钴修饰碳纳米管瓶刷助力锂硫电池多硫化物转化

开发具有多层次结构(包括多孔结构、杂化骨架和/或拓扑形貌)的超结构碳材料,对于满足电化学储能和转换系统中复杂催化反应的需求非常关键.在本文中,我们以钴纳米颗粒为催化位点,在杂化碳纳米管骨架表面可控接枝毛发状碳纳米管,开发了一类层次化多孔的钴修饰碳纳米管瓶刷(Co/CNTBs).其中,精确的瓶刷状拓扑形貌和分级多孔结构能够有效地提供可及表/界面和高导电网络,钴修饰的杂化骨架可以促进硫的氧化还原反应动力学.因此,基于Co/CNTBs功能化隔膜的锂硫电池具有优异的倍率性能(在10 C下比容量为707 mA h g^(-1))和长效的循环稳定性.更重要的是,基于Co/CNTBs催化剂的高硫载量电池(6.72 mg cm^(-2))在0.1 C下循环100圈后仍具有4.81 mA h cm^(-2)的高面积容量.本工作为高性能超结构杂化碳材料的原位接枝合成策略带来了新的思路,有望用于众多具有挑战性的应用.

Bottlebrush inspired injectable hydrogel for rapid prevention of postoperative and recurrent adhesion

Postsurgical adhesion is a common clinic disease induced by surgical trauma,accompanying serious subsequent complications.Current non-surgical approaches of drugs treatment and biomaterial barrier administration only show limited prevention effects and couldn’t effectively promote peritoneum repair.Herein,inspired by bottlebrush,a novel self-fused,antifouling,and injectable hydrogel is fabricated by the free-radical polymerization in aqueous solution between the methacrylate hyaluronic acid(HA-GMA)and N-(2-hydroxypropyl)methacrylamide(HPMA)monomer without any chemical crosslinkers,termed as H-HPMA hydrogel.The H-HPMA hydrogel can be tuned to perform excellent self-fused properties and suitable abdominal metabolism time.Intriguingly,the introduction of the ultra-hydrophilic HPMA chains to the H-HPMA hydrogel affords an unprecedented antifouling capability.The HPMA chains establish a dense hydrated layer that rapidly prevents the postsurgical adhesions and recurrent adhesions after adhesiolysis in vivo.The H-HPMA hydrogel can repair the peritoneal wound of the rat model within 5 days.Furthermore,an underlying mechanism study reveals that the H-HPMA hydrogel significantly regulated the mesothelial-to-mesenchymal transition(MMT)process dominated by the TGF-β-Smad2/3 signal pathway.Thus,we developed a simple,effective,and available approach to rapidly promote peritoneum regeneration and prevent peritoneal adhesion and adhesion recurrence after adhesiolysis,offering novel design ideas for developing biomaterials to prevent peritoneal adhesion.

A boronate affinity restricted-access material with external hydrophilic bottlebrush polymers for pretreatment of cis-diols in biological matrices

Restricted-access materials （RAMs） have found their broad application in sample pretreatment of bioanalysis. Boronate affinity （BA） adsorption is a very efficient and facile method for isolation and enrichment of cis-diol containing biomolecules which are a large important group compounds in biosystems. However, preparation of BA-RAMs are rarely reported to date. In this study, a novel BA-RAM with external surface comprised of hydrophilic bottlebrush polymers was prepared exploiting the excellent capability of the bottlebrush polymers for protein exclusion. A diblock copolymer poly（3- acrylamidophenylboronic acid）-block-poly（2-hydroxyethyl methacrylate） （PAAPBA-b-PHEMA） was first grafted from the silica surface via surface-initiated reversible addition-fragmentation chain transfer polymerization （SI-RAFT）, and poly（N-isopropylacrylamide） （PNIPAAm） was then grafted from the PHEMA via surface-initiated atom transfer radical polymerization （SI-ATRP） to yield the BA-RAM. The BA- RAM exhibits high selectivity to cis-diol containing small molecules and has good capability to exclude proteins. Its practical application in bioanalysis was tested by pretreatment of serum sample for analysis of catecholamines with high recoveries and good precision. The preparation strategy for the BA-RAM is very versatile and is easy to be expanded to other modes of RAMs.

Microporous Organic Nanotube Networks from Hyper Cross-linking Core-shell Bottlebrush Copolymers for Selective Adsorption Study

We report a synthesis of microporous organic nanotube networks（MONNs） by a combination of hyper cross-linking and molecular templating of core-shell bottlebrush copolymers. The intrabrush and interbrush cross-linking of polystyrene（PS） shell layer in the core-shell bottlebrush copolymers led to the formation of micropores and large-sized nanopores（meso/macrospores） in MONNs, respectively, while selective removal of polylactide（PLA） core layer generated mesoporous tubular structure. The size of PLA-templated mesoporous cores and porous structure both at micro-and meso-scale could be controlled by simple tuning of the ratio of core/shell or the PLA core fraction in the bottlebrush precursors. Moreover, the resultant MONNs showed a highly selective adsorption capacity for the positively charged dyes on the basis of multi-porosity and carboxylate group-rich structure. In addition, MONNs also exhibited effective performance in size-selective adsorption of biomacromolecules. This work represents a new avenue for the preparation of MONNs and also provides a new application for molecular bottlebrushes in nanotechnology.

A supramolecular bottlebrush polymer assembled on the basis of cucurbit[8]uril-encapsulation-enhanced donor-acceptor interaction

A supramolecular bottlebrush polymer has been constructed in water through the self-assembly of a rigid electron-deficient building block and an electron-rich monomer which bears two tetraethylene glycol chains,driven by CB[8]-encapsulation-enhanced donor-acceptor interaction.The as-formed supramolecular bottlebrush polymer has been characterized by -1H NMR titration experiment,UV-vis spectroscopy,DLS and 2D -1H NMR DOSY.

Reactive Core-Shell Bottlebrush Copolymer as Highly Effective Additive for Epoxy Toughening

Herein,we designed a core-shell structured bottlebrush copolymer(BBP),which is composed of rubbery poly(butyl acrylate)(PBA)core and an epoxy miscible/reactive poly(glycidyl methacrylate)(PGMA)shell,as an epoxy tougheni ng age nt.The PGMA shell allows BBP to be uniformly dispersed within the epoxy matrix and to react with the epoxy groups,while the rubbery PBA block simultaneously induced nanocavitation effect,leading to improvement of mechanical properties of the epoxy resin.The mechanical properties were measured by the adhesion performance test,and the tensile and fracture test using universal testing machine.When BBP additives were added to the epoxy resin,a sign ifica nt improveme nt in the adhesion stren gth(2-fold increase)and fracture toughness(2-fold in crease in Kic and 5-fold in crease in Gic)compared to the neat epoxy was observed.In contrast,linear additives exhibited a decrease in adhesion strength and no improvement of fracture toughness over the neat epoxy.Such a difference in mechanical performance was investigated by comparing the morphologies and fracture surfaces of the epoxy resins containing linear and BBP additives,confirming that the nanocavitation effect and void formation play a key role in strengthening the BBP-modified epoxy resins.

From Polymerization Inhibition to Controlled Ring-Opening Metathesis Polymerization of Macromonomers with Tertiary Amine Groups:The Effect of Spacer Chain

Main observation and conclusion Ring-opening metathesis polymerization(ROMP)is a powerful toolbox in preparation of bottlebrush polymers for its high activity.However,the ROMP of macromonomers with repeating tertiary amine groups,for example,poly(2-(dimethylamino)ethyl methacrylate)(PDMAEMA).

Controlling the orientation of hole transport molecules in bottlebrush polymers for enhanced OLED performance

Organic light-emitting diodes(OLEDs)have been widely applied in lighting and display technologies.The performance of OLED devices depends on not only material composition but also the packing and morphology of each functional layer.Much effort has been devoted to control the alignment of charge transport functionalities to achieve a higher OLED efficiency by lowering the hole-injection barrier.