scholarly journals Flexible and High Thermal Conductivity Composites Based on Graphite Nanoplates Paper Impregnated with Polydimethylsiloxane

2021 ◽  
Vol 5 (12) ◽  
pp. 309
Author(s):  
Daniele Battegazzore ◽  
Erica Fadda ◽  
Alberto Fina

This paper deals with the design, preparation, and characterization of conductive and flexible nanopapers based on graphite nanoplates (GNP) and polydimethylsiloxane (PDMS). Highly porous GNP nanopapers were first prepared by filtration from a GNP suspension in a solvent. Subsequently, PDMS impregnation was carried out to obtain a composite material. By varying the concentration of the polymer solution and the deposition time, PDMS/GNP nanopapers were produced with a wide range of PDMS contents, porosities, and densities. Thermal diffusivity of the composite films (both in-plane and cross-plane) were measured and correlated with the structure of the nanopapers. Selected formulations were investigated in detail for their physical, thermal, and mechanical properties, exhibiting high flexibility and resistance to more than 50 repeated bendings, stiffness of up to 1.3 MPa, and thermal conductivity of up to 25 W/m∙K. Based on the properties obtained, the materials presented in this paper may find applications in modern lightweight and flexible electronic devices.

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 379
Author(s):  
Seonmin Lee ◽  
Jooheon Kim

Aggregated boron nitride (ABN) is advantageous for increasing the packing and thermal conductivity of the matrix in composite materials, but can deteriorate the mechanical properties by breaking during processing. In addition, there are few studies on the use of Ti3C2 MXene as thermally conductive fillers. Herein, the development of a novel composite film is described. It incorporates MXene and ABN into poly(vinyl alcohol) (PVA) to achieve a high thermal conductivity. Polysilazane (PSZ)-coated ABN formed a heat conduction path in the composite film, and MXene supported it to further improve the thermal conductivity. The prepared polymer composite film is shown to provide through-plane and in-plane thermal conductivities of 1.51 and 4.28 W/mK at total filler contents of 44 wt.%. The composite film is also shown to exhibit a tensile strength of 11.96 MPa, which is much greater than that without MXene. Thus, it demonstrates that incorporating MXene as a thermally conductive filler can enhance the thermal and mechanical properties of composite films.


2019 ◽  
Vol 8 (1) ◽  
pp. 935-943
Author(s):  
Luis Miguel Araque ◽  
Ana Carolina Lemos de Morais ◽  
Tatianny Soares Alves ◽  
Joyce Batista Azevedo ◽  
Laura Hecker Carvalho ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aaditya A. Candadai ◽  
Emily J. Nadler ◽  
Jack S. Burke ◽  
Justin A. Weibel ◽  
Amy M. Marconnet

AbstractWith advances in flexible and wearable device technology, thermal regulation will become increasingly important. Fabrics and substrates used for such applications will be required to effectively spread any heat generated in the devices to ensure user comfort and safety, while also preventing overheating of the electronic components. Commercial fabrics consisting of ultra-high molecular weight polyethylene (UHMW-PE) fibers are currently used in personal body armor and sports gear owing to their high strength, durability, and abrasion resistance. In addition to superior mechanical properties, UHMW-PE fibers exhibit very high axial thermal conductivity due to a high degree of polymer chain orientation. However, these materials have not been widely explored for thermal management applications in flexible and wearable devices. Assessment of their suitability for such applications requires characterization of the thermal and mechanical properties of UHMW-PE in the fabric form that will ultimately be used to construct heat spreading materials. Here, we use advanced techniques to characterize the thermal and mechanical properties of UHMW-PE fabrics, as well as other conventional flexible materials and fabrics. An infrared microscopy-based approach measures the effective in-plane thermal conductivity, while an ASTM-based bend testing method quantifies the bending stiffness. We also characterize the effective thermal behavior of fabrics when subjected to creasing and thermal annealing to assess their reliability for relevant practical engineering applications. Fabrics consisting of UHMW-PE fibers have significantly higher thermal conductivities than the benchmark conventional materials while possessing good mechanical flexibility, thereby showcasing great potential as substrates for flexible and wearable heat spreading application.


2021 ◽  
Vol 190 ◽  
pp. 110272 ◽  
Author(s):  
Md. Habibur Rahman ◽  
Emdadul Haque Chowdhury ◽  
Didarul Ahasan Redwan ◽  
Sungwook Hong

2021 ◽  
Author(s):  
Yue Zhu ◽  
Qingyu Peng ◽  
Haowen Zheng ◽  
Fuhua Xue ◽  
Pengyang Li ◽  
...  

With the development of multifunction and miniaturization in modern electronics, polymeric films with strong mechanical performance and high thermal conductivity are urgently needed. Two-dimensional transition metal carbides and nitrides (MXenes)...


2021 ◽  
Vol 36 (2) ◽  
pp. 137-143
Author(s):  
S. A. Awad

Abstract This paper aims to describe the thermal, mechanical, and surface properties of a PVA/HPP blend whereby the film was prepared using a solution casting method. The improvements in thermal and mechanical properties of HPP-based PVA composites were investigated. The characterization of pure PVA and PVA composite films included tensile tests, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The results of TGA and DSC indicated that the addition of HPP increased the thermal decomposition temperature of the composites. Mechanical properties are significantly improved in PVA/HPP composites. The thermal stability of the PVA composite increased with the increase of HPP filler content. The tensile strength increased from 15.74 ± 0.72 MPa to 27.54 ± 0.45 MPa and the Young’s modulus increased from 282.51 ± 20.56 MPa to 988.69 ± 42.64 MPa for the 12 wt% HPP doped sample. Dynamic mechanical analysis (DMA) revealed that at elevated temperatures, enhanced mechanical properties because of the presence of HPP was even more noticeable. Morphological observations displayed no signs of agglomeration of HPP fillers even in composites with high HPP loading.


2004 ◽  
Vol 19 (11) ◽  
pp. 3270-3278 ◽  
Author(s):  
Xinwen Zhu ◽  
Hiroyuki Hayashi ◽  
You Zhou ◽  
Kiyoshi Hirao

Dense β–Si3N4 ceramics were fabricated from α–Si3N4 raw powder by gas-pressure sintering at 1900 °C for 12 h under a nitrogen pressure of 1 MPa, using four different kinds of additive compositions: Yb2O3–MgO, Yb2O3–MgSiN2, Y2O3–MgO, and Y2O3–MgSiN2. The effects of additive composition on the microstructure and thermal and mechanical properties of β–Si3N4 ceramics were investigated. It was found that the replacement of Yb2O3 by Y2O3 has no significant effect on the thermal conductivity and fracture toughness, but the replacement of MgO by MgSiN2 leads to an increase in thermal conductivity from 97 to 113 Wm-1K-1and fracture toughness from 8 to 10 MPa m1/2, respectively. The enhanced thermal conductivity of the MgSiN2-doped materials is attributed to the purification of β–Si3N4 grain and increase of Si3N4–Si3N4 contiguity, resulting from the enhanced growth of large elongated grains. The improved fracture toughness of the MgSiN2-doped materials is attributed to the increase of grain size and fraction of large elongated grains. However, the same thermal conductivity between the Yb2O3- and Y2O3-doped materials is related to not only their similar microstructures, but also the similar abilities of removing oxygen impurity in Si3N4 lattice between Yb2O3 and Y2O3. The same fracture toughness between the Yb2O3- and Y2O3-doped materials is consistent with their similar microstructures. This work implies that MgSiN2 is an effective sintering aid for developing not only high thermal conductivity (>110 Wm−1K−1) but also high fracture toughness (>10 MPa m1/2) of Si3N4 ceramics.


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