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Ultrafine SnO2/Sn nanoparticles encapsulated into the adjustable mesoporous carbon matrix has been successfully fabricated by a facile route. The mesoporous carbon effectively improve the conductivity of the SnO2/Sn, prevent the aggregation, accommodate the strain of volume change and provide high interface area with the electrolyte, thus resulting in excellent cycling performance. A reversible capacity of 1105 mAh g–1 still retained after 290 cycles at 200 mA g–1, and the capacity still can keep at 107 mAh g–1 at high current density of 10 A g–1. The porous structures by the in situ SiOx template provide an appropriate specific surface area, which contributes to a relatively high capacitive contribution.

Binders play a crucial role in maintaining mechanical integrity of electrodes in lithium-ion batteries. However, the conventional binders lack proper elasticity, and they are not suitable for high-performance silicon anodes featuring huge volume change during cycling. Herein, a poly(siloxane imide) copolymer (PSI) has been designed, synthesized, and utilized as a binder for silicon-based anodes. A rigidness/softness coupling mechanism is demonstrated by the PSI binder, which can accommodate volume expansion of the silicon anode upon lithiation. The electrochemical performance in terms of cyclic stability and rate capability can be effectively improved with the PSI binder as demonstrated by a silicon nanoparticle anode.

Direct non-oxidative methane conversion (DNMC) has been recognized as a single-step technology that directly converts methane into olefins and higher hydrocarbons. High reaction temperature and low catalyst durability, resulting from the endothermic reaction and coke deposition, are two main challenges. We show that a millisecond catalytic wall reactor enables stable methane conversion, C2+ selectivity, coke yield, and long-term durability. These effects originate from initiation of the DNMC on a reactor wall and maintenance of the reaction by gas-phase chemistry within the reactor compartment. The results obtained under various temperatures and gas flow rates form a basis for optimizing the process towards lighter C2 or heavier aromatic products. A process simulation was done by Aspen Plus to understand the practical implications of this reactor in DNMC. High carbon and thermal efficiencies and low cost of the reactor materials are realized, indicating the technoeconomic viability of this DNMC technology.

Summary: A pyrene end-labeled amphiphilic block copolymer, poly(e-caprolactone)-block-poly[6-O-(4-vinylbenzyl)-D-galactose] (Py-PCL-b-PVBG), was synthesized by a four-step method. The aggregation behavior of the diblock copolymer in solution was studied by monitoring the fluorescence of pyrene. TEM measurements revealed that the aggregates obtained by first dissolving the copolymer in N,N-dimethylformamide (DMF), followed by the addition of water, were primarily spheres with the PCL blocks in the core. The PVBG corona was then crosslinked with glutaraldehyde. Final removal of the PCL core was accomplished by degradation under basic conditions, which resulted in the formation of hollow glycopolymer nanospheres. Structure of poly(e-caprolactone)-block-poly[6-O-(4-vinylbenzyl)-D-galactose].

A detailed exploration of the atom transfer radical polymerization (ATRP) of a sugar-carrying monomer, 6-O-methacryloyl-1,2;3,4-di-O-isopropylidene-D-galactopyranose (MAIPGal) was performed. The factors pertinent to ATRP, such as initiators, ligands, catalysts, and temperature were optimized to obtain good control over the polymerization. The kinetics were examined in detail when the polymerization was initiated by methyl 2-bromoisopropionate (2-MBP), ethyl 2-bromoisobutyrate (2-EBiB), or a macroinitiator, [α-(2-bromoisobutyrylate)-ω-methyl PEO] (PEO–Br), with bipyridine (bipy) as the ligand at 60 °C or by 2-EiBB with N,N,N′,N″,N″-pentamethyldiethylenetriamine (PMDETA) as the ligand at room temperature (23 °C). The effects of the catalysts (CuBr and CuCl) were also investigated. We demonstrate that the successful ATRP of MAIPGal can be achieved for 2-EBiB/CuBr/bipy and 2-MBP/CuCl/bipy at 60 °C and for 2-EBiB/CuBr/PMDETA at room temperature. The initiation by 2-EBiB at room temperature with PMDETA as the ligand should be the most optimum operation for its moderate condition and suppression of many side reactions. Chain extension of P(MAIPGal) prepared by ATRP with methyl methacrylate (MMA) as the second monomer was carried out and a diblock copolymer, P(MAIPGal)-b-PMMA, was obtained. Functional polymers, poly(D-galactose 6-methacrylate) (PGMA), PEO-b-PGMA, and PGMA-b-PMMA were obtained after removal of the protecting groups. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 752–762, 2005