@article{AbbasiXuKhezrietal.2022, author = {Abbasi, Ali and Xu, Yaolin and Khezri, Ramin and Etesami, Mohammad and Lin, C. and Kheawhom, Soorathep and Lu, Yan}, title = {Advances in characteristics improvement of polymeric membranes/separators for zinc-air batteries}, series = {Materials Today Sustainability}, volume = {18}, journal = {Materials Today Sustainability}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2589-2347}, doi = {10.1016/j.mtsust.2022.100126}, pages = {17}, year = {2022}, abstract = {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.}, language = {en} } @article{AlNakeebKochovskiLietal.2019, author = {Al Nakeeb, Noah and Kochovski, Zdravko and Li, Tingting and Zhang, Youjia and Lu, Yan and Schmidt, Bernhard V. K. J.}, title = {Poly(ethylene glycol) brush-b-poly(N-vinylpyrrolidone)-based double hydrophilic block copolymer particles crosslinked via crystalline alpha-cyclodextrin domains}, series = {RSC Advances}, volume = {9}, journal = {RSC Advances}, number = {9}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {2046-2069}, doi = {10.1039/c8ra10672j}, pages = {4993 -- 5001}, year = {2019}, abstract = {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.}, language = {en} } @article{GuRisseLuetal.2019, author = {Gu, Sasa and Risse, Sebastian and Lu, Yan and Ballauff, Matthias}, title = {Mechanism of the oxidation of 3,3′,5,5′-tetramethylbenzidine catalyzed by peroxidase-like Pt nanoparticles immobilized in spherical polyelectrolyte brushes}, series = {ChemPhysChem}, volume = {21}, journal = {ChemPhysChem}, number = {5}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1439-4235}, doi = {10.1002/cphc.201901087}, pages = {450 -- 458}, year = {2019}, abstract = {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.}, language = {en} } @article{JiaFriebeSchubertetal.2019, author = {Jia, He and Friebe, Christian and Schubert, Ulrich S. and Zhang, Xiaozhe and Quan, Ting and Lu, Yan and Gohy, Jean-Francois}, title = {Core-Shell Nanoparticles with a Redox Polymer Core and a Silica Porous Shell as High-Performance Cathode Material for Lithium-Ion Batteries}, series = {Energy technology : generation, conversion, storage, distribution}, volume = {8}, journal = {Energy technology : generation, conversion, storage, distribution}, number = {3}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {2194-4288}, doi = {10.1002/ente.201901040}, pages = {8}, year = {2019}, abstract = {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.}, language = {en} } @article{JiaGaoMeietal.2018, author = {Jia, He and Gao, Haitao and Mei, Shilin and Kneer, Janosch and Lin, Xianzhong and Ran, Qidi and Wang, Fuxian and Palzer, Stefan and Lu, Yan}, title = {Cu2O@PNIPAM core-shell microgels as novel inkjet materials for the preparation of CuO hollow porous nanocubes gas sensing layers}, series = {Journal of materials chemistry : C, Materials for optical and electronic devices}, volume = {6}, journal = {Journal of materials chemistry : C, Materials for optical and electronic devices}, number = {27}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {2050-7526}, doi = {10.1039/c8tc01995a}, pages = {7249 -- 7256}, year = {2018}, abstract = {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.}, language = {en} } @article{JiaQuanLiuetal.2019, author = {Jia, He and Quan, Ting and Liu, Xuelian and Bai, Lu and Wang, Jiande and Boujioui, Fadoi and Ye, Ran and Vald, Alexandru and Lu, Yan and Gohy, Jean-Francois}, title = {Core-shell nanostructured organic redox polymer cathodes with superior performance}, series = {Nano Energy}, volume = {64}, journal = {Nano Energy}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2211-2855}, doi = {10.1016/j.nanoen.2019.103949}, pages = {9}, year = {2019}, abstract = {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.}, language = {en} } @article{KhodeirErnouldBrassinneetal.2019, author = {Khodeir, Miriam and Ernould, Bruno and Brassinne, Jeremy and Ghiassinejad, Sina and Jia, He and Antoun, Sayed and Friebe, Christian and Schubert, Ulrich S. and Kochovski, Zdravko and Lu, Yan and Van Ruymbeke, Evelyne and Gohy, Jean-Francois}, title = {Synthesis and characterisation of redox hydrogels based on stable nitroxide radicals}, series = {Soft matter}, volume = {15}, journal = {Soft matter}, number = {31}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1744-683X}, doi = {10.1039/c9sm00905a}, pages = {6418 -- 6426}, year = {2019}, abstract = {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.}, language = {en} } @article{KochovskiChenYuanetal.2020, author = {Kochovski, Zdravko and Chen, Guosong and Yuan, Jiayin and Lu, Yan}, title = {Cryo-Electron microscopy for the study of self-assembled poly(ionic liquid) nanoparticles and protein supramolecular structures}, series = {Colloid and polymer science : official journal of the Kolloid-Gesellschaft}, volume = {298}, journal = {Colloid and polymer science : official journal of the Kolloid-Gesellschaft}, number = {7}, publisher = {Springer}, address = {New York}, issn = {0303-402X}, doi = {10.1007/s00396-020-04657-w}, pages = {707 -- 717}, year = {2020}, abstract = {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.}, language = {en} } @misc{KochovskiJiaLu2018, author = {Kochovski, Zdravko and Jia, He and Lu, Yan}, title = {Morphological study of microgel-based colloidal systems by cryogenic transmission electron microscopy (cryo-TEM)}, series = {Abstracts of papers : joint conference / The Chemical Institute of Cananda, CIC, American Chemical Society, ACS}, volume = {256}, journal = {Abstracts of papers : joint conference / The Chemical Institute of Cananda, CIC, American Chemical Society, ACS}, publisher = {American Chemical Society}, address = {Washington}, issn = {0065-7727}, pages = {2}, year = {2018}, language = {en} } @article{MeiJaftaLauermannetal.2017, author = {Mei, Shilin and Jafta, Charl J. and Lauermann, Iver and Ran, Qidi and Kaergell, Martin and Ballauff, Matthias and Lu, Yan}, title = {Porous Ti4O7 Particles with Interconnected-Pore Structure as a High-Efficiency Polysulfide Mediator for Lithium-Sulfur Batteries}, series = {Advanced functional materials}, volume = {27}, journal = {Advanced functional materials}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1616-301X}, doi = {10.1002/adfm.201701176}, pages = {10}, year = {2017}, abstract = {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.}, language = {en} }