scholarly journals Millimeter-Size Spherical Polyurea Aerogel Beads with Narrow Size Distribution

Gels ◽  
2018 ◽  
Vol 4 (3) ◽  
pp. 66 ◽  
Author(s):  
Despoina Chriti ◽  
Grigorios Raptopoulos ◽  
Maria Papastergiou ◽  
Patrina Paraskevopoulou
Keyword(s):  
Size Distribution ◽  
Large Scale ◽  
High Surface ◽  
High Surface Area ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Scale Production ◽  
High Porosity ◽  
Narrow Size Distribution ◽  
Angle Spinning

We report the room temperature synthesis of spherical millimeter-size polyurea (PUA) aerogel beads. Wet-gels of said beads were obtained by dripping a propylene carbonate solution of an aliphatic triisocyanate based on isocyanurate nodes into a mixture of ethylenediamine and heavy mineral oil. Drying the resulting wet spherical gels with supercritical fluid (SCF) CO2 afforded spherical aerogel beads with a mean diameter of 2.7 mm, and a narrow size distribution (full width at half maximum: 0.4 mm). Spherical PUA aerogel beads had low density (0.166 ± 0.001 g cm–3), high porosity (87% v/v) and high surface area (197 m2 g–1). IR, 1H magic angle spinning (MAS) and 13C cross-polarization magic angle spinning (CPMAS) NMR showed the characteristic peaks of urea and the isocyanurate ring. Scanning electron microscopy (SEM) showed the presence of a thin, yet porous skin on the surface of the beads with a different (denser) morphology than their interior. The synthetic method shown here is simple, cost-efficient and suitable for large-scale production of PUA aerogel beads.

scholarly journals Large scale production of novel g-C3N4 micro strings with high surface area and versatile photodegradation ability

CrystEngComm ◽  
2014 ◽  
Vol 16 (9) ◽  
pp. 1825 ◽  
Author(s):  
Muhammad Tahir ◽  
Chuanbao Cao ◽  
Faheem K. Butt ◽  
Sajid Butt ◽  
Faryal Idrees ◽  
...  
Keyword(s):  
Surface Area ◽  
Large Scale ◽  
High Surface ◽  
High Surface Area ◽  
Scale Production ◽  
Large Scale Production

Large-scale production of spherical Y2O3:Eu3+ phosphor powders with narrow size distribution using a two-step spray drying method

RSC Advances ◽  
2014 ◽  
Vol 4 (108) ◽  
pp. 62965-62970 ◽  
Author(s):  
Jung Sang Cho ◽  
Kyeong Youl Jung ◽  
Mun Young Son ◽  
Yun Chan Kang
Keyword(s):  
Size Distribution ◽  
Spray Drying ◽  
Mass Production ◽  
Large Scale ◽  
Scale Production ◽  
Narrow Size Distribution ◽  
Drying Method ◽  
Large Scale Production

Dense spherical Y2O3:Eu3+ phosphor particles with a narrow size distribution were successfully prepared by using a two-step spray drying method. This method is easily scalable and can therefore be applied to the mass production of phosphor particles with high photoluminescence.

scholarly journals Mussel inspired ZIF8 microcarriers: a new approach for large-scale production of stem cells

RSC Advances ◽  
2020 ◽  
Vol 10 (34) ◽  
pp. 20118-20128 ◽  
Author(s):  
Mahsa Asadniaye Fardjahromi ◽  
Amir Razmjou ◽  
Graham Vesey ◽  
Fatemeh Ejeian ◽  
Balarka Banerjee ◽  
...  
Keyword(s):  
Cell Culture ◽  
Surface Roughness ◽  
Large Scale ◽  
Cell Attachment ◽  
High Surface ◽  
High Surface Area ◽  
3D Cell Culture ◽  
Scale Production ◽  
New Approach ◽  
Large Scale Production

Mussel inspired ZIF8 microcarriers with high surface area, biocompatibility, and nanoscale surface roughness are applied to enhance mesenchymal stem cell attachment and proliferation in 3D cell culture.

scholarly journals Review—Synthesis and Electrochemical Applications of Molybdenum Carbide: Recent Progress and Perspectives

2022 ◽  
Author(s):  
Sanjay Upadhyay ◽  
Om Prakash Pandey
Keyword(s):  
Electrochemical Performance ◽  
Large Scale ◽  
High Surface ◽  
High Surface Area ◽  
Cost Effective ◽  
Research Progress ◽  
Energy Storage And Conversion ◽  
Synthesis Methods ◽  
Scale Production ◽  
Electrochemical Applications

Abstract In this review, we summarize the latest research progress on Mo2C based materials for various electrochemical applications. It starts with discussing the different synthesis methods and the tactics for modifying the physicochemical characteristics of Mo2C. In addition, the variables that influence the morphology and electrochemical performance of Mo2C have been explored. The synthesis methods are examined based on their tricks, benefits, and drawbacks, including solid-gas, solid-solid, solid-liquid, and some other processes (chemical vapor deposition, Sonochemical, microwave-assisted, plasma, etc.). Methods that are safe, cost-effective, environmentally friendly, and suited for large-scale production of Mo2C are given special consideration. The solid-solid reaction is found to be a facile and cost-effective method to synthesize Mo2C structures having high surface area and small particle size. Also, the various electrochemical applications of Mo2C are reviewed. Mo2C is an extremely active and durable electrocatalyst mainly for hydrogen evolution reaction (HER). The electrochemical parameters such as activity, stability, etc., are examined and described in detail. The possible ways to improve the electrochemical performance of Mo2C are discussed. Finally, the difficulties in developing Mo2C nanostructures that are suited for energy storage and conversion applications are discussed.

scholarly journals Aerogel-Based TiO2 Stable Inks for Direct Inkjet Printing of Nanostructured Layers

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Aline M. Barreiro ◽  
Geneviève K. Pinheiro ◽  
Bruno N. Wesling ◽  
Daliana Müller ◽  
Letícia T. Scarabelot ◽  
...  
Keyword(s):  
Inkjet Printing ◽  
Large Scale ◽  
High Surface ◽  
High Surface Area ◽  
Scale Production ◽  
Electrical Measurements ◽  
Stable Suspension ◽  
Large Scale Production ◽  
Nanostructured Layers ◽  
Triton X

Inkjet printing presents a high potential for cost reduction of electronic devices manufacturing due to the capacity to deposit materials with high precision, less material waste, and large-scale production through the roll-to-roll printing processes. In this work, a nanostructured TiO2 ink was developed using TiO2 aerogel and an alkaline aqueous solution, which resulted in a very stable suspension. A high-intensity ultrasonic mixer was used to fragment and disperse TiO2 aerogels producing suspensions with particles smaller than 200 nm, which are suitable for the inkjet printing process. For the development of the ink, the viscosity and surface tension were adjusted by using glycerol and a surfactant (Triton X-100). The influence of those components on the properties of the ink was evaluated for different concentrations. After formulation of the inks, the printing parameters were adjusted to optimize the process. Films with high surface area and less than 100 nm grain size were successfully produced. Electrical measurements revealed a resistive-like behavior with the sheet resistance increasing with number of printed layers.

CP-Mas NMR AND In-Situ FTIR Study of AIN Surface Reactivity

1995 ◽  
Vol 410 ◽  
Author(s):  
S. A. Monie ◽  
D. J. Aurentz ◽  
C. G. Pantano
Keyword(s):  
Surface Layer ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Magic Angle Spinning ◽  
Surface Reactivity ◽  
Mas Nmr ◽  
Magic Angle ◽  
Cp Mas Nmr

ABSTRACTThe hydrolytic stability of aluminum nitride (AlN) is an important issue from the standpoint of technology development of AlN as an electronic packaging material. Although numerous studies have been made of the hydrolysis of AlN and characterization of the reaction products, an understanding of the interaction between surface sites and molecular species is still lacking.A combination of Magic-Angle-Spinning Nuclear Magnetic Resonance (MAS NMR) and in-situ Fourier Transform Infrared (FTIR) spectroscopies was used to study the surface reactivity of AlN. The specimens used were specially fabricated self-supported AIN films of high-surface-area (∼25 m2/g), made by nitridation of sol-gel derived pseudoboehmite (AIO(OH)). The in-situ FTIR spectra suggest the formation of a surface layer on the AlN films upon storage. MAS NMR was used to further characterize the surface layer. Using the chemical shifts obtained by 1H-27Al Cross Polarization (CP) MAS NMR experiments, we were able to identify the surface cation sites. The assignment of these sites to Al3+ cations in either tetrahedral coordination with nitrogen or octahedral coordination with oxygen was used to monitor the evolution of the surface upon exposure to the atmosphere. The results indicate that high-surface-area AlN rapidly acquires a surface layer (probably AlO(OH)/Al(OH)3) upon exposure to the atmosphere.

scholarly journals High-Resolution Magic Angle Spinning (HR-MAS) NMR-Based Fingerprints Determination in the Medicinal Plant Berberis laurina

Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3647
Author(s):  
Sher Ali ◽  
Gul Badshah ◽  
Caroline Da Ros Montes D’Oca ◽  
Francinete Ramos Campos ◽  
Noemi Nagata ◽  
...  
Keyword(s):  
High Resolution ◽  
Medicinal Plant ◽  
Large Scale ◽  
Magic Angle Spinning ◽  
Mas Nmr ◽  
Chemical Compositions ◽  
Magic Angle ◽  
Metabolic Pattern ◽  
Plant Parts ◽  
Angle Spinning

Berberis laurina (Berberidaceae) is a well-known medicinal plant used in traditional medicine since ancient times; however, it is scarcely studied to a large-scale fingerprint. This work presents a broad-range fingerprints determination through high-resolution magical angle spinning (HR-MAS) nuclear magnetic resonance (NMR) spectroscopy, a well-established flexible analytical method and one of most powerful “omics” platforms. It had been intended to describe a large range of chemical compositions in all plant parts. Beyond that, HR-MAS NMR allowed the direct investigation of botanical material (leaves, stems, and roots) in their natural, unaltered states, preventing molecular changes. The study revealed 17 metabolites, including caffeic acid, and berberine, a remarkable alkaloid from the genus Berberis L. The metabolic pattern changes of the leaves in the course of time were found to be seasonally dependent, probably due to the variability of seasonal and environmental trends. This metabolites overview is of great importance in understanding plant (bio)chemistry and mediating plant survival and is influenceable by interacting environmental means. Moreover, the study will be helpful in medicinal purposes, health sciences, crop evaluations, and genetic and biotechnological research.

Functionalized Nanoparticles for Composite Polymer Electrolyte

2007 ◽  
Vol 1006 ◽  
Author(s):  
Gilles Toussaint ◽  
Catherine Henrist ◽  
Christophe Detrembleur ◽  
Robert Jerome ◽  
Rudi Cloots
Keyword(s):  
High Surface ◽  
Magic Angle Spinning ◽  
Epoxide Ring ◽  
Composite Polymer Electrolyte ◽  
Magic Angle ◽  
Covalent Grafting ◽  
Ir Analysis ◽  
Poly Ethylene ◽  
Angle Spinning ◽  
Surface Silica

AbstractThe covalent grafting of low-molecular weight poly(ethylene glycol) (PEG) onto high surface silica nanoparticles (Cab-O-Sil EH5) has been accomplished by a multi-step reaction. Reaction involved PEG attachment by epoxide-terminated ring opening of a sylilation agent previously grafted. A maximum grafting density of 0.42 PEG per nm2 has been determined by thermogravimetric analysis (TGA). Differential scanning (DSC) calorimetry confirmed the modification of silica after reaction. Infra-Red (IR) analysis and Carbon-13 Magic Angle Spinning Nuclear Magnetic Resonance (13C MAS NMR) confirmed PEG fixation and opening of the epoxide ring.

Pulse Shaped Dynamic Nuclear Polarization Under Magic Angle Spinning

2019 ◽  
Author(s):  
ASIF EQUBAL ◽  
Kan Tagami ◽  
Songi Han
Keyword(s):  
Electron Spin ◽  
Lattice Relaxation ◽  
Magic Angle Spinning ◽  
Spin Lattice Relaxation ◽  
Magic Angle ◽  
Total Electron ◽  
Spin Lattice ◽  
Maximum Benefit ◽  
Selective Saturation ◽  
Angle Spinning

In this paper, we report on an entirely novel way of improving the MAS-DNP efficiency by shaped μw pulse train irradiation for fast and broad-banded (FAB) saturation of the electron spin resonance. FAB-DNP achieved with Arbitrary Wave Generated shaped μw pulse trains facilitates effective and selective saturation of a defined fraction of the total electron spins, and provides superior control over the DNP efficiency under MAS. Experimental and quantum-mechanics based numerically simulated results together demonstrate that FAB-DNP significantly outperforms CW-DNP when the EPR-line of PAs is broadened by conformational distribution and exchange coupling. We demonstrate that the maximum benefit of FAB DNP is achieved when the electron spin-lattice relaxation is fast relative to the MAS frequency, i.e. at higher temperatures and/or when employing metals as PAs. Calculations predict that under short T<sub>1e </sub>conditions AWG-DNP can achieve as much as ~4-fold greater enhancement compared to CW-DNP.

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