Solid-State MAS NMR Studies of Sulfonic Acid-Functionalized SBA-15

Solid-state magic-angle spinning (MAS) nuclear magnetic resonance (NMR) was used to characterize propylsulfonic acid-functionalized SBA-15 materials prepared by the cocondensation method. The propylsulfonic acid-group concentration and distribution was systematically varied from 2.5 to 10%. As a way of coupling two acid sites and controlling the acid site spatial distribution, tethered propylsulfonic acid groups were incorporated into SBA-15. ¹³C, ²⁹Si and ¹H MAS NMR were used to determine the extent of functionalization. Probe molecules, such as triethylphosphine oxide and diphenyldiphosphines were used to evaluate acid site strength and acid site distributions, respectively. Authors' address: Sarah C. Larsen, Department of Chemistry, University of Iowa, Iowa City, IA 52242, USA     

Investigation on the performance,emissions and combustion characteristics of CRDI engine fueled with tallow methyl ester biodiesel blends with exhaust gas recirculation

This paper demonstrates the study of performance, combustion and emission characteristics of a common rail diesel injection (CRDI) engine with the influence of exhaust gas recirculation (EGR) (5, 15 and 25%) at various fuel injection pressures (400, 500 and 600 bar) under the effective load conditions (0, 25, 50, 75 and 100%). The experiments were carried out in a controlled manner using the CRDI engine fuelled with 80% (D80) diesel (98% purity) blended with 20% (B20) tallow biodiesel. The engine has been operated at a rated speed of 1500 rpm on all load conditions, fuel injection timings of 10°, 15° and 20° bTDC, fuel injection pressures of 400, 500 and 600 bar, respectively. Combustion-influenced performance characteristics such as variation of in-cylinder pressure and net heat release rate in J deg^?1 are also studied with the above operating conditions. It was observed that the usage of 20% biofuel blend shows considerable improvement in combustion, and it further enhances with an increase in the injection pressures. Besides, EGR (up to 25%) reduced significant pollutants at higher operating pressures (600 bar) at higher load conditions. It was also observed that CO₂ emission increased with increase in the % EGR with an increase in the load conditions. However, for CO emission increased up to 50% load condition and subsequently tends to decrease due to improved combustion at higher load; hence higher temperature. NO_x, smoke opacity continue to increase with the increase in pressure and the percentage increase in EGR due to its attainment of adiabatic temperature, which leads to the pathway for the Zeldovich mechanism. The present work shows light on the usage of tallow methyl ester produced from the wastes in the tannery industry as alternate biofuel operating the CRDI engines without compromising its combustion and emission characteristics to deliver the same power as petro-diesel.

     

Hexagonal, hollow, aluminium-containing ZSM-5 tubes prepared from mesoporous silica templates

Hexagonal hollow ZSM-5 tubes were synthesized using mesoporous silica with a worm-like morphology as the template. A new method for aluminium incorporation during the hydrothermal synthesis step was developed.     

Acridine Based Small Molecular Hole Transport Type Materials for Phosphorescent OLED Application

Two small molecular hole-transporting type materials, namely 4-(9,9-dimethylacridin-10(9H)-yl)-N-(4-(9,9-dimethylacridin-10(9H)-yl)phenyl)-N-phenylaniline (TPA-2ACR) and 10,10′-(9-phenyl-9H-carbazole-3,6-diyl)bis(9,9-dimethyl-9,10-dihydroacridine) (PhCAR-2ACR), were designed and synthesized using a single-step Buchwald–Hartwig amination between the dimethyl acridine and triphenylamine or carbazole moieties. Both materials showed high thermal decomposition temperatures of 402 and 422 °C at 5% weight reduction for PhCAR-2ACR and TPA-2ACR, respectively. TPA-2ACR as hole-transporting material exhibited excellent current, power, and external quantum efficiencies of 55.74 cd/A, 29.28 lm/W and 21.59%, respectively. The achieved device efficiencies are much better than that of the referenced similar, 1,1-Bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC)-based device (32.53 cd/A, 18.58 lm/W and 10.6%). Moreover, phenyl carbazole-based PhCAR-2ACR showed good device characteristics when applied for host material in phosphorescent OLEDs.