Double-emulsion templated macroporous cellulose microspheres as a high-performance chromatographic media for protein separation

Cellulose - Cellulose microspheres are commonly chromatographic media yet seriously limited in biomacromolecules separation and purification due to the slow mass transfer kinetics resulting from...     

High-strength and low-swelling chitosan/cellulose microspheres as a high-efficiency adsorbent for dye removal

Cellulose - Dye contamination of water supplies has a serious threat to human health, prompting the development of highly effective and eco-friendly adsorbents. In this work, polyelectrolyte...     

Synthesis and characterization of PrBaCo2 − x Ni x O5 + δ cathodes for intermediate temperature SOFCs

Nickel-substituted layered perovskite PrBaCo_{2 ? x} Ni _x O_{5 + δ} (PBCN) powders with various proportions of nickel (x?=?0, 0.1, 0.2, and 0.3, abbreviated as PBCN-0, PBCN-1, PBCN-2, and PBCN-3, respectively) are investigated as potential cathode materials for intermediate temperature solid oxide fuel cells (IT-SOFCs) based on the yttria-stabilized zirconia (YSZ) electrolyte. It is found that PBCN-1 has the highest electrical conductivity of 1,397 S cm^?1 at 400 °C. Substitution of Co by Ni decreases the thermal expansion coefficient (TEC) clearly. The average TEC at the temperature range of 35–900 °C decreases from 22.8?×?10^?6 K^?1 for PBCN-0 to 18.9?×?10^?6 K^?1 for PBCN-3. The polarization resistances of PBCN samples on YSZ electrolyte at 800 °C are 0.053, 0.048, 0.052, and 0.042 Ω cm² for PBCN-0, PBCN-1, PBCN-2, and PBCN-3, respectively. The single fuel cell with the configuration of PBCN-3/YSZ/Pt delivers the highest power densities of 100, 185, 360, 495, and 660 mW cm^?2 at 600, 650, 700, 750, and 800 °C, respectively.     

New analytical method for the study of the metabolism of gentiopicroside in rats after oral administration by LC–TOF‐MS following picolinoyl derivatization

The metabolism of gentiopicroside (GPS) in vivo was studied for the first time by LC–MS following picolinoyl derivatization. Incubation of erythrocentaurin, one of the main in vitro metabolites of GPS by intestinal bacteria, with liver microsome indicated that GPS might be metabolized to a final metabolite 3,4‐dihydro‐5‐(hydroxymethyl)isochroman‐1‐one (HMIO) in vivo. After hydrolysis with sulfatase, HMIO was successfully detected in rat plasma after oral administration of GPS by LC–MS following picolinoyl derivatization. 4‐Methoxyphenyl methanol was used as an internal standard to quantify HMIO in rat plasma. A metabolic pathway of GPS in rats is proposed. The monoterpene compound GPS was found to be metabolized to dihydroisocoumarin, which may be responsible for the pharmacological effect of GPS.     

Growth of Single-Walled Carbon Nanotubes with Controlled Structure: Floating Carbide Solid Catalysts

Single-walled carbon nanotube (SWNT) horizontal arrays with specific chirality can be enriched using solid carbide catalysts on substrates. However, scale-up production by continuous loading of the solid catalysts onto the substrates is challenging. Described here is the preparation of a floating carbide solid catalyst (FSC) for the controlled growth of SWNTs. The FSC, titanium carbide (TiC) nanoparticle, was directly obtained in the carrier gas phase by decomposition and carbonization of the titanocene dichloride precursor at high temperature. By using the TiC nanoparticle FSC, both SWNT horizontal arrays and randomly distributed networks can be obtained. The chirality of the as-grown SWNTs were thermodynamically controlled to have fourfold symmetry. Further optimization of growth condition resulted in an abundance of (16,8) tubes with about a 74 % content. This FSC chemical vapor deposition (FSCCVD) method has potential for realizing mass growth of SWNTs with controlled structures.     

A Non-Conjugated Polymer Acceptor for Efficient and Thermally Stable All-Polymer Solar Cells

A non-conjugated polymer acceptor PF1-TS4 was firstly synthesized by embedding a thioalkyl segment in the mainchain, which shows excellent photophysical properties on par with a fully conjugated polymer, with a low optical band gap of 1.58 eV and a high absorption coefficient >10⁵ cm⁻¹, a high LUMO level of −3.89 eV, and suitable crystallinity. Matched with the polymer donor PM6, the PF1-TS4-based all-PSC achieved a power conversion efficiency (PCE) of 8.63 %, which is ≈45 % higher than that of a device based on the small molecule acceptor counterpart IDIC16. Moreover, the PF1-TS4-based all-PSC has good thermal stability with ≈70 % of its initial PCE retained after being stored at 85 °C for 180 h, while the IDIC16-based device only retained ≈50 % of its initial PCE when stored at 85 °C for only 18 h. Our work provides a new strategy to develop efficient polymer acceptor materials by linkage of conjugated units with non-conjugated thioalkyl segments.     

Unveiling the Promotion of Surface-Adsorbed Chalcogenate on the Electrocatalytic Oxygen Evolution Reaction

Transition metal chalcogenides (TMCs) are efficient oxygen evolution reaction (OER) pre-electrocatalysts, and will in situ transform into metal (oxy)hydroxides under OER condition. However, the role of chalcogen is not fully elucidated after oxidation and severe leaching. Here we present the vital promotion of surface-adsorbed chalcogenates on the OER activity. Taking NiSe₂ as an example, in situ Raman spectroscopy revealed the oxidation of Se-Se to selenites (SeO₃²⁻) then to selenates (SeO₄²⁻). Combining the severe Se leaching and the strong signal of selenates, it is assumed that the selenates are rich on the surface and play significant roles. As expected, adding selenites to the electrolyte of Ni(OH)₂ dramatically enhance its OER activity. And sulfates also exhibit the similar effect, suggesting the promotion of surface-adsorbed chalcogenates on OER is universal. Our findings offer unique insight into the transformation mechanism of materials during electrolysis.     

磷脂膜的相行为对氧化石墨烯与磷脂膜相互作用的影响

通过使用不同相变温度的磷脂分子并调节二者的比例构筑了不同相态的磷脂膜, 并利用表面增强红外光谱和激光共聚焦显微镜研究了磷脂膜的相行为对氧化石墨烯和磷脂膜相互作用的影响. 结果表明, 氧化石墨烯对磷脂膜中磷脂分子的抽提作用具有显著的相态选择性, 其选择性地抽提流动相的磷脂分子; 氧化石墨烯对流动相磷脂的抽提作用受到膜中凝胶相磷脂存在比例的影响, 只有在流动相磷脂分子占磷脂膜中磷脂分子的绝大部分时才能够发生抽提作用, 且只有流动相的磷脂分子被抽提.     

Effect of methoxy position on dynamic mechanical and shape memory properties of methoxyphenol-based polybenzoxazines

Abstract

Two series of benzoxazines were synthesized from o-, m-, and p-methoxyphenols, two polyetheramines with different molecular weights, and formaldehyde. The glass transition temperatures (T _gs) of m-methoxyphenol-based polybenzoxazines are respectively higher than those of o- and p-methoxyphenol-based counterparts. The polybenzoxazines exhibit thermally induced one-way dual-shape memory behavior based on T _g, and the o- and p-methoxyphenol-based polybenzoxazines exhibit higher shape memory performance than m-methoxyphenol-based counterparts under motion constraints.