12 research outputs found
Intracluster Ion Molecule Reactions Following the Generation of Mg+ Within Polar Clusters
In this work we investigated the intracluster ion molecule reactions following the generation of Mg+ within the polar clusters (water, methanol, ether and acetonitrile), using time of flight mass spectrometry. In the case of Mg+/water and Mg+/methanol, dehydrogenation reactions are observed after the addition of five molecules. However, no dehydrogenation reactions are observed in the case of Mg+/ether or Mg+/acetonitrile clusters. This confirms the role of the H atom in (O–H) in the dehydrogenation reaction, and rules out any contribution from the H atom in the CH3 group. In addition, the magic numbers in the time of flight (TOF) mass spectra of the Mg+Xn clusters (X = H2O, CH3OH, CH3OCH3 and CH3CN) have been investigated. Finally, the role of ground electronic magnesium ion Mg+(2S1/2), and excited electronic magnesium ion Mg+(2P1/2) in the dehydrogenation reaction were investigated using Ion Mobility Mass spectrometry. The results offer direct evidence confirming the absence of the electronically excited, Mg+(2P1/2)
PEG Coated Fe3O4/RGO Nano-Cube-Like Structures for Cancer Therapy via Magnetic Hyperthermia
Superparamagnetic iron oxide nanoparticles (SPIONs) have high saturation magnetization and are promising candidates for hyperthermia. They may act as magnetic heating agents when subjected to magnetic field in nano-based hyperthermia. In this work, cube-like Fe3O4 nanoparticles (labelled as cubic SPIONs) with reduced graphene oxide (RGO) nanocomposites were prepared by a microwave hydrothermal method. The shape and size of magnetic nanoparticles were controlled by varying synthesis parameters, including reaction time, pressure and microwave power. This study successfully synthesized cubic SPIONs nanocomposites with an average particle size between 24–34 nm. Poly-(ethylene) glycol (PEG) was used as a coating material on SPIONs to enhance biocompatibility. The RGO sheets provided a high surface area-to-volume ratio for SPIONs to be dispersed on their surface, and hence, they prevented aggregation of the SPIONs in the nanocomposites. Magnetically induced heating studies on the optimized nanocomposite (Fe3O4/RGO/PEG) demonstrated heating capabilities for magnetic hyperthermia application with a promising specific absorption rate (SAR) value of 58.33 W/g in acidic solution. Cytotoxicity tests were also performed to ensure low nanoparticle toxicity before incorporation into the human body. The results of the standard assay for the toxicity determination of the nanocomposites revealed over 70% cell survival after 48 h, suggesting the feasibility of using the synthesized nanocomposites for magnetic hyperthermia
Synthesis and Characterization of the in Situ Bulk Polymerization of PMMA Containing Graphene Sheets Using Microwave Irradiation
molecule
Evaluation of nanomechanical properties of (styrene-methyl methacrylate) copolymer composites containing graphene sheets
Magnetic based graphene composites with steroidal diamine dimer as potential drug in hyperthermia cancer therapy
Hyperthermia is a non-invasive process of killing cells through heat, as cells go into apoptosis when heated in the range of 41 °C–47 °C. In this work, the biologically active 4-pregnen-3-one-20 β -carboxaldehyde (ketobisnoraldehyde) based steroidal diamine dimer (KPD) was chemically grafted on GO surface (GO-KPD) for the first time through an amidation reaction between amine groups of KPD and activated carboxylic acid sites of GO. Magnetite nanoparticles (Fe _3 O _4 ) were dispersed on the prepared nanocomposite surface to produce GO-KPD-Fe _3 O _4 nanocomposite with superparamagnetic property. To study the structural effect of KPD, 1,4 diamonobutane (Putrescine) was also grafted chemically on GO via amidation reaction. Successful functionalization of GO surface was confirmed using Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, X-ray diffraction (XRD), elemental analysis, and thermogravimetric analysis (TGA). The morphology of the functionalized GO was characterized by scanning electron microscopy (SEM). Furthermore, a cytotoxicity test on Michigan Cancer Foundation-7 (CMF-7) human breast cancer cell line was conducted. The data suggest that the prepared nanocomposite (GO-KPD-Fe _3 O _4 ) has a cytotoxic potential against the MCF-7 cell line, thus it could be investigated as potential drug in hyperthermia cancer therapy
Physico-Chemical and Catalytic Properties of Mesoporous CuO-ZrO2 Catalysts
Mesoporous CuO-ZrO2 catalysts were prepared and calcined at 500 °C. The performance of the synthesized catalysts for benzylation of benzene using benzyl chloride was studied. The bare support (macroporous ZrO2) offered 45% benzyl chloride conversion after reaction time of 10 h at 75 °C. Significant increase in benzyl chloride conversion (98%) was observed after CuO loading (10 wt. %) on porous ZrO2 support. The conversion was decreased to 80% with increase of CuO loading to 20 wt. %. Different characterization techniques (XRD, Raman, diffuse reflectance UV-vis, N2-physisorption, H2-TPR, XPS and acidity measurements) were used to evaluate physico-chemical properties of CuO-ZrO2 catalysts; the results showed that the surface and structural characteristics of the ZrO2 phase as well as the interaction between CuO-ZrO2 species depend strongly on the CuO content. The results also indicated that ZrO2 support was comprised of monoclinic and tetragonal phases with macropores. An increase of the volume of monoclinic ZrO2 phase was observed after impregnation of 10 wt. % of CuO; however, stabilization of tetragonal ZrO2 phase was noticed after loading of 20 wt. % CuO. The presence of low-angle XRD peaks indicates that mesoscopic order is preserved in the calcined CuO-ZrO2 catalysts. XRD reflections due to CuO phase were not observed in case of 10 wt. % CuO supported ZrO2 sample; in contrast, the presence of crystalline CuO phase was observed in 20 wt. % CuO supported ZrO2 sample. The mesoporous 10 wt. % CuO supported ZrO2 catalyst showed stable catalytic activity for several reaction cycles. The observed high catalytic activity of this catalyst could be attributed to the presence of a higher number of dispersed interactive CuO (Cu2+-O-Zr4+) species, easy reducibility, and greater degree of accessible surface Lewis acid sites