Dielectric materials can be used to control/ store charge and electric energy, which has important potential application value for the dielectric energy storage and intelligent sensing in areas such as aerospace, electronics, and military engineering. [1,2] The dielectric materials with high dielectric permittivity (ε 0 ) and low dielectric loss (tanδ) are of great significance to national security defense and economic development. [3][4][5][6] Ceramic-based dielectric materials are widely used in electronic components in communication, military, and other related fields due to their extremely high dielectric permittivity. [7][8][9] However, the complex preparation process, high processing temperature, brittleness, and low breakdown strength of ceramics greatly limit their application range. [10] Polymers are the industrial choice of dielectric materials for charge storage applications mainly because of their high breakdown strength and excellent processability. Nevertheless, it is a great challenge that the pure polymers always have a very low dielectric permittivity. [11][12][13] Therefore, the high dielectric composite materials obtained by integrating high dielectric particles and polymers in a certain physical/chemical way have great application prospects. One common approach is to add ceramic fillers such as barium titanate (BaTiO 3 ), barium strontium titanate (Ba x Sr 1-x TiO 3 ), and calcium copper titanate (CaCu 3 Ti 4 O 12 ) to the polymers to improve their dielectric properties. [14][15][16][17] However, a higher dielectric permittivity usually requires a higher loading of ceramic filler, which affects the machinability and mechanical strength of the composites. Another approach is to add conductive fillers such as Cu, Ag, graphene, and carbon nanotubes (CNTs) to the polymers, which can obtain very high dielectric permittivity at a low conductive filler loading. [18][19][20][21][22][23] Unfortunately, the conductive fillers are prone to agglomerate, resulting in excessive leakage current, which will cause the sharp increase in dielectric loss of the conductive filler/polymer composites. In recent years, researchers have been keen to combine
With the booming development of communication technology and electronic equipment, the leakage of electromagnetic waves causes serious damages to the sensitive electronic equipment and electronic components, resulting in the instability or loss of control of electronic devices in aerospace, weapon equipment, and wearable devices. [1][2][3][4] Moreover, it brings great harm to human blood, immune system, reproductive system, and embryo development. [5][6][7] To ensure the normal operation of electronic equipment and protect human health, it is necessary to use electromagnetic interference (EMI) shielding materials to block electromagnetic waves. To date, metals are the most widely used modern industrial EMI shielding materials because of their high electrical conductivity and outstanding EMI shielding effectiveness (SE). [8,9] However, owing to their high mass density, poor flexibility, inferior corrosion resistance, and difficult processibility, the metal materials cannot meet the miniaturization, lightweight, and integration requirements for electronic and communication equipment. Moreover, the reflected electromagnetic waves on the surface of metals due to poor impedance mismatching cause the secondary pollution problems. [10,11] Recently, the conductive polymer composites (CPCs) with one single or hybrid conductive fillers dispersed in the single-phase or multiphase polymer matrix have taken great attention. [12][13][14] Compared with the traditional metal materials, CPCs show a wide application prospect due to their advantages of low density, [15] excellent corrosion resistance, [16] good chemical stability, [17] easy processing, [18] and low cost. [19] Nevertheless, to obtain the desirable EMI shielding performances, high filling amounts of conductive fillers are usually needed, which is disadvantageous to the mechanical properties and processibility of CPCs due to the agglomeration of conductive fillers. [20,21] Constructing conductive segregated structures is an effective strategy to decrease the conductive percolation threshold and enhances the EMI SE of CPCs. In comparison with the homogeneous structures, the unique segregated structures with conductive fillers selectively distributed at the interfaces between adjacent polymer microregions show high-efficiency continuous 3D conductive networks. This leads to the decreased percolation threshold, significantly improved electrical conductivities and EMI shielding performances. [22][23][24] Yan et al. [25] assembled the reduced graphene oxide (rGO) on polystyrene (PS) particles, and prepared the segregated PS@rGO composites via
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