TY - JOUR A1 - Abbasi, Ali A1 - Xu, Yaolin A1 - Khezri, Ramin A1 - Etesami, Mohammad A1 - Lin, C. A1 - Kheawhom, Soorathep A1 - Lu, Yan T1 - Advances in characteristics improvement of polymeric membranes/separators for zinc-air batteries JF - Materials Today Sustainability N2 - Zinc-air batteries (ZABs) are gaining popularity for a wide range of applications due to their high energy density, excellent safety, and environmental friendliness. A membrane/separator is a critical component of ZABs, with substantial implications for battery performance and stability, particularly in the case of a battery in solid state format, which has captured increased attention in recent years. In this review, recent advances as well as insight into the architecture of polymeric membrane/separators for ZABs including porous polymer separators (PPSs), gel polymer electrolytes (GPEs), solid polymer electrolytes (SPEs) and anion exchange membranes (AEMs) are discussed. The paper puts forward strategies to enhance stability, ionic conductivity, ionic selectivity, electrolyte storage capacity and mechanical properties for each type of polymeric membrane. In addition, the remaining major obstacles as well as the most potential avenues for future research are examined in detail. KW - Ionic selectivity KW - Ionic conductivity KW - Gel polymer KW - Ion exchange KW - Porous KW - polymer Y1 - 2022 U6 - https://doi.org/10.1016/j.mtsust.2022.100126 SN - 2589-2347 VL - 18 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Al Nakeeb, Noah A1 - Kochovski, Zdravko A1 - Li, Tingting A1 - Zhang, Youjia A1 - Lu, Yan A1 - Schmidt, Bernhard V. K. J. T1 - Poly(ethylene glycol) brush-b-poly(N-vinylpyrrolidone)-based double hydrophilic block copolymer particles crosslinked via crystalline alpha-cyclodextrin domains JF - RSC Advances N2 - Self-assembly of block copolymers is a significant area of polymer science. The self-assembly of completely water-soluble block copolymers is of particular interest, albeit a challenging task. In the present work the self-assembly of a linear-brush architecture block copolymer, namely poly(N-vinylpyrrolidone)-b-poly(oligoethylene glycol methacrylate) (PVP-b-POEGMA), in water is studied. Moreover, the assembled structures are crosslinked via alpha-CD host/guest complexation in a supramolecular way. The crosslinking shifts the equilibrium toward aggregate formation without switching off the dynamic equilibrium of double hydrophilic block copolymer (DHBC). As a consequence, the self-assembly efficiency is improved without extinguishing the unique DHBC self-assembly behavior. In addition, decrosslinking could be induced without a change in concentration by adding a competing complexation agent for alpha-CD. The self-assembly behavior was followed by DLS measurement, while the presence of the particles could be observed via cryo-TEM before and after crosslinking. Y1 - 2019 U6 - https://doi.org/10.1039/c8ra10672j SN - 2046-2069 VL - 9 IS - 9 SP - 4993 EP - 5001 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Gu, Sasa A1 - Risse, Sebastian A1 - Lu, Yan A1 - Ballauff, Matthias T1 - Mechanism of the oxidation of 3,3′,5,5′-tetramethylbenzidine catalyzed by peroxidase-like Pt nanoparticles immobilized in spherical polyelectrolyte brushes BT - a kinetic study JF - ChemPhysChem N2 - Experimental and kinetic modelling studies are presented to investigate the mechanism of 3,3 ',5,5 '-tetramethylbenzidine (TMB) oxidation by hydrogen peroxide (H2O2) catalyzed by peroxidase-like Pt nanoparticles immobilized in spherical polyelectrolyte brushes (SPB-Pt). Due to the high stability of SPB-Pt colloidal, this reaction can be monitored precisely in situ by UV/VIS spectroscopy. The time-dependent concentration of the blue-colored oxidation product of TMB expressed by different kinetic models was used to simulate the experimental data by a genetic fitting algorithm. After falsifying the models with abundant experimental data, it is found that both H2O2 and TMB adsorb on the surface of Pt nanoparticles to react, indicating that the reaction follows the Langmuir-Hinshelwood mechanism. A true rate constant k, characterizing the rate-determining step of the reaction and which is independent on the amount of catalysts used, is obtained for the first time. Furthermore, it is found that the product adsorbes strongly on the surface of nanoparticles, thus inhibiting the reaction. The entire analysis provides a new perspective to study the catalytic mechanism and evaluate the catalytic activity of the peroxidase-like nanoparticles. KW - kinetics KW - nanoparticles KW - reaction mechanisms KW - spherical polyelectrolyte KW - brushes KW - UV KW - vis spectroscopy Y1 - 2019 U6 - https://doi.org/10.1002/cphc.201901087 SN - 1439-4235 SN - 1439-7641 VL - 21 IS - 5 SP - 450 EP - 458 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Jia, He A1 - Friebe, Christian A1 - Schubert, Ulrich S. A1 - Zhang, Xiaozhe A1 - Quan, Ting A1 - Lu, Yan A1 - Gohy, Jean-Francois T1 - Core-Shell Nanoparticles with a Redox Polymer Core and a Silica Porous Shell as High-Performance Cathode Material for Lithium-Ion Batteries JF - Energy technology : generation, conversion, storage, distribution N2 - A facile and novel method for the fabrication of core-shell nanoparticles (PTMA@SiO2) based on a poly(2,2,6,6-tetramethylpiperidinyloxy-4-yl methacrylate) (PTMA) core and a porous SiO2 shell is reported. The core-shell nanoparticles are further self-assembled with negatively charged multi-walled carbon nanotubes (MWCNTs), which results in the formation of a free-standing cathode electrode. The porous SiO2 shell not only effectively improves the stability of the linear PTMA redox polymer with low molar mass in organic electrolytes but also leads to the uniform dispersion of PTMA active units in the MWCNTs conductive network. The PTMA@SiO2@MWCNT composite electrode exhibits a specific capacity as high as 73.8 mAh g at 1 C and only 0.11% capacity loss per cycle at a rate of 2 C. KW - composite electrodes KW - core-shell nanoparticles KW - energy storage KW - lithium-ion batteries KW - redox polymers Y1 - 2019 U6 - https://doi.org/10.1002/ente.201901040 SN - 2194-4288 SN - 2194-4296 VL - 8 IS - 3 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Jia, He A1 - Gao, Haitao A1 - Mei, Shilin A1 - Kneer, Janosch A1 - Lin, Xianzhong A1 - Ran, Qidi A1 - Wang, Fuxian A1 - Palzer, Stefan A1 - Lu, Yan T1 - Cu2O@PNIPAM core-shell microgels as novel inkjet materials for the preparation of CuO hollow porous nanocubes gas sensing layers JF - Journal of materials chemistry : C, Materials for optical and electronic devices N2 - There has been long-standing interest in developing metal oxide-based sensors with high sensitivity, selectivity, fast response and low material consumption. Here we report for the first time the utilization of Cu2O@PNIPAM core-shell microgels with a nanocube-shaped core structure for construction of novel CuO gas sensing layers. The hybrid microgels show significant improvement in colloidal stability as compared to native Cu2O nanocubes. Consequently, a homogeneous thin film of Cu2O@PNIPAM nanoparticles can be engineered in a quite low solid content (1.5 wt%) by inkjet printing of the dispersion at an optimized viscosity and surface tension. Most importantly, thermal treatment of the Cu2O@PNIPAM microgels forms porous CuO nanocubes, which show much faster response to relevant trace NO2 gases than sensors produced from bare Cu2O nanocubes. This outcome is due to the fact that the PNIPAM shell can successfully hinder the aggregation of CuO nanoparticles during pyrolysis, which enables full utilization of the sensor layers and better access of the gas to active sites. These results point out great potential of such an innovative system as gas sensors with low cost, fast response and high sensitivity. Y1 - 2018 U6 - https://doi.org/10.1039/c8tc01995a SN - 2050-7526 SN - 2050-7534 VL - 6 IS - 27 SP - 7249 EP - 7256 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Jia, He A1 - Quan, Ting A1 - Liu, Xuelian A1 - Bai, Lu A1 - Wang, Jiande A1 - Boujioui, Fadoi A1 - Ye, Ran A1 - Vald, Alexandru A1 - Lu, Yan A1 - Gohy, Jean-Francois T1 - Core-shell nanostructured organic redox polymer cathodes with superior performance JF - Nano Energy N2 - Core-shell nanoparticles stabilized by a cationic surfactant are prepared from the poly(2,2,6,6-tetra-methylpiperidinyloxy-4-yl methacrylate) redox polymer. The nanoparticles are further self-assembled with negatively charged reduced graphene oxide nanosheets and negatively charged mull-walled carbon nanotubes. This results in the formation of a free-standing cathode with a layered nanostructure and a high content of redox polymer that exhibits 100% utilization of the active substance with a measured capacity as high as 105 mAh/g based on the whole weight of the electrode. KW - Nanostructured KW - Redox polymer KW - Organic electrode KW - Lithium ion battery KW - Energy storage Y1 - 2019 U6 - https://doi.org/10.1016/j.nanoen.2019.103949 SN - 2211-2855 SN - 2211-3282 VL - 64 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Khodeir, Miriam A1 - Ernould, Bruno A1 - Brassinne, Jeremy A1 - Ghiassinejad, Sina A1 - Jia, He A1 - Antoun, Sayed A1 - Friebe, Christian A1 - Schubert, Ulrich S. A1 - Kochovski, Zdravko A1 - Lu, Yan A1 - Van Ruymbeke, Evelyne A1 - Gohy, Jean-Francois T1 - Synthesis and characterisation of redox hydrogels based on stable nitroxide radicals JF - Soft matter N2 - The principle of encapsulation/release of a guest molecule from stimuli responsive hydrogels (SRHs) is mainly realised with pH, temperature or light stimuli. However, only a limited number of redox responsive hydrogels have been investigated so far. We report here the development of a SRH that can release its guest molecule upon a redox stimulus. To obtain this redox hydrogel, we have introduced into the hydrogel the 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) stable nitroxide radical, which can be reversibly oxidized into an oxoammonium cation (TEMPO+). Water solubility is provided by the presence of the (oligoethyleneglycol)methacrylate (OEGMA) comonomer. Electrochemical and mechanical characterization showed that those gels exhibit interesting physicochemical properties, making them very promising candidates for practical use in a wide range of applications. Y1 - 2019 U6 - https://doi.org/10.1039/c9sm00905a SN - 1744-683X SN - 1744-6848 VL - 15 IS - 31 SP - 6418 EP - 6426 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Kochovski, Zdravko A1 - Chen, Guosong A1 - Yuan, Jiayin A1 - Lu, Yan T1 - Cryo-Electron microscopy for the study of self-assembled poly(ionic liquid) nanoparticles and protein supramolecular structures JF - Colloid and polymer science : official journal of the Kolloid-Gesellschaft N2 - Cryo-electron microscopy (cryo-EM) is a powerful structure determination technique that is well-suited to the study of protein and polymer self-assembly in solution. In contrast to conventional transmission electron microscopy (TEM) sample preparation, which often times involves drying and staining, the frozen-hydrated sample preparation allows the specimens to be kept and imaged in a state closest to their native one. Here, we give a short overview of the basic principles of Cryo-EM and review our results on applying it to the study of different protein and polymer self-assembled nanostructures. More specifically, we show how we have applied cryo-electron tomography (cryo-ET) to visualize the internal morphology of self-assembled poly(ionic liquid) nanoparticles and cryo-EM single particle analysis (SPA) to determine the three-dimensional (3D) structures of artificial protein microtubules. KW - self-assembly KW - poly(ionic liquid) nanoparticles KW - protein self-assembly KW - cryo-electron microscopy KW - single particle analysis KW - cryo-electron KW - tomography Y1 - 2020 U6 - https://doi.org/10.1007/s00396-020-04657-w SN - 0303-402X SN - 1435-1536 VL - 298 IS - 7 SP - 707 EP - 717 PB - Springer CY - New York ER - TY - GEN A1 - Kochovski, Zdravko A1 - Jia, He A1 - Lu, Yan T1 - Morphological study of microgel-based colloidal systems by cryogenic transmission electron microscopy (cryo-TEM) T2 - Abstracts of papers : joint conference / The Chemical Institute of Cananda, CIC, American Chemical Society, ACS Y1 - 2018 SN - 0065-7727 VL - 256 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Mei, Shilin A1 - Jafta, Charl J. A1 - Lauermann, Iver A1 - Ran, Qidi A1 - Kaergell, Martin A1 - Ballauff, Matthias A1 - Lu, Yan T1 - Porous Ti4O7 Particles with Interconnected-Pore Structure as a High-Efficiency Polysulfide Mediator for Lithium-Sulfur Batteries JF - Advanced functional materials N2 - Multifunctional Ti4O7 particles with interconnected-pore structure are designed and synthesized using porous poly(styrene-b-2-vinylpyridine) particles as a template. The particles can work efficiently as a sulfur-host material for lithium-sulfur batteries. Specifically, the well-defined porous Ti4O7 particles exhibit interconnected pores in the interior and have a high-surface area of 592 m(2) g(-1); this shows the advantage of mesopores for encapsulating of sulfur and provides a polar surface for chemical binding with polysulfides to suppress their dissolution. Moreover, in order to improve the conductivity of the electrode, a thin layer of carbon is coated on the Ti4O7 surface without destroying its porous structure. The porous Ti4O7 and carbon-coated Ti4O7 particles show significantly improved electrochemical performances as cathode materials for Li-S batteries as compared with those of TiO2 particles. KW - lithium-sulfur batteries KW - porous particles KW - poly(styrene-b-2-vinylpyridine) (PS-P2VP) KW - Ti4O7 Y1 - 2017 U6 - https://doi.org/10.1002/adfm.201701176 SN - 1616-301X SN - 1616-3028 VL - 27 PB - Wiley-VCH CY - Weinheim ER -