Assessment on the Effect of Sulfuric Acid Concentration on Physicochemical Properties of Sulfated-Titania Catalyst and Glycerol Acetylation Performance

In this research, a solid acid catalyst was synthesized to catalyse glycerol acetylation into acetins. The sulphated-titania catalysts were prepared via the wet impregnation method at different sulfuric acid concentrations (5%, 10%, 15%, and 20%) and denoted as 5SA, 10SA, 15SA, and 20SA, respectively. The synthesized catalysts were characterized using FTIR, XRD, TGA, BET, NH3-TPD, XRF, and SEM-EDX. The synthesized catalysts were tested on glycerol acetylation reaction at conditions: 0.5 g catalyst loading, 100–120 °C temperature, 1:6 glycerol/acetic acid molar ratios, and 2–4 h reaction time. The final product obtained was analysed using GC-FID. An increment in sulfuric acid concentration reduces the surface area, pore volume, and particles size. However, the increment has increased the number of active sites (Lewis acid) and strong acid strength. 15SA catalyst exhibited excellent glycerol conversion (>90%) and the highest selectivity of triacetin (42%). Besides sufficient surface area (1.9 m2 g−1) and good porosity structure, the great performance of the 15SA catalyst was attributed to its high acid site density (342.6 µmol g−1) and the high active site of metal oxide (95%).

Direct Amide Synthesis over Composite Magnetic Catalysts in a Continuous Flow Reactor

Composite magnetic catalysts containing different amounts of sulfated titania (33–50 wt %) have been prepared by means of high energy ball-milling between TiO2 and NiFe2O4. The catalysts have been characterized with N2 adsorption/desorption isotherms, XRD, temperature programmed oxidation (TPO) and vibrating sample magnetometer (VSM). The catalytic activity was measured in the reaction of aniline and 4-phenylbutyric acid in the continuous mode under conventional and inductive heating. The effect of catalyst loading in the reactor on reaction and deactivation has been studied, indicating the catalyst containing 50 wt % titania gave the highest reaction rate and least deactivation. The operation in a flow reactor under inductive heating increased the amide yield by 25% as compared to conventional heating. The initial reaction rate decreased by 30% after a period of 15 h on stream. The catalyst activity was fully restored after a treatment with an air flow at 400 °C.

Chitosan-Sulfated Titania Composite Membranes with Potential Applications in Fuel Cell: Influence of Cross-Linker Nature

Chitosan-sulfated titania composite membranes were prepared, characterized, and evaluated for potential application as polymer electrolyte membranes. To improve the chemical stability, the membranes were cross-linked using sulfuric acid, pentasodium triphosphate, and epoxy-terminated polydimethylsiloxane. Differences in membranes’ structure, thickness, morphology, mechanical, and thermal properties prior and after cross-linking reactions were evaluated. Membranes’ water uptake capacities and their chemical stability in Fenton reagent were also studied. As proved by dielectric spectroscopy, the conductivity strongly depends on cross-linker nature and on hydration state of membranes. The most encouraging results were obtained for the chitosan-sulfated titania membrane cross-linked with sulfuric acid. This hydrated membrane attained values of proton conductivity of 1.1 × 10−3 S/cm and 6.2 × 10−3 S/cm, as determined at 60 °C by dielectric spectroscopy and the four-probes method, respectively.

Synthesis of New 4-Chloro-6-Methylpyrimidin-2-yl-Aminophosphonates as Potential DU145 and A549 Cancer Cell Inhibitors

: A series of new α-aminophosphonates containing potential anticancer active 4-chloro-6- methylpyrimidin-2-amino pharmacophore were synthesized. Background: α-Aminophosphonates are of growing interest to the researchers due to their biological activities. Besides aminophosphoryl functionality, which is responsible for the vital activity, incorporation of a captivating pharmacophore on it will definitely enrich its activity. Objective: Erstwhile many of the reported α-aminophosphonates impregnated with bioactive heterocycles like quinazoline, chromene, pyrazole, furan and thiophene were used as anticancer drugs, and we are intended to enhance the anticancer potentiality of α-aminophosphonates by substituting a new 4-chloro-6-methylpyrimidin-2-yl group into its structure, specifically on nitrogen atom. Methods: Title compounds were synthesized by Kabachnik-Fields reaction by using sulfated Titania, a solid acid catalyst that is encompassed with high density of Lewis acidic reaction sites. The series of synthesized compounds were screened for in vitro anti-cancer activity and their ADMET, QSAR and drug properties studied. Results: Structures of all the title compounds synthesized in high yields were confirmed by spectral & elemental analyses. Their anti-cancer screening studies on various cell lines and evaluation of other properties revealed their potentiality towards the inhibition of growth of DU145 & A549 cell lines. Conclusion: The substitution of 4-chloro-6-methylpyrimidin-2-amino moiety on to the amino functionality of the α-aminophosphonates is a critical task invariably due to the substitutions that are located on α-carbon. As such, this substitution had increased the scope for growth inhibition of DU145 and A549 cancer cells.

Dehydration of glucose/fructose to 5-hydroxymethylfurfural (5-HMF) over an easily recyclable sulfated titania (SO42−/TiO2) catalyst

An efficient SO42−/TiO2 catalyst was developed which demonstrated a maximum of ∼75% and ∼37% yield of 5-HMF in the presence of fructose and glucose, respectively. Brønsted/Lewis acidic ratio of catalyst played a crucial role in the yield of 5-HMF.

Novel nanocomposite membranes based on cross-linked eco-friendly polymers doped with sulfated titania nanotubes for direct methanol fuel cell application

Developing low cost and highly active fuel cell is one of the high-priority research directions for fuel cell commercialization, whereas durable electrodes and electrolyte membranes are keys for its optimization. Herein, a novel nanocomposite electrolyte membranes for direct methanol fuel cell were prepared from eco-friendly polymer blend composed of poly(vinyl alcohol) (PVA) and iota carrageenan (IC). Sulfated titania (SO4TiO2) nanotubes are synthesized by impregnation–calcination method and incorporated as doping agents into the polymer matrix with different percentage ranged between 1 wt% and .5 wt%. The PVA/IC/SO4TiO2 nanocomposite membranes exhibited reduction in water and methanol uptake compared to that of undoped membrane, while the thermal properties and oxidative stability increased as the doping agent content increased. Methanol permeability of PVA/IC/[Formula: see text]-TiO2-7.5 membrane was 0.62 × 10−7 cm2 s−1, which is 43 times lower than Nafion 117 (26.9 × 10−7 cm2 s−1). Furthermore, it was noticed that the ion exchange capacity and mechanical properties of the nanocomposite membranes are higher than that of Nafion 117.