Facile preparation of high dielectric flexible films based on titanium dioxide and cellulose nanofibrils

• Published in: Cellulose (London) 2019-07, Vol.26 (10), p.6087-6098
• Main Authors: Tao, Jie, Cao, Shun-an, Liu, Wei, Deng, Yulin
• Format: Article
• Language: English
• Subjects: Bioorganic Chemistry; Cellulose; Ceramics; Chemical industry; Chemistry; Chemistry and Materials Science; Composites; Dielectric loss; Dielectric properties; Dielectric strength; Dynamic mechanical properties; Dynamic stability; Electronics; Glass; Heat treatment; Mechanical properties; Natural Materials; Organic Chemistry; Original Research; Physical Chemistry; Polymer Sciences; Stability analysis; Sustainable Development; Thermal stability; Titanium; Titanium dioxide
• ISSN: 0969-0239; 1572-882X
• DOI: 10.1007/s10570-019-02495-w

A series of high dielectric composite films based on low-cost and eco-friendly titanium dioxide (TiO 2 ) and cellulose nanofibril (CNF) was prepared under a facile condition. The relative dielectric constants (ε r ) and dielectric loss ( tan δ ) were studied as the function of frequency and filler content. The ε r of CNF/TiO 2 composite film was 19.51 (at 1 kHz) with a relatively low dielectric loss. Compared with pure CNF films (ε r  = 6.92 at 1 kHz), the ε r of the composite film was improved about three times with the dielectric loss increased slightly. The effects of TiO 2 addition and hot-press treatment on microstructure, thermal stability, and dynamic mechanical properties of the composite films were also analyzed. It was found that the addition of TiO 2 particles reduces the cellulose–cellulose bonding so generates more pores in the films, which has significant impacts on both dielectric and physical strength properties. Graphical abstract