Functional nanocellulose-boron nitride composite film and preparation method thereof

Abstract

The invention discloses a functional nanocellulose-boron nitride composite film. A deposition layer is formed after suction filtration of a nanocellulose / boron nitride dispersion liquid on a mixed cellulose ester micro-porous filter membrane, and the deposition layer is hot-pressed and dried to form the inner layer of the composite film; and the inner layer of the composite film is a nanocellulose-boron nitride composite monolayer structure containing 1-7 wt% of boron nitride. The invention also discloses a preparation method of the composite film. The preparation method comprises: (1) mixing,stirring and ultrasonically crushing a nanocellulose dispersion and a boron nitride dispersion to obtain the nanocellulose-boron nitride dispersion; and (2) placing the obtained dispersion on the mixed cellulose ester filter membrane, carrying out vacuum suction filtration to form the deposition layer, removing the mixed cellulose ester filter membrane, and hot-pressing and drying the depositionlayer to obtain the inner layer of the composite film. The composite film provided by the invention has a high heat conduction coefficient and a high hydrophobic insulation performance, and can be widely used in the fields of electronic devices and biomaterials.

Description

technical field [0001] The invention relates to a functional nano-cellulose-boron nitride composite film and a preparation method thereof, in particular to a heat-conducting and insulating film with a hydrophobic function, which belongs to the field of heat-conducting composite materials. Background technique [0002] With the rapid development of electronic technology, communication circuits, semiconductors and other equipment tend to be miniaturized and dense. These high-power devices will generate a lot of heat while running at high speed. Long-term use will not only affect the accuracy of electronic devices, but also cause damage to the equipment and affect its life. Therefore, it is very necessary to study high-performance thermal management devices with good heat dissipation characteristics. Most of the substrates of thermally conductive plastics come from petrochemical products, which are not easy to degrade after being discarded, which brings serious problems to the...

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Problems solved by technology

[0006] However, the composite film in the above invention has a large number of layers, complex preparation process and difficult mass production; at the same time, because the nanocellulose has a very large specific surface area, and the surface is rich in hydroxyl groups and has strong hydrophilicity, once water droplets adhere to the The surface of the composite material will be severely damaged; on the other hand, strong hydrogen bonding is easily formed between the hydroxyl groups, resulting in the aggregation of nanocellulose, which has poor biocompatibility with the hydrophobic matrix, so the composite film does not have Hydrophobicity, to a large extent, limits the application of the composite film in real life, and it is difficult to meet various needs in the field of electronic devices and biomaterials (with thermal conductivity, insulation, and hydrophobic properties at the same time)

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