Chemical modification of exfoliated graphite nanoplatelets with CTBN rubber and highly enhanced impact strength of vinyl ester resin by them

2021 ◽  
Author(s):  
Sang Gyu Ji ◽  
Lawrence T. Drzal ◽  
Donghwan Cho
Keyword(s):  
Impact Strength ◽  
Chemical Modification ◽  
Vinyl Ester ◽  
Exfoliated Graphite ◽  
Graphite Nanoplatelets ◽  
Vinyl Ester Resin ◽  
Exfoliated Graphite Nanoplatelets

Kinetic Adsorption of Humic Acids Mixture Obtained from Microalgae on Exfoliated Graphite Nanoplatelets

2018 ◽  
Vol 69 (1) ◽  
pp. 191-195
Author(s):  
Elena Radu ◽  
Elena Emilia Oprescu ◽  
Cristina Emanuela Enascuta ◽  
Catalina Calin ◽  
Rusandica Stoica ◽  
...  
Keyword(s):  
Humic Acid ◽  
Humic Acids ◽  
Alkali Treatment ◽  
Exfoliated Graphite ◽  
Acid Mixture ◽  
Acidic Ph ◽  
Graphite Nanoplatelets ◽  
Mixture Concentration ◽  
Ft Ir ◽  
Exfoliated Graphite Nanoplatelets

The dehydration of polysaccharides fraction in the presence of acid catalysts, is a chemical process in which results as secondary product humic matter. In our work, the humic acid mixture was for the first time based on our knowledge extracted from defatted microalgae biomass rich in polysaccharides by standard alkali treatment, followed by precipitation at acidic pH. The dried humic acid mixture has been characterized using infrared spectroscopic measurements (FT-IR). Exfoliated graphite nanoplatelets (xGnP) were used as new adsorbents for this type of humic acids mixture, their adsorption being investigated. The effect of several parameters such as: contact time, concentration of humic acid mixture, concentration of xGnP, temperature and pH of the solutions were studied. The process of adsorption took place with good results, in the following conditions: at a concentration of humic acid mixture of 18.6 mg L-1, an xGnP amount of 0.01 mg in 25 mL of solution, at a temperature of 25 �� and at acidic pH values, in aqueous solution.

Co-milling-assisted exfoliated graphite nanoplatelets filler introduction in polyethylene and alumina composites

2018 ◽  
Vol 53 (13) ◽  
pp. 1815-1826
Author(s):  
Sheng Cai Tan ◽  
Jimmy KW Chan ◽  
Kian Ping Loh
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Composite Materials ◽  
Exfoliated Graphite ◽  
Flexural Properties ◽  
Graphite Nanoplatelets ◽  
Alumina Composites ◽  
Exfoliated Graphite Nanoplatelets ◽  
Polyethylene Composites

This paper aims to investigate the effect of co-milling-assisted exfoliation of graphite into polyethylene and alumina matrices on the mechanical properties of the composites. Tensile mechanical properties of composite materials based on polyethylene reinforced with graphite and graphite-derived fillers at 0–0.75 wt% loading were investigated, while hardness and flexural properties of alumina composites with 0.25 wt% loading of the same additives were assessed. Exfoliated graphite, applied at 0.25–0.75 wt% in pre-exfoliated form or in a co-milling-assisted fashion, has been demonstrated to be effective in enhancing the tensile strength of polyethylene composites. Similar enhancement in hardness and flexural properties was observed in alumina composites with 0.25 wt% loading of the exfoliated graphite. Co-milling-assisted exfoliated graphite nanoplatelets additive introduction has been found to effect a more desirable mechanical properties enhancement in the composites investigated in this study.

Performance Evaluation of Minimum Quantity Lubrication With Exfoliated Graphite Nanoplatelets in Turning Titanium Alloy

2018 ◽  
Author(s):  
Dinh Nguyen ◽  
Pil-Ho Lee ◽  
Yang Guo ◽  
Patrick Kwon ◽  
Kyung-Hee Park
Keyword(s):  
Minimum Quantity Lubrication ◽  
Exfoliated Graphite ◽  
Experimental Result ◽  
Graphite Nanoplatelets ◽  
Crater Wear ◽  
Minimum Quantity ◽  
Preliminary Experimental Result ◽  
Tribological Surfaces ◽  
Exfoliated Graphite Nanoplatelets ◽  
Carbide Inserts

This paper evaluates the performances of dry, minimum quantity lubrication (MQL) and MQL with nanofluid in turning the most common titanium (Ti) alloy, Ti-6Al-4V, in a solution treated and aged (STA) microstructure. In particular, the nanofluid evaluated here is vegetable oil (rapeseed) mixed with small concentrations of exfoliated graphite nanoplatelets (xGnP). The focus of this paper is on turning process because it poses a challenging condition to apply oil droplets directly onto the tribological surfaces of a cutting tool due to the continuous engagement of tool and work material. A series of turning experiments was conducted with uncoated carbide inserts while measuring the cutting forces with the dynamometer under various conditions to determine its effectiveness and optimal MQL condition in turning. The worn inserts are retrieved to measure flank and crater wear using confocal microscopy. This preliminary experimental result shows that the use of MQL and nanofluid is effective in improving the machinability of Ti alloys in turning processes.

scholarly journals Mechanical properties and microstructural investigation of polypropylene/exfoliated graphite nanoplatelets/ nano-magnesium oxide composites

2018 ◽  
Vol 7 (2) ◽  
pp. 897
Author(s):  
A I. Alateyah ◽  
F H. Latief
Keyword(s):  
Mechanical Properties ◽  
Flexural Modulus ◽  
Exfoliated Graphite ◽  
Graphite Nanoplatelets ◽  
Microstructural Investigation ◽  
The Matrix ◽  
Exfoliated Graphite Nanoplatelets ◽  
Polypropylene Matrix ◽  
Xrd Patterns ◽  
Oxide Composites

Polypropylene/exfoliated graphite nanoplatelets composites reinforced with a low concentration of nano-magnesia have been successfully fabricated, using injection molding machine. The mechanical properties and microstructure of the composites were investigated, in the present study. The XRD patterns of the composites showed the peaks of xGnP and n-MgO, where the intensity of the xGnP peaks became stronger with increasing the concentration of xGnP added into polypropylene matrix. In addition, the SEM micrographs revealed a good dispersion of fillers within the matrix. The results showed that increasing the amount of exfoliated graphite nanoplatelets up to 10 wt. % resulted in increasing the composite flexural strength, flexural modulus, and hardness up to 35% and 91%, 6.7%, respectively, compared to the monolithic polypropylene.  

Thermo-electrical behaviour of cyclic olefin copolymer/exfoliated graphite nanoplatelets nanocomposites foamed through supercritical carbon dioxide

2019 ◽  
Vol 55 (3) ◽  
pp. 263-282 ◽  
Author(s):  
A Dorigato ◽  
A Biani ◽  
W Bonani ◽  
A Pegoretti
Keyword(s):  
Carbon Dioxide ◽  
Electrical Resistivity ◽  
Supercritical Carbon Dioxide ◽  
Surface Heating ◽  
Exfoliated Graphite ◽  
Cyclic Olefin Copolymer ◽  
Graphite Nanoplatelets ◽  
Cyclic Olefin ◽  
Exfoliated Graphite Nanoplatelets ◽  
Supercritical Carbon

In this work, novel electrically conductive cyclic olefin copolymer/exfoliated graphite nanoplatelets foams were prepared through a supercritical carbon dioxide treatment starting from the corresponding unfoamed materials prepared by melt compounding, in order to investigate their thermo-electrical properties. For both unfoamed and foamed samples, the exfoliated graphite nanoplatelets introduction led to a systematic enhancement of the thermal degradation temperature. Dynamic-mechanical thermal analysis revealed that the nanofiller addition promoted an enhancement of the storage modulus and of the glass transition temperature over the whole range of the applied foaming pressures. While for unfoamed materials exfoliated graphite nanoplatelets introduction determined an important decrease of the electrical resistivity, the foaming process induced the breakage of the conductive path, with a consequent increase of electrical resistivity. Evaluation of the surface heating upon voltage application showed that the surface temperature of unfoamed materials could be noticeably increased at relatively low voltage levels, while a less pronounced surface heating could be obtained with the corresponding nanocomposite foams.

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