Ferroelectric polymers based on poly(vinylidene fluoride) (PVDF) and its copolymers are good candidates for electric energy storage because of their relatively high permittivity (10-20) and high dc breakdown strength. However, the hysteresis loss for PVDF and its copolymers is too high due to their normal ferroelectricity. To realize low hysteresis for PVDF copolymers during electric polarization, either relaxor/paraelectric (single narrow loop) or antiferroelectric (double hysteresis loop) behaviors are highly desired. In this year, we continued the ferroelectric characterization of orientation and temperature dependent double hysteresis behavior in P(VDF-TrFE-CTFE)-g-PS graft copolymers. From the top panel of Fig. 1, linear dielectric behavior is observed for the nonoriented film. Double hysteresis loops gradually develop with increasing the crystal orientation. This is attributed to enhanced dipole switching in the crystals with increasing crystal orientation. From the bottom panel of Fig. 1, double hysteresis loops persist until 75 °C, above which Nanoconfined Polymer Ferroelectricity Lei Zhu, Case Western Reserve University, DMR 0907580 -15 0 -10 0 -5 0 0 50 100 150 -3 0 -2 0 -1 0 0 10 20 30 D (m C/m 2 ) E (M V/m ) -150 -100 -5 0 0 50 100 150 -30 -20 -10 0 10 20 30 D (m C/m 2 ) E (M V/m ) -1 50 -1 00 -5 0 0 50 100 150 -3 0 -2 0 -1 0 0 10 20 30 D (m C/m 2 ) E (M V/m ) -1 50 -10 0 -50 0 50 100 150 -3 0 -2 0 -1 0 0 10 20 30 D (m C/m 2 ) E (M V/m ) D C B A f=0.0 f=0.54 f=0.62 f=0.72 -300 -20 0 -1 00 0 100 200 300 -6 0 -4 0 -2 0 0 20 40 60 D (m C/m 2 ) E (M V/m ) -300 -2 00 -100 0 100 200 300 -6 0 -4 0 -2 0 0 20 40 60 D (m C/m 2 ) E (M V/m ) -3 00 -20 0 -10 0 0 100 200 300 -6 0 -4 0 -2 0 0 20 40 60 D (m C/m 2 ) E (M V/m ) -30 0 -20 0 -100 0 100 200 300 -6 0 -4 0 -2 0 0 20 40 60 D (m C/m 2 ) E (M V/m ) -300 -200 -10 0 0 100 200 300 -6 0 -4 0 -2 0 0 20 40 60 D (m C/m 2 ) E (M V/m ) -3 00 -200 -100 0 100 200 300 -60 -40 -20 0 20 40 60 D (m C/m 2 ) E (M V/m ) -30 0 -20 0 -10 0 0 100 200 300 -60 -40 -20 0 20 40 60 D (m C/m 2 ) E (M V/m ) A B C D E F G -40°C 0°C 25°C 50°C 75°C 100°C 125°C -15 0 -1 00 -5 0 0 50 100 150 -30 -20 -10 0 10 20 30 D (m C/m 2 ) E (M V/m ) 1stcycle 2nd cycle 3rd cycle 5th cycle 10th cycle 20th cycle 50th cycle 100th cycle 200th cycle 300th cycle H Fig. 1. (top panel) D-E hysteresis loops for the P(VDF-TrFE-CTFE)-g-PS(14%) graft copolymer with different draw ratios; from A to D, 100%, 200%, 280%, and 450%, respectively. (bottom panel) D-E hysteresis loops for the P(VDF-TrFE-CTFE)-g-PS(14%) graft copolymer (A-G) under different temperatures and (H) continuous poling for 300 cycles at room temperature.