Multifunctional bionanocomposites with ultraviolet blocking, infrared reflection and thermal conductivity

Abstract

The objective of this paper is investigating the effect of different localizations of titanium dioxide (TiO 2) and hexagonal boron nitride (hBN) nanoparticles in the poly(lactic acid) (PLA)/poly(ε-caprolactone) (PCL) blends on the ultraviolet (UV) blocking, infrared reflection (NIR), and thermal conductivity of the nanocomposites for the fabrication of bionanocomposites with high performance. Transmission electron microscopy images demonstrated that the different mixing sequences induced different nanoparticle localization in the immiscible PCL/PLA blend. These different localizations yielded differences in the properties of the hybrid quaternary nanocomposite. When the nanoparticles had different localizations, TiO 2 at the interface and hBN in the PCL phase, the thermal conductivity was 0.86 Wm −1 K −1 , 100% of UV radiation (λ = 300 nm) was blocked and 74% of NIR radiation was reflected. This nanocomposite has a strong potential for application as a multifunctional biodegradable film for agriculture, capable of absorbing UV radiation, reflecting NIR radiation, and conducting thermal energy.

Study on preparation of highly dispersed graphite composite expandable polystyrene foam by homogeneous dissolution‐suspension polymerization with waste polystyrene

“…The thermal radiation λ r mainly depends on the size of the foam material. [28][29][30] The smaller the diameter of the bubble hole is, the more thermal radiation is absorbed and reflected, and the λ r value is smaller. As GEPS and EPS pore materials themselves have similar pore structure, the pore structure itself contributes similarly to thermal radiation.…”

Preparation of continuous carbon fiber‐filled silicone rubber with high thermal conductivity through wrapping

“…Therefore, to avoid the accumulation of excessive heat in localized areas of the devices, which could cause irreversible damage, improve device safety, and extend their lifespan, the demand for high thermal conductive materials in related fields is increasing. [1][2][3][4][5][6][7][8][9] Silicone rubber (SR) is widely used due to its excellent insulating and shock-absorbing properties, but its thermal conductivity is only around 0.2 W m À1 K À1 . [10][11][12] However, by incorporating high-performance thermal conductive fillers into the matrix, such as boron nitride (BN), [13][14][15] silicon carbide (SiC [16][17][18] ), aluminum oxide (Al 2 O 3 [19][20][21][22] ), as insulating thermal conductive fillers, and materials like graphite, [23][24][25] carbon nanotubes (CNT [26][27][28][29][30] ), as conductive and insulating fillers, the thermal conductivity of SR can be effectively improved.…”

Thermally conductive and mechanically strengthened bio‐epoxy/boron nitride nanocomposites: The effects of particle size, shape, and combination

“…High-thermal conductivity, low-thermal expansion, good thermal shock resistance, high-electrical resistance, low-dielectric constant and loss tangent, microwave transparency, non-toxicity, easily machinability non-abrasive and lubricious, chemical inertness, and non-wetting by most molten metals are key BN properties. [46,47] The substitution of C atoms by B and Natoms, as well as the crystallization of BN occur in its structure. Though researchers hypothesize that the size, shape, aspect ratio, chemical composition, and surface modification of different BN structures should have a significant impact on the properties of nanocomposite materials, the detailed mechanism of how the filler properties influence the properties of the epoxy matrix through their interaction remains unknown.…”