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In this article, novel nanocomposites of poly(3- or m-aminobenzenesulfonic acid) and TiO2 were synthesized by very simple in-situ polymerization of monomer (m-ABS) by FeCl3.6H2O as an oxidant and TiO2 particles as inorganic phase under solid-state condition. The combination of N-type TiO2 and P-type PABS led to the preparation of two new P–N junction type nanocomposites. The polymer-hybrid solar cells were fabricated using the nanocomposites as FTO/TiO2/NCPABS-TiO2/Al and under simulated solar irradiation demonstrated power conversion efficiencies (PCE, η) about 1%. The other advantages of this work were fewer fabrication costs, ease-of-processing, green synthesis condition, a simple structure of the solar cell (single layer), and the high stability of the resulted cells. The synthesized nanocomposites (NCPABS-TiO2-1 and 2) were characterized by FT-IR, UV–vis, VSM, XRD, CV, TGA, and CHNS analysis. The electrical properties and conductivity of the nanocomposites were shown that are electro-active and semi-conductive. The morphology of the compounds was investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) that revealed core–shell and nanosheet morphologies, respectively. Also, the effect of core–shell and nanosheet morphology, the presence of -SO3H group, and TiO2 enhancer phase as a separate hole transition layer in solar cell and as an inorganic phase in nanocomposite matrix (active layer) on the power conversion efficiency of hybrid solar cells was investigated. Indeed, it is shown even a small amount of magnetic (nano)material [FeCl2, FeCl3, and/or high spin Fe (ii, iii) complexes] can increase the efficiency of the cell due to conversion of photogenerated state from spin singlet to triplet. [ABSTRACT FROM AUTHOR]

Fe(acac)3/silica/PVA hybrid xerogel nanocomposite was obtained by one pot acid catalysed sol-gel synthesis using the homogeneous mixture of iron(III) acetylacetonate (Fe(acac)3), tetraethylorthosilicate (TEOS), and polyvinyl alcohol (PVA). Nominal composition ratio of iron oxide/silica was 15/85 (weight percent). Nitric acid was used as catalyst. Another sample of Fe(acac)3/silica xerogel without PVA addition was prepared in the similar processing conditions. Based on thermal analysis studies, the thermal behaviour of both xerogel samples was unveiled and it allowed choosing the optimal calcination temperatures in order to obtain iron oxide silica magnetic nanocomposite samples. The two xerogel (with and without PVA) samples were thermally treated, in air, at 220, 260 and 300 °C and characterized by different techniques. XRD investigations revealed phase composition evolution with calcination temperature, from cubic spinel phase (maghemite) to hexagonal stable hematite containing nanocomposite of 10–20 nm average crystallite size. These findings were confirmed by Mössbauer spectroscopy. Up to 300 °C, the surface area and total pores volume increased with temperature for all samples. By calcination at the same temperature, the hybrid xerogel containing PVA resulted in significantly higher magnetization and free volume values in comparison with the sample without PVA.

Authors aimed to provide a magnetic responsiveness to bone-mimicking nano-hydroxyapatite (n-HA). For this purpose, dextran-grafted iron oxide nanoarchitectures (DM) were synthesized by a green-friendly and scalable alkaline co-precipitation method at room temperature and used to functionalize n-HA crystals. Different amounts of DM hybrid structures were added into the nanocomposites (DM/n-HA 1:1, 2:1 and 3:1weight ratio) which were investigated through extensive physicochemical (XRD, ICP, TGA and Zeta-potential), microstructural (TEM and DLS), magnetic (VSM) and biological analyses (MTT proliferation assay). X-ray diffraction patterns have confirmed the n-HA formation in the presence of DM as a co-reagent. Furthermore, the addition of DM during the synthesis does not affect the primary crystallite domains of DM/n-HA nanocomposites. DM/n-HAs have shown a rising of the magnetic moment values by increasing DM content up to 2:1 ratio. However, the magnetic moment value recorded in the DM/n-HA 3:1 do not further increase showing a saturation behaviour. The cytocompatibility of the DM/n-HA was evaluated with respect to the MG63 osteoblast-like cell line. Proliferation assays revealed that viability, carried out in the absence of external magnetic field, was not affected by the amount of DM employed. Interestingly, assays also suggested that the DM/n-HA nanocomposites exhibit a possible shielding effect with respect to the anti-proliferative activity induced by the DM particles alone. [ABSTRACT FROM AUTHOR]

Magnetic nanoparticles yielded by chemical route were surface modified with stabilizing agents being further coated by sol-gel method with silica shell to be used for various applications. Iron oxide magnetic cores were dispersed in water by single citrate layer and, respectively, by double oleate hydrophilic coating. Sol-gel reaction with tetraethylorthosilicate provided further coating with silica that confers increased reactivity for ligand coupling. Microstructural and magnetic properties were investigated by standard methods evidencing nanometric size, good crystallinity, and superparamagnetic behavior. Comparative analysis evidenced similar crystallite size for both citrate- and oleate-coated magnetic nanoparticles, while granularity was changed after silica adding. Saturation magnetization diminished less for oleate-stabilized nanoparticles than for citrate-stabilized ones after silica coating and moderate thermal treatment. Such prepared magnetic nanocomposites could have possible utilization as magnetic vectors for targeted biomolecules. Graphical Abstract: [ABSTRACT FROM AUTHOR]