Hydrous manganese dioxide-polyacrylonitrile (MnO(2)-PAN) was chemically synthesized and evaluated, as an organic-inorganic composite material, for the removal of radio-contaminant cesium-137 from aqueous solutions. The physico-chemical characterization was carried out by Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), CHN elemental analysis, scanning electron microscopy (SEM), nitrogen adsorption-desorption studies and thermogravimetry-differential scanning calorimetry (TGA-DSC). Batch experiments were carried out as a function of contact time, interference of the coexisting ions and initial pH of adsorptive solution applying a radiotracer technique. The effect of temperature on the distribution coefficient of cesium has been utilized in order to evaluate the changes in the standard thermodynamic parameters. The results indicated that Cs(+) ions could be efficiently removed using MnO(2)-PAN composite in the pH range of 4-9 from aqueous solutions and the uptake of cesium is affected to varying degrees by the presence of some diverse co-ions. The equilibrium isotherms have been determined and the sorption data were successfully modeled using Freundlich model.
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http://dx.doi.org/10.1016/j.apradiso.2011.10.018 | DOI Listing |
PLoS One
January 2025
Glycologix, Inc., 100 Cummings Center, Beverly, Massachusetts, United States of America.
Chemical modification of naturally derived glycosaminoglycans (GAGs) expands their potential utility for applications in soft tissue repair and regenerative medicine. Here we report the preparation of a novel crosslinked chondroitin sulfate (~200 to 2000 kilodaltons) that is both soluble in aqueous solution and microfilterable. We refer to these materials as "SuperGAGs.
View Article and Find Full Text PDFJ Chem Theory Comput
January 2025
Instituto de Ciencia Molecular, Universitat de València, 22085 València, Spain.
Determining the energetics of triplet electronic states of nucleobases in the biological macromolecular environment of nucleic acids is essential for an accurate description of the mechanism of photosensitization and the design of drugs for cancer treatment. In this work, we aim at developing a methodological approach to obtain accurate free energies of triplets in DNA beyond the state of the art, able to reproduce the decrease of triplet energies measured experimentally for in DNA (270 kJ/mol) vs in the isolated nucleotide in aqueous solution (310 kJ/mol). For such purposes, we adapt the free energy perturbation method to compute the free energy related to the transformation of a pure singlet state into a pure triplet state via "alchemical" intermediates with mixed singlet-triplet nature.
View Article and Find Full Text PDFNanomaterials (Basel)
January 2025
Yunnan Key Laboratory of Modern Separation Analysis and Substance Transformation, College of Chemistry and Chemical Engineering, Yunnan Normal University, Kunming 650500, China.
We successfully synthesize monodisperse sulfhydryl-modified mesoporous organosilica nanospheres (MONs-SH) via one-step hydrolytic condensation, where cetyltrimethylammonium chloride and dodecyl sulfobetaine are employed as dual-template agents with (3-mercaptopropyl)triethoxysilane and 1,2-bis(triethoxysilyl)ethane as the precursors and concentrated ammonia as the alkaline catalyst. The prepared MONs-SHs deliver a large specific surface area (729.15 m g), excellent monodispersity, and homogeneous particle size.
View Article and Find Full Text PDFNanomaterials (Basel)
January 2025
Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
Environmental changes, such as applied medication, nutrient depletion, and accumulation of metabolic residues, affect cell culture activity. The combination of these factors reflects on the local temperature distribution and local oxygen concentration towards the cell culture scaffold. However, determining the temporal variation of local temperature, independent of local oxygen concentration changes in biological specimens, remains a significant technological challenge.
View Article and Find Full Text PDFNanomaterials (Basel)
January 2025
Department of Chemical Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada.
The interactions between cellulose nanocrystals and six different polymers (three anionic, two non-ionic, and one cationic) were investigated using rheological measurements of aqueous solutions of nanocrystals and polymers. The experimental viscosity data could be described adequately by a power-law model. The variations in power-law parameters (consistency index and flow behavior index) with concentrations of nanocrystals and polymers were determined for different combinations of nanocrystals and polymers.
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