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Enhanced Electromechanical Properties of Three‐Phased Polydimethylsiloxane Nanocomposites via Surface Encapsulation of Barium Titanate and Multiwalled Carbon Nanotube with Polydopamine
Author(s) -
Cai Cheng,
Chen Tao,
Chen Xian,
Zhang Yanting,
Gong Xinghou,
Wu Chonggang,
Hu Tao
Publication year - 2021
Publication title -
macromolecular materials and engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.913
H-Index - 96
eISSN - 1439-2054
pISSN - 1438-7492
DOI - 10.1002/mame.202100046
Subject(s) - materials science , composite material , nanocomposite , polydimethylsiloxane , barium titanate , nanotube , dielectric loss , dielectric , carbon nanotube , ceramic , optoelectronics
Owing to its low modulus, high breakdown strength, and low dielectric loss, polydimethylsiloxane (PDMS) is used as a great dielectric elastomer despite its low dielectric permittivity. Herein, polydopamine (PDA) is used to encapsulate barium titanate (BT) and multiwalled carbon nanotube (MWCNT) in situ during its polymerization to prepare core–shell structured fillers, which are then solution‐compounded with PDMS, and subsequently vulcanized with a cross‐linking agent. The resulting three‐phased nanocomposites exhibit improved filler‐PDMS interactions upon filler PDA‐encapsulation likely due to interfacial hydrogen bonding, thereby to enhance filler dispersion within the PDMS matrix. Compared with the unencapsulated PDMS nanocomposites, a softening effect (i.e., decreased cross‐linking) by the finer filler‐dispersion, in the context of a hardening effect by filler network formation, strengthens in the PDA‐modified nanocomposites to produce their lower moduli. Additionally, the insulating, interfacial PDA partially inhibits the formation of conductive paths and leakage currents, causing decreased dielectric loss while increased breakdown strength of the nanocomposites. Therefore, the PDA‐encapsulated BT and MWCNT filled PDMS nanocomposites display excellent electromechanical properties with a largest possible actuated strain of 7.0% at a breakdown strength of 13.9 kV mm −1 , which is 1.8 times that (3.9%@15.0 kV mm −1 ) of their unencapsulated counterparts and 4.7 times that (1.5%@18.4 kV mm −1 ) of unfilled, neat PDMS.