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Out‐of‐plane polarization is a highly desired property of two‐dimensional (2D) ferroelectrics for application in vertical sandwich‐type photoferroelectric devices, especially in ultrathin ferroelectronic devices. Nevertheless, despite great advances that have been made in recent years, out‐of‐plane polarization remains unrealized in the 2D hybrid double perovskite ferroelectric family. Here, from our previous work 2D hybrid double perovskite HQERN ((S3HQ)4EuRb(NO3)8, S3HQ=S‐3‐hydroxylquinuclidinium), we designed a molecular strategy of F‐substitution on organic component to successfully obtain FQERN ((S3FQ)4EuRb(NO3)8, S3FQ=S‐3‐fluoroquinuclidinium) showing circularly polarized luminescence (CPL) response. Remarkably, compared to the monopolar axis ferroelectric HQERN, FQERN not only shows multiferroicity with the coexistence of multipolar axis ferroelectricity and ferroelasticity but also realizes out‐of‐plane ferroelectric polarization and a dramatic enhancement of Curie temperature of 94 K. This is mainly due to the introduction of F‐substituted organic cations, which leads to a change in orientation and a reduction in crystal lattice void occupancy. Our study demonstrates that F‐substitution is an efficient strategy to realize and optimize ferroelectric functional characteristics, giving more possibility of 2D ferroelectric materials for applications in micro‐nano optoelectronic devices. [ABSTRACT FROM AUTHOR]

Wide-line solid-state proton nuclear magnetic resonance (1H NMR) spectrometry is a classical technique to study the phase structures of semi-crystalline polymers. In this paper, the wide-line solid-state 1H NMR spectrum of semi-crystalline polyethylene was acquired, and fitted with the combination of Gaussian/Sinc, Gaussian and Lorentzian functions. The four signal components decomposed from the wide-line solid-state 1H NMR spectra were assigned to the crystallization phase, crystalline interface phase, amorphous interface phase and amorphous phase, respectively. The chain dynamics in different phase was also studied with the temperature-dependent wide-line solid-state 1H NMR method. The difficulties in determining the crystallinity of semi-crystalline polymers with wide-line solid-state 1H NMR were discussed.

All solid state lithium-ion batteries have the advantages of high safety, long cycle life and high energy density, as compared with the conventional lithium-ion batteries, and have been attracting more and more research interest. Solid electrolyte is a crucial component of all solid state lithium-ion batteries, which largely determine the performance of the batteries. In this work, a polymer-lithium-ceramics complex was designed and synthesized. The structure and dynamics of the polymer-ceramic interface was studied with solid-state NMR techniques.

Hyperbranched polyethylenimine terminated with isobutyramide groups (HPEI-IBAm), 4-(phenylazo)benzoic acid (PABA), and α-cyclodextrin (α-CD) were assembled together at pH≈7 to form the three-component supramolecular complexes that were verified by (1) H and 2D ROESY (1) H NMR spectroscopy. UV/Vis spectrometric titration experiments showed that the content of α-CD in the three-component complexes was less than the feed amount and it was difficult for all the PABA units in the complexes to further form complexes with α-CD. The obtained three-component supramolecular complexes exhibited thermoresponsive properties in water. Increasing the α-CD concentration led to a sharp increase in the cloud point temperature (Tcp ) at the beginning, but after the [α-CD]/[PABA] ratio was in the region of 1.3-1.6, the Tcp increased gradually When the concentration of α-CD was low, a higher concentration of PABA led to a lower Tcp , however, the opposite was observed when the concentration of α-CD was high. For the three-component complex, increasing the α-CD concentration at pH≈7 or at pH≈9 led to different Tcp temperatures. In the low α-CD concentration range, adjusting the pH from ≈7-≈9 resulted in an increase in the Tcp , similar but not so pronounced as that of the two-component system of HPEI-IBAm/[PABA]. When the concentration of α-CD was high, adjusting the pH from ≈7-≈9 decreased the Tcp ; this observation is different to that of the two-component system of HPEI-IBAm/[PABA]. Reversible trans-to-cis photoisomerization of azobenzene units in the complexes occurred, following irradiation with UV or visible light. Trans-to-cis isomerization of azobenzene units decreased the Tcp . However, this result differed to that of the two-component system of HPEI-IBAm/PABA., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Highly conductive, crystalline, polymer electrolytes, β-cyclodextrin (β-CD)-polyethylene oxide (PEO)/LiAsF6 and β-CD-PEO/NaAsF6 , were prepared through supramolecular self-assembly of PEO, β-CD, and LiAsF6 /NaAsF6 . The assembled β-CDs form nanochannels in which the PEO/X(+) (X=Li, Na) complexes are confined. The nanochannels provide a pathway for directional motion of the alkali metal ions and, at the same time, separate the cations and the anions by size exclusion., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)