Synergistic“Anchor‑Capture”Enabled by Amino and Carboxyl for Constructing Robust Interface of Zn Anode

While the rechargeable aqueous zinc-ion batteries(AZIBs)have been recognized as one of the most viable batteries for scale-up application,the instability on Zn anode–electrolyte interface bottleneck the further development dramatically.Herein,we utilize the amino acid glycine(Gly)as an electrolyte additive to stabilize the Zn anode–electrolyte interface.The unique interfacial chemistry is facilitated by the synergistic“anchor-capture”effect of polar groups in Gly molecule,manifested by simultaneously coupling the amino to anchor on the surface of Zn anode and the carboxyl to capture Zn^(2+)in the local region.As such,this robust anode–electrolyte interface inhibits the disordered migration of Zn^(2+),and effectively suppresses both side reactions and dendrite growth.The reversibility of Zn anode achieves a significant improvement with an average Coulombic efficiency of 99.22%at 1 mA cm^(−2)and 0.5 mAh cm^(−2)over 500 cycles.Even at a high Zn utilization rate(depth of discharge,DODZn)of 68%,a steady cycle life up to 200 h is obtained for ultrathin Zn foils(20μm).The superior rate capability and long-term cycle stability of Zn–MnO_(2)full cells further prove the effectiveness of Gly in stabilizing Zn anode.This work sheds light on additive designing from the specific roles of polar groups for AZIBs.

A functional gel polymer electrolyte based on PVDF-HFP/gelatin toward dendrite-free lithium metal batteries

The leakage of liquid electrolyte and the formation of lithium dendrites pose challenges to safety and stability of lithium metal batteries(LMBs).The appearance of gel polymer electrolyte(GPE)has obviously improved the safety of traditional LMBs.However,the limited inhibition of GPE on lithium dendrites is detrimental to the safety of LMBs.Herein,a kind of poly(vinylidene fluoride-co-hexafluoropropylene)(PVDF-HFP)/gelatin(GN)GPE with high ionic conductivity,high-temperature resistance,and flame-retardancy,was prepared by electrospinning and soaking method.Utilizing the electrospinning network of PVDF-HFP,its affinity to liquid electrolytes,makes this GPE more beneficial to ions transport and the formation of gel.And,the GN with sol–gel properties,enhances the mechanical property(13.5 MPa)of HFP-GN GPE.Meanwhile,X-ray photoelectron spectroscopy(XPS)and density functional theory(DFT)suggest that the attraction of polar groups of GN to Li+can regulate the distribution of Li+and protect Li anodes.Consequently,the application of HFP-GN GPEs to LMBs with cathodes of LiFePO_(4) and LiCoO_(2) deliver excellent electrochemical performances:after 300 cycles,the LiFePO_(4)/HFP-GN GPE/Li battery keeps a low capacity decay rate of 0.09%at 5 C;after 400 cycles at 2 C,the LiCoO_(2)/HFP-GN GPE/Li cell retains a high capacity retention of 74%.This GPE is demonstrated for the application prospect of safe LMBs.

Mechanistic insights of the controlled release capacity of polar functional group in transdermal drug delivery system:the relationship of hydrogen bonding strength and controlled release capacity

Background:Hydrogen bonding interaction was considered to play a critical role in controlling drug release from transdermal patch.However,the quantitative evaluation of hydrogen bonding strength between drug and polar functional group was rarely reported,and the relationship between hydrogen bonding strength and controlled release capacity of pressure sensitive adhesive(PSA)was not well understood.The present study shed light on this relationship.Methods:Acrylate PSAs with amide group were synthesized by a free radical-initiated solution polymerization.Six drugs,i.e.,etodolac,ketoprofen,gemfibrozil,zolmitriptan,propranolol and lidocaine,were selected as model drugs.In vitro drug release and skin permeation experiments and in vivo pharmacokinetic experiment were performed.Partial correlation analysis,fourier-transform infrared spectroscopy and molecular simulation were conducted to provide molecular details of drug-PSA interactions.Mechanical test,rheology study,and modulated differential scanning calorimetry study were performed to scrutinize the free volume and molecular mobility of PSAs.Results:Release rate of all six drugs from amide PSAs decreased with the increase of amide group concentrations;however,only zolmitriptan and propranolol showed decreased skin permeation rate.It was found that drug release was controlled by amide group through hydrogen bonding,and controlled release extent was positively correlated with hydrogen bonding strength.Conclusion:From these results,we concluded that drugs with strong hydrogen bond forming ability and high skin permeation were suitable to use amide PSAs to regulate their release rate from patch.

Air-Stable Dy(III)-Macrocycle Enantiomers:From Chiral to Polar Space Group

Magnetoelectric(ME)multiferroic materials have unique advantages in low-power and high-density information storage,because they can simultaneously display ferroelectricity and ferromagnetism.However,research on how to construct air-stable highperformance ME single-molecule magnets(SMMs)is nonexistent.Herein,by introducing homochirality while reducing molecular symmetry,two doubledecker Dy(III)enantiomers adopting the polar space group P2_(1) and exhibiting excellent thermal stability were obtained.They displayed zero field SMM behavior with an anisotropy barrier(Ueff)of ca.100 cm^(−1).This work establishes a rational chemical design strategy for crystallizing SMMs in polar space groups and elucidates the direction for future research,that is,engineering small-size high-performance SMMs.

Computer simulation of shearing deformation in polymer systems with polar groups

In this work,shear strain modeling in materials consisting of a thin polymer layer(~15 nm),adhesive bonded to a rigid substrate,considered not to be impacted by deformation,was performed.A discrete-continuum model of chains system with a given stiffness with polar groups is developed.The polymer chain was considered in the framework of the persistene model,and the polar groups were based on the lattice model on the tetragonal lattice.It was assumed that the main contribution to the energy of interchain interactions is due to the potential of the polar groups and was calculated using the Metropolis algorithm.The potential interactions between the nearest polar groups of chains included the energy of dipole–dipole interactions(Keesom energy)and the Lennard–Jones potential.It is taken into account that the possible orientations of the polar groups are determined by the average elongation of the chain.Calculations showed that the dependence of free energy on the interchain distance has two minima.The first minimum is characterized by the orientational ordering of the polar groups,the second—by their disordered state.The depth and position of the minima depend on temperature,bending stiffness of the chain,the modulus of the dipole moment of the polar groups and the depth of the potential well in the Lennard–Jones energy.A step-by-step simulation of shear strain in a polymer layer in an orientationally disordered state was carried out.The obtained stress–strain diagrams make it possible to estimate the value of the elastic limit and also to determine the stresses at the points of phase transitions from a disordered to an orientationally ordered state.

Negative Sentiment Shift on a Chinese Movie-Rating Website

Shifting to negativity is more and more prevalent in online communities and may play a key role in group polarization.While current research indicates a close relationship between group polarization and negative sentiment,they often link negative sentiment shifts with echo chambers and misinformation within echo chambers.In this work,we explore the sentiment drift using over 4 million comments from a Chinese online movie-rating community that is less affected by misinformation than other mainstream online communities and has no echo chamber structures.We measure the sentiment shift of the community and users of different engagement levels.Our analysis reveals that while the community does not show a tendency toward negativity,users of higher engagement levels are generally more negative,considering factors like the different movies they consume.The results indicate a fitting-in process,suggesting the possible mechanism of group identity on sentiment shift on social media platforms.These findings also provide guidance on web design to tackle the negativity issue and expand sentiment shift analysis to non-English contexts.

Design and Synthesis of Multi-Functional Polymeric Binders for High-Performance Lithium-Sulfur Batteries Based on Ring Opening Polymerization of Thiolactone

The application of high-performance lithium-sulfur(Li-S)batteries is severely influenced by the“shuttle effect”of polysulfides and the volume change of sulfur cathode.Herein,two different polymeric binders SOT-A and SOT-C with three-dimensional network structure containing polar groups(sulfhydryl groups,amide groups and amino groups)are synthesized by the nucleophilic ring-opening polymerization(ROP)of thiolactone with amino groups.The network structure formed by hydrogen bonds and functional groups can resist the volume change of the cathode.The sulfhydryl groups and the S-S bond formed by oxidative dehydrogenation of sulfhydryl group participate in the charge and discharge process of the battery as active materials,which improves the discharge specific capacity of the battery.Polar functional groups have strong chemisorption on polysulfides and effectively inhibit the“shuttle effect”.The electrochemical performances of Li-S batteries containing SOT-A and SOT-C binders are significantly enhanced.At 1 C rate,the batteries achieve initial discharge specific capacity of 871 and 837 mAh·g^(-1),respectively,and have 83.9%and 62.5%capacity retention after 500 cycles.