Offretite zeolite synthesis in the presence of cetyltrimethylammonium bromide (CTABr) is reported. The offretite crystals were synthesized with a high crystallinity and hexagonal prismatic shape after only 72 h of hydrothermal treatment at 180 °C. The CTABr has dual-functions during the crystallization of offretite, viz. as structure-directing agent and as mesoporogen. The resulting offretite crystals, with a Si/Al ratio of 4.1, possess more acid sites than the conventional offretite due to their high crystallinity and hierarchical structure. The synthesized offretite is also more reactive than its conventional counterpart in the acylation of 2-methylfuran for biofuel production under non-microwave instant heating condition, giving 83.5% conversion with 100% selectivity to the desired product 2-acetyl-5-methylfuran. Hence, this amphiphile synthesis approach offers another cost-effective and alternative route for crystallizing zeolite materials that require expensive organic templates.
The possible magnetophoretic migration of iron oxide nanoparticles through the cellulosic matrix within a single layer of paper is challenging with its underlying mechanism remained unclear. Even with the recent advancements of theoretical understanding on magnetophoresis, mainly driven by cooperative and hydrodynamics phenomena, the contributions of these two mechanisms on possible penetration of magnetic nanoparticles through cellulosic matrix of paper have yet been proven. Here, by using iron oxide nanoparticles (IONPs), both nanospheres and nanorods, we have investigated the migration kinetics of these nanoparticles through grade 4 Whatman filter paper with a particle retention of 20-25 μm. By performing droplet tracking experiments, the real-time stained area growth of the particle droplet on the filter paper, under the influences of a grade N40 NdFeB magnet, were recorded. Our results show that the spatial and temporal expansion of the IONP stain is biased toward the magnet and such an effect is dependent on (i) particle concentration and (ii) particle shape. The kinetics data were first analyzed by treating it as a radial wicking fluid, and later the IONP distribution within the cellulosic matrix was investigated by optical microscopy. The macroscopic flow front velocities of the stained area ranged from 259 μm/s to 16 040 μm/s. Moreover, the microscopic magnetophoretic velocity of nanorod cluster was also successfully measured as ∼214 μm/s. Findings in this work have indirectly revealed the strong influence of cooperative magnetophoresis and the engineering feasibility of paper-based magnetophoretic technology by taking advantage of magnetoshape anisotropy effect of the particles.