Hydrothermal Stability of Mesostructured Cellular Silica Foams

The hydrothermal stability of mesostructured cellular silica foams (MCFs) was studied in detail for the first time, using a variety of techniques including transmission electron microscopy, nitrogen sorption, small-angle X-ray scattering, 29Si solid-state nuclear magnetic resonance, and Fourier transform infrared spectroscopy. It was found that the high aging temperature, greater microporosity, and high calcination temperature contribute to the stability of MCFs in high-temperature steam. The frameworks of MCFs calcined at 550 °C are stable in 100% steam at 600 °C for 12 h, but cannot withstand more critical conditions of 800 °C steam and collapse completely. By elevating the calcination temperature of MCFs to 900 °C, the polymerization degree of the silica frameworks is further enhanced, and the obtained MCF materials exhibit high hydrothermal stability under steam at 800 °C for 12 h. The results indicate that increasing the calcination temperature is an effective method to improve the hydrothermal stability of MCFs. It is concluded that 3-D disordered MCFs show structural variations during the high-temperature steam treatments different from those of 2-D ordered hexagonal SBA-15 materials. The pore size, window size, and wall thickness were unaltered for the steam-treated MCFs, while the pore size decreased and the pore wall thickness became thicker for SBA-15

All-Electrochem-Active Thick Electrode with Dual-Continuous TiO₂‑Carbon Integrated Skeletons for Low-Temperature Lithium Storage

Newly designed all-electrochem-active thick electrode (∼500 μm) with dual-continuous integrated skeletons of defective rutile-anatase TiO2 (D-R-A-TiO2) heterojunctions and carbon have been introduced to enhance efficient electron–ion transport for high-rate energy storage, which provides a new idea for low-temperature lithium storage. For the first time, we anneal anatase TiO2 integrated carbon under CO2 atmosphere for converting anatase to rutile and activating carbon simultaneously, to fabricate freestanding all-electrochem-active thick electrode. The D-R-A-TiO2 heterojunctions contain a type II staggered band alignment, which significantly induce highly localized electrons and lower the migration barrier of ions. The continuous D-R-A-TiO2 heterojunctions form synergistically advantageous electronic networks, and the thick electrode (up to 60.97 mg cm–2) delivers outstanding areal capacity (14.14 mAh cm–2 at 0.61 mA cm–2) under 30 °C. The areal capacity is 8.62 mAh cm–2 at 0.57 mA cm–2 under −10 °C. When the temperature drops to −20 °C, the areal capacity still delivers 4.92 mAh cm–2 at 0.57 mA cm–2. And the D-R-A-TiO2 electrode still delivers 3.2 mAh cm–2 capacity after 70 cycles at 0.57 mA cm–2 under −20 °C

Relevance of P2X1–4 subunits staining with four types of I_ATPs.

<p>+ stands for positive staining, − stands for negative staining.</p

Co-localizations of two P2X subunits in nodose ganglia.

<p>(A–C) Immunoreactivity of P2X1 and P2X2 (A–C), P2X1 and P2X3 (D–F), and P2X2 and P2X3 (G–I) subunits in the NG. Scale bars = 50 µm.</p

Porous Carbon and Carbon/Metal Oxide Microfibers with Well-Controlled Pore Structure and Interface

Porous Carbon and Carbon/Metal Oxide Microfibers with Well-Controlled Pore Structure and Interfac

Ordered Mesoporous Crystalline γ-Al₂O₃ with Variable Architecture and Porosity from a Single Hard Template

In this paper, an efficient route is developed for controllable synthesis of ordered mesoporous alumina (OMA) materials with variable pore architectures and high mesoporosity, as well as crystalline framework. The route is based on the nanocasting pathway with bimodal mesoporous carbon as the hard template. In contrast to conventional reports, we first realize the possibility of creating two ordered mesopore architectures by using a single carbon hard template obtained from organic−organic self-assembly, which is also the first time such carbon materials are adopted to replicate ordered mesoporous materials. The mesopore architecture and surface property of the carbon template are rationally designed in order to obtain ordered alumina mesostructures. We found that the key factors rely on the unique bimodal mesopore architecture and surface functionalization of the carbon hard template. Namely, the bimodal mesopores (2.3 and 5.9 nm) and the surface functionalities make it possible to selectively load alumina into the small mesopores dominantly and/or with a layer of alumina coated on the inner surface of the large primary mesopores with different thicknesses until full loading is achieved. Thus, OMA materials with variable pore architectures (similar and reverse mesostructures relative to the carbon template) and controllable mesoporosity in a wide range are achieved. Meanwhile, in situ ammonia hydrolysis for conversion of the metal precursor to its hydroxide is helpful for easy crystallization (as low as ∼500 °C). Well-crystallized alumina frameworks composed of γ-Al2O3 nanocrystals with sizes of 6−7 nm are obtained after burning out the carbon template at 600 °C, which is advantageous over soft-templated aluminas. The effects of synthesis factors are demonstrated and discussed relative to control experiments. Furthermore, our method is versatile enough to be used for general synthesis of other important but difficult-to-synthesize mesoporous metal oxides, such as magnesium oxide. We believe that the fundamentals in this research will provide new insights for rational synthesis of ordered mesoporous materials

Immunofluorescent staining of cultured NG neurons.

<p>NG neurons were stained using antibodies against P2X1, P2X2, P2X3, and P2X4 receptor subunits (A, D, G, and J, respectively). The nuclei of cultured NG neurons were stained with antibodies against NeuN (B, E, H, K). Merged images (C, F, I, L) representing co-staining of P2X receptor subunits and NeuN are shown. The scale bar shown in L is representative of all images, and represents 50 µm.</p

Concentration-response relationships and the efficacy order of P2X receptor antagonists on I_ATPs.

<p>(A) Sequential current traces of F, I, S, and VS ATP-activated currents recorded from rat NG neurons in response to different concentrations of ATP (from 10⁻⁵ to 3×10⁻³ M). Current traces of each type were obtained from the same neuron. (B) The dose-response curves for each type of I_ATPs. Each point represents the means ± SEM of 10–15 neurons. All ATP-induced currents were normalized to the response induced by 3×10⁻³ M ATP in each type. The holding potential was set at −60 mV. The data for ATP were a good fit to the Hill equation I = I_max/[1+ (EC50/C) n], where C is the concentration of ATP, I is the normalized amplitude of I_ATP, and EC50 is the concentration of ATP for the half maximal current response. (C) The efficacy order of the inhibitory effects of P2X receptor antagonists on four distinct I_ATPs. The columns in the bar graph show the inhibitory effects of the P2X receptor antagonists: PPADS (10⁻⁴M), suramin (10⁻⁴ M), and RB2 (10⁻⁴ M). F-type, suramin >PPADS > RB2; I-type, suramin > PPADS > RB2; S-type, suramin > RB2> PPADS; VS-type: suramin > RB2> PPADS. *<i>p</i><0.05, **<i>p</i><0.01.</p

Relevance of the P2X1–4 subunits on the four types of I_ATP.

<p>(A) Schematic view of the setup for the whole cell patch clamp and a representative image of a recorded cell under the phase contrast microscope and immunohistochemistry. (B) Immunohistochemistry revealed positive or negative staining for P2X1–4 subunits, which correlated with the type of I_ATP and cell size. The samples in each row were from four different neurons that responded to ATP with different types of ATP-activated current. P2X3 staining was positive in all four types of I_ATP neurons. P2X1 was positive in F, I, and S I_ATPs, but negative in VS. P2X2 staining was only absent in neurons with type I I_ATP, and P2X4 was positive in neurons with type F, I, and some S I_ATPs.</p

Distribution and expression of P2X1–4 subunits in NG tissue.

<p>(A) A schematic diagram of the maximum cross section of a rat nodose ganglion (A, corresponding to panel B). (B) Representative graph of the distribution of P2X receptor-positive cells throughout the whole nodose ganglion section under a 20× light microscopic field. (C–F) Immunohistochemical staining using polyclonal antibodies against P2X1 (C), P2X2 (D), P2X3 (E), and P2X4 (F); 100× magnification. Scale bars in B = 500 µm and F = 100 µm.</p