scholarly journals Acid Free Oxidation and Simple Dispersion Method of MWCNT for High-Performance CFRP

Nanomaterials ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 912 ◽  
Author(s):  
Gerald Singer ◽  
Philipp Siedlaczek ◽  
Gerhard Sinn ◽  
Harald Rennhofer ◽  
Matej Mičušík ◽  
...  
Keyword(s):  
High Performance ◽  
Mechanical Performance ◽  
Industrial Applications ◽  
Mechanical Tests ◽  
Processing Route ◽  
Limiting Factor ◽  
Ultrasonic Dispersion ◽  
Surrounding Matrix ◽  
Wide Range ◽  
Cost Efficient

Carbon nanotubes (CNT) provide an outstanding property spectrum which can be used to improve a wide range of materials. However, the transfer of properties from the nanoscale to a macroscopic material is a limiting factor. Different approaches of functionalizing the surface of a CNT can improve the interaction with the surrounding matrix but is connected to difficult and expensive treatments, which are usually inconvenient for industrial applications. Here, a simple and eco-friendly method is presented for the oxidation of CNT, where hydrogen peroxide (H2O2) is the only chemical needed and no toxic emissions are released. Also, the extensive step of the incorporation of CNT to an epoxy matrix is simplified to an ultrasonic dispersion in the liquid hardener component. The effectiveness is proven by mechanical tests of produced CNT/CFRP and compared to a conventional processing route. The combination of those simple and cost efficient strategies can be utilized to produce multiscale composites with improved mechanical performance in an ecological and economical way.

scholarly journals Effects of a Twin-Screw Extruder Equipped with a Molten Resin Reservoir on the Mechanical Properties and Microstructure of Recycled Waste Plastic Polyethylene Pellet Moldings

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1058
Author(s):  
Hikaru Okubo ◽  
Haruka Kaneyasu ◽  
Tetsuya Kimura ◽  
Patchiya Phanthong ◽  
Shigeru Yao
Keyword(s):  
Mechanical Properties ◽  
Mechanical Performance ◽  
Value Added ◽  
Industrial Applications ◽  
Twin Screw Extruder ◽  
Screw Extruder ◽  
Polymer Properties ◽  
Wide Range ◽  
Twin Screw ◽  
Recycled Plastics

Each year, increasing amounts of plastic waste are generated, causing environmental pollution and resource loss. Recycling is a solution, but recycled plastics often have inferior mechanical properties to virgin plastics. However, studies have shown that holding polymers in the melt state before extrusion can restore the mechanical properties; thus, we propose a twin-screw extruder with a molten resin reservoir (MSR), a cavity between the screw zone and twin-screw extruder discharge, which retains molten polymer after mixing in the twin-screw zone, thus influencing the polymer properties. Re-extruded recycled polyethylene (RPE) pellets were produced, and the tensile properties and microstructure of virgin polyethylene (PE), unextruded RPE, and re-extruded RPE moldings prepared with and without the MSR were evaluated. Crucially, the elongation at break of the MSR-extruded RPE molding was seven times higher than that of the original RPE molding, and the Young’s modulus of the MSR-extruded RPE molding was comparable to that of the virgin PE molding. Both the MSR-extruded RPE and virgin PE moldings contained similar striped lamellae. Thus, MSR re-extrusion improved the mechanical performance of recycled polymers by optimizing the microstructure. The use of MSRs will facilitate the reuse of waste plastics as value-added materials having a wide range of industrial applications.

Multi-Scale Study of Abrasion Signature by 2D Wavelet Decomposition

2005 ◽  
Author(s):  
H. Zahouani ◽  
S. Mezghani ◽  
R. Vargiolu ◽  
M. Dursapt
Keyword(s):  
Surface Topography ◽  
Wavelet Decomposition ◽  
High Performance ◽  
Industrial Applications ◽  
Point Of View ◽  
Continuous Wavelet ◽  
New Approach ◽  
Multi Scale ◽  
Abrasive Finishing ◽  
Wide Range

The high performance of industrial applications, requires increasingly technical functional surfaces, particulary from the point of view of topography and microtexture. To study the effect of abrasive finishing in a wide range of wavelengths of surface topography, we developed a multi-scale approach, based on the decomposition of surface topography by 2D continuous wavelet transform. This new approach made it possible to determine the multi-scale transfer function of machining by abrasion for each stage of finishing. The methodology can be extended to characterize abrasive wear in a wide range of scales.

Extremely Light Weight Rheocast Components for Automotive Space Frame

2012 ◽  
Vol 192-193 ◽  
pp. 545-550 ◽  
Author(s):  
Mario Rosso ◽  
Ildiko Peter ◽  
Gianluigi Chiarmetta ◽  
Ivano Gattelli
Keyword(s):  
High Performance ◽  
Mechanical Tests ◽  
Standard Samples ◽  
Fe Content ◽  
Wide Range ◽  
Automotive Parts ◽  
Fracture Surface Analysis ◽  
High Level ◽  
Non Destructive ◽  
Very High

This paper presents an analysis of a new rheocasting process suitable for the manufacturing of high performance automotive parts. The process is able for the realization of components using Al alloys. An important aspect is related to the possibility to obtain quite wide range of thicknesses, starting from 2.5 mm. The used alloy is the well known A356, with low Fe content, maximum 0.08 wt%. T6 heat treatments has been performed, while the soundness of the parts has been certified by non destructive tests. These parts are produced to be mounted on a top level and famous sport car. Non standard samples for mechanical tests have been machined directly from the components. Following the mechanical tests fracture surface analysis has been carried out by SEM to observe some morphological details and to evaluate the influence of the process and of the alloy conditions on the fracture behaviour. On the polished transverse sections of the samples morphological analysis has been performed. The obtained results shown high level of mechanical strength for all series of components. The reliability of the process is very high at a convenient level of manufacturing rate. The weldability of the parts has been demonstrated.

The role of phenylalanine hydroxylase in lipogenesis in the oleaginous fungus Mortierella alpina

Microbiology ◽  
2021 ◽  
Vol 167 (8) ◽  
Author(s):  
Hongchao Wang ◽  
Chunmei Wang ◽  
Weiwei Yuan ◽  
Haiqin Chen ◽  
Wenwei Lu ◽  
...  
Keyword(s):  
Fatty Acid Biosynthesis ◽  
Phenylalanine Hydroxylase ◽  
Transcript Level ◽  
Cellular Fatty Acid ◽  
Industrial Applications ◽  
Mortierella Alpina ◽  
Limiting Factor ◽  
Wide Range ◽  
Oleaginous Fungus

Phenylalanine hydroxylase (PAH) catalyses the irreversible hydroxylation of phenylalanine to tyrosine, which is the rate-limiting reaction in phenylalanine metabolism in animals. A variety of polyunsaturated fatty acids can be synthesized by the lipid-producing fungus Mortierella alpina, which has a wide range of industrial applications in the production of arachidonic acid. In this study, RNA interference (RNAi) with the gene PAH was used to explore the role of phenylalanine hydroxylation in lipid biosynthesis in M. alpina. Our results indicated that PAH knockdown decreased the PAH transcript level by approximately 55% and attenuated cellular fatty acid biosynthesis. Furthermore, the level of NADPH, which is a critical reducing agent and the limiting factor in lipogenesis, was decreased in response to PAH RNAi, in addition to the downregulated transcription of other genes involved in NADPH production. Our study indicates that PAH is part of an overall enzymatic and regulatory mechanism supplying NADPH required for lipogenesis in M. alpina.

scholarly journals Preparation and Characterization of Nanocomposite Films Containing Nano-Aluminum Nitride and Cellulose Nanofibrils

Nanomaterials ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 1121 ◽  
Author(s):  
Shuangxi Nie ◽  
Yuehua Zhang ◽  
Linmao Wang ◽  
Qin Wu ◽  
Shuangfei Wang
Keyword(s):  
Thermal Stability ◽  
Aluminum Nitride ◽  
High Performance ◽  
Mechanical Performance ◽  
Cellulose Nanofibrils ◽  
Crystal Form ◽  
Mechanical Tests ◽  
Substrate Material ◽  
Nanocomposite Films ◽  
Sodium Chlorite

Nanocomposites consisting of cellulose nanofibrils (CNFs) and nano-aluminum nitride (AlN) were prepared using a simple vacuum-assisted filtration process. Bleached sugarcane bagasse pulp was treated with potassium hydroxide and sodium chlorite, and was subsequently ultra-finely ground and homogenized to obtain CNFs. Film nanocomposites were prepared by mixing CNFs with various AlN amounts (0–20 wt.%). X-ray diffraction revealed that the crystal form of CNF-AlN nanocomposites was different to those of pure CNFs and AlN. The mechanical performance and thermal stability of the CNF-AlN nanocomposites were evaluated through mechanical tests and thermogravimetric analysis, respectively. The results showed that the CNF-AlN nanocomposites exhibited excellent mechanical and thermal stability, and represented a green renewable substrate material. This type of nanocomposite could present great potential for replacing traditional polymer substrates, and could provide creative opportunities for designing and fabricating high-performance portable electronics in the near future.

scholarly journals Solvent-Free Ultrasonic Dispersion of Nanofillers in Epoxy Matrix

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 308
Author(s):  
Benjamin Zanghellini ◽  
Patrick Knaack ◽  
Sebastian Schörpf ◽  
Karl-Heinz Semlitsch ◽  
Helga C. Lichtenegger ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Industrial Applications ◽  
Limiting Factor ◽  
Dispersion Parameters ◽  
Ultrasonic Dispersion ◽  
Established Method ◽  
Dispersion Process ◽  
Roll Mill ◽  
Processing Step ◽  
Microscopy Images

Dispersion of carbon nanotubes and carbon nanofibers is a crucial processing step in the production of polymer-based nanocomposites and poses a great challenge due to the tendency of nanofillers to agglomerate. One of the most effective methods for dispersion is the use of a three-roll mill, which is a well-established method and results in agglomerates below 5 µm. Nevertheless, this process is time-consuming and thus a limiting factor for industrial applications. Our aim was to establish an easy and efficient ultrasonic dispersion process, characterize the dispersion parameters, and compare both methods, ultrasonication and the three-roll mill. We applied rheological tests and analyzed the agglomerate sizes by an image fit of the microscopy images. All these analyses combined deliver a valuable set of information about the dispersion’s quality and, therefore, allows the improvement and further adaptation of the dispersion process.

scholarly journals Lignin-Based High-Performance Fibers by Textile Spinning Techniques

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3378
Author(s):  
Yanhong Jin ◽  
Jiaxian Lin ◽  
Yu Cheng ◽  
Chunhong Lu
Keyword(s):  
Molecular Weight ◽  
High Performance ◽  
Mechanical Performance ◽  
Direct Conversion ◽  
Industrial Applications ◽  
Fiber Spinning ◽  
Raw Material ◽  
Spinning Process ◽  
Renewable Raw Material ◽  
Modified Lignin

As a major component of lignocellulosic biomass, lignin is one of the largest natural resources of biopolymers and, thus, an abundant and renewable raw material for products, such as high-performance fibers for industrial applications. Direct conversion of lignin has long been investigated, but the fiber spinning process for lignin is difficult and the obtained fibers exhibit unsatisfactory mechanical performance mainly due to the amorphous chemical structure, low molecular weight of lignin, and broad molecular weight distribution. Therefore, different textile spinning techniques, modifications of lignin, and incorporation of lignin into polymers have been and are being developed to increase lignin’s spinnability and compatibility with existing materials to yield fibers with better mechanical performance. This review presents the latest advances in the textile fabrication techniques, modified lignin-based high-performance fibers, and their potential in the enhancement of the mechanical performance.

scholarly journals Acid Phosphatases from the Bread Fruit Artocarpus communis Seeds as Novel Plant Phosphorylating Biocatalysts

2019 ◽  
pp. 1-8
Author(s):  
Hubert Kouassi Konan ◽  
Michel Djary Koffi ◽  
Desire Yapi Assoi Yapi ◽  
Lucien Patrice Kouame
Keyword(s):  
High Performance ◽  
Time Course ◽  
Food Additives ◽  
Product Yield ◽  
Industrial Applications ◽  
Synthesis Product ◽  
Acid Phosphatases ◽  
Short Period ◽  
Donor And Acceptor ◽  
Wide Range

Aims: Investigation on the phosphotransferase activity of two non-specific acid phosphatases (EC 3.1.3.2) designated as AP1 and AP2, previously isolated from breadfruit (Artocarpus communis) seeds for further biotechnological and industrial applications. Methodology: Transphosphorylation reactions were tested with sodium pyrophosphate as the phosphoryl donor and phenol as its acceptor. Transfer products were quantified by using high performance liquid chromatography. Results: The two acid phosphatases were able to catalyse phosphoconjugates synthesis using pyrophosphate as the phosphoryl donor and phenol as acceptor. The optimal conditions of transphosphorylation reactions indicated that this synthesis was highly dependent on pH, temperature, time course, donor and acceptor concentrations and enzyme amount. A very short period (1.25 h) was observed for these synthesis reactions catalysed by acid phosphatases isolated from breadfruit (Artocarpus communis) seeds. This suggested energy saving during biotransformation processes. The high average yields of 84.20 and 66.78% obtained for AP1 and AP2, respectively, made them useful to phosphorylate a wide range of nucleophile compounds such as nucleotides often used as food additives and pharmaceutical intermediates. Conclusion: The acid phosphatase AP1 would be the most promising on the basis the better synthesis product yield (84.20%). The two biocatalysts could be considered as new valuable tools for bioprocesses.

Investigation on mechanical properties of hybrid aluminum/composite tubes manufactured by filament winding and hand lay-up

2021 ◽  
pp. 096739112110598
Author(s):  
Hani Yadegari ◽  
Reza Taherian ◽  
Soheil Dariushi
Keyword(s):  
Compressive Force ◽  
Single Layer ◽  
Carbon Layer ◽  
Industrial Applications ◽  
Mechanical Tests ◽  
Filament Winding ◽  
Composite Tubes ◽  
Aluminum Composite ◽  
Wide Range ◽  
Hybrid Carbon

Nowadays, composite tubes have a wide range of applications in industries. Composite tubes are appropriate alternatives for metal energy absorbers. In this investigation, aluminum-composite tubes are made using Filament Winding (FW) and hand lay-up methods. Carbon Fiber (CF) and Glass Fiber (GF) are used in the FW method, and for the hand lay-up method, glass cloth is used. Five samples were fabricated with different stacking sequences, specimens with one, two, and three glass layers, one carbon layer, and hybrid carbon/glass layers. Characterization is performed by Scanning Electron Microscopy (SEM) analysis and mechanical tests (bending, compressive, and fatigue). The maximum bending force in the triple-layer GF tube is higher than other samples, while the maximum compressive force is observed in the hybrid carbon and GF tube. On the other hand, the fatigue strength of single-layer CF tubes is higher than single-layer GF tubes, so that the fracture cycles of single-layer CF tubes (600597) is significantly more than that of single-layer GF tubes (470068) at the force of 35  N. In addition, the compressive and bending energies absorption of samples were calculated. The hybrid carbon and GF tube absorbed higher energy than other samples. In GF and CF hybrid tubes, failure did not occur suddenly but gradually. This appropriate failure mechanism in the hybrid tube resulted in higher energy absorption and made it a suitable choice for industrial applications.

Acid phosphatases from the breadfruit Artocarpus communis seeds as novel plant phosphorylating biocatalysts

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Hubert Kouassi Konan ◽  
Michel Djary Koffi ◽  
Desire Yapi Assoi Yapi ◽  
Lucien Patrice Kouame
Keyword(s):  
High Performance ◽  
Time Course ◽  
Food Additives ◽  
Product Yield ◽  
Industrial Applications ◽  
Synthesis Product ◽  
Acid Phosphatases ◽  
Short Period ◽  
Donor And Acceptor ◽  
Wide Range

Abstract Objective Investigation on the phosphotransferase activity of two non-specific acid phosphatases (EC 3.1.3.2) designated as AP1 and AP2, previously isolated from breadfruit (Artocarpus communis) seeds for further biotechnological and industrial applications. Methods Transphosphorylation reactions were tested with sodium pyrophosphate as the phosphoryl donor and phenol as its acceptor. Transfer products were quantified by using high performance liquid chromatography. Results The two acid phosphatases were able to catalyze phosphoconjugates synthesis using pyrophosphate as the phosphoryl donor and phenol as acceptor. The optimal conditions of transphosphorylation reactions indicated that this synthesis was highly dependent on pH, temperature, time course, donor and acceptor concentrations and enzyme amount. A very short period (1.25 h) was observed for these synthesis reactions catalyzed by acid phosphatases isolated from breadfruit (Artocarpus communis) seeds. This suggested energy saving during biotransformation processes. The high average yields of 84.20 and 66.78% obtained for AP1 and AP2, respectively, made them useful to phosphorylate a wide range of nucleophile compounds such as nucleotides often used as food additives and pharmaceutical intermediates. Conclusion The acid phosphatase AP1 would be the most promising on the basis the better synthesis product yield (84.20%). The two biocatalysts could be considered as new valuable tools for bioprocesses.

Sign in / Sign up

Export Citation Format

Share Document