Designing Advanced Electrolytes for High-Safety and Long-Lifetime Sodium-Ion Batteries via Anion-Cation Interaction Modulation.

Safety hazards caused by flammable electrolytes have been major obstacles to the practical application of sodium-ion batteries (SIBs). The adoption of nonflammable all-phosphate electrolytes can effectively improve the safety of SIBs; however, traditional low-concentration phosphate electrolytes are not compatible with carbon-based anodes. Herein, we report an anion-cation interaction modulation strategy to design low-concentration phosphate electrolytes with superior physicochemical properties.

Distinctly different solvation behaviors of poly(,-diethylacrylamide) gels in water/acetone and water/DMSO mixtures.

The solvation behaviors and intermolecular interactions of a poly(,-diethylacrylamide) (PDEA) gel network in water/DMSO and water/acetone mixtures have been investigated by variable-temperature high-resolution H MAS NMR. Unlike decreasing volume phase transition temperature (VPTT) of the typical thermosensitive poly(-isopropylacrylamide) (PNIPAM) gel induced by both acetone and DMSO in a water-rich region, distinct phase transition behaviors are revealed for the PDEA gel. That is, acetone is found to increase the VPTT of PDEA directly in the water-rich region while DMSO is also found to increase the VPTT of PDEA at a very low concentration but then decrease the VPTT as the concentration further increases.

Preparation and characterization of curdlan with unique single-helical conformation and its assembly with Congo Red.

Elucidating the structure-activity relationship of curdlan is hampered by a lack of characterization with unique specific conformations (i.e., single- or triple-helix).

Dynamic mechanism of halide salts on the phase transition of protein models, poly(N-isopropylacrylamide) and poly(N,N-diethylacrylamide).

The effects of salts on protein systems are not yet fully understood. We investigated the ionic dynamics of three halide salts (NaI, NaBr, and NaCl) with two protein models, namely poly(N-isopropylacrylamide) (PNIPAM) and poly(N,N-diethylacrylamide) (PDEA), using multinuclear NMR, dispersion corrected density functional theory (DFT-D) calculations and dynamic light scattering (DLS) methods. The variation in ionic line-widths and chemical shifts induced by the polymers clearly illustrates that anions rather than cations interact directly with the polymers.

Inverse solubility of chitin/chitosan in aqueous alkali solvents at low temperature.

The low-temperature dissolving mechanism of chitin/chitosan in the alkali (LiOH, NaOH and KOH) aqueous solvents has not been well established yet. As revealed by our XRD and NMR methods, the prepared deacetylated chitins can be categorized as chitin (DA = 0.94-0.

Preferential adsorption of the additive is not a prerequisite for cononsolvency in water-rich mixtures.

Cononsolvency of poly(N-isopropylacrylamide) (PNIPAM) gels in binary mixed solvents (water-acetone and water-DMSO) has been comparatively investigated by H HR-MAS NMR spectroscopy. The results demonstrate that, although the addition of both acetone and DMSO gives rise to cononsolvency behavior, PNIPAM preferentially interacts with acetone rather than DMSO in a water-rich regime, regardless of whether the temperature is above or below the volume phase transition temperature (VPTT). It suggests that the preferential adsorption of the additive cannot be deemed as a prerequisite for the cononsolvency in water-rich mixtures.

Inhomogeneous-collapse driven micelle-vesicle transition of amphiphilic block copolymers.

Understanding the morphological transition dynamics related to the hydrophilic-hydrophobic interface has been a challenge due to the lack of an effective evaluation method. Herein, nuclear magnetic resonance spectroscopy was employed to study the morphological transition related chain collapse of poly(N,N'-diethylaminoethylmethacrylate)-b-poly(N-isopropylacrylamide) (PDEAEMA-b-PNIPA) and poly(N,N'-dimethylaminoethylmethacrylate)-b-poly(N-isopropylacrylamide) (PDMAEMA-b-PNIPA) and was proved to be a powerful technique in morphological transition mechanism studies once combined with dynamic light scattering and transmission electron microscopy. Unlike the cooperative coil collapse of two blocks in the PDMAEMA-b-PNIPA alkaline solution upon heating which induces the assembly of a nanostructure (∼200 nm) with a hydrophobic core containing both collapsed PDMAEMA and PNIPA segments and a hydrophilic surface part consisting of un-shrunk PDMAEMA and PNIPA segments, PDEAEMA-b-PNIPA with a low-temperature core-shell micelle structure showed a micelle-vesicle transition due to temperature-induced inhomogeneous-collapse of PNIPA.