Anderson Localization Enhanced Spin Selective Transport of Electrons in DNA

Recent experiments revealed the unusual strong spin effects with high spin selective transmission of electrons in double-stranded DNA. We propose a new mechanism that the strong spin effects could be understood in terms of the combination of the ehiral structure, spin-orbit coupling, and especially spin-dependent Anderson localization. The presence of chiral structure and spin-orbit coupling of DNA induce weak Fermi energy splitting between two spin polarization states. The intrinsic Anderson localization in generic DNA molecules may result in remarkable enhancement of the spin selective transport. In particular, these two spin states with energy splitting have different localization lengths. Spin up/down channel may have shorter/longer localization length so that relatively less/more spin up/down electrons may tunnel through the system. In addition, the strong length dependence of spin selectivity observed in experiments can be naturally understood. Anderson localization enhanced spin selectivity effect may provide a deeper understanding of spin-selective processes in molecular spintronics and biological systems.

Ionic covalent organic frameworks with tailored anionic redox chemistry and selective ion transport for high-performance Na-ion cathodes

Employing cathode materials with multiple redox couples and electrolytes with efficient cation transport kinetics are two effective approaches to improving the electrochemical performance of batteries.In this work,for the first time,we present a design strategy of simultaneously realizing reversible cationic and anionic redox chemistries as well as selective anion/cation transport in the viologen-based COFs(BAVCOF:X,coordinated anions of X=Cl^(-),Br^(-),I^(-),and ClO_(4)^(-))for high-performance Na-ion cathodes.Besides the cationic redox of viologen segments,the different redox activities of anions effectively tune the total capacities of the COFs.Meanwhile,electrochemical analysis and ab-initial molecular dynamics(AIMD)calculation illustrate that the anion/cation transport kinetics of electrolytes caged in the COFs'channels can be selectively tuned by the coordinated anions.As a result,combining high-potential Br-/Br_(2)redox couple,cationic redox of viologen segments,and enhanced Na+transport kinetics,the BAV-COF:Brdemonstrates stable performance with energy densities of 358.7 and 145.2 Wh kg^(-1)at power densities of 116.5 and 2124.1 W kg^(-1),respectively.This study offers new insight into the fabrication of organic cathodes with anionic redox and the advantages of COFs electrode materials in anion/cation transport selectivity for energy storage applications.

Transport and selectivity of indium through polymer inclusion membrane in hydrochloric acid medium

In the present paper, a polymer inclusion membrane （PIM） containing polyvinyl chloride （PVC）, and bis-（2-ethylhexyl） phosphate （D2EHPA） which was used as extracting agent was used for the recovery of In（Ⅲ） ions in hydrochloric acid medium. The effects of carrier concentration, feed phase pH, strip phase HCI concentration, temperature on the transport, and the membrane＇s stability and thickness were examined. And the conditions for the selective separation of In（Ⅲ） and CU（Ⅱ） were optimized. The results showed that the transport of In（Ⅲ） across PIM was consistent with the first order kinetics equation, and also it was controlled by both the diffusion of the metal complex in the membrane and the chemical reaction at the interface of the boundary layers. The transport flux （J0） was inversely proportional to the membrane thickness, however, the transport stability improved as the membrane thickness increased. The transport flux of In（Ⅲ） and CU（Ⅱ） was decreased by excessive acidity of feed phase and high concentration of Cl^- . The selectivity separation coefficient of In（Ⅲ）/Cu（Ⅱ） was up to 34.33 when the original concentration of both In（Ⅲ） and Cu（Ⅱ） was 80 mg· L^ -1 as well as the pH of the feed phase and the concentration of Cl^- in the adjusting context were 0.6 and 0.5 mol· L^-1, respectively. Within the range of pH = 1-3, the separation selectivity of In（Ⅲ）/Cu（Ⅱ） reached the peak in the case when the Cl^- concentration was 0.7 mol·L^ -1.

Transport Selectivity of a Diethylene Glycol Dimethacrylate- Based Thymine-imprinted Polymeric Membrane over a Cellulose Support for Nucleic Acid Bases

The binding mechanism between 9-vinyladenine and pyrimidine base thymine in methanol was studied with UV-visible spectrophotometric method. Based on this study, using thymine as a template molecule, 9-vinyladenine as a novel functional monomer and diethylene glycol dimethacrylate as a new cross-linker, a specific diethylene glycol dimethacrylate-based molecularly imprinted polymeric membrane was prepared over a cellulose support. Then, the resultantly polymeric membrane morphologies were visualized with scanning electron microscopy and its permselectivity was examined using thymine, uracil, cytosine, adenine and guanine as substrates. This result showed that the imprinting polymeric membrane prepared with diethylene glycol dimethacrylate exhibited higher transport capacity for the template molecule thymine and its optimal analog uracil than other nucleic acid bases. The membrane also took on higher permselectivity than the imprinted membrane made with ethylene glycol dimethacrylate as a cross-linker. When a mixture including five nucleic acid bases thymine, uracil, cytosine, adenine and guanine passed through the diethylene glycol dimethacrylate-based thymine-imprinted polymeric membrane, recognition of the membrane for the template molecule thymine and its optimal analog uracil was demonstrated. It was predicted that the molecularly imprinted membrane prepared with diethylene glycol dimethacrylate as cross-linker might be applicable to thymine assay of absolute hydrolysates of DNA or uracil assay of absolute hydrolysates of RNA in biological samples because of its high selectivity for the template molecule thymine and its optimal analog uracil.

Unimolecular artificial transmembrane channel with terminal dihydrogen phosphate groups showing transport selectivity for ammonium

A new artificial transmembrane channel molecule bearing dihydrogen phosphate groups has been synthesized.The terminal dihydrogen phosphate groups enable the channel to be highly negatively charged at both ends of the channel structures.The artificial channel could incorporate into the lipid bilayer efficiently under low concentration.The channel displays high NH4+/K+selectivity due to the electrostatic interaction and hydrogen bonding between NH4+and the terminal dihydrogen phosphate groups.

Highly active artificial potassium channels having record-high K^(+)/Na^(+) selectivity of 20.1

Replicating extraordinarily high membrane transport selectivity of protein channels in artificial channel is a challenging task.In this work,we demonstrate that a strategic application of steric code-based social self-sorting offers a novel means to enhance ion transport selectivities of artificial ion channels,alongside with boosted ion transport activities.More specifically,two types of mutually compatible sterically bulky groups(benzo-crown ether and tert-butyl group)were appended onto a monopeptide-based scaffold,which can order the bulky groups onto the same side of a one-dimensionally aligned H-bonded structure.Strong steric repulsions among the same type of bulky groups(either benzo-crown ethers or tert-butyl groups),which are forced into proximity by H-bonds,favor the formation of hetero-oligomeric ensem-bles that carry an alternative arrangement of sterically compatible benzo-crown ethers and tert-butyl groups,rather than homo-oligomeric ensembles containing a single type of either benzo-crown ethers or tert-butyl groups.Coupled with side chain tuning,this social self-sorting strategy delivers highly ac-tive hetero-oligomeric K+-selective ion channel(5F12-BF12)_(n),displaying the highest K+/Na+selectivity of 20.1 among artificial potassium channels and an excellent ECso value of 0.50μmol/L(0.62 mo1%relative to lipids)in terms of single channel concentration.

Carbon dots for ultrastable solid-state batteries

Among the solid electrolytes for solid-state Li batteries,polymer electrolytes are actively explored on the basis of the good interfacial contact and easy making,while it is still constrained by slow ionic transport and low lithium ion transference number.Herein,functional carbon dots-based Li+conductor(CD-Li)is designed to improve the dynamics and selectivity of Li+transport in polyethylene oxide(PEO)electrolyte.High ionic conductivity(1.0×10^(−4) S/cm,25℃)and Li+transference number(0.60)were successfully achieved within the CD‐Li‐based PEO composite electrolyte,which could be attributed to the enhanced chain movement and the limited motion of anion.Moreover,the characteristics of big volume of individual anions of CD-Li can provide more free Li^(+).As well,benefiting from the existence of F atom in the CD-Li,in-situ constructed LiF-containing interfacial layer is in favor of maintaining the interface stability and facilitating the rapid transmission of Li ions.The composite electrolyte with CD-Li can address the ionic conductivity issues accompanied with strengthening the interfacial stability.The distinctive composite electrolyte realizes the stable cycle performance for Li/LiFePO_(4) and Li/LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2)batteries.The exploration of multifunctional carbon dot fillers provides new ideas for the efficient development of composite electrolytes.