Cellulose/BaTiO3 nanofiber dielectric films with enhanced energy density by interface modification with poly(dopamine)

A review of cellulose-based catechol-containing functional materials for advanced applications

With the increment in global energy consumption and severe environmental pollution, it is urgently needed to explore green and sustainable materials. Inspired by nature, catechol groups in mussel adhesion proteins have been successively understood and utilized as novel biomimetic materials. In parallel, cellulose presents a wide class of functional materials rating from macro-scale to nano-scale components. The cross-over among both research fields alters the introduction of impressive materials with potential engineering properties, where catechol-containing materials supply a general stage for the functionalization of cellulose or cellulose derivatives. In this review, the role of catechol groups in the modification of cellulose and cellulose derivatives is discussed. A broad variety of advanced applications of cellulose-based catechol-containing materials, including adhesives, hydrogels, aerogels, membranes, textiles, pulp and papermaking, composites, are presented. Furthermore, some critical remaining challenges and opportunities are studied to mount the way toward the rational purpose and applications of cellulose-based catechol-containing materials.

Flexible layered cotton cellulose-based nanofibrous membranes for piezoelectric energy harvesting and self-powered sensing

Cellulose has attracted an increasing attention for piezoelectric energy harvesting. However, the limited piezoelectricity of natural cellulose constraints the applications. Therefore, we demonstrate the development of piezoelectric nanogenerators based on robust, durable layered membranes composed of cotton cellulose interfaced maleic-anhydride-grafted polyvinylidene fluoride (PVDF-g-MA) nanofibers. Exploiting polydopamine@BaTiO₃ (pBT) nanoparticles as interlayer bridges, interlocked layer-layer interfaces that covalently bind component layers are constructed by a facile and scalable approach. As-obtained membranes exhibit significantly improved piezoelectricity with a maximum piezoelectric coefficient of 27.2 pC/N, power density of 1.72 μW/cm², and stability over 8000 cycles. Substantial enhancement in piezoelectricity over pristine cellulose is ascribed to the synergy of components and the localized stress concentration induced by pBT nanoparticles. The self-powered device could also be used to detect human physiological motions in different forms. Such cellulose-based membranes can be up-scaled to fabricate ecofriendly, flexible and durable energy harvesters and self-powered wearable sensors.