Discoid Bicelles as Efficient Templates for Pillared Lamellar Periodic Mesoporous Silicas at pH 7 and Ultrafast Reaction Times

We report the first synthesis of periodic mesoporous silicas templated by bicelles. The obtained materials form novel pillared lamellar structures with a high degree of periodic order, narrow pore size distributions, and exceptionally high surface areas

Large Scale Synthesis of Highly Pure Single Crystalline Tellurium Nanowires by Thermal Evaporation Method

Single crystalline tellurium nanowires were successfully synthesized in large scale by a facile approach of vaporizing tellurium metal and condensing the vapor in an inert atmosphere onto a Si substrate. Tellurium was evaporated by heating at 300 C at 1 torr and condensed on the Si substrate at 100-150 C, in the downstream of argon (Ar) gas at a flow rate of 25 sccm for 30 min. The as-synthesized nanowires have diameters between 100-300 nm and lengths up to several micrometers. The single crystalline nanowires grew in a preferred [0001] direction. The obtained nanowires were highly pure as only tellurium metal was used in the vaporization process, and no other reagent, surfactant, or template were used for the growth. This low temperature and high-yield approach to the tellurium nanowires synthesis may facilitate its industrial production for various applications

Periodic Mesoporous Organosilica Nanorice

A periodic mesoporous organosilica (PMO) with nanorice morphology was successfully synthesized by a template assisted sol–gel method using a chain-type precursor. The PMO is composed of D and T sites in the ratio 1:2. The obtained mesoporous nanorice has a surface area of 753 m2 g−1, one-dimensional channels, and a narrow pore size distribution centered at 4.3 nm. The nanorice particles have a length of ca. 600 nm and width of ca. 200 nm

Simple Systematic Synthesis of Periodic Mesoporous Organosilica Nanoparticles with Adjustable Aspect Ratios

One-dimensional periodic mesoporous organosilica (PMO) nanoparticles with tunable aspect ratios are obtained from a chain-type molecular precursor octaethoxy-1,3,5-trisilapentane. The aspect ratio can be tuned from 2:1 to >20:1 simply by variation in the precursor concentration in acidic aqueous solutions containing constant amounts of triblock copolymer Pluronic P123. The mesochannels are highly ordered and are oriented parallel to the longitudinal axis of the PMO particles. No significant Si–C bond cleavage occurs during the synthesis according to29Si MAS NMR. The materials exhibit surface areas between 181 and 936 m2 g−1

Hemorrhage and ischemia in different hemispheres in a child with moyamoya disease: Case report and review of literature

Hemorrhagic type of moyamoya disease (MMD) is extremely rare in children. Ischemia following hemorrhage is very rare in MMD. There are only 11 reports of mixed-type of MMD, with the patient having both hemorrhage and ischemia in the same hemisphere at the time of presentation, or at different time periods. The ischemia is usually secondary to a precipitating cause. However, there are no reports of a child presenting with both ischemia and hemorrhage in different hemispheres. We present a previously unreported phenomenon of MMD, presenting as hemorrhage and ischemia in opposite hemispheres and review the relevant literature

Cyclophosphazene-Based Hybrid Nanoporous Materials as Superior Metal-Free Adsorbents for Gas Sorption Applications

Cyclophosphazene-based inorganic–organic hybrid nanoporous materials (CHNMs) have been synthesized by a facile solvothermal method. The condensation of pyrrole with the reaction product of phosphonitrilic chloride trimer and 4-hydroxybenzaldehyde resulted in the formation of high-surface-area CHNMs. The maximum specific surface area (SA_BET) of 1328 m² g^–1 with hierarchical pore structures having micropores centered at 1.18 nm and mesopores in the range of 2.6–3.6 nm was estimated from the N₂ sorption analysis. Observation of high SA_BET could be attributed to the synergy effect exerted by the cyclophosphazene moiety owing to its three-dimensional paddle wheel structure. The metal-free adsorbent exhibited a high and reversible CO₂ uptake of 22.8 wt % at 273 K and 1 bar. The performance is on the higher side among the reported metal-free inorganic–organic hybrid nanoporous adsorbents. Moreover, the high H₂ uptake of 2.02 wt % at 77 K and 1 bar is an added advantage. The superior performance of the adsorbents for the gas sorption applications could be attributed to the combined effect of high SA_BET and hierarchical pore structure, which has made CHNMs good candidates for energy and environmental applications

Discoid Bicelles as Efficient Templates for Pillared Lamellar Periodic Mesoporous Silicas at pH 7 and Ultrafast Reaction Times

<p>Abstract</p> <p>We report the first synthesis of periodic mesoporous silicas templated by bicelles. The obtained materials form novel pillared lamellar structures with a high degree of periodic order, narrow pore size distributions, and exceptionally high surface areas.</p

Identifying the Point of Attachment in the Hypercrosslinking of Benzene for the Synthesis of a Nanoporous Polymer as a Superior Adsorbent for High-Pressure CO₂ Capture Application

The point of attachment in the hypercrosslinking of benzene using formaldehyde dimethyl acetal as the crosslinker, anhydrous ferric chloride as the catalyst, and 1,2 dichloroethane as the solvent for the synthesis of poly-benz is reported. A fast microwave-assisted synthesis, within a reaction time of 60 min, resulted in the formation of nanoporous poly-benz having a specific surface area of 1168 m2 g–1. A thorough analysis of poly-benz using 13C cross-polarization magic angle spinning nuclear magnetic resonance and X-ray photoelectron spectra has revealed the hypercrosslinking at the meta position of the benzene ring. The synthesized poly-benz further shows a high CO2 capture capacity of 65.3 wt % at 298 K and 30 bar. Various adsorption isotherm models have been fitted at different temperatures up to 30 bar to represent the equilibrium CO2 adsorption data