Preparation and piezoelectric properties of bacterial cellulose/chitosan/barium titanate aerogels

To prepare piezoelectric sensors with good mechanical and piezoelectric properties, BC/CS and BC/CS/BT-OH composite aerogels were fabricated using bacterial cellulose(BC) and chitosan(CS) as the aerogel matrix and hydroxylated barium titanate nanoparticles(BT-OH) as the piezoelectric material via freeze-drying. The surface morpho-logy, chemical structure, mechanical properties, and piezoelectric properties of the composite aerogels were characte-rized by scanning electron microscopy(SEM), Fourier transform infrared spectroscopy(FTIR), X-ray diffraction(XRD), a universal testing machine, and an electrometer. The results showed that the incorporation of BT-OH into the BC/CS composite aerogel rendered the internal structure more porous and the surface microstructure rougher, with BT-OH nanoparticles uniformly distributed throughout the composite. FTIR and XRD analyses confirmed the successful hydroxylation of BT nanoparticles. When the BT-OH mass fraction was 2.0%, the BC/CS/BT-OH composite aerogel exhibited optimal mechanical performance, achieving a compressive stress of 77.69 kPa at 70% strain, which was1.93 times that of the BC/CS composite aerogel under the same strain condition, demonstrating excellent fatigue resistance. The introduction of BT-OH also enhanced the piezoelectric output. At a BT-OH mass fraction of 2.0%, the output voltage and current of the BC/CS/BT-OH aerogel both reached 3.56 times those of the BC/CS composite aerogel.