Cellulose nanofibrils-based hybrid foam generated from Pickering emulsion toward high-performance microwave absorption. (1st March 2021)

• Record Type: Journal Article
• Authors: He, Yingying; Li, Shuai; Zhou, Li; Wei, Chun; Yu, Chuanbai; Chen, Yunhua; Liu, Hongxia
• Is Part Of: Carbohydrate polymers. Volume 255(2021)
• Publication Date: 2021-03-01
• Subjects: Pickering emulsion -- Cellulose nanofibrils -- Magnetic foam -- Microwave absorption -- Photo-thermal conversion -- Multifunction; Polysaccharides -- Periodicals; Polysaccharides -- Periodicals; Polysaccharides -- Périodiques; Electronic journals; 547.78
• DOI: 10.1016/j.carbpol.2020.117333
• Languages: English
• ISSNs: 0144-8617

Abstract

Graphical abstract: In this study, a multifunctional hybrid foam was facilely fabricated through Pickering emulsion gelation technology combined with the freeze-drying. In the obtained CNF/CNT/PLA/Fe3O4 foam, cellulose nanofibrils (CNF) and polylactic acid (PLA) form the three-dimensional (3D) skeleton, on which carbon nanotubes (CNT) and Fe3O4 nanoparticles were homogeneously attached, interconnecting into a conductive network with multiple hetero-interfaces. The optimal CNF/CNT/PLA/Fe3O4 foam exhibits excellent microwave absorption performances with the optimal reflection loss value reaching to −65.14 dB at 8.2 GHz at a thickness of 3 mm, and the effective bandwidth of 3.4 GHz (10.8 − 14.2 GHz) for the thickness of 2.0 mm. It benefits from the synergistic effect between Fe3O4 nanoparticles with magnetic loss, CNT with dielectric loss, and interfacial polarization raised from the hetero-interfaces in the foam. Specially, the obtained foam possesses multifunction, such as excellent thermal insulation and photo-thermal conversion. Highlights: A facile preparation for multifunctional foam was realized by Pickering emulsion. The conductive network of CNT and multiple hetero-interfaces endow the foam special property. The foam exhibits prominent microwave absorption property with reflection loss of −65.14 dB. The foam possesses remarkable photo-thermal conversion and thermal insulation performance. Abstract: The development of multifunctional microwave absorbers that worked in complex environments remains challenging. In this study, oil-in-water Pickering emulsion gelation approach was combined with freeze-drying to prepare foam-based microwave absorbers along with appealing photo-thermal conversion and thermal insulation. In hybrid foam, cellulose nanofibrils (CNF) and polylactic acid (PLA) serve as three-dimensional skeleton, where carbon nanotubes (CNT) and Fe3 O4 nanoparticles are homogeneously incorporated, which forms a conductive network with hetero-interfaces. The optimal reflection loss value of the foam reaches −65.14 dB with a thickness of 3.0 mm. The foam also demonstrate high photo-thermal conversion performance with its surface temperature up to 97 °C after irradiation under 1 Sun for 5 min. Additionally, the foam shows superior thermal insulation comparing with the commercial polyvinyl alcohol and polyurethane foams. This study may offer a promising approach to develop ultralight and high-performance microwave absorber with great potential for multifunctional applications.