Flexible materials with excellent radiation shielding and flexibility are essential to the personal protective equipments (PPEs) for protecting workers from nuclear radiations. However, it is an enormous challenge to obtain the desired materials since high loading filler in polymer nanocomposites usually promotes radiation shielding while restrains its flexibility. Here, a facile “thiol-ene click” means is applied to chemically bond high loading boron nitride (BN) nanoparticles with silicone rubber (SR) in SR/BN nanocomposites for thermal neutron shielding. Uniform dispersion of BN nanoparticles and good compatibility of interfaces in the nanocomposites with high loading filler lead to increased flexibility instead of decrease. In particular, the nanocomposite with 40 wt% BN displays 911% of elongation at break that is about 50% enhancement to that of neat SR. Furthermore, higher loading BN in the nanocomposites means better thermal neutron shielding. Namely, enhanced thermal neutron shielding and flexibility is achieved at SR/BN nanocomposite with 40 wt% BN. The present work provides a facile strategy towards superior integrated performance of flexible materials for radiation shielding, such as wearable devices.
Shanshan Chen,Zhijian Li,Jizhen Huang,Lizheng Sha,Zhaoqing Lu
The growing high demand for electronic sensors with both wearability and multi-functional integration has attracted tremendous attention in the field of flexible electronic devices like artificial intelligence and human–computer interaction. The nanocomposites with the Janus structure are being developed into the new generation sensor applied in flexible wearable electronic devices. Herein, boron nitride nanosheets (BNNS) and carbon nanotubes (CNT) were introduced to the aramid nanofibers (ANF) matrix and prepared to gels, respectively. The (B/A)-(C/A) (BNNS/ANF-CNT/ANF) Janus film that contains BNNS/ANF layer and CNT/ANF layer was further fabricated via a vacuum-assisted filtration method. A robust and steady interfacial adhesion was achieved based on a unique gel-gel assembling. It was found that the mechanical, conductive and thermal management properties of the entire Janus film were affected by the synergies between BNNS and CNT with different content combinations. The (30B/A)-(40C/A) Janus film (30 wt% BNNS and 40 wt% CNT) integrated the properties of high mechanical strength (86.8 MPa), electrical insulation (88.6 kV/m), conductive (221.4 S·m −1 ) and good through-plane thermal transmission (0.42 W/(m·K)) was used as a sensor for motion monitoring, showing good stability and reliability (1000 cycles). Additionally, the Janus film exhibited good Joule heating performance. Overall, the prepared (B/A)-(C/A) Janus film showed promising prospects in lightweight, flexible and multifunctional electronics.
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