scholarly journals Improving Fracture Toughness of Tetrafunctional Epoxy with Functionalized 2D Molybdenum Disulfide Nanosheets

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4440
Author(s):  
Megha Sahu ◽  
Lakshmi Narasimhan ◽  
Ashok M. Raichur ◽  
Alexandru Sover ◽  
Romeo C. Ciobanu ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Molybdenum Disulfide ◽  
Cetyltrimethylammonium Bromide ◽  
Epoxy Polymer ◽  
Thermomechanical Properties ◽  
Epoxy Nanocomposites ◽  
Organically Modified ◽  
Molybdenum Disulfide Nanosheets ◽  
Tetrafunctional Epoxy

In this work, improved fracture toughness of tetra-functional epoxy polymer was obtained using two-dimensional (2H polytype) molybdenum disulfide (MoS2) nano-platelets as a filler. Simultaneous in-situ exfoliation and functionalization of MoS2 were achieved in the presence of cetyltrimethylammonium bromide (CTAB) via sonication. The aim was to improve the dispersion of MoS2 nanoplatelets in epoxy and enhance the interfacial interaction between nanoplatelets and epoxy matrix. Epoxy nanocomposites with CTAB functionalized MoS2 (f-MoS2) nanoplatelets, ranging in content from 0.1 wt% up to 1 wt%, were fabricated. Modified MoS2 improved the fracture properties (81%) of tetrafunctional epoxy nanocomposites. The flexural strength and compressive strength improved by 64% and 47%, respectively, with 0.25 wt% loading of f-MoS2 nanoplatelets compared to neat epoxy. The addition of f-MoS2 nanoplatelets enhanced the thermomechanical properties of epoxy. This work demonstrated the potential of organically modified MoS2 nanoplatelets for improving the fracture and thermal behavior of tetrafunctional epoxy nanocomposites.

scholarly journals In Situ Thermal-Stage Fitted-STEM Characterization of Spherical-Shaped Co/MoS2 Nanoparticles for Conversion of Heavy Crude Oils

Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1239
Author(s):  
Manuel Ramos ◽  
Félix Galindo-Hernández ◽  
Brenda Torres ◽  
José Manuel Domínguez-Esquivel ◽  
Martin Heilmaier
Keyword(s):  
Molybdenum Disulfide ◽  
Sodium Molybdate ◽  
Interlayer Spacing ◽  
Scanning Transmission Electron Microscope ◽  
Interplanar Distance ◽  
Scanning Transmission ◽  
Heavy Crude ◽  
C 50 ◽  
Nano Catalysts

We report the thermal stability of spherically shaped cobalt-promoted molybdenum disulfide (Co/MoS2) nano-catalysts from in-situ heating under electron irradiation in the scanning transmission electron microscope (STEM) from room temperature to 550 °C ± 50 °C with aid of Fusion® holder (Protochip©, Inc.). The catalytic nanoparticles were synthesized via a hydrothermal method using sodium molybdate (Na2MoO4·2H2O) with thioacetamide (CH3CSNH2) and cobalt chloride (CoCl2) as promoter agent. The results indicate that the layered molybdenum disulfide structure with interplanar distance of ~0.62 nm remains stable even at temperatures of 550 °C, as observed in STEM mode. Subsequently, the samples were subjected to catalytic tests in a Robinson Mahoney Reactor using 30 g of Heavy Crude Oil (AGT-72) from the golden lane (Mexico’s east coast) at 50 atm using (ultrahigh purity) UHP hydrogen under 1000 rpm stirring at 350 °C for 8 h. It was found that there is no damage on the laminar stacking of Co/MoS2 with temperature, with interlayer spacing remaining at 0.62 nm; these sulfided catalytic materials led to aromatics rise of 22.65% and diminution of asphaltenes and resins by 15.87 and 3.53%, respectively.

Influence of filler hybridization on thermomechanical properties of hemp/silver epoxy composite

2020 ◽  
pp. 096739112097811
Author(s):  
Munjula Siva Kumar ◽  
Santosh Kumar ◽  
Krushna Gouda ◽  
Sumit Bhowmik
Keyword(s):  
Thermal Conductivity ◽  
Silver Nanoparticles ◽  
Epoxy Polymer ◽  
Hybrid Composites ◽  
Conductive Filler ◽  
Weight Fraction ◽  
Mechanical Analysis ◽  
Thermomechanical Properties ◽  
Material Behavior ◽  
Good Crystallinity

The polymer composite material’s thermomechanical properties with fiber as reinforcement material have been widely studied in the last few decades. However, these fiber-based polymer composites exhibit problems such as fiber orientation, delamination, fiber defect along the length and bonding are the matter of serious concern in order to improve the thermomechanical properties and obtain isotropic material behavior. In the present investigation filler-based composite material is developed using natural hemp and high thermal conductive silver nanoparticles (SNP) and combination of dual fillers in neat epoxy polymer to investigate the synergetic influence. Among various organic natural fillers hemp filler depicts good crystallinity characteristics, so selected as a biocompatible filler along with SNP conductive filler. For enhancing their thermal conductivity and mechanical properties, hybridization of hemp filler along with silver nanoparticles are conducted. The composites samples are prepared with three different combinations such as sole SNP, sole hemp and hybrid (SNP and hemp) are prepared to understand their solo and hybrid combination. From results it is examined that, chemical treated hemp filler has to maximized its relative properties and showed, 40% weight % of silver nanoparticles composites have highest thermal conductivity 1.00 W/mK followed with hemp filler 0.55 W/mK and hybrid 0.76 W/mK composites at 7.5% of weight fraction and 47.5% of weight fraction respectively. The highest tensile strength is obtained for SNP composite 32.03 MPa and highest young’s modulus is obtained for hybrid composites. Dynamic mechanical analysis is conducted to find their respective storage modulus and glass transition temperature and that, the recorded maximum for SNP composites with 3.23 GPa and 90°C respectively. Scanning electron microscopy examinations clearly illustrated that formation of thermal conductivity chain is significant with nano and micro fillers incorporation.

scholarly journals Sonochemical edge functionalisation of molybdenum disulfide

Nanoscale ◽  
2019 ◽  
Vol 11 (33) ◽  
pp. 15550-15560 ◽  
Author(s):  
Aline Amorim Graf ◽  
Matthew J. Large ◽  
Sean P. Ogilvie ◽  
Yuanyang Rong ◽  
Peter J. Lynch ◽  
...  
Keyword(s):  
Molybdenum Disulfide ◽  
Boiling Point ◽  
Molybdenum Oxides ◽  
High Quality ◽  
Molybdenum Disulfide Nanosheets

We demonstrate the spontaneous edge functionalisation of molybdenum disulfide nanosheets exfoliated in acetone. Formation of molybdenum oxides explains the observed high-quality and stability of the dispersion in a low boiling point solvent.

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