated materials. Strain that originates from the lattice mismatch of thin films and substrates has been widely studied to support the creation of desired functionalities. However, the shear strain induced by the symmetry mismatch of heterostructures has rarely been considered. Here, we report evidence of twin domains of stabilized vanadium dioxide (VO2) epitaxial films grown on sapphire substrates with a miscut along the a-plane. A systematic investigation of lattice variations, including lattice rotations and lattice distortions, reveals that both normal strain and shear strain can be manipulated by vicinal sapphire surfaces using different miscut angles. Consequently, the critical phenomenon of metal-insulator transitions (MITs) in VO2 epitaxial films is strongly coupled with lattice variations. A significantly sharpened MIT transition, over four orders of magnitude in resistance change, is also achieved by controlling interfacial shear strain. Our results demonstrate that the degree of freedom of shear lattice deformation opens the door to fine-tune the critical properties of heterostructures of strongly correlated oxides to aid in the development of electronic devices. Materials science ; Condensed matter physics ; Heterojunction ; Phase transition ; Sapphire ; Epitaxy ; Vicinal ; Lattice (music) ; Shear (geology) ; Thin film ; Crystallography ; Composite material ; Nanotechnology ; Optoelectronics ; Optics ; Chemistry Transition Metal Oxide Nanomaterials ; Ga2O3 and related materials ; Gas Sensing Nanomaterials and Sensors
Authors: Bowen Zheng | Grace X. Gu
Source: Nanotechnology (article, 2019-11-04)
Field: Materials Science — Materials Chemistry

Recovery from mechanical degradation of graphene by defect enlargement The extraordinary properties of graphene have made it an elite candidate for a broad range of emerging applications since its discovery. However, the introduction of structural defects during graphene production often compromises the theoretically predicted performance of graphene-based technologies to a great extent. In this study, a counterintuitive defect enlargement strategy to recover from defect-induced mechanical degradation is explored, of which the realization may lead to an enhanced operating efficiency and manufacturing feasibility. Our molecular-dynamics simulation results show that the enlargement of a preexisting defect to an elliptical shape can potentially recover from the mechanical degradation that the very defect has caused. For a defective graphene sheet having a failure strain of 48% of the pristine graphene sheet, enlarging the defect can enhance the failure strain up to 80% of the pristine graphene sheet. The mechanism of degradation recovery lies in a reduced change in curvature during deformation, which is further solidified by theoretical quantification and stress-field analysis. This theory can also predict and pinpoint the location of the initiation of the fracture-where the curvature changes most significantly during the deformation. In addition, the influence of an elliptical defect on the mechanical properties of a graphene sheet is systematically studied, which is not well understood today. Finally, the degradation recovery potential of defect of various sizes is examined, showing that the initial defect that can create the highest degree of geometric asymmetry has the best potential for degradation recovery. This study investigates the recovery from defect-induced mechanical degradation and the influence of elliptical defects on the mechanical properties of a graphene sheet, which widens our understanding of the possibility of fine-tuning mechanical properties via defect engineering and has the potential to improve materials for emerging technologies such as supercapacitor devices. Graphene ; Materials science ; Degradation (telecommunications) ; Curvature ; Deformation (meteorology) ; Composite material ; Molecular dynamics ; Nanotechnology ; Computer science ; Geometry Graphene research and applications ; Graphene and Nanomaterials Applications ; Carbon Nanotubes in Composites
Authors: Iago Neira | Cristina Alvariño | Olaya Domarco | Víctor Blanco | Carlos Peinador | Marcos D. García | José M. Quintela
Source: Chemistry - A European Journal (article, 2019-08-17)
Field: Chemistry — Organic Chemistry

Tuning of the Self‐Threading of Ring‐in‐Ring Structures in Aqueous Media A series of aryl-extended N-monoalkyl-4,4'-bipyridinium salts L (aryl=1,4-phenyl, 4,4'-biphenyl, 2,6-naphthyl and 9,10-anthracenyl) have been implemented by Pd<sup>II</sup> /Pt<sup>II</sup> -directed self-assembly into constitutionally dynamic systems (CDSs). As a result, the intended processes produced not only (en)M<sub>2</sub> L<sub>2</sub> (en=ethylenediamine) metallacyclic species but also (en)M<sub>4</sub> L<sub>4</sub> ring-in-ring aggregates, in equilibrium with the former, as a consequence of the hydrophobic nature of the aryl rings within the 4,4'-bipyridinium scaffold. The key feature of the obtained dynamic systems is the possibility of modulating their response against external stimuli by modifying the hydrophobic character of the ligand. While the different dynamic libraries follow the same trends upon changes in concentration, temperature, polarity of the medium, or addition of an aromatic chemical effector, subtle changes in the ligand hydrophobic core results in a fine-tuning of the speciation when applying a certain degree of the different stimulus. The exception is the anthracene-containing derivative, which does not form inclusion complexes or self-threaded structures. Chemistry ; Anthracene ; Biphenyl ; Aryl ; Ring (chemistry) ; Ethylenediamine ; Aqueous solution ; Ligand (biochemistry) ; Hydrophobic effect ; Stereochemistry ; Photochemistry ; Organic chemistry ; Receptor ; Alkyl Supramolecular Chemistry and Complexes ; Molecular Sensors and Ion Detection ; Chemical Synthesis and Analysis
Authors: Hongxing Mi | Shen Cao | Zhongyue Huang | Han Li | Guiying Xu | Ju Xu
Source: Materials Research Express (article, 2019-11-04)
Field: Materials Science — Materials Chemistry

Improved thermoelectric properties of Ag-doped polycrystalline SnSe with facile electroless plating The thermoelectric (TE) performance of polycrystalline SnSe is limited by its low electrical properties, and normally doped with metals like Ag, Na etc by simply mixing with SnSe in melting. In this paper, a facile electroless plating is introduced to improve its TE performance for the first time. The results showed Ag was coated on the surface of SnSe powders homogeneously even after sintered with SPS. The influence of the Ag dopant on the electrical and thermal transport is analyzed. The silver coating with electroless plating could obviously improve average power factor (nearly fourfold) with minor effects (only 13% enhancement) on thermal conductivity. Therefore, a peak ZT value of 0.68 is achieved at 873 K in 1.0% Ag doped SnSe parallel to SPS pressing direction. In addition, the anisotropic properties are also found in this Ag doping SnSe by electroless plating. Compared with sample along parallel direction in 0.5% Ag coating, the power factor along the perpendicular direction improves over 50%, and thermal conductivity only increases 12.35%, resulting in a ZT peak value of 0.85 at 873 K. Compared with traditional mixing method, electroless plating is a facile and more homogenous doping method, and could be an improved way for doping to finer tune other thermoelectric materials performance. Materials science ; Thermoelectric effect ; Dopant ; Doping ; Plating (geology) ; Crystallite ; Thermal conductivity ; Coating ; Electrical resistivity and conductivity ; Composite material ; Metallurgy ; Optoelectronics ; Electrical engineering Advanced Thermoelectric Materials and Devices ; Chalcogenide Semiconductor Thin Films ; Thermal Radiation and Cooling Technologies
Authors: Ugo Sidoli | Hisaschi T. Tee | Ivan Raguzin | Jakob Mühldorfer | Frederik R. Wurm | Alla Synytska
Source: International Journal of Molecular Sciences (article, 2019-12-13)
Field: Materials Science — Surfaces, Coatings and Films

Thermo-Responsive Polymer Brushes with Side Graft Chains: Relationship Between Molecular Architecture and Underwater Adherence During the last few decades, wet adhesives have been developed for applications in various fields. Nonetheless, key questions such as the most suitable polymer architecture as well as the most suitable chemical composition remain open. In this article, we investigate the underwater adhesion properties of novel responsive polymer brushes with side graft chain architecture prepared using "<i>grafting through</i>" approach on flat surfaces. The incorporation in the backbone of thermo-responsive poly(<i>N</i>-isopropylacrylamide) (PNIPAm) allowed us to obtain LCST behavior in the final layers. PNIPAm is co-polymerized with poly(methyl ethylene phosphate) (PMEP), a poloyphosphoester. The final materials are characterized studying the surface-grafted polymer as well as the polymer from the bulk solution, and pure PNIPAm brush is used as reference. PNIPAm-g-PMEP copolymers retain the responsive behavior of PNIPAm: when T > LCST, a clear switching of properties is observed. More specifically, all layers above the critical temperature show collapse of the chains, increased hydrophobicity and variation of the surface charge even if no ionizable groups are present. Secondly, effect of adhesion parameters such as debonding rate and contact time is studied. Thirdly, the reversibility of the adhesive properties is confirmed by performing adhesion cycles. Finally, the adhesive properties of the layers are studied below and above the LCST against hydrophilic and hydrophobic substrates. Lower critical solution temperature ; Polymer ; Adhesive ; Copolymer ; Materials science ; Adhesion ; Side chain ; Polymer chemistry ; Polymer brush ; Chemical engineering ; Thermoresponsive polymers in chromatography ; Polymerization ; Grafting ; Nanotechnology ; Composite material ; Chemistry ; Organic chemistry ; Phase (matter) ; Layer (electronics) Polymer Surface Interaction Studies ; Adhesion, Friction, and Surface Interactions ; Surface Modification and Superhydrophobicity