Nanocellulose‐assisted preparation of electromagnetic interference shielding materials with diversified microstructure

Abstract

Sustainable and renewable nanocellulose attracts more and more attention in various fields due to its high strength‐to‐weight ratio, small diameter, large aspect ratio, and abundant functional groups. The excellent properties and structural characteristics enabled a great potential of nanocellulose for efficient interactions with functional nanomaterials such as carbon nanotube, graphene, transition metal carbides/nitrides (MXenes), and metal nanoparticles, which is beneficial for preparing high‐performance electromagnetic interference (EMI) shields. We review the advances in the nanocellulose‐assisted preparation of composite films and aerogels for EMI shielding application. The nanocellulose‐based composites are evaluated in terms of their EMI shielding performance and the shielding mechanisms, including conduction, polarization, and multiple reflections are summarized. In addition to the constituent structure and contents, we highlight the significance of the microstructure design in enhancing the EMI shielding performance of the nanocellulose‐based EMI shields. Finally, the current challenges and outlook for these fascinating nanocellulose‐based EMI shielding composites are discussed.

Biopolymer‐Based Aerogels for Electromagnetic Wave Shielding and Absorbing

“…Moreover, the proposed biomimetic honeycomb microstructure greatly enhanced the reflection and dissipation of EMWs, which had been illustrated in previous reports. [ 43‐44 ] Finally, this aerogel exhibited remarkable SSE and SSE/ d up to 30660 dB·cm 3 ·g –1 and 189400 dB·cm 2 ·g –1 , respectively.…”

Recent advance in three-dimensional porous carbon materials for electromagnetic wave absorption

“…Traditional biomass materials such as wood, peels, and seeds seem to require a larger filler loading, which may be attributed to the relatively high density. In sharp contrast, emerging biomass- derived carbon materials such as cellulose and silk fibers show significantly lower filler loading, which may become a new trend [160]. However, the microscopic morphology, which depends on the original structure of biomass, is difficult to be customized, making it hard to find the optimal structure for EMW absorp-tion.…”

Stretchable, self‐healable, and breathable biomimetic iontronics with superior humidity‐sensing performance for wireless respiration monitoring

“…To resolve this, degradable, renewable, and nontoxic sustainable biomass is expected to be extensively applied in the construction of environmental‐ and human‐friendly hydrogels, thereby avoiding skin irritation and accelerating the advancement of carbon neutrality 29,30 . Typically, cellulose nanofibers (CNFs) are a ubiquitous natural polymer material extracted from plants, which is undoubtedly available to prepare carbon‐neutral hydrogels with enhanced mechanical properties 31,32 . Then, although the feasibility of hydrogels for the detection of strain, temperature, pressure, and humidity has been demonstrated, 33–36 these hydrogel‐based sensing devices are mainly based on bulk materials with poor flexibility and air permeability, which cannot satisfy the requirements of electronic skin and integrated electronics.…”

“…29,30 Typically, cellulose nanofibers (CNFs) are a ubiquitous natural polymer material extracted from plants, which is undoubtedly available to prepare carbon-neutral hydrogels with enhanced mechanical properties. 31,32 Then, although the feasibility of hydrogels for the detection of strain, temperature, pressure, and humidity has been demonstrated, [33][34][35][36] these hydrogel-based sensing devices are mainly based on bulk materials with poor flexibility and air permeability, which cannot satisfy the requirements of electronic skin and integrated electronics. To this end, the development of hydrogel films with excellent flexibility, air permeability, and transparency is urgently required.…”