Controllable assembly of nitrogen-doped mesoporous carbon with different pore structures onto CNTs for excellent lithium storage

Mesoporous carbon nanomaterials have shown a great application potential in energy storage and conversion fields due to their outstanding conductivity,tunable pore structure,and good chemical stability.Nevertheless,how to accurately control the pore structure,especially directly assembling the mesoporous carbon onto different substrates remains a big challenge.Herein,we have successfully assembled two kinds of highly nitrogen-doped mesoporous carbon onto carbon nanotubes(NMC/CNTs)based on a facile cooperative assembly process assisted by triblock PEO_(20)PPO_(70)PEO_(20)(P123)and PEO_(106)PPO_(70)PEO_(106)(F127)copolymers.The experimental results indicate that the P_(123)/F_(127)mass ratio has a profound effect on the pore structure,leading to the formation of NMC/CNTs composites with spherical pore structure(S-NMC/CNTs)and cylindrical pore structure(CNMC/CNTs).In virtue of fast electron/ion transfer kinetics,the as-prepared S-NMC/CNTs anode demonstrates an excellent electrochemical performance for lithium-ion batteries,and it delivers a high reversible capacity of 588.1 mAh∙g^(−1)at the current of 0.1 A∙g^(−1)after 100 cycles,along with a superior cycling stability.Specifically noted,the controlled assembly route developed in our work can also be applied to other support materials with different structures and compositions.

Magnetic Fe_3O_4-Reduced Graphene Oxide Nanocomposites-Based Electrochemical Biosensing

An electrochemical biosensing platform was developed based on glucose oxidase(GOx)/Fe3O4-reduced graphene oxide(Fe3O4-RGO) nanosheets loaded on the magnetic glassy carbon electrode(MGCE).With the advantages of the magnetism, conductivity and biocompatibility of the Fe3O4-RGO nanosheets, the nanocomposites could be facilely adhered to the electrode surface by magnetically controllable assembling and beneficial to achieve the direct redox reactions and electrocatalytic behaviors of GOx immobilized into the nanocomposites. The biosensor exhibited good electrocatalytic activity, high sensitivity and stability. The current response is linear over glucose concentration ranging from 0.05 to 1.5 m M with a low detection limit of0.15 μM. Meanwhile, validation of the applicability of the biosensor was carried out by determining glucose in serum samples. The proposed protocol is simple, inexpensive and convenient, which shows great potential in biosensing application.

Control of random self-assembly of pyrogallol[4]arene-based nanocapsule or framework

The controlled self-assembly of discrete metal-organic nanocapsules(MONCs),and metal-organic frameworks(MOFs)based on the MONCs are achieved.Specifically,the solvothermal reaction of nickel nitrate hexahydrate and C-methylpyrogallol[4]arene in mixed DMF/MeOH solution leads to the unexpected form of discrete nickel-seamed hexameric pyrogallol[4]arene MONCs,and MONC-based three-dimensional(3D)MOF.Notably,the latter MOF is constructed from the aforementioned nickelseamed MONC building blocks and formate linkers in-situ generated from the hydrolysis of DMF solve nt.Interestingly,introducing pyridine and formic acid in the reaction conditions leads to the controlled assemblies of the discrete MONC and MONC-based 3D MOF structures.Moreover,the variabletemperature magnetic susceptibilities of both the abovementioned compounds have been investigated,indicating typical antiferromagnetic interactions between the metal centers.

Controlled Molecular Assembly of Tetrazine Derivatives on Surfaces

While self-assembly is relatively well-known and widely used to form hierarchical structures and thin film coatings,controlled assembly is less known and utilized.Our prior work has demonstrated the concept of controlled assembly of macromolecules such as star polymers[molecular weight(M_(w))∼383 kDa,hydrodynamic radius R∼13.8 nm]in droplets.This work extends this concept to smaller molecules,in this case,poly(ethylene glycol)bis-tetrazine(PEGbisTz,M_(w) 8.1 kDa,R∼1.5 nm).The key to controlled molecular assembly is to first deliver ultrasmall volumes(sub-fL)of solution containing PEG-bisTz to a substrate.The solvent evaporates rapidly due to the minute volume,thus forcing the assembly of solute,whose overall size and dimension are dictated by the initial liquid geometry and size.Using prepatterned surfaces,this work revealed that the initial liquid shape can be further tuned,and we could control the final assembly of solute such as PEGbisTz molecules.The degree of control was demonstrated by varying the micropatterns and delivery conditions.This work demonstrated the validity of controlled assembly for PEG-bisTz and enables three-dimensional(3D)nanoprinting of functional materials.The technology has promising applications in nanophotonics,nanoelectronics,nanocomposite materials,and tissue engineering.

Adaptive iron-based magnetic nanomaterials of high performance for biomedical applications

With unique physicochemical properties and biological effects,magnetic nanomaterials(MNMs)play a crucial role in the biomedical field.In particular,magnetic iron oxide nanoparticles(MIONPs)are approved by the United States Food and Drug Administration(FDA)for clinical applications at present due to their low toxicity,biocompatibility,and biodegradability.Despite the unarguable effectiveness,massive space for improving such materials'performance still needs to be filled.Recently,many efforts have been devoted to improving the preparation methods based on the materials'biosafety.Besides,researchers have successfully.regulated the performance of magnetic nanoparticles(MNPs)by changing their sizes,morphologies,compositions;or by.aggregating as-synthesized MNPs in an orderly arrangement to meet various clinical requirements.The rise of cloud computing and artificial intelligence techniques provides novel ways for fast material characterization,automated data analysis,and mechanism demonstration.In this review,we summarized the studies that focused on the preparation routes and performance regulations of high-quality MNPs,and their special properties applied in biomedical detection,diagnosis,and treatment.At the same time,the future.development of MNMs was also discussed.