Novel peapod-like Co@carbon and Co(3)O(4)@carbon composite nanostructures have been successfully fabricated for the first time based on rational design and elaborate analyses. The nanostructures exhibit the unique feature of Co or Co(3)O(4) nanoparticles (20 nm) encapsulated inside and well-graphitized carbon layers coating outside. The peapod-like Co@carbon and Co(3)O(4)@carbon nanostructures exhibit intriguing morphologies, architectures, and chemical compositions. What is more important, the unique morphologies, architectures, and chemical compositions will lead to perfect performances in many applications. In this paper, a good example of Li-ion battery testing is given to demonstrate the superior stability and rate capability of the Co(3)O(4)@carbon. The peapod-like nanostructure of Co(3)O(4)@carbon demonstrates very high specific capacity (around 1000 mAh/g at the charge/discharge rate of 1C) and wonderful cyclability (at least 80% retention is available when cycled back from very high charge/discharge rate of 10C) during the galvanostatic cycling, indicating it as the promising candidate for Li-ion batteries' anodes. Additionally, the excellent electrochemical performance is significantly associated with the unique architecture in the samples, which verifies the feasibility of rational design of hierarchical materials for the actual applications. Meanwhile, the Co@carbon and Co(3)O(4)@carbon nanostructures demonstrate the regular and uniform distribution of magnetic nanoparticles in well-graphitized carbon fiber, which is a great achievement in the field of monodispersing and isolating magnetic nanoparticles. The prepared samples can also be potentially applied in other fields, such as gene delivery, catalysis, and magnetism.

A novel biomass-based nitrogen-doped free-standing fused carbon fibrous mat was fabricated from lignin-polyethylene oxide (PEO) (90:10) blend via electrospinning followed by carbonization and thermal annealing in the presence of urea. The morphology and structure of the carbon fibers were characterized by field-emission scanning electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and elemental analysis, and their electrochemical properties were investigated for the first time as anode in lithium ion batteries (LIBs). The fused carbon fibers without nitrogen doping exhibited high specific capacity up to 445 mA h g(-1) at a current density of 30 mA g(-1) (comparable to polyacrylonitrile (PAN) derived carbon nanofibers) and good cyclic stability at different current rates. After thermal annealing in the presence of urea, the charge capacity was further improved to as high as 576 mA h g(-1) and still maintained a good capacity of about 200 mAh g(-1) even at a high current rate of 2000 mA g(-1). This research demonstrates the great promise of lignin-derived nanocarbon materials for applications in energy storage systems.

In recent years, the synthesis and applications of magnetic nanoparticles (MNPs) have attracted increasing interest in catalysis research, and MNP‐derived catalysts have been employed in such industrially important reactions as hydrogenation, hydroformylation, Suzuki–Miyaura and Heck couplings, and olefin metathesis. The hybrid nanocomposite species display sustainable catalytic activities and great advantages concerning catalyst recycling processes. A number of examples using these innovative hybrids in catalysis have been reported with promising results. This Minireview primarily addresses recent catalytic applications of magnetic nanocomposites, including a discussion of the synthetic methodologies that are commonly used.

Isomerically pure exo-norbornene esters containing either a Pd II SCS pincer complex or a diaminopyridine unit were synthesized, polymerized, and copolymerized by ring-opening metathesis polymerization using a ruthenium initiator. All polymerizations are living under mild reaction conditions. A comparison between the pure exo monomers and the commonly employed 80:20 endo/exo mixtures was carried out. The exo-norbornene isomers exhibit significantly higher rates of propagation under milder conditions when compared to the endo/exo mixtures. Kinetic studies have shown that the k p values are highly dependent upon the isomeric purity but completely independent of the terminal diaminopyridine or Pd II SCS Pincer functional groups. The living character of the polymerization has allowed for the first block copolymerization of norbornene metal-containing pincer complexes and diaminopyridine-based hydrogen-bonding receptors.

A novel methodology for random copolymer functionalization based on a noncovalent, one-step, multifunctionalization strategy has been developed. Random copolymers possessing both palladated-pincer complexes and diaminopyridine moieties (hydrogen-bonding entities) have been synthesized using ring-opening metathesis polymerization. Noncovalent functionalization of the resultant copolymers is accomplished via (1) directed self-assembly, (2) multistep self-assembly, and (3) one-step orthogonal self-assembly. This system shows complete specificity of each recognition motif for its complementary unit, with no observable changes in the association constants regardless of the degree of functionalization.

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Lignin-based polyurethane elastomers (LPUe) with high stiffness, strength, and toughness were facilely prepared by direct cross-linking of unfunctionized lignin as hard segments and poly­(propylene glycol) tolylene 2,4-diisocyanate terminated (PPGTDI) as soft domains. The effects of lignin molecular weight (3600 and 600 g mol–1) and weight fraction (5–40 wt %) on the thermal and mechanical properties of LPUe were studied. With an increase in lignin content, LPUe exhibited improved thermal stability, and the glass transition temperature (T g) also increased, especially for LPUe derived from lignin with low lignin molecular weight of 600 g mol–1 (600-LPUe). Furthermore, LPUe also exhibits excellent mechanical properties. For 600-LPUe with 40 wt % of lignin, the Young’s modulus, tensile strength, and strain at break reach 176.4 MPa, 33.0 MPa, and 1394%, respectively, which could be attributed to better dispersion of low molecular weight lignin in elastomers as evident from DSC, SEM, and TEM studies. Our results demonstrate the potential application of unmodified lignin in developing biobased high-performance PU materials. This is in contrast to many current studies of LPUe systems that need lignin modification to prepare PU materials.

Polymers containing terminal hydrogen-bonding recognition motifs based on diaminotriazine and diaminopyridine groups in their side chains for the self-assembly of appropriate receptors have been prepared by ring-opening metathesis polymerization (ROMP) of norbornenes. A new synthetic method for the preparation of norbornene monomers based on pure alkyl spacers is introduced. These monomers show unprecedented high reactivity using ROMP. To suppress self-association of diaminotriazine-based polymers, polymerizations were run in presence of N-butylthymine. The butylthymine acts as a protecting group via self-assembly onto the hydrogen-bonding sites of the polymeric scaffold, thereby solubilizing the polymer. Diaminopyridine monomers do not require the presence of a protecting group due to their low propensity to dimerize. In addition, they exhibit a high affinity for hydrogen-bonded receptors on both monomeric and polymeric level. These polymers present our first building blocks towards the design and synthesis of a "universal polymer scaffold".