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Modification is mostly used to adjust and increase the performance of polymers by employing organic or inorganic fillers in composites. It is significant to investigate the functions of different fillers in polymer matrix. In this work, we prepared a series of composites by using polyurethane/acrylic dispersions as polymer matrix and nanofillers (cellulose nanocrystals, carbon nanotubes and aluminum oxide nanoparticles) as modifiers to study their micro-structure and applied performance. It is found that the different nanofillers can be dispersed in PUA homogenously, which are inclusive physically. Different nanofillers have a noticeable influence on the T g for the acrylate copolymers and the T g of the interphase between the acrylate and polyurethane. The CNTs significantly increases the elongation to 127.29%, and gives the highest dielectric response. We imply that the CNTs may be the most significant fillers to increase the mechanical and electrical properties.

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With the advantages of large piezoelectric constant, wide frequency response range and good flexibility, Poly(vinylidine fluoride) (PVDF) is receiving heightened attention as a promising alternative to traditional piezoelectric materials. This paper focuses on investigating the magnetoelectric effect of a three-layer composite consisting of a core layer of PVDF and two layers of silver-plated electrodes under the action of AC and DC magnetic fields. The resonance frequency of the measurement system is firstly determined to obtain the maximum magnetoelectric response. Then, the existence of magnetoelectric effect in the laminated sample is further verified, which is realized through the coupling of the piezoelectric effect and the Ampere forces caused by the eddy current under the DC bias magnetic field. The experimental results show that the magnetoelectric voltage has an excellent linear response to both AC and DC magnetic fields. The magnetoelectric voltage coefficient is obtained as 299.97 mV/cm•Oe at the resonance frequency under the DC magnetic field of 1000 Oe amplitude. Besides, the theoretical model of the magnetoelectric energy conversion is established, which matches well with the experimental results. Consequently, both AC and DC magnetic field sensing can be realized by observing the magnetoelectric voltage. Without requiring a magnetostrictive phase and power supply, the three-layer composite with a considerable magnetoelectric effect is promising for the application of online monitoring sensors used in the smart grid.

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