A single-step hydrothermal synthesis of a TiO2–Mil-125 composite was applied for the first time to produce a depleted perovskite/TiO2–MOF heterojunction solar cell with 6.4% power conversion efficiency.
9 January 2015 in Journal of Materials Chemistry B
In this work, new efficient drug delivery systems based on cellulose nanofiber–titania nanocomposites grafted with three different types of model drugs such as diclofenac sodium, penicillamine-D and phosphomycin were successfully synthesized and displayed distinctly different controlled long-term release profiles. Three different methods of medicine introduction were used to show that various interactions between TiO2 and drug molecules could be used to control the kinetics of long-term drug release. All synthesis reactions were carried out in aqueous media. The morphology, chemical structure and properties of the obtained materials were characterized by SEM, TEM and AFM microscopy, nanoparticle tracking analysis, X-ray diffraction, and TGA analysis. According to FT-IR and UV-Vis spectroscopy data, the titania binds to cellulose nanofibers via formation of ester bonds and to drug molecules via formation of surface complexes. The drug release kinetics was studied in vitro for diclofenac sodium and penicillamine-D spectrophotometrically and for phosphomycin using a radio-labeling analysis with 33P-marked ATP as a model phosphate-anchored biomolecule. The results demonstrated that the obtained nanocomposites could potentially be applied in transdermal drug delivery for anesthetics, analgesics and antibiotics.
Presentwork is devoted to investigation of structure and functional properties of hybrid nanomaterials based on\ud the TiO2-modified cellulose fibers of cotton. The titania hydrosol was successfully prepared using the titanium\ud tetraisopropoxide as precursor and the nitric acid as peptizing agent via the low-temperature sol–gel synthesis\ud in aqueous medium and applied to cotton fabric. For cross-linking of titania nanoparticles to cotton the 1,2,3,4-butanetetracarboxylic acid (BTCA) was used as a spacer. The morphology and composition of the surface pure and TiO2 modified cotton fibers were investigated by the scanning electron microscopy (SEM). The cotton/TiO2\ud composite was characterized by the dielectric permittivity. For the estimation of total titania concentration, all samples were calcined at 650 °C. The antimicrobial activity of the treated TiO2 cotton fibers was investigated against Escherichia coli as a model Gram-negative bacteria after exposure to UV-irradiation for 10 mi
Spherical cellulose nanocrystal-based hybrids grafted with titania nanoparticles were successfully produced for topical drug delivery. The conventional analytical filter paper was used as a precursor material for cellulose nanocrystals (CNC) production. Cellulose nanocrystals were extracted via a simple and quick two-step process based on first the complexation with Cu(II) solution in aqueous ammonia followed by acid hydrolysis with diluted H2SO4. Triclosan was selected as a model drug for complexation with titania and further introduction into the nanocellulose based composite. Obtained materials were characterized by a broad variety of microscopic, spectroscopic, and thermal analysis methods. The drug release studies showed long-term release profiles of triclosan from the titania based nanocomposite that agreed with Higuchi model. The bacterial susceptibility tests demonstrated that released triclosan retained its antibacterial activity against Escherichia coli and Staphylococcus aureus. It was found that a small amount of titania significantly improved the antibacterial activity of obtained nanocomposites, even without immobilization of model drug. Thus, the developed hybrid patches are highly promising candidates for potential application as antibacterial agents.