Epoxy composite with significantly improved thermal conductivity by constructing a vertically aligned three-dimensional network of silicon carbide nanowires/ boron nitride nanosheets

Thermal Conductivity and Cure Kinetics of Epoxy-Boron Nitride Composites—A Review

“…First, the usually observed upward curvature in the dependence of the thermal conductivity on BN content is not displayed by the results of Yung and Liem [54], which are shown separately in Figure 8; instead, there appears to be a tendency to reach a limiting value as the BN content increases. Second, the results of Yung et al [151] Open circles refer to data from references [54,151], open squares refer to data from references [89,90,114,116,125,127,132,143,147,153,158]. The dashed trend lines indicate the overall tendency for the dependence of thermal conductivity on BN content (excluding the data represented by the open circles): an upper trend line, below which more than 95% of the values fall; and a lower trend line, below which fewer than 5% of the values fall.…”

“…These are the data which correspond to samples in which orientation of the BN particles has deliberately been introduced. The orientation can be induced by various means: gravity alignment and subsequent resin infiltration [147]; the application of high pressure to partially cured samples before the final cure [90,153,158]; spin-coating of films and hot pressing after pre-cure [116]; magnetic alignment of Fe 3 O 4 -decorated BN particles [114,125,127]; or by resin infiltration of hierarchically ordered 3-dimensional templates [89,132,143]. The orientation induced usually results in a highly anisotropic thermal conductivity.…”

“…Filtration through a die was also the technique adopted by Xiao et al [ 143 ] to induce orientation of BNNS in composites. They used a more elaborate fabrication procedure, in which the BNNS were first exfoliated from 12 μm BN platelets by sonication in isopropyl alcohol and were then both functionalised with GPTMS and decorated with SiC nanowires (SiC w , 0.1 to 0.6 μm in diameter and 50 to 100 μm long) in an ethanol solution before being vacuum filtrated through a die.…”

Hydroxylated boron nitride materials: from structures to functional applications

“…The treatment can generate some other defects in HO-BNs. If the temperature reaches 1500°C, the products have to be hydroxylated by the above methods [47][48][49][50][51][52][53] h-BNNSs Sonication-assisted exfoliation It is a facile method to directly exfoliate BN bulk into HO-BNNSs The hydroxyl degree is relatively low For a high hydroxyl degree, some additives have to be introduced, such as, acid, base, salt, etc [31,[55][56][57][58][59][60][61][62][63] Ball-milling-assisted exfoliation Situations similar to ''sonication-assisted exfoliation'' [64][65][66][67][68][69][70][71][72] Hummer's-like routes The use of strong oxidants (i.e., H 2 SO 4 , H 2 O 2 , KMnO 4 , and their mixtures) requires an extra attention Sometimes the oxidization process can lead to the presence of a few by-products of BN dots [73][74][75][76] Multi-step functionalization method It can be divided into two stages: one is from BN to BNNS and then to HO-BNNS, the other is from BN to HO-BN and then to HO-BNNS [82][83][84][85][86][87][88][89][90][91][92] Bottom-up routes It generally requires high temp...…”

“…Hydroxylated h-BNNSs can also be obtained by exfoliating bulk HO-BNs [89][90][91][92]. According to Fu et al [89], HO-BNNSs can be prepared by the following two steps: firstly, a hydrothermal method is used to hydroxylate BN powders by NaOH and KOH; in a second step, the HO-BNs can be exfoliated by sonication.…”