Ciobanu Romeo Cristian, Aflori Magdalena, Scheiner Cristina Mihaela, Aradoaei Mihaela, Buncianu Dorel
Department of Electrical Measurements and Materials, Gheorghe Asachi Technical University, 700050 Iasi, Romania.
Petru Poni Institute of Macromolecular Chemistry, 41 A Gr. Ghica Voda Alley, 700487 Iasi, Romania.
Polymers (Basel). 2025 Jan 15;17(2):204. doi: 10.3390/polym17020204.
This study investigated silicone composites with distributed boron nitride platelets and carbon microfibers that are oriented electrically. The process involved homogenizing and dispersing nano/microparticles in the liquid polymer, aligning the particles with DC and AC electric fields, and curing the composite with IR radiation to trap particles within chains. This innovative concept utilized two fields to align particles, improving the even distribution of carbon microfibers among BN in the chains. Based on SEM images, the chains are uniformly distributed on the surface of the sample, fully formed and mature, but their architecture critically depends on composition. The physical and electrical characteristics of composites were extensively studied with regard to the composition and orientation of particles. The higher the concentration of BN platelets, the greater the enhancement of dielectric permittivity, but the effect decreases gradually after reaching a concentration of 15%. The impact of incorporating carbon microfibers into the dielectric permittivity of composites is clearly beneficial, especially when the BN content surpasses 12%. Thermal conductivity showed a significant improvement in all samples with aligned particles, regardless of their composition. For homogeneous materials, the thermal conductivity is significantly enhanced by the inclusion of carbon microfibers, particularly when the boron nitride content exceeds 12%. The biggest increase happened when carbon microfibers were added at a rate of 2%, while the BN content surpassed 15.5%. The thermal conductivity of composites is greatly improved by adding carbon microfibers when oriented particles are present, even at BN content over 12%. When the BN content surpasses 15.5%, the effect diminishes as the fibers within chains are only partly vertically oriented, with BN platelets prioritizing vertical alignment. The outcomes of this study showed improved results for composites with BN platelets and carbon microfibers compared to prior findings in the literature, all while utilizing a more straightforward approach for processing the polymer matrix and aligning particles. In contrast to current technologies, utilizing homologous materials with uniformly dispersed particles, the presented technology reduces ingredient consumption by 5-10 times due to the arrangement in chains, which enhances heat transfer efficiency in the desired direction. The present technology can be used in a variety of industrial settings, accommodating different ingredients and film thicknesses, and can be customized for various applications in electronics thermal management.
本研究调查了含有分布氮化硼薄片和电取向碳微纤维的有机硅复合材料。该过程包括将纳米/微粒在液态聚合物中均匀化和分散，利用直流和交流电场使微粒取向，并通过红外辐射固化复合材料以将微粒捕获在链内。这一创新概念利用两个场使微粒取向，改善了碳微纤维在链中氮化硼之间的均匀分布。基于扫描电子显微镜图像，链均匀分布在样品表面，已完全形成且成熟，但其结构关键取决于组成。针对微粒的组成和取向，对复合材料的物理和电学特性进行了广泛研究。氮化硼薄片的浓度越高，介电常数的增强越大，但在达到15%的浓度后，这种效应逐渐减弱。将碳微纤维加入到复合材料的介电常数中所产生的影响显然是有益的，尤其是当氮化硼含量超过12%时。对于所有微粒取向的样品，无论其组成如何，热导率都有显著提高。对于均质材料，加入碳微纤维会显著提高热导率，特别是当氮化硼含量超过12%时。当以2%的比例添加碳微纤维且氮化硼含量超过15.5%时，热导率增加幅度最大。当存在取向微粒时，即使氮化硼含量超过12%，加入碳微纤维也能极大地提高复合材料的热导率。当氮化硼含量超过15.5%时，由于链内纤维仅部分垂直取向，而氮化硼薄片优先垂直取向，这种效应会减弱。本研究的结果表明，与文献中先前的发现相比，含有氮化硼薄片和碳微纤维的复合材料有更好的结果，同时在处理聚合物基体和使微粒取向方面采用了更直接的方法。与当前利用具有均匀分散微粒的同源材料的技术相比，由于链状排列，本技术将成分消耗降低了5至10倍，这提高了在所需方向上的传热效率。本技术可用于各种工业环境，适用于不同的成分和薄膜厚度，并可针对电子热管理中的各种应用进行定制。
