Can Be a Bimetal Oxide ZnO-MgO Nanoparticles Anticancer Drug Carrier and Deliver? Doxorubicin Adsorption/Release Study.

Bimetal oxide ZnO-MgO nanoparticles were synthesised by precipitation method at low temperature and characterised by analytical techniques such as XRD, SEM and FT-IR. In order to know the efficiency of uptake and release of anticancer drug, the adsorption and release of doxorubicin, on bimetal oxide nanoparticles was performed in dark room at room temperature. The adsorption models such as Henry, Freundlich and Langmuir models were validated with obtained experimental data. Due to heterogeneous surface of bimetal oxides, data followed well with Henry and Freundlich models but not Langmuir that proposed homogeneous adsorbent surface. The strong affinity between drug and nanoparticles is certainly due to the electrostatic interaction between positively charged doxorubicin molecules and negatively charged surface of ZnO-MgO nanoparticles and hydrogen bonding between them that confirmed from FT-IR analysis. The doxorubicin release from ZnO-MgO nanoparticles was performed at pH 4 and 7 to evaluate the kinetic of drug release using various mathematical models. At neutral pH, the doxo release was found to be ~14% whereas at acidic pH (pH 4) nearly 68% of doxo was released at 6.5 hours due to dissolution and neutralising the surface charge of ZnO-MgO nanoparticles. Various mathematical models such as zero order, first order, Higuchi and Hixson-Crowell were approached to evaluate the kinetic release of drug from the nanoparticles. The obtained release data for acidic pH followed Hixson-Crowell model, proposes erosion dependent release system, compared to Higuchi that confirmed doxo release is due to dissolution of ZnO-MgO nanoparticles. In this study, it is concluded that ZnO-MgO nanoparticles will be a promising drug vehicle in drug delivery system.

Low temperature growth of double walled carbon nanotubes using FeMoMgO catalyst.

The chemical vapour deposition technique was utilised to grow the double walled carbon nanotubes (DWCNTs) over FeMoMgO catalyst at low temperature (550 degrees C) under the mixture of argon, hydrogen and acetylene gas. Thermogravimetric analysis revealed that synthesised nanotubes have thermal stability and high purity. The high-resolution transmission electron microscopy image showed the formation of DWCNTs with tube diameter of 2.5-3.5 nm. We observed radial breathing mode (RBM) in Raman spectrum, which is related to the diameter of DWCNTs. This synthesis process is simple and economically viable ascribed to low synthesis temperature, simplicity and well graphitization with high yield.

Intrusion/Extrusion of water into organic grafted SBA-15 silica materials for energy storage.

Mesoporous SBA-15 silica materials were grafted with trialkylsilyl compounds having short (C1) and long (C8) carbon chain and characterized by XRD, N2 physisorption analysis, 29Si MAS-NMR and contact angle (CA) measurements. A drastic enhancement of the hydrophobic property after grafting was observed by forced intrusion water; it occurred in two steps and with quite high intrusion pressures (mean values - 10 and - 15 MPa). The hydrophobic nature of both internal and external surface area was confirmed by 29Si MAS-NMR and CA measurements, respectively. After contact with water, materials displayed a partial hydrophobic behaviour with uncompleted spontaneous extrusion. The energies absorbed during water intrusion correspond to 4.3 and 6.1 J x g(-1) for C1 and C8 grafted species, respectively.

Three-dimensional ultralarge-pore ia3d mesoporous silica with various pore diameters and their application in biomolecule immobilization.

Highly ordered mesoporous three-dimensional Ia3d silica (KIT-6) with different pore diameters has been synthesized by using pluronic P123 as surfactant template and n-butanol as cosolvent at different synthesis temperatures in a highly acidic medium. The materials were characterized by XRD and N(2) adsorption. The synthesis temperature plays a significant role in controlling the pore diameter, surface area, and pore volume of the materials. The material prepared at 150 degrees C, KIT-6-150, has a large pore diameter (11.3 nm) and a high specific pore volume (1.53 cm(3) g(-1)). We also demonstrate immobilization of lysozyme, which is a stable and hard protein, on KIT-6 materials with different pore diameters. The amount of lysozyme adsorbed on large-pore KIT-6 is extremely large (57.2 micromol g(-1)) and is much higher than that observed for mesoporous silicas MCM-41, SBA-15, and KIT-5, mesoporous carbons, and carbon nanocages. The effect of various parameters such as buffer concentration, adsorption temperature, concentration of the lysozyme, and the textural parameter of the adsorbent on the lysozyme adsorption capacity of KIT-6 was studied. The amount adsorbed mainly depends on solution pH, ionic strength, adsorption temperature, and pore volume and pore diameter of the adsorbent. The mechanism of adsorption on KIT-6 under different adsorption conditions is discussed. In addition, the structural stability of lysozyme molecules and the KIT-6 adsorbent before and after adsorption were investigated by XRD, nitrogen adsorption, and FTIR spectroscopy.

Novel microporous carbon material with flower like structure templated by MCM-22.

Novel flower like microporous carbons with very high surface area have been synthesized for the first time using MCM-22 zeolite as a template and sucrose as a carbon source. The textural parameters of the materials can easily be tuned by the simple adjustment of the sucrose to MCM-22 weight ratio. It has been also found that the specific surface area of the microporous carbon materials is much higher as compared with that of its parent zeolite template.

Effective uptake of decontaminating agent (citric acid) from aqueous solution by mesoporous and microporous materials: an adsorption process.

The presence of citric acid in decontamination waste can cause complexation of the radioactive cations resulting in interferences in their removal by various treatment processes such as chemical precipitation, ion-exchange, etc., which are employed for the removal of radioactivity and may cause potential danger to the environment. Mesoporous Al-MCM-41 (Si/Al=30, 51, 72 and 97) and Si-MCM-41 molecular sieves were synthesized hydrothermally and characterized by XRD, BET (surface area) and FT-IR to evaluate the removal of citric acid through an adsorption process. Adsorption of citric acid over Al-MCM-41 shows the applicability of Freundlich and Langmuir isotherm and follows first order kinetics. The effects of contact time, concentration of citric acid, adsorbents (various Si/Al ratios of Al-MCM-41, Si-MCM-41, Hbeta zeolite and commercial carbon) and pH have been investigated. It has been found that the amount of citric acid adsorbed per unit gram of catalyst followed the order Al-MCM-41 (Si/Al=30)>Al-MCM-41 (Si/Al=51)>activated charcoal>Al-MCM-41 (Si/Al=72)>Al-MCM-41 (Si/Al=97)>Si-MCM-41>Hbeta zeolite.