Ultrathin Biomimetic Polymeric Ti₃C₂T_x MXene Composite Films for Electromagnetic Interference Shielding

Abstract

Lightweight, ultrathin, and flexible electromagnetic interference (EMI) shielding materials with high electromagnetic shielding effectiveness (SE) and excellent mechanical robustness are greatly desired for miniaturized and highly integrated electronics. Herein, for the first time, a freestanding, ultrathin, and flexible Ti3C2T x /poly­(3,4-ethylenedioxythiophene)–poly­(styrenesulfonate) (PEDOT:PSS) composite film with a “brick-and-mortar” structure is biomimetically designed and fabricated via a vacuum-assisted filtration process. The ultrathin polymeric composite film with a weight ratio 7:1 of Ti3C2T x to PEDOT:PSS is only 11.1 μm in thickness but exhibits a high EMI SE value of 42.10 dB. Meanwhile, the tensile strength increases considerably from 5.62 to 13.71 MPa and the corresponding ruptured strain increases from 0.18 to 0.29% compared with pure Ti3C2T x MXene film, respectively. Moreover, the hybrid film displays a superior conductivity of 340.5 S/cm and an outstanding specific EMI shielding efficiency of 19 497.8 dB cm2 g–1. The superior electrical conductivity and specific EMI shielding efficiency imply the excellent potential of the Ti3C2T x /PEDOT:PSS composite films for ultrathin, lightweight, and flexible EMI shielding materials.

MXene interlayered crosslinked conducting polymer film for highly specific absorption and electromagnetic interference shielding

“…The C-O stretching is observed near 1259 cm À1 . 19 The sulfonate SQO stretching resonances can be seen between 1300 cm À1 and 1500 cm À1 . 20 The peak at 1536 cm À1 corresponds to the aromatic CQC stretching in PEDOT:PSS.…”

“…The Ti 3 C 2 T x MXene peak at around 475 cm À1 corresponds to the C-Cl stretching and the peak at 585 cm À1 corresponds to the Ti-O bond. 19 The peak at around 709 cm À1 could be assigned to C-H bonds. The C-O stretching is observed near 1259 cm À1 .…”

“…1 In addition, the SE value also intrinsically depends on the EMI shield's structureproperty relationship. [15][16][17][18][19] When an incident electromagnetic wave (EMW) strikes the crosslinked PEDOT:PSS-MXene nanocomposite, three phenomena occur, viz. immediate absorption, reflection and multiple internal reflections.…”

“…An EMI SE of B40 dB was reported for the PEDOT:PSS-Ti 3 C 2 T x MXene film (10 mm) in the X-band (8.2-12.4 GHz). 19 However, PEDOT:PSS stand-alone thin films exhibit high moisture sensitivity and thus are not suitable for real time EMI shielding applications. Recently, Mantione et al reported a crosslinking method to make moisture resistant PEDOT:PSS free-standing films.…”

“…films for EMI shielding have been studied. 19 However, crosslinked conducting polymer (PEDOT:PSS) films possess some extraordinary properties, such as better conductivity and better mechanical strength, and most importantly they change from hydrophilic to hydrophobic. 20 To the best of our knowledge, the electromagnetic properties of MXene interlayered crosslinked PEDOT:PSS films have not been investigated before.…”