scholarly journals Enhancing thermal conductivity of polyimide composite film by electrostatic self-assembly and two-step synergism of Al2O3 microspheres and BN nanosheets

RSC Advances ◽  
2020 ◽  
Vol 10 (69) ◽  
pp. 42584-42595
Author(s):  
Dongxu Liu ◽  
Chuanguo Ma ◽  
Hongtao Chi ◽  
Shihui Li ◽  
Ping Zhang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Composite Film ◽  
Self Assembly

A strategy of electrostatic self-assembly and two-step synergism was proposed to significantly improve the thermal conductivity of the PI composite film.

High thermal conductivity property of polyamide-imide/boron nitride composite films by doping boron nitride quantum dots

2019 ◽  
Vol 7 (44) ◽  
pp. 13896-13903 ◽  
Author(s):  
Shuaishuai Zhou ◽  
Tongle Xu ◽  
Fang Jiang ◽  
Na Song ◽  
Liyi Shi ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Quantum Dots ◽  
Boron Nitride ◽  
Composite Film ◽  
Self Assembly ◽  
Composite Films ◽  
Conductivity Property ◽  
Assembly Method ◽  
Boron Nitride Nanosheet ◽  
Evaporation Induced Self Assembly

In this study, we report a flexible polyamide-imide (PAI)/boron nitride nanosheet (BNNS) composite film with improved thermal conductivity by doping boron nitride quantum dots (BNQDs) using an evaporation-induced self-assembly method.

Enhanced thermal conductivity of polyimide composite film filled with hybrid fillers

2021 ◽  
pp. 095400832110003
Author(s):  
Ruiyi Li ◽  
Chengcheng Ding ◽  
Juan Yu ◽  
Xiaodong Wang ◽  
Pei Huang
Keyword(s):  
Thermal Conductivity ◽  
Composite Film ◽  
Hexagonal Boron Nitride ◽  
Composite Films ◽  
Resistance Index ◽  
Reference Value ◽  
Residual Rate ◽  
Practical Applications ◽  
Hybrid Fillers ◽  
The Matrix

In this article, the polyimide (PI) composite films with synergistically improving thermal conductivity were prepared by adding a few graphene nanoplatelets (GNP) and various hexagonal boron nitride (h-BN) contents into the PI matrix. The thermal conductivity of PI composite film with 1 wt% GNP and 30 wt% h-BN content was 1.21 W(m·k)− 1, which was higher than that of the PI composite film with 30 wt% h-BN content (0.45 W(m·k)− 1), the synergistic efficiency of GNP under various h-BN content (10 wt%, 20 wt%, and 30 wt%) were 1.70, 2.71, and 3.09, respectively. And it was found that the increased h-BN content can suppress the dielectric properties caused by GNP in the matrix. The dielectric permittivity and dielectric loss tangent of 1 wt% GNP/PI composite film were 10.69, 0.661 at 103 Hz, respectively, and that of the 30 wt% h-BN + GNP/PI composite film were 4.29 and 0.1367, respectively. Moreover, the mechanical properties of the PI composite film were suitable for practical applications. And the heat resistance index and the residual rate at 700°C of PI composite film increased to 326.8°C, 74.43%, respectively, and these of PI film were 292.6°C and 59.26%. Thus, it may provide a reference value for applying the filler hybridization/PI film in the electronic packaging materials.

The Evaluation of TiTe2 as a Diffusion Barrier in the Formation of Low Thermal Conductivity Nanolaminates with Bi2Te3 and Sb2Te3

2010 ◽  
Vol 74 ◽  
pp. 38-47
Author(s):  
Clay Mortensen ◽  
Paul Zschack ◽  
David C. Johnson
Keyword(s):  
Thermal Conductivity ◽  
Diffusion Barrier ◽  
Self Assembly ◽  
Low Temperatures ◽  
Annealing Temperature ◽  
The Self ◽  
High Angle ◽  
X Ray Diffraction ◽  
Amorphous Precursor ◽  
X Ray

The evolution of designed [(Ti-Te)]x[(Sb-Te)]y, [(Bi-Te)]x[(Sb-Te)]y, [(Ti-Te)]w[(Bi-Te)]x[(Sb-Te)]y and [(Ti-Te)]w[(Bi-Te)]x[(Ti-Te)]y[(Sb-Te)]z precursors were followed as a function of annealing temperature and time using both low and high angle x-ray diffraction techniques to probe the self assembly into nanolaminate materials. The [(Bi-Te)]x[(Sb-Te)]y precursors were found to interdiffuse at low temperatures to form a (BixSb1-x)2Te3 alloy. The [(Ti-Te)]x[(Bi-Te)]y and [(Ti-Te)]x[(Sb-Te)]y precursors formed ordered nanolaminates [{(TiTe2)}1.35]x[Bi2Te3]y and [{(TiTe2)}1.35]x[Sb2Te3]y respectively. The [(Ti-Te)]w[(Bi-Te)]x[(Sb-Te)]x precursors formed [{(TiTe2)}1.35]w[(Bi0.5Sb0.5)2Te3]2x nanolaminates on annealing, as the bismuth and antimony layers interdiffused. Over the range of TiTe2 thicknesses used in [(Ti-Te)]w[(Bi-Te)]x[(Ti-Te)]y[(Sb-Te)]z precursors, Bi and Sb were found to interdiffuse through the 2-4 nm thick Ti-Te layers, resulting in the formation of (BixSb1-x)2Te3 alloy layers as part of the final nanolaminated products. When the Bi-Te and Sb-Te thicknesses were equal in the amorphous precursors, symmetric [{(TiTe2)}1.35]m[(Bi0.5Sb0.5)2Te3]n nanolamiantes were formed. When the thicknesses of Bi-Te and Sb-Te layers were not equal in the amorphous precursor, asymmetric [(TiTe2)1.35]m[(BixSb1-x)2Te3]n[(TiTe2)1.35]m[(BixSb1-x)2Te3]p nanolaminates were formed. These results imply that to form (A)w(B)x(C)y nanolaminates using designed layered precursors all three components must be immiscible. To form (A)x(B)y(A)x(C)z nanolaminates, the components must be immiscible or the precursor to the A component and the A component itself must be an effective interdiffusion barrier preventing B and C from mixing.

Improvement of thermal conductivity of composite film composed of cellulose nanofiber and nanodiamond by optimizing process parameters

Cellulose ◽  
2018 ◽  
Vol 25 (7) ◽  
pp. 3973-3983 ◽  
Author(s):  
Yuichi Tominaga ◽  
Kimiyasu Sato ◽  
Yuji Hotta ◽  
Hitoshi Shibuya ◽  
Mai Sugie ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Composite Film ◽  
Process Parameters ◽  
Cellulose Nanofiber

Self-assembly of 3D-graphite block infiltrated phase change materials with increased thermal conductivity

2019 ◽  
Vol 235 ◽  
pp. 359-368 ◽  
Author(s):  
Huibin Yin ◽  
Shiyuan Gao ◽  
Chengcheng Liao ◽  
Chaomei Li ◽  
Zhuodi Cai ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Phase Change ◽  
Self Assembly ◽  
Phase Change Materials ◽  
Graphite Block

Array of Fe3O4 Nanoparticles in PS-b-P2VP thin Films

2013 ◽  
Vol 345 ◽  
pp. 193-196
Author(s):  
Xin Kang Gao ◽  
Jun Liu ◽  
Ting Hua Wang ◽  
Xue Li ◽  
Xiao Kai Zhang
Keyword(s):  
Thin Films ◽  
High Temperature ◽  
Composite Film ◽  
Self Assembly ◽  
Spin Coating ◽  
Diblock Copolymers ◽  
Carbon Substrate ◽  
Mixed Solution ◽  
Long Time ◽  
Oriented Parallel

In this study, a method to generate arrays of Fe3O4 nanoparticles (MNPs) via block copolymer (BC) self-assembly was developed. A composite film of polystyrene-block-poly (2-vinylpyridine) (PS-b-P2VP)/MNPs was first prepared by spin-coating the PS-b-P2VP/MNPs mixed solution on a carbon substrate. After the composite film was annealed at high temperature for 2 days, it was found that the modified MNPs could be selectively incorporated into P2VP cylinders in PS-b-P2VP diblock copolymers and the P2VP cylinders were oriented parallel to the substrate. For a long time annealing (10 days), the P2VP cylinders become normal to the substrate and MNPs are located at the interface of P2VP and PS phases.

Thermophysical Properties and Pool Boiling Characteristics of Water-in-Polyalphaolefin Nanoemulsion Fluids

2013 ◽  
Vol 135 (9) ◽  
Author(s):  
Jiajun Xu ◽  
Bao Yang ◽  
Boualem Hammouda
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Thermophysical Properties ◽  
Self Assembly ◽  
Boiling Heat Transfer ◽  
Small Angle Neutron Scattering ◽  
Room Temperature ◽  
Pool Boiling ◽  
Water Concentration ◽  
Interesting Phenomenon

In this work, thermophysical properties, microstructure, and pool boiling characteristics of water-in-polyalphaolefin (PAO) nanoemulsion fluids have been measured in the water concentration range of 0–10.3 vol. %, in order to gain basic data for nanoemulsion boiling. Water-in-PAO nanoemulsion fluids are formed via self-assembly with surfactant: sodium sullfosuccinate (AOT). Thermal conductivity of these fluids is found to increase monotonically with water concentration, as expected from the Maxwell equation. Unlike thermal conductivity, their dynamic viscosity first increases with water concentration, reaches a maximum at 5.3 vol. %, and then decreases. The observed maximum viscosity could be attributed to the attractive forces among water droplets. The microstructures of the water-in-PAO nanoemulsion fluids are measured via the small-angle neutron scattering (SANS) technique, which shows a transition from sphere to elongated cylinder when the water concentration increases above 5.3 vol. %. The pool boiling heat transfer of these water-in-PAO nanoemulsion fluids is measured on a horizontal Pt wire at room temperature (25 °C, subcooled condition). One interesting phenomenon observed is that the pool boiling follows two different curves randomly when the water concentration is in the range of 5.3 vol. % to 7.8 vol. %.

scholarly journals Linear Assembles of BN Nanosheets, Fabricated in Polymer/BN Nanosheet Composite Film

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Hong-Baek Cho ◽  
Tadachika Nakayama ◽  
Tsuneo Suzuki ◽  
Satoshi Tanaka ◽  
Weihua Jiang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electric Field ◽  
Composite Film ◽  
High Speed ◽  
Film Plane ◽  
Digital Microscopy ◽  
X Ray Diffraction ◽  
High Anisotropy ◽  
Dc Electric Field ◽  
First Time

Linear assembles of BN nanosheets (LABNs) were fabricated in polysiloxane/BN nanosheet composite film under a high DC electric field. The hexagonal BN nanosheets were dispersed by sonication in a prepolymer mixture of polysiloxane followed by a high-speed mixing. The homogeneous suspension was cast on a spacer of microscale thickness and applied to a high DC electric field before it became cross-linked. X-ray diffraction, scanning electron microscopy, and digital microscopy revealed that LABNs formed in the polysiloxane matrix and that the BN nanosheets in the LABNs were aligned perpendicular to the film plane with high anisotropy. This is the first time that linear assemblies of nanosheets have been fabricated in an organic-inorganic hybrid film by applying a DC electric field. The enhanced thermal conductivity of the composite film is attributed to the LABNs. The LABN formation and heat conduction mechanisms are discussed. The polysiloxane/BN nanosheet composite film has the potential to be used semiconductor applications that require both a high thermal conductivity and a high electric insulation.

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