Application of Novel Zeolite Y Nanoparticles in Catalytic Cracking Reactions

The cracking activity of a fluid catalytic cracking (FCC) catalyst containing novel zeolite Y nanoparticles fabricated using mesoporous silica (average particle size of 150 nm) was examined and compared with the performance of other catalysts. The activity experiments were carried out in a fluidized bench-scale batch riser simulator reactor. The bulky probing compound of 1,3,5-triisopropylbenzene (TIPB) was cracked to lighter compounds over a catalyst containing 25% of the developed zeolite. The synthesized sodium-type zeolite nanoparticles were subjected to two cycles of ion-exchange treatment using ammonium sulfate and lanthanum chloride and then to calcination. To investigate the effects of particle size on the activity, three additional catalysts were prepared with the mean particle size of the supported zeolites ranging from 450 to 1800 nm. The preparation of the FCC catalysts was conducted by mixing the highly aqueous dispersed zeolite Y nanoparticles with colloidal silica–alumina as a matrix and silica sol as a binder. The results of the catalytic cracking of TIPB demonstrated the significant effect of the size reduction of the synthesized zeolite Y nanoparticles on the catalytic performance of the catalyst. The FCC catalyst that contained zeolite Y nanoparticles (150 nm) showed superior conversion and selectivity percentages for the main products. The results of this study have a direct implication on the preparation of colloidal catalysts containing zeolite Y nanoparticles, which form stable emulsion with petroleum products. These emulsions can be utilized for slurry and ebullated bed reactors in heavy oil upgrading applications.     

Selective and facile oxidative desulfurization of thioureas and thiobarbituric acids with singlet molecular oxygen generated from trans-3,5-dihydroperoxy-3,5-dimethyl-1,2-dioxolane

An efficient and facile procedure using trans-3,5-dihydroperoxy-3,5-dimethyl-1,2-dioxolane has been developed for oxidative desulfurization of thioureas and thiobarbituric acids. The reactions proceeded smoothly very fast under mild conditions in basic media at room temperature to afford the respective ureas in excellent yields. Simple procedure and work up, mild conditions, high yields, short reaction times, use of highly potent and non-toxic oxidant are the main merits of the present method.     

Toughening PVC with Biocompatible PCL Softeners for Supreme Mechanical Properties,Morphology, Shape Memory Effects,and FFF Printability

In this article, a first of its kind blend of polyvinyl chloride (PVC) and biocompatible polycaprolactone (PCL) is introduced by melt mixing and then 3D printed successfully via Fused Filament Fabrication (FFF). Experimental tests are carried out on PCL-PVC blends to assess thermo-mechanical behaviors, morphology, fracture toughness, shape-memory effects and printability. Macro and microscopic tests reveal that PVC-PCL compounds are miscible due to high molecular compatibility and strong interaction. This causes extraordinary mechanical properties specially for PVC-10 wt% PCL. In addition to the desired tensile strength (45 MPa), this material has a completely rubbery behavior at ambient temperature, and its total elongation is more than 81%. In addition, due to the high formability of PVC-PCL at ambient temperature, it has capability of being programed via different shape-memory protocols. Programming tests show that PVC-PCL blends have an excellent shape-memory effect and result in 100% shape recovery. SEM results prove a high improvement of PVC printability with the addition of 10 wt% PCL. Toughened PVC by PCL is herein added to the materials library of FFF 3D printers and expected to revolutionize applications of PVC compounds in the field of biomedical 3D and 4D printing due to its appropriate thermo-mechanical properties, supreme printability, and excellent biocompatibility.