scholarly journals Characterization and Preparation of Furanic-Glyoxal Foams

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 692 ◽  
Author(s):  
Xuedong Xi ◽  
Antonio Pizzi ◽  
Hong Lei ◽  
Guanben Du ◽  
Xiaojian Zhou ◽  
...  
Keyword(s):  
Ignition Temperature ◽  
Furfuryl Alcohol ◽  
Room Temperature ◽  
Laser Desorption ◽  
Open Cell ◽  
Molar Ratios ◽  
Cell Structures ◽  
Closed Cell ◽  
Combustion Properties ◽  
Compression Resistance

Synthetic foams have become an essential industrial product for a great variety of applications. Furfuryl alcohol, as a biomass chemical, was reacted with glyoxal at room temperature to prepare furanic-glyoxal rigid foams, and p-toluenesulfonic acid was used as a catalyst to initiate the reaction. Foams with different molar ratios (furfuryl alcohol/glyoxal) were prepared in this work, and uniform cells foams have been obtained. Their compression resistance, 24-h water absorption, density, and other basic properties were tested. Scanning electron microscopy (SEM) was used to observe the cellular morphology of the foams prepared, thermogravimetric analysis (TGA) helped to understand their thermal and combustion properties, and FTIR and Matrix Assisted Laser Desorption Ionisation Time of Flight (MALDI ToF) mass spectroscopy to explain the structure of the resulting foams to clarify the reactions occurring during foaming. The results show that the compression resistance of furanic-glyoxal foams declined as the furfuryl alcohol/glyoxal ratio decreases also. SEM observations revealed that foams with open-cell were obtained when furfuryl alcohol was added in greater amounts, and more closed cell structures were formed as the proportion of glyoxal increased. TGA results showed that the initial ignition temperature of furanic-glyoxal foams is ~200 °C higher than that of wood, and the smaller comprehensive combustion index S (about 0.15 × 10−7 (%2 K−3 min−2)) indicates that the foam burns slowly and has poor flammability, that is, it is not easy to burn.

Open-Cell Foam Metal Production and Characterization by Aluminum Solid Mold Investment Casting

2019 ◽  
Author(s):  
Kerem Altug Guler
Keyword(s):  
Investment Casting ◽  
Replication Process ◽  
Open Cell ◽  
Metal Fabrication ◽  
Cell Structures ◽  
Closed Cell ◽  
Small Complex ◽  
Open Cell Foam ◽  
Foam Metal ◽  
Cell Foam

Foam metals can be categorized in two basic classes: open-cell and closed-cell structures, which both have different numerous unique properties. Up to the present, several production processes have been developed for each class. Investment casting is known as a replication process for open-cell foam metal fabrication. Solid mold, which can be evaluated as a subtechnique of the investment casting, is specialized especially for small complex shapes with ultrathin sections. This work is a presentation of aluminum open-cell foam production with solid mold investment casting using two different kinds of patterns. The first one is “burnable,” in which liquid metal directly fills the shape of pattern and the second is “leachable,” in which metal takes the form of intergranular network shape of porous salt preforms.

Compressive properties of two-layered aluminum foams with closed-cell and open-cell structures

2020 ◽  
Vol 24 ◽  
pp. 101249
Author(s):  
Yoshihiko Hangai ◽  
Mizuki Ando ◽  
Masataka Ohashi ◽  
Kenji Amagai ◽  
Ryosuke Suzuki ◽  
...  
Keyword(s):  
Compressive Properties ◽  
Aluminum Foams ◽  
Open Cell ◽  
Cell Structures ◽  
Closed Cell

Numerical Prediction of the Effective Thermal Conductivity of Open- and Closed-Cell Foam Structures

2010 ◽  
Vol 297-301 ◽  
pp. 1210-1217 ◽  
Author(s):  
Seyed Mohammad Hossein Hosseini ◽  
Andreas Öchsner ◽  
Thomas Fiedler
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Relative Density ◽  
Effective Thermal Conductivity ◽  
Linear Trend ◽  
Space Filling ◽  
Open Cell ◽  
Cell Structures ◽  
Closed Cell ◽  
Cell Foam

This paper investigates the thermal properties of metallic open-cell and closed-cell foam structures in space filling and non-space filling configurations. In both, i.e. open-cell and closed-cell structures, a linear trend depending on the relative density has been reported. However the closed-cell structures compared to open-cell ones have a higher thermal conductivity for the same relative density.

scholarly journals Fabrication of Two-Layered Aluminum Foam with Closed-Cell and Open-Cell Structures and Shaping of Closed-Cell Layer by Press Forming Immediately after Foaming

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 140
Author(s):  
Yoshihiko Hangai ◽  
Mizuki Ando ◽  
Masataka Ohashi ◽  
Kenji Amagai
Keyword(s):  
Aluminum Alloy ◽  
Melting Point ◽  
Aluminum Foam ◽  
Cell Layer ◽  
Open Cell ◽  
Press Forming ◽  
Cell Structures ◽  
Closed Cell ◽  
The Press

Two-layered aluminum foam consisting of both closed and open cells is expected to improve the functionality of aluminum foam, because the cells have different morphologies and characteristics. In this study, press forming of the closed-cell layer of the two-layered aluminum foam immediately after foaming was performed to shape the closed-cell layer. By measuring the temperatures of the two layers during foaming, we found that it is necessary to use aluminum alloy with a higher melting point for the open-cell layer than that for the closed-cell layer to foam the closed-cell layer. In the press forming experiments, the closed-cell layer could be shaped by press forming while the shape of the open-cell layer was maintained.

Green synthesis of mixed metallic nanoparticles using room temperature self-assembly

2017 ◽  
Vol 13 (2) ◽  
pp. 4671-4677 ◽  
Author(s):  
A. M. Abdelghany ◽  
A.H. Oraby ◽  
Awatif A Hindi ◽  
Doaa M El-Nagar ◽  
Fathia S Alhakami
Keyword(s):  
Self Assembly ◽  
Metallic Nanoparticles ◽  
Room Temperature ◽  
Bimetallic Nanoparticles ◽  
Reduction Process ◽  
Nano Particles ◽  
Nano Structure ◽  
Small Shift ◽  
Molar Ratios ◽  
Vis Spectroscopy

Bimetallic nanoparticles of silver (Ag) and gold (Au) were synthesized at room temperature using Curcumin. Reduction process of silver and gold ions with different molar ratios leads to production of different nanostructures including alloys and core-shells. Produced nanoparticles were characterized simultaneously with FTIR, UV/vis. spectroscopy, transmission electron microscopy (TEM), and Energy-dispersive X-ray (EDAX). UV/vis. optical absorption spectra of as synthesized nanoparticles reveals presence of surface palsmon resonance (SPR) of both silver at (425 nm) and gold at (540 nm) with small shift and broadness of gold band after mixing with resucing and capping agent in natural extract which suggest presence of bimetallic nano structure (Au/Ag). FTIR and EDAX data approve the presence of bimetallic nano structure combined with curcumin extract. TEM micrographs shows that silver and gold can be synthesized separately in the form of nano particles using curcumin extract. Synthesis of gold nano particles in presence of silver effectively enhance and control formation of bi-metallic structure.

Low-profile visualized intraluminal support Blue stenting within a Neuroform Atlas stent for a large wide-necked aneurysm: A case report and a bench-top experiment

2021 ◽  
pp. 197140092110269
Author(s):  
Tomoko Hayashi ◽  
Hiroyuki Ikeda ◽  
Ryota Ishibashi ◽  
Toshio Fujiwara ◽  
Ryosuke Kaneko ◽  
...  
Keyword(s):  
Case Report ◽  
Coil Embolization ◽  
Cell Design ◽  
Open Cell ◽  
Aneurysm Neck ◽  
Low Profile ◽  
Closed Cell ◽  
High Metal ◽  
Silicon Tube ◽  
Aneurysm Occlusion

Low-profile visualized intraluminal support deployment in an Enterprise has been reported; however, that in an Atlas has yet to be in detail. Enterprise has a closed-cell design, while Atlas has an open-cell design. We detail here a case of a large wide-necked aneurysm treated by coil embolization with low-profile visualized intraluminal support Blue deployment within a Neuroform Atlas and a bench-top experiment using a silicon tube to test low-profile visualized intraluminal support, Atlas, Enterprise, and their combinations. A better low-profile visualized intraluminal support expansion was achieved by simultaneously pushing the wire and the system within the Atlas placed at the aneurysm neck, which resulted in an increased metal coverage of the aneurysm neck and a shorter transition zone with low metal coverage at both ends of the aneurysm neck. This technique may enable a high metal coverage by low-profile visualized intraluminal support expansion without restriction by the Atlas and contribute to aneurysm occlusion by increasing the flow-diverting effect.

scholarly journals Green Solvents as an Alternative to DMF in ZIF-90 Synthesis

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1573
Author(s):  
Aljaž Škrjanc ◽  
Ciara Byrne ◽  
Nataša Zabukovec Logar
Keyword(s):  
Room Temperature ◽  
Product Yield ◽  
Solvent Exchange ◽  
Green Solvents ◽  
Zeolitic Imidazolate Framework ◽  
Short Treatment ◽  
Molar Ratios ◽  
Primary Particles ◽  
High Product Yield

The use of green solvents as an alternative to dimethylformamide (DMF) in the synthesis of zeolitic imidazolate framework-90 (ZIF-90) was investigated. Two biobased aprotic dipolar solvents CyreneTM and γ-valerolactone (GVL) proved to successfully replace DMF in the synthesis at room temperature with a high product yield. While the CyreneTM—based product shows reduced porosity after activation, the use of GVL resulted in materials with preserved crystallinity and porosity after activation, without prior solvent exchange and a short treatment at 200 °C. The primary particles of 30 nm to 60 nm in all products further form agglomerates of different size and interparticle mesoporosity, depending on the type and molar ratios of solvents used.

scholarly journals Study of Physical Properties and Shock Absorption Abilities of Starch Polymer Foam as Cushioning Material for Packaging

2018 ◽  
Vol 225 ◽  
pp. 06010
Author(s):  
N. Amir ◽  
Mohamed Syakir Mohamed Hisham ◽  
Kamal Ariff Zainal Abidin
Keyword(s):  
Average Density ◽  
Curing Process ◽  
Polymer Foam ◽  
Shock Absorption ◽  
Open Cell ◽  
Lack Of Information ◽  
Closed Cell ◽  
Open Cell Foam ◽  
Cell Foam ◽  
Cushioning Material

Lack of information about the formulation and fabrication process of starch polymer foam and lack of study in the shock absorption ability of starch polymer foam were the reasons this research was executed. In this project starch polymer foam was produced to be used as cushioning material for packaging. Starch polymer foam were developed from starch, polyvinyl alcohol (PVA), urea, citric acid, and deionised water. Water amount with drying and curing process were the variables manipulated to produce the best starch polymer foam. It was determined then, that the optimized ratio of starch:PVA:citric acid was 1:1:4. The amount of water used was 10 ml/gram of starch/PVA weight. The suitable foaming mixing was done at a speed of 1500 rpm for 40 minutes. Drying process was done at 70°C for 24 hours, followed by curing process at 100°C for 1 hour to produce closed-cell foam. While for the open-cell foam, the foam was dried and cured at 100ºC for 6 hours. The open-cell and closed-cell foams produced were cut to 6 cm height x 6 cm width x 0.5 cm thick. The average density was calculated and then the foams were subjected to weight drop destructive test. The test was done by placing a foam on top of a piece of mirror, and a weight is dropped onto the foam, with increasing height until the mirror break. Three weights were used with mass of 50 g, 100 g and 200 g. The starch foams were compared to polyurethane and polystyrene foams in terms of the minimum height that can cause the mirror to break. The results showed that starch closed-cell foam absorbed the highest impact energy followed by polystyrene foam, starch open-cell foam and polyurethane foam.

scholarly journals A green approach to the synthesis of a nano catalyst and the role of basicity, calcination, catalytic activity and aging in the green synthesis of 2-aryl bezimidazoles, benzothiazoles and benzoxazoles

RSC Advances ◽  
2017 ◽  
Vol 7 (67) ◽  
pp. 42000-42012 ◽  
Author(s):  
Pramod K. Sahu
Keyword(s):  
Catalytic Activity ◽  
Green Synthesis ◽  
Room Temperature ◽  
Molar Ratios ◽  
Green Approach ◽  
Grinding Method ◽  
Nano Catalyst ◽  
Layered Catalyst

A green synthesis of hydrotalcite (a double layered catalyst) by a grinding method using Al/Mg molar ratios of 1.0–3.0 at room temperature is described.

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