Dielectric elastomers(DEs)have drawn much attention owing to their application prospects in artificial muscles and soft robotics,it is still a big challenge to prepare DEs with high electromechanical performances.This...Dielectric elastomers(DEs)have drawn much attention owing to their application prospects in artificial muscles and soft robotics,it is still a big challenge to prepare DEs with high electromechanical performances.This work reports a highly stretchable poly(thioether)-b-polysiloxane-b-poly(thioether)triblock copolymer based homogenous DEs with high electromechanical properties.The triblock copolymer(PSiPGE)was synthesized through the ring-opening polymerization(ROP)of phenyl glycidyl ether(PGE)and carbonyl sulfide(COS)catalyzed by silicon alkoxides.The dipoles(benzene rings)on the side groups of PSiPGE improved the dipole polarizations and the phase separation structure of this triblock copolymer enhanced the interfacial polarizations between poly(thioether)and polysiloxane,and thus improving the dielectric constant(ε',up to 5.8).In addition,the PSiPGE exhibited low elastic modulus(Y,0.04 MPa),and thus possessed high electromechanical sensitivity(β,~145 MPa^(-1)) which is much higher than that of most homogenous DEs.This work provides a new strategy to construct homogenous DEs with excellent electromechanical performances,leading to a greater application aspect in the actuated devices.展开更多
We conducted a study on Mn doping in 67Pb(Mg_(1/3)Nb_(2/3))O_(3)-33PbTiO_(3)(67PMN-33PT),which is a ferroelectric material exhibiting a morphotropic phase boundary(MPB).The samples were doped with MnO_^(2) at mass rat...We conducted a study on Mn doping in 67Pb(Mg_(1/3)Nb_(2/3))O_(3)-33PbTiO_(3)(67PMN-33PT),which is a ferroelectric material exhibiting a morphotropic phase boundary(MPB).The samples were doped with MnO_^(2) at mass ratios ranging from 0.5 to 5.0 wt.%and subsequently sintered at temperatures ranging from 1200 to 1260℃.Experimental analysis of electrical properties was performed within the temperature range of-80-200℃.Electron paramagnetic resonance(EPR)testing was conducted on these samples to investigate Mn solubility in PMN-PT ceramics and their existence in different valence states.The results indicate that at a doping ratio of 0.5 wt.%and sintering temperature of 1220-1240℃,Mn ions achieved a homogeneous dispersion within the crystal lattice,leading to the enhanced electromechanical Q_(m) factor(510)and the reduced dielectric loss tan to minimum(0.30%)compared to the no doping Mn,however,as the Mn ions dopant content increase higher than 1.0 wt.%and sintering temperatures 1200-1260°,the unexpected results have been observed that both Q_(m) and tan 8 are enhanced to about 1200,0.87 up to 1.5 wt.%MnO_^(2),and then,Q_(m) decreases to 510,but tan increases to 3.78% for 5 wt.%MnO_^(2).The machinal Q_(m) and dielectric loss can be understood by the(Mn-Vo)defect dipoles in lattice,domain wall and grain-bounary,together with the increasing of the MnO_^(2),Mn_(2)O_(3) or their mixed phase of Mn_(3)O_(4) in the grain boundary.展开更多
基金National Natural Science Foundation of China(Nos.51973190 and 21774108)Zhejiang Provincial Department of Science and Technology(No.2020R52006)for financial supports。
文摘Dielectric elastomers(DEs)have drawn much attention owing to their application prospects in artificial muscles and soft robotics,it is still a big challenge to prepare DEs with high electromechanical performances.This work reports a highly stretchable poly(thioether)-b-polysiloxane-b-poly(thioether)triblock copolymer based homogenous DEs with high electromechanical properties.The triblock copolymer(PSiPGE)was synthesized through the ring-opening polymerization(ROP)of phenyl glycidyl ether(PGE)and carbonyl sulfide(COS)catalyzed by silicon alkoxides.The dipoles(benzene rings)on the side groups of PSiPGE improved the dipole polarizations and the phase separation structure of this triblock copolymer enhanced the interfacial polarizations between poly(thioether)and polysiloxane,and thus improving the dielectric constant(ε',up to 5.8).In addition,the PSiPGE exhibited low elastic modulus(Y,0.04 MPa),and thus possessed high electromechanical sensitivity(β,~145 MPa^(-1)) which is much higher than that of most homogenous DEs.This work provides a new strategy to construct homogenous DEs with excellent electromechanical performances,leading to a greater application aspect in the actuated devices.
基金supported by the Natural Science Foundation of China(No.U2241242)the National Key Research and Development Program of China(No.2023YFB3812000)+1 种基金the National Key R&D Program of China(No.2021Y FA0716502)Shanghai"Super Postdoctoral"Incentive Plan,National Postdoctoral Fellowship Program(GZC20232826).
文摘We conducted a study on Mn doping in 67Pb(Mg_(1/3)Nb_(2/3))O_(3)-33PbTiO_(3)(67PMN-33PT),which is a ferroelectric material exhibiting a morphotropic phase boundary(MPB).The samples were doped with MnO_^(2) at mass ratios ranging from 0.5 to 5.0 wt.%and subsequently sintered at temperatures ranging from 1200 to 1260℃.Experimental analysis of electrical properties was performed within the temperature range of-80-200℃.Electron paramagnetic resonance(EPR)testing was conducted on these samples to investigate Mn solubility in PMN-PT ceramics and their existence in different valence states.The results indicate that at a doping ratio of 0.5 wt.%and sintering temperature of 1220-1240℃,Mn ions achieved a homogeneous dispersion within the crystal lattice,leading to the enhanced electromechanical Q_(m) factor(510)and the reduced dielectric loss tan to minimum(0.30%)compared to the no doping Mn,however,as the Mn ions dopant content increase higher than 1.0 wt.%and sintering temperatures 1200-1260°,the unexpected results have been observed that both Q_(m) and tan 8 are enhanced to about 1200,0.87 up to 1.5 wt.%MnO_^(2),and then,Q_(m) decreases to 510,but tan increases to 3.78% for 5 wt.%MnO_^(2).The machinal Q_(m) and dielectric loss can be understood by the(Mn-Vo)defect dipoles in lattice,domain wall and grain-bounary,together with the increasing of the MnO_^(2),Mn_(2)O_(3) or their mixed phase of Mn_(3)O_(4) in the grain boundary.
