Study of heat and sound insulation for polymeric composites reinforced with nano clay

Composite materials were prepared using epoxy as a matrix and nanoclay as a reinforcement with weight fractions 5% and 10%, using hand lay-up as a preparation technique. An unreinforced epoxy cast was also prepared for comparison. Heat and acoustic insulation were studied, in addition to tensile, compression, and impact tests. The results showed that the sound levels were the highest in the unreinforced specimen, and decreased gradually with nanoclay, suggesting that the nanoclay have impeded the path for sound waves transmission. The same behavior was observed with thermal conductivity. The tensile strength for the 5% wt. specimens were about 40% higher than that of the 10% wt. specimens, and about 60% higher than the unreinforced epoxy. The Young's modulus was 1.899 MPa, 3.25 MPa, and 4.143 MPa for the 5%, 10%, and unreinforced epoxy, respectively. Impact and compressive strengths were directly proportional with nano clay content. Scanning electron microscopy was used to reveal the microscopic details. The results prove that the addition of nanoparticles must be optimized to get the desired results.

Structural and thermoelectric properties of the Pr2Zr2O7 compound

ECORFAN Journal-Democratic Republic of Congo ◽

10.35429/ejdrc.2019.9.5.4.9 ◽

2019 ◽

pp. 4-9

Author(s):

Adolfo Quiroz-Rodríguez ◽

Cesia Guarneros-Aguilar ◽

Ricardo Agustin-Serrano

Keyword(s):

Electron Microscopy ◽

Thermal Conductivity ◽

Thermoelectric Properties ◽

Crystal Size ◽

Ambient Pressure ◽

X Ray Diffraction ◽

X Ray ◽

Increasing Temperature ◽

Thermal Stability Of ◽

In this research, it is presented a detailed study of the structural and thermoelectric properties of the pyrochlore zirconium Pr2Zr2O7 compound prepared by solid-state reaction (SSR) in air at ambient pressure. The synthesized sample was characterized using powder X-ray diffraction. The thermal stability of the thermoelectric compound (TE) Pr2Zr2O7 was tested by thermogravimetric analysis (TGA) and differential thermal analysis (DTA). Scanning electron microscopy shows that the crystal size varies between 0.69 and 2.81μm. Electrical conductivity (\sigma) of the sample calcined at 1400 °C presented values increase irregularly with the increasing temperature from 0.001 to 0.018 S cm-1 as expected in a semiconductor material. The thermal conductivity is lower than 0.44 - 775 W m-1 K-1 which is quite anomalous in comparison with the thermal conductivity of other oxides.

Studies on Preparation Technique of Human Erythrocytes for Clinical Scanning Electron Microscopy

Archivum histologicum japonicum ◽

10.1679/aohc1950.38.321 ◽

1975 ◽

Vol 38 (4) ◽

pp. 321-334

Author(s):

Sa'di F. AL-SAMARRAI

Keyword(s):

Electron Microscopy ◽

Human Erythrocytes ◽

Preparation Technique ◽

USE OF NANOFLUIDS BASED ON CARBON NANOPARTICLES TO DISPLACE OIL FROM THE POROUS MEDIUM MODEL

Tyumen State University Herald Physical and Mathematical Modeling Oil Gas Energy ◽

10.21684/2411-7978-2020-6-4-141-157 ◽

2020 ◽

Vol 6 (4) ◽

pp. 141-157

Author(s):

Yuri V. Pakharukov ◽

Farid K. Shabiev ◽

Ruslan F. Safargaliev ◽

Boris S. Yezdin ◽

Valery V. Kalyada

Keyword(s):

Electron Microscopy ◽

Thermal Conductivity ◽

Electrical Conductivity ◽

Porous Medium ◽

Synergistic Effect ◽

Transition Region ◽

Dimensional Structure ◽

Hybrid Nanofluids ◽

Graphene, due to its two-dimensional structure, has some unique properties. For example, the thermal conductivity and electrical conductivity of graphene are an order of magnitude higher than the thermal conductivity and electrical conductivity of copper. For this reason, graphene-based nanofluids are now used in many industries. Due to the effect of self-organization of graphene nanoparticles with hydrocarbon molecules, the use of graphene has become possible in the oil industry. Graphene-based nanofluids are used as a displacement fluid to increase the oil recovery coefficient. The displacing ability of graphene-based nanofluids is concentration dependent. An increase in the concentration of nanoparticles entails an increase in viscosity, which negatively affects the performance characteristics of the nanofluid. This problem is partially solved due to the synergistic effect, hybrid nanofluids consisting of nanoparticles of graphene and metals or carbides enhance the displacing ability. Using atomic force microscopy, scanning electron microscopy and molecular modelling methods, this work has studied the formation of supramolecular structures that form a transition region at the oil-nanofluid interface with low surface tension as a result of a synergistic effect in the interaction of graphene planar nanoparticles and silicon carbide nanoparticles covered with graphene layers (Core-shell). The model experiments on a Hele-Shaw cell have shown that in a porous medium, such hybrid nanofluids have a high displacement ability of residual oil. At the same time, the oil — nanofluid interface remains stable, without the formation of viscous fingers. During the study by scanning electron microscopy, a transition region was observed, in the structuring of which the nanoparticles were directly involved. The displacement efficiency of a hybrid nonofluid depends on the concentration of nanoparticles and their interaction.

Fabrication of a Thick Crystalline Al2O3 Coating with Insulation and High Thermal Conductivity via Anodic Oxidation and Subsequent Mic Arc Discharge Treatment

Coatings ◽

10.3390/coatings10010038 ◽

2020 ◽

Vol 10 (1) ◽

pp. 38

Author(s):

Wei Song ◽

Bailing Jiang ◽

Dongdong Ji

Keyword(s):

Crystal Structure ◽

Electron Microscopy ◽

Thermal Conductivity ◽

Anodic Oxidation ◽

Arc Discharge ◽

Al2o3 Coating ◽

Compact Structure ◽

X Ray ◽

Amorphous Al2o3 ◽

Amorphous Al2O3 coating with a thickness of 143 μm was firstly prepared by anodic oxidation, then the amorphous Al2O3 was transformed into crystalline Al2O3 through applying micro arc discharge. The crystal structure of the Al2O3 coatings was analyzed with an X-ray diffractometer. Results indicated that the coating consisted of amorphous and crystalline Al2O3. The microstructure of the coating was characterized by scanning electron microscopy, which showed that the coating had a compact structure. The thermal conductivity of the coating was 23.7 W/m·K, which is significantly higher than that of amorphous Al2O3 coating. The total and specific breakdown voltages of the coating were 3.85 kV and 26.92 kV/mm, which is suitable to apply for high power LED heat sink substrate.

Thermal Conductivity of Boron Carbides

MRS Proceedings ◽

10.1557/proc-97-77 ◽

1987 ◽

Vol 97 ◽

Cited By ~ 3

Author(s):

Marvin Moss

Keyword(s):

Electron Microscopy ◽

Thermal Conductivity ◽

Raman Spectroscopy ◽

Temperature Dependence ◽

Rutherford Backscattering ◽

Rutherford Backscattering Spectroscopy ◽

Theoretical Density ◽

Increasing Temperature ◽

ABSTRACTThe thermal conductivity, k, of boron carbides of various B/C ratios, two modes of preparation – hot pressed and carbothermic, and two isotopic variants of boron – 11B and normal boron 10.81B, was measured from 300 to 1023 K. The density and composition of the samples were reflected in the magnitude and temperature dependence of k, and were investigated further with scanning electron microscopy, Rutherford backscattering spectroscopy, and Raman spectroscopy. While lower than theoretical density in B4C reduces k, the characteristic monotonic decline of k with increasing temperature is retained. This k-vs.-T behavior distinguishes B4C from material with larger B/C ratios for which the temperature dependence is essentially nil.

Study on Preparation and Properties of Vitrified Beads-Polystyrene Particles Insulation Mortar

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.538.3 ◽

2014 ◽

Vol 538 ◽

pp. 3-6

Author(s):

Yu Peng Chen ◽

Wen Hong Tao ◽

Xing Hua Fu ◽

Li Yuan Dong ◽

Hai Tao Yu

Keyword(s):

Electron Microscopy ◽

Thermal Conductivity ◽

Compressive Strength ◽

Dry Density ◽

Function Mechanism ◽

Testing Method ◽

Hydrophobic Agent ◽

Polypropylene Monofilament ◽

Softening Coefficient ◽

Orthogonal testing method was used to study the effects of polystyrene particles, hydrophobic agent, air-entraining agent, polypropylene monofilament fiber on dry density, compressive strength, water absorption and softening coefficient of composite insulation mortar. The optimal ratio was obtained as: 3% of the weight are polystyrene particles, 0.2% is hydrophobic agent, air-entraining agent counts for 0.4wt%，and polypropylene monofilament fiber 0.6%. The main performances of the mortar were recorded as: dry density was 228Kg/m3, 28 day compressive strength after conserved for 28 days was 0.54MPa, and thermal conductivity 0.0596W/(m•K). Microstructure of the composite insulation mortar was analyzed by SEM (scanning electron microscopy) and its function mechanism was studied preliminarily.

Synthesis and thermal conductivity of functionalized biocarbon-Fe3O4 nanocomposite-based green nanofluid for heat transfer applications

E3S Web of Conferences ◽

10.1051/e3sconf/202132101003 ◽

2021 ◽

Vol 321 ◽

pp. 01003

Author(s):

Divya Barai ◽

Sohan Parbat ◽

Bharat Bhanvase

Keyword(s):

Heat Transfer ◽

Electron Microscopy ◽

Thermal Conductivity ◽

Nanocomposite Particles ◽

X Ray ◽

Conductivity Enhancement ◽

Water Based ◽

One Step ◽

Ultrasound Assisted ◽

Bio-based graphitic carbon was synthesized in this work by one-step carbonization of bamboo waste at low temperature. This bio-based carbon was then functionalized in order to decorated it with Fe3O4 nanoparticles. The functionalized biocarbon-Fe3O4 (f-biocarbon-Fe3O4) nanocomposite was synthesized using ultrasound-assisted coprecipitation method which was then confirmed by scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffractometry. Water-based nanofluid was prepared using the synthesized f-biocarbon-Fe3O4 nanocomposite particles. Thermal conductivity of this nanofluid was analyzed at different concentrations and temperatures. A thermal conductivity enhancement of almost 80% was recorded at 35°C for nanofluid containing 0.1 vol.% of f-biocarbon-Fe3O4 nanocomposite particles compared to water. Also, empirical model is developed for prediction of thermal conductivity as a function of concentration and temperature of bamboo waste-derived f-biocarbon-Fe3O4 nanocomposite-based green nanofluid.

Graphene oxide-loaded shortening as an environmentally friendly heat transfer fluid with high thermal conductivity

Thermal Science ◽

10.2298/tsci150312199v ◽

2017 ◽

Vol 21 (5) ◽

pp. 2247-2254

Author(s):

Thammasit Vongsetskul ◽

Peeranut Prakulpawong ◽

Panmanas Sirisomboon ◽

Jonggol Tantirungrotechai ◽

Chanasuk Surasit ◽

...

Keyword(s):

Heat Transfer ◽

Electron Microscopy ◽

Thermal Conductivity ◽

Graphene Oxide ◽

Environmentally Friendly ◽

High Thermal Conductivity ◽

Chemical Degradation ◽

Heat Transfer Fluid ◽

Increasing Temperature ◽

Graphene oxide-loaded shortening (GOS), an environmentally friendly heat transfer fluid with high thermal conductivity, was successfully prepared by mixing graphene oxide (GO) with a shortening. Scanning electron microscopy revealed that GO particles, prepared by the modified Hummer?s method, dispersed well in the shortening. In addition, the latent heat of GOS decreased while their viscosity and thermal conductivity increased with increasing the amount of loaded GO. The thermal conductivity of the GOS with 4% GO was higher than that of pure shortening of ca. three times, from 0.1751 to 0.6022 W/mK, and increased with increasing temperature. The GOS started to be degraded at ca. 360?C. After being heated and cooled at 100?C for 100 cycles, its viscosity slightly decreased and no chemical degradation was observed. Therefore, the prepared GOS is potentially used as environmentally friendly heat transfer fluid at high temperature.

Tuning the Ablation, Thermal and Mechanical Characteristics of Phenolic Resin Reinforced EPDM Ultra-High Temperature Insulation

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.875.88 ◽

2021 ◽

Vol 875 ◽

pp. 88-95

Author(s):

Sadia Sagar Iqbal ◽

Tasawer Shahzad Ahmad ◽

Arshad Bashir ◽

Ali Bahadar ◽

Farzana Siddique

Keyword(s):

Electron Microscopy ◽

Thermal Conductivity ◽

Mechanical Characteristics ◽

Phenolic Resin ◽

Ethylene Propylene Diene Monomer ◽

Polymer Melting ◽

Base Matrix ◽

Ablation Characteristics ◽

The present research reports the influences of variant phenolic resin concentrations on the thermo-mechanical and ablation characteristics of ethylene propylene diene monomer (EPDM) elastomer. Backface temperature acclivity (BTA), charring rates, and insulation indexes were executed for the fabricated composite specimens. It was noticed that BTA was enhanced while linear/radial/mass ablation rates were significantly diminished with increasing concentration of phenolic resin (PR) in base matrix (elastomeric polymer). The composite (30wt%PR/EPDM) has 25% high thermal endurance compared to virgin EPDM composite. Thermal conductivity was increased with increasing PR to EPDM ratio. PR incorporation has remarkably enhanced the ultimate tensile strength of the EPDM elastomer. An efficient improvement in elastomeric hardness was also observed with increasing PR contents in EPDM matrix. Scanning Electron Microscopy (SEM) results showed the porosity generation and polymer melting during ablation.

The Effects of Clay Content and Sonication Time on Water Uptake in Epoxy-Organoclay Nanocomposites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.445.509 ◽

2012 ◽

Vol 445 ◽

pp. 509-513 ◽

Cited By ~ 3

Author(s):

Zuhair M. Gasem ◽

Necar Merah ◽

M.J. Adinoyi ◽

Zafarullah Khan

Keyword(s):

Electron Microscopy ◽

Water Uptake ◽

Room Temperature ◽

Clay Content ◽

Sonication Time ◽

Nacl Solution ◽

Glass Transition Temperatures ◽

Clay Loading ◽

The effects of clay loading and the extent of sonication time on water uptake in epoxy-organoclay based nanocomposites have been investigated as a function of exposure time in 3.5% NaCl at room temperature. Three clay loadings (2%, 4%, and 5wt.%) were dispersed in the epoxy resin by 10 and 60 minute sonication. The weight gains in the neat epoxy and the nanocomposites with 2 wt.% and 4 wt.% clay loadings showed a common asymptotic saturation value of 0.72 wt.% after 1000 hours of exposure. The saturation value was independent of sonication time. Nanocomposite with 5% clay loading and 60 minutes sonication exhibited a unique behavior and did not show saturation after 1000 hours of exposure. Scanning electron microscopy of tensile fractured nanocomposite specimens revealed the presence of organoclay aggregates, the size and number of which increased with an increase in clay loading. The Glass transition temperatures (Tg) for the nanocomposites decreased by approximately 20-25C° after 1000 hours of exposure in 3.5% NaCl solution.