Investigation of the dielectric and thermal conductive properties of core–shell structured HGM@hBN/PTFE composites

Pan, Chen; Kou, Kaichang; Zhang, Yu; Li, Ziyu; Ji, Tiezheng; Wu, Guanglei

doi:10.1016/j.mseb.2018.12.015

Cited by 57 publications

(25 citation statements)

References 60 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The decomposition rate curves of all samples are similar (Figure ). Thermal stability of composites can be characterized by thermal decomposition temperature at 10% weight loss (T d10 ) . Compared with the unstretched PTFE, the curves of stretched specimens show that the temperature has inappreciable effects on thermal decomposition below 500 °C, which can be attributed to the special helix structure of PTFE and high bond energy from carbon atoms and fluorine atoms.…”

Section: Resultsmentioning

confidence: 99%

Effect of tensile rates on thermal and mechanical properties of porous PTFE composites

Kou

Pan

et al. 2019

J of Applied Polymer Sci

Self Cite

View full text Add to dashboard Cite

To achieve polymer‐matrix composites for sealing materials with thermostability and toughness, PTFE composites filled with short glass fibers (SGFs) were hyperthermal stretched to prepare a substrate material with high thermal stability and porosity. The effects of various tensile rates on the thermal and mechanical properties and morphologies were investigated. The results revealed that the thermal stability could be improved slightly and the thermal expansion coefficient of composites increased by the tensile rate. Through observing the morphologies, tensile process produced cavities and the increased tensile rate had negligible effects on porosity, which also could be proved by density test. From mechanical properties analysis, stretched composites exhibited that the tensile strength increases first and then decreases with the increased tensile rate. Although the variation tendency of Young's modulus is similar to that of tensile strength, which is smaller than that of unstretched composite. When the tensile rate reached 50 mm·min−1, the tensile strength and Young's modulus of the stretched composites increased by 65 and 9% to maximum, respectively. Meanwhile, elongation at break and shore hardness decreased. The thermal and mechanical properties improvement could be ascribed to the strain‐induced crystallization and crystal alignment. In addition, the interplanar spacing and grain size were inversely proportional to the tensile rate. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48175.

show abstract

Section: Resultsmentioning

confidence: 99%

Effect of tensile rates on thermal and mechanical properties of porous PTFE composites

Kou

Pan

et al. 2019

J of Applied Polymer Sci

Self Cite

View full text Add to dashboard Cite

show abstract

“…The peak at approximately 810 cm −1 represents the B–N bending vibration. The peak at 1380 cm −1 corresponds to stretching vibrations of B–N 14 . The absorbance peak observed at 2330 cm −1 is most likely due to the reaction with carbon dioxide in the atmosphere 15 .…”

Section: Resultsmentioning

confidence: 99%

Non-cytotoxic hydroxyl-functionalized exfoliated boron nitride nanoflakes impair the immunological function of insect haemocytes in vivo

Czarniewska

Mrówczyńska

Jędrzejczak-Silicka

et al. 2019

Sci Rep

View full text Add to dashboard Cite

To induce the water solubility of hexagonal boron nitride (h-BN), we exfoliated and functionalized bulk h-BN with hydroxyl groups (h-BN-OH-n). Short-term studies showed that h-BN-OH-n induced low cytotoxicity in different models: insect haemocytes (in vivo), human erythrocytes and mouse fibroblasts (in vitro). We also demonstrated that Alexa Fluor 647-h-BN-OH-n administered topically to the insects passed through the cuticle barrier and was phagocytosed by haemocytes. Nanoflakes did not affect the haemocyte cell membrane and did not interfere with the phagocytosis of latex beads. Long-term immunoassays showed that h-BN-OH-n, despite not inducing haemocytotoxicity, impaired nodulation, the most important cellular immune response in insects. The haemocytes exposed to h-BN-OH-n and then to bacteria differed in morphology and adhesiveness from the haemocytes exposed only to bacteria and exhibited the same morphology and adhesiveness as the control haemocytes. The h-BN-OH-n-induced decrease in nodulation can therefore result from the reduced ability of haemocytes to recognize bacteria, migrate to them or form microaggregates around them, which can lead to dysfunction of the immune system during pathogen infection. Long-term in vivo studies with animal models are still necessary to unambiguously confirm that h-BN is biocompatible and useful for application as a platform for drug delivery or for bioimaging.

show abstract

“…The BN/PTFE composites have good moisture resistance, and the maximum moisture absorption rate is only 0.11% [43] while the moisture absorption requirement of intermetallic dielectrics is less than 1% [44]. Therefore, in order to study the effect of water content on the dielectric properties of PTFE dielectric materials, the PTFE model and BN/PTFE model were mixed with 0~1% water, and the water content increment step was 0.1%.…”

Section: Simulation Methods and Resultsmentioning

confidence: 99%

Molecular Dynamics Simulation of Improving the Physical Properties of Polytetrafluoroethylene Cable Insulation Materials by Boron Nitride Nanoparticle under Moisture-Temperature-Electric Fields Conditions

2019

View full text Add to dashboard Cite

The physical properties in amorphous regions are important for the insulation aging assessment of polytetrafluoroethylene (PTFE) cable insulation materials. In order to study the effect of boron nitride (BN) nanoparticles on the physical properties of PTFE materials under moisture, temperature, and electric fields conditions at the molecular level, the amorphous region models of PTFE, BN/PTFE, water/PTFE, and water/BN/PTFE were respectively constructed by molecular dynamics (MD) simulation. The mechanical properties including Young’s modulus, Poisson’s ratio, bulk modulus, and shear modulus, along with glass transition temperature, thermal conductivity, relative dielectric constant, and breakdown strength of the four models have been simulated and calculated. The results show that the mechanical properties and the glass transition temperature of PTFE are reduced by the injection of water molecules, whereas the same, along with the thermal conductivity, are improved by incorporating BN nanoparticles. Moreover, thermal conductivity is further improved by the surface grafting of BN nanoparticles. With the increase of temperature, the mechanical properties and the breakdown strength of PTFE decrease gradually, whereas the thermal conductivity increases linearly. The injection of water molecules increases the water content in the PTFE materials, which causes a gradual increase in its relative dielectric constant. This work has shown that this effect is significantly reduced by incorporation of BN nanoparticles. The variation of physical properties for PTFE and its composites under the action of moisture, temperature, and electric fields is of great significance to the study of wet, thermal, and electrical aging tests as well as the life prediction of PTFE cable insulation materials.

show abstract

Investigation of the dielectric and thermal conductive properties of core–shell structured HGM@hBN/PTFE composites

Cited by 57 publications

References 60 publications

Effect of tensile rates on thermal and mechanical properties of porous PTFE composites

Effect of tensile rates on thermal and mechanical properties of porous PTFE composites

Non-cytotoxic hydroxyl-functionalized exfoliated boron nitride nanoflakes impair the immunological function of insect haemocytes in vivo

Molecular Dynamics Simulation of Improving the Physical Properties of Polytetrafluoroethylene Cable Insulation Materials by Boron Nitride Nanoparticle under Moisture-Temperature-Electric Fields Conditions

Contact Info

Product

Resources

About