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The proliferation of mosquito-borne diseases is a major health concern worldwide. An effective strategy to prevent the transmission of mosquito-borne diseases is using larvae control. Cinnamaldehyde, a substance from the cinnamon tree, is widely used in larvicide formulations, yet applications are limited due to the poor water solubility of cinnamaldehyde. Therefore, we prepared a sodium alginate–chitosan nanocomposite as a nanocarrier of cinnamaldehyde, and we tested the effect of this encapsulated cinnamaldehyde on Aedes aegypti larvae. The nanocomposites/cinnamaldehyde formulations were characterised by Fourier transform infrared spectroscopy and nuclear magnetic resonance, which evidenced encapsulation. A ratio of 150:1 w/w nanocomposite/cinnamaldehyde induced the highest encapsulation efficiency of 95.25%, a loading capacity of 81.42%. This extended the cinnamaldehyde release by 28 h and controlled mosquito larvae. [ABSTRACT FROM AUTHOR]

SUMMARY Exploitation of biomass wastes gives new hopes in the exploration of clean alternative fuel source such as hydrogen energy. The application of catalysts plays a major role in the process by enhancing the production of hydrogen via reformation and tar cracking reaction. However, certain drawbacks such as catalyst cost, deactivation, and regeneration remain unsolved in this process. In this study, we focused on potential Malaysian dolomite (Perlis) as the source of catalysts for palm frond gasification. The influences of mechanochemical treatment in three different media (air, ethanol, and water) on the catalytic activity of the material were analyzed. Important changes in the properties of the dolomite along with the high catalytic performance were noted as the results of the treatment. Notable changes in the dolomite structure and porosity were observed because of the impact of the treatment. Increment in the surface area of the catalysts boosts the H2 production and catalytic activity of dolomite. Moreover, substantial CO2 reduction was also observed during reaction as a result of the absorption capacity of treated dolomite. Thus, through mechanochemical treatment, the property of Malaysian dolomite is being greatly altered, which really suits as a potential catalyst for gasification. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The synthesis of carbon nanotubes (CNTs) by the chemical vapour deposition (CVD) method using natural calcite from Anadara granosa shells as the metal catalyst support was studied. Hexane and iron (Fe) were used as the carbon precursor and the active component of the catalyst, respectively. Response surface methodology (RSM) based on central composite design (CCD) was used to optimise the effect of total iron loading, the duration of reaction, and reaction temperature. The optimal conditions were total iron loading of 7.5%, a reaction time of 45 min, and a temperature of 850°C with a resulting carbon yield of 131.62%. Raman spectra, field-emission-scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) analyses showed that the CNTs were of the multiwalled type (MWNTs). [ABSTRACT FROM AUTHOR]

The present work addresses the influence of microwave irradiation on undoped and doped vanadium phosphate catalysts. These catalysts were prepared via VOPO4 · 2H2O. The catalyst’s precursors‚ VOHPO4 · 0.5H2O were subjected to microwave irradiation and comparison was made with the conventional heating. The interaction of these complex materials with microwave and the addition of several doponts (Nb, Bi, Co, Mo) provide interesting improvements in catalyst preparation found to be a faster, develop higher surface area, higher activity and selectivity for the oxidation of n-butane to maleic anhydride. All the catalysts were characterized by using a combination of powder XRD, H2-TPR, BET surface area and SEM. [ABSTRACT FROM AUTHOR]

Two vanadium phosphate catalysts (VPH1 and VPH2) prepared via hydrothermal method are described and discussed. Both catalysts exhibited only highly crystalline pyrophosphate phase. SEM showed that the morphologies of these catalysts are in plate-like shape and not in the normal rosette-type clusters. Temperature-programmed reduction in H2 resulted two reduction peaks at high temperature in the range of 600–1100 K. The second reduction peak appeared at 1074 K occurred as a sharp peak indicated that the oxygen species originated from V4+ phase are having difficulty to be removed and their nature are less reactive compared to other methods of preparation. Modified VPH2 gave better catalytic performance for n-butane oxidation to maleic anhydride contributed by a higher BET surface area, high mobility and reactivity of the lattice oxygen associated to the V4+ which involved in the hydrocarbon’s activation. A slight increased of the V5+ phase also enhanced the activity of the VPH2 catalyst. [ABSTRACT FROM AUTHOR]

A 1 bismuth-doped VPO catalyst was prepared by refluxing Bi(NO3)3 and VOPO4 ⋅ 2H2O in isobutanol. The incorporation of Bi into the VPO lattice lowered the overall V oxidation state from 4.24 to 4.08. It also lowered both the peak maximum temperature for the desorption of oxygen from the lattice from 1001K (undoped) to 964K with a shoulder at 912K and the peak maxima for {\rm H}_2 temperature-programed reduction from 863, 1011 and 1143K (undoped) to 798, 906 and 1151K. The total oxygen desorbed from the Bi-doped catalyst was only one-fourth that of the undoped catalyst, while the amount of oxygen removed by TPR was roughly the same for both catalysts. These results suggest that in anaerobic oxidation, the Bi-doped catalyst will have roughly the same activity as in undoped catalyst in C4 hydrocarbon oxidation but will have a higher selectivity to products such as olefins and maleic anhydride. [ABSTRACT FROM AUTHOR]