jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Erika M. Saffer
Source: Scholarworks (University of Massachusetts Amherst) (article, 2020-06-26)
Field: Materials Science — General Materials Science

STRUCTURE OF NEARLY IDEAL AND MULTI-COMPONENT POLYMERIC BIOMATERIALS Hydrogels have long been considered ideal candidates for biomaterial and tissue engineering applications due to their many desirable properties, such as high water content and tunable gelation conditions. Although these materials have undergone extensive research and development, some mechanical and physical properties are still difficult to achieve. The reason for this is often related to the structure of the hydrogel network. Understanding how network structures are influenced by changes in formulation parameters (i.e. polymer molecular weight, initial polymer concentration, ratio of hydrophilic to hydrophobic polymer), and correlating these results to known mechanical and physical properties would yield well characterized systems that are more easily tuned for specific applications. The work presented in this thesis focuses on the characterization of the micro- to nano-scale network structures of three distinct hydrogel systems: tetra-functional poly(ethylene glycol) (PEG)-based hydrogels, tetra-functional PEG/polydimethylsiloxane (PDMS)-based hydrogels, and commercial contact lenses. The tetra-functional PEG and PEG/PDMS hydrogel systems were synthesized with a novel cross-linking technique that was developed by the Tew Group in the Polymer Science and Engineering department at the University of Massachusetts Amherst. This technique was designed to reduce the formation of network defects. The resulting hydrogels are optically clear, and display highly resilient mechanical properties which suggest relatively defect free (or ideal) network structures. In collaboration with the Tew group, we performed a series of small-angle neutron scattering (SANS) studies on these systems. The results from the tetra-functional PEG hydrogels confirmed the presence of nearly ideal network structures. Additionally, those from the tetra-functional PEG/PDMS hydrogels revealed the presence of a two-phase network structure with a local, lamellar-like order. For both systems, the resulting structures were found to be dependent upon polymer molecular weight, initial polymer concentration, and the ratio of hydrophilic to hydrophobic polymer. These results confirm the effectiveness of the novel cross-linking technique used to synthesize the PEG and PEG/PDMS tetra-functional hydrogels. Their unique and predictable network structures provide an excellent starting point for the development of these systems for specific applications, such as tendon tissue engineering scaffolds. Component (thermodynamics) ; Ideal (ethics) ; Materials science ; Polymer science ; Physics ; Philosophy Material Properties and Applications
Authors: Farid I. El‐Dossoki | Sara K. Rady | Nasser Mohammed Hosny
Source: Alfarama Journal of Basic & Applied Sciences (article, 2020-03-30)
Field: Chemistry — Organic Chemistry

Spectral and Physical Studies on Some Metal Complexes of Lysine Amino Acid and the Adsorption Properties of their Nano Oxides Lys-Zn, Lys-Co, Lys-Cu and Lys-Ni complexes prepared by reaction of metal acetates with lysine (Lys). Complexes were characterized by elemental analysis (C, H, N and M), FT-IR, (UV/Vis) electronic spectra, 1H-13C NMR, thermal analyses (TGA), (ESR) spectroscopy and magnetic moments measurements. Physical studies were applied on the synthesis complexes such as solubility, density, molar volume, refractive index and excess refractive index and electronic (UV/Vis) spectra measurements. NiO nanoparticles were synthesized from calcinations of complex at 800 oC. Nanoparticles were characterized by X-ray powder diffraction (XRD) and transmittance electron microscope (TEM). Particle size is at range 43-52 nm. Nanoparticles were used to remove dyes from aqueous solution such as methylene blue (MB) and the percent of removal is 96 %. The best model which represents the adsorption of MB is Langmuir isotherm. The best model for adsorption kinetic of MB is pseudo-second-order model with determination coefficient (R2) close to the unity. Adsorption ; Aqueous solution ; Solubility ; Nanoparticle ; Elemental analysis ; Spectroscopy ; Analytical Chemistry (journal) ; Infrared spectroscopy ; Nuclear chemistry ; Chemistry ; Metal ; Powder diffraction ; Particle size ; Materials science ; Physical chemistry ; Inorganic chemistry ; Crystallography ; Organic chemistry ; Nanotechnology Inorganic and Organometallic Chemistry
Authors: Malcolm Lockett
Source: eScholarship (California Digital Library) (article, 2020-01-01)
Field: Materials Science — Materials Chemistry

Synthesis of Large Area and Continuous Multi-Layer Graphene Oxide and Reduced Graphene Oxide Sheets as Alternative to Flakes for Sensing and Electronic Applications Graphene oxide is a promising nanomaterial due to its surface versatility by substitution of functional groups and controllable d-spacing. However, most common methods to prepare graphene oxide are based on chemical exfoliation by strong oxidation agents forming small flake dispersions that are used to form thin films of aggregatedflakes. These methods are problematic due to the high amount of crack formation\nduring the oxidation process. Due to their discontinuous and amorphous morphology, graphene oxide films have poor thermal, electronic and mechanical properties. To improve their poor performance, increasing the mean area (&amp;gt;10 µm) of the flakes is the best strategy. Common large area graphene oxide synthesis methods focus on chemical or mechanical exfoliation techniques for production. These techniques are outdated and still need to be assembled into a film for device fabrication. However, we developed and studied a novel and quick method to obtain large and continuous\ngraphene oxide multilayers by directly converting a chemical vapor deposited multilayer graphene into graphene oxide. Our direct conversion of graphene to graphene oxide shows great promise for further improved transport properties and enhanced performance for filtering, molecule separation, binderless batteries, and metal detection. The size of the novel graphene oxide has been grown up to 225 mm2, which is 4 orders of magnitude larger than flake processes can produce. When reduced, the film shows a conductivity increase of 40% compared to other large sheet graphene\noxide. To test this novel large area graphene oxide for applications we developed a sensor low level detection of Pb2+ in water and an ultrathin, binderless, silicon intercalated anode for lithium ion batteries. The sensor has a limit of detection of 0.21 nM and 0.101 nM for electrochemical and electric analysis, respectively. This is lower than the recommended limit provided by the Wolrd Health Organization and two magnitudes lower than epitaxial graphene can achieve. The binderless silicon intercalated anode shows a specific capacity of 2247 mAh/g, an efficiency of 98% over 90 cycles, a diameter of 15 mm, and a thickness of 5 µm. This is 60% thinner than the thinnest reported binderless anode and has the unique ability to grow silicon nanowires on its surface via oxide assisted growth mechanism. Graphene ; Oxide ; Materials science ; Graphene oxide paper ; Exfoliation joint ; Nanotechnology ; Graphene foam ; Nanomaterials ; Graphene nanoribbons ; Metallurgy Graphene research and applications ; Graphene and Nanomaterials Applications ; Supercapacitor Materials and Fabrication
Authors: Leaf Huang
Source: UNC Libraries (article, 2020-11-04)
Field: Materials Science — Biomaterials

Stromal barriers and strategies for the delivery of nanomedicine to desmoplastic tumors Nanoparticle based delivery formulations have become a leading delivery strategy for cancer imaging and therapy. The success of nanoparticle-based therapy relies heavily on their ability to utilize the enhanced permeability and retention (EPR) effect and active targeting moieties to their advantage. However, these methods often fail to enable a uniform NP distribution across the tumor, and lead to insufficient local concentrations of drug. Oftentimes, this heterogeneous drug distribution is one of the primary reasons for suboptimal treatment efficacy in NP delivery platforms. Herein, we seek to examine the biophysical causes of heterogeneous NP distribution in stroma-rich desmoplastic tumors; namely the abnormal tumor vasculature, deregulated extracellular matrix and high interstitial hypertension associated with these tumors. It is suggested that these factors help explain the discrepancy between promising outlooks for many NP formulations in preclinical studies, but suboptimal clinical outcomes for most FDA approved nanoformulations. Furthermore, examination into the role of the physicochemical properties of NPs on successful drug delivery was conducted in this review. In light of the many formidable barriers against successful NP drug delivery, we provided possible approaches to mitigate delivery issues from the perspective of stromal remodeling and NP design. In all, this review seeks to provide guidelines for optimizing nanoparticle-based cancer drug delivery through both modified nanoparticle design and alleviation of biological barriers to successful therapy. Nanomedicine ; Stromal cell ; Computer science ; Cancer research ; Nanotechnology ; Medicine ; Materials science ; Nanoparticle Nanoparticle-Based Drug Delivery ; Sarcoma Diagnosis and Treatment ; Cancer Cells and Metastasis
Authors: Gietu Yirga Abate | Adugna Nigatu Alene | Adere Tarekegne Habte | Desiew Mekuanint Getahun
Source: Research Square (preprint, 2020-09-16)
Field: Chemistry — Analytical Chemistry

Adsorptive&amp;nbsp;removal&amp;nbsp;of&amp;nbsp;malachite&amp;nbsp;green&amp;nbsp;dye&amp;nbsp;from&amp;nbsp;aqueous&amp;nbsp;solution&amp;nbsp;onto&amp;nbsp;activated carbon of Catha edulis stem as a low cost bio-adsorbent Abstract Background: The release of hazardous synthetic dyes into industrial effluents has emerged as an environmental problem requiring remediation. The present study focused on the preparation of a new and environmentally-friendly material (adsorbent) for the remediation of hazardous dyes from aqueous solution. The low cost adsorbent was prepared from locally available khat (Catha edulis) stem which considered as waste and accumulated on waste disposal areas of Woldia town, Ethiopia. Comprehensive characterization studies were carried out on the bio-adsorbent such as proximate analyses, specific surface area, point of zero charge and FT-IR analysis. Results: The proximate analysis shows the prepared adsorbent has very high fixed carbon content (83.65%), which refers to high quality of the adsorbent. The adsorption performance of the prepared activated carbon was optimized by varying operational parameters such as initial dye concentration (10 mg/L), pH (10), dosage (0.5 g), and contact time (60 min). The maximum removal efficiency of the prepared adsorbent at those optimum conditions was 98.8%. The experimental data was tested by most common kinetics and isotherm models. It was observed that the pseudo-second-order kinetic model fits better with good correlation coefficient and the equilibrium data fitted well with the Freundlich isotherm model. Conclusion: In summery this study demonstrated that the waste bio sorbent could be employed as an effective and eco-friendly alternative for the cleanup of dye-polluted aqueous system. Adsorption ; Aqueous solution ; Activated carbon ; Sorbent ; Chemistry ; Point of zero charge ; Malachite green ; Freundlich equation ; Nuclear chemistry ; Wastewater ; Environmental chemistry ; Waste management ; Organic chemistry Dye analysis and toxicity ; Adsorption and biosorption for pollutant removal
Authors: Peter T. Cummings | Clare McCabe | Christopher R. Iacovella | Ákos Lédeczi | Eric Jankowski | Arthi Jayaraman | Jeremy C. Palmer | Edward J. Maginn | Sharon C. Glotzer | Joshua A. Anderson | Ilja Siepmann | Jeffrey J. Potoff | Raymond Matsumoto | Justin Gilmer | Ryan S. DeFever | Ramanish Singh | Brad Crawford
Source:  (preprint, 2020-11-30)
Field: Materials Science — Materials Chemistry

Open-Source Molecular Modeling Software in Chemical Engineering Focusing on the Molecular Simulation Design Framework Molecular simulation has emerged as an important sub-field of chemical engineering, due in no small part to the leadership of Keith Gubbins. A characteristic of the chemical engineering molecular simulation community is the commitment to freely share simulation codes and other key software components required to perform a molecular simulation under open-source licenses and distribution on public repositories such as GitHub. Here we provide an overview of open-source molecular modeling software in Chemical Engineering, with focus on the Molecular Simulation Design Framework (MoSDeF). MoSDeF is an open-source Python software stack that enables facile use of multiple open-source molecular simulation engines, while at the same time ensuring maximum reproducibility. Python (programming language) ; Computer science ; Software ; Open source ; Simulation software ; Modeling and simulation ; Open source software ; Software engineering ; Computational science ; Simulation ; Operating system Machine Learning in Materials Science ; Scientific Computing and Data Management ; Innovative Microfluidic and Catalytic Techniques Innovation
Authors: Subhankar Kundu | A. Kasem Chowdhury | Somen Nandi | Kankan Bhattacharyya | Abhijit Patra
Source: ChemRxiv (preprint, 2020-12-08)
Field: Materials Science — Biomaterials

Deciphering Molecular Self-Assembly through Electron Microscopy and Fluorescence Correlation Spectroscopy Supramolecular self-assembly of small organic molecules has emerged as a powerful tool to construct well-defined micro- and nanoarchitecture through fine-tuning a range of intermolecular interactions. The size, shape, and optical properties of these nanostructures largely depend on the temperature and polarity of the medium, along with the specific self-assembled pattern of molecular building units. The engineering of supramolecular self-assembled nanostructures with morphology-dependent tunable emission is in high demand due to the promising scope in nanodevices and molecular machines. However, challenges are probing the evolution of molecular aggregates from a true solution and directing the self-assembly process in a pre-defined fashion. The structure of molecular aggregates in the solution can be predicted from fluorescence correlation spectroscopy (FCS) and dynamic light scattering (DLS) analysis. On the other hand, the morphology of the aggregates can also be visualized through electron microscopy. Nevertheless, a direct correlation between emission from molecular aggregates in the aqueous dispersion and their morphology obtained through a solid-state characterization is missing. In the present study, we decipher the sequential evolution of molecular nanofibers from solution to spherical and oblong-shaped nanoparticles through the variation of solvent polarity, adjusting the &lt;a&gt;hydrophobic-hydrophilic interactions&lt;/a&gt;. The intriguing case of molecular self-assembly is elucidated employing a newly designed π-conjugated thiophene derivative (TPAn) through a combination of steady-state absorption, emission measurements, FCS, and electron microscopy. The FCS analysis and microscopy results infer that small-sized nanofibers in the dispersion are further agglomerated, resulting in a network of nanofibers upon solvent evaporation. &lt;a&gt;The evolution of organic nanofibers and subtle control over the self-assembly process demonstrated in the current investigation provides a general paradigm to correlate the size, shape, and emission properties of diverse fluorescent molecular aggregates in complex heterogeneous media, including a human cell. &lt;/a&gt; Fluorescence correlation spectroscopy ; Dynamic light scattering ; Materials science ; Self-assembly ; Supramolecular chemistry ; Spectroscopy ; Fluorescence spectroscopy ; Nanotechnology ; Chemical physics ; Fluorescence ; Nanoparticle ; Chemistry ; Molecule ; Organic chemistry ; Optics Supramolecular Self-Assembly in Materials ; Luminescence and Fluorescent Materials ; Fullerene Chemistry and Applications
Authors: Jun-Gang Wang | Lifang Shi | Yingying Su | Liwei Liu | Jin Xie | Yang Tian | Di Li
Source: Research Square (preprint, 2020-11-19)
Field: Materials Science — Electronic, Optical and Magnetic Materials

In-Situ Plasmonic Tracking Oxygen Evolution Revealing Multistage Oxygen Diffusion and Accumulating Inhibition In situ ; Oxygen ; Diffusion ; Plasmon ; Tracking (education) ; Nanotechnology ; Chemistry ; Materials science ; Physics ; Optoelectronics ; Psychology ; Thermodynamics Gold and Silver Nanoparticles Synthesis and Applications ; Spectroscopy and Quantum Chemical Studies ; Receptor Mechanisms and Signaling
Authors: Chizyuka G. Chizyuka | Shamitiba B. Kanyanga
Source: Journal of Natural and Applied Sciences (article, 2020-12-18)
Field: Materials Science — Polymers and Plastics

Effects of Hydrothermal Ageing on the Microbond Interfacial Shear Strength of NaOH Treated Sisal Fibre Reinforced Polyester Composites Engineering structural failures can be related to the fracture of one or more of the constituent materials that form a composite. Such failures often occur unpredictably and suddenly. It is, therefore, necessary to minimise undesired failures and their consequences when designing and analysing modern-day structures. To suitably design structural components, not only do the fundamental mechanical properties of the components’ material constituents need to be known, but also the effects of the service environment on these properties. Moisture is one critical environmental factor that can be destructive to properties of composite materials. Composite constituent components, most especially in natural fibre- reinforced composites constantly absorb or desorb moisture due to varying temperature and relative humidity levels in their service environment. In this regard, this paper presents results of a study on the influence of hydrothermal effects on the composite material microbond interfacial shear strength as a function of ageing period under different thermal loading states. Results from the microbond test coupled with Scanning Electron Microscope (SEM) fractographic analyses indicate that debonding is an established fracture mechanism in this hydrothermally aged NaOH treated sisal fibrepolyester composite systems. SISAL ; Composite material ; Materials science ; Composite number ; Hydrothermal circulation ; Service life ; Scanning electron microscope ; Moisture ; Relative humidity ; Chemical engineering Natural Fiber Reinforced Composites ; Mechanical Behavior of Composites ; Textile materials and evaluations
Authors: Shen Kung Liao
Source: Trends in Textile Engineering & Fashion Technology (article, 2020-07-08)
Field: Materials Science — Polymers and Plastics

Looking For Eco‐Friendly Clothing That Coexists With The Environment Trends in Textile Engineering & Fashion Technology Looking For Eco‐Friendly Clothing That Coexists With The Environment Shen‐Kung Liao* Department of Fiber and Composite Materials, Feng Chia University, Taiwan *Corresponding author: Shen‐Kung Liao, Department of Fiber and Composite Materials, Feng Chia University, Taiwan Submission: June 17, 2020; Published: July 08, 2020 DOI: 10.31031/TTEFT.2020.06.000629 ISSN 2578-0271 Volume 6 Issue 1 Clothing ; Textile ; Environmentally friendly ; Fiber ; Architectural engineering ; Engineering ; Materials science ; Geography ; Composite material ; Archaeology ; Biology ; Ecology Textile materials and evaluations ; Fashion and Cultural Textiles ; Dyeing and Modifying Textile Fibers
Authors: Yadav OP
Source: COJ Technical & Scientific Research (article, 2020-10-23)
Field: Chemistry — Organic Chemistry

Equilibrium and Kinetic Study of Cadmium Ions Removal from Contaminated Water Using Adsorbent Materials Derived from Parthenium hysterophorussp Weed Plants Adsorption behavior of Cadmium ions, in aqueous solution, at raw powder and activated carbon derived from Parthenium hysterophorussp weed plants, have been studied.The adsorbent materials were characterized using XRD and FTIR techniques.Effects of adsorbent dose, Cd(II) ions concentration, pH and adsorbate-adsorbent contact time for the removal of Cd(II) ions from aqueous solution have been investigated.The observed adsorption data was analyzed in the light of Langmuir and Freundlich adsorption isotherm models.The adsorption data better followed the pseudo second order kinetic model than the pseudo-first order model.It was found that the removal of Cd(II) ions by the adsorbents may concurrently involve both surface adsorption as well as intra-particle diffusion.Though the adsorption of Cd(II) ions at the studied adsorbents is endothermic, yet it becomes feasible due to the predominate entropy gain.With Cd(II) ions initial concentration 50mgL -1 , their maximum percent removal by raw plant powder and the derivedactivated carbon, were 97% and 99.5%, respectively and their adsorption capacities for the Cd(II) ions, predicted byLangmuirmodel, were: 7.4 and 45.1mg g -1 ,respectively. Cadmium ; Adsorption ; Weed ; Contamination ; Parthenium ; Environmental chemistry ; Contaminated water ; Chemistry ; Kinetic energy ; Ion ; Water treatment ; Environmental science ; Environmental engineering ; Agronomy ; Physics ; Biology ; Organic chemistry ; Ecology Inorganic and Organometallic Chemistry ; Electrochemical Analysis and Applications ; Nanotechnology research and applications
Authors: Chen Shahar | Yaron Tidhar | Yunmin Jung | Haim Weissman | Sidney Cohen | Ronit Bitton | Iddo Pinkas | Gilad Haran | Boris Rybtchinski
Source:  (preprint, 2020-09-07)
Field: Materials Science — Materials Chemistry

Control over size, shape, and photonics of self-assembled organic nanocrystals Facile fabrication of free-floating organic nanocrystals (ONCs) was achieved via kinetically controlled self-assembly of simple amphiphilic perylene diimide building blocks in aqueous media. The ONCs have a thin rectangular shape, with the aspect ratio that is controlled via organic co-solvent (THF) content. The nanocrystals were characterized in solution by cryogenic transmission electron microscopy (cryo-TEM) and small angle X-ray scattering (SAXS); the ONCs retain their structure upon drying as was evidenced by TEM and AFM. Photophysical studies, including femtosecond transient absorption spectroscopy, revealed a distinct influence of the ONC morphology on their photonic properties (excitation energy transfer was observed only in the high aspect ONCs). Convenient control over structure and function of organic nanocrystals can enhance their utility in new and developed technologies. Materials science ; Small-angle X-ray scattering ; Nanocrystal ; Transmission electron microscopy ; Perylene ; Femtosecond ; Absorption (acoustics) ; Self-assembly ; Dynamic light scattering ; Chemical engineering ; Nanotechnology ; Nanostructure ; Amphiphile ; Diimide ; Scattering ; Nanoparticle ; Copolymer ; Polymer ; Organic chemistry ; Chemistry ; Optics ; Molecule ; Composite material Luminescence and Fluorescent Materials ; Nanoplatforms for cancer theranostics ; Polydiacetylene-based materials and applications