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Bioinspired hybrid nanofibers on the basis of polystyrene and Spirulina biomass—pristine and modified—were produced. These nanofibers were characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, and thermogravimetric analysis. The hybrid nanofibers have been utilized as adsorbents for the removal of copper and manganese ions from synthetic solution in batch mode at pH = 7, during a 2-h experiment. The maximum adsorption capacity was achieved for nanofibers with maximum Spirulina biomass loading: q = 8.7 mg/g for copper and 7.3 mg/g for manganese (with pristine biomass); q = 8.2 mg/g for copper and 7.0 mg/g for manganese (with modified biomass). The obtained results showed that the hybrid nanofiber could be successfully applied for metal removal from industrial effluents. [ABSTRACT FROM AUTHOR]

Nanofabrication via self-assembled hybrid building blocks into well-defined structures is a powerful tool for engineering functional materials with designed properties. This review demonstrates different concepts for fabrication of one-dimensional (1D) nanostructures based on hybrid materials via directed self-assembly. The concepts describe how different types of self-assembled organic phases drive the unidirectional assembly of the inorganic moieties. The organic matrices are used to control the size and size distribution of the generated inorganic nanoparticles. Formation of the 1D structures is dependent on many parameters, such as nature of chemical composition of the hybrid organic–inorganic materials, the pH of the wet chemistry medium and the types of interactions at the interface that drive the structure formation. The collective properties of the designed 1D structures are induced by means of the degree of anisotropy and the alignment of different types of inorganic nanoparticles within the organic matrices. This cost-effective approach could potentially be extended to fabricate varieties of hybrid low dimensional nanostructures possessing unique collective electronic and optical properties, leading to a wide range of applications such as catalysis, bionanotechnology, nanoelectronics, photonics and optoelectronics. [ABSTRACT FROM AUTHOR]

Thermal decomposition of suitable coordination compounds may be used as efficient route for fabrication of semiconducting layers. A new potential CdS precursor-a cadmium complex with all-sulfur Cd-coordination sphere [Cd{ μ-SSi(OBu)}(SCNCH)] 1-has been prepared, and its properties are investigated. The complex was obtained in the reaction between dimeric bis(tri- tert-butoxysilanethiolato)cadmium(II) [Cd{SSi(OBu)}] and ammonium N, N-tetrametylene-dithiocarbamate and characterized by spectral methods (IR, UV-Vis, MS, and NMR). X-ray structure analysis revealed the complex as molecular and dimeric in solid state with each of chelating dithiocarbamate ligands bonded to one Cd center and sulfur atoms from two tri- tert-butoxysilanethiolato ligands bridging metallic centers and thus completing the CdS coordination sphere. Thin film of the precursor prepared on SiO substrates via spin-coating technique was analyzed by AFM. Its decomposition was studied by thermal analysis methods (TG, DSC, and TG-FTIR). After melting at 227 °C, [Cd{ μ-SSi(OBu)}(SCNCH)] undergoes endothermic decomposition leading to CdS as the only solid product further identified by XRD, EDS, FIR as hexagonal CdS form. Its morphology is characteristic and may be described as 'micro-noodles'. [ABSTRACT FROM AUTHOR]

The presented study concerns the preparation and investigation of silver particles in presence of hydroxylated polyester dendrimers used as stabilizing agent. Altogether a full series of water soluble and aliphatic bis-MPA dendrimers from first to fifth generation was used as to stabilize silver nanoparticles in situ. A special focus is set on the biological properties. The antibacterial properties of the dendrimer stabilized silver particles are tested against Escherichia coli and the toxicity against human cells is tested with the human epithelial cell line A549. Under the chosen testing arrangement, it was observed that the silver particles contain a significant antibacterial effect against E. coli. Silver particles stabilized in situ with dendrimers of higher generation seem to contain a stronger antibacterial property. No toxicity against human cells was observed for the silver particles even in case of the highest investigated silver concentration. Altogether the here prepared and investigated silver particles could offer a great potential for application as antibacterial agent with low human toxicity. [ABSTRACT FROM AUTHOR]

A simple concept is proposed for templating in situ synthesised CdSe quantum dots (QDs) into an organised nano-pattern using the crystalline lamellae structure of polyamide 66 (PA66). The morphology obtained for PA66 and the hybrid material on Si/SiO solid substrate was characterised by means of atomic force microscope. Controlling the PA66 concentration in solution and the organic-inorganic interactions are found to be the keys factors to direct the assembly of CdSe QDs along the PA66 linear crystalline structure. This simple approach could be opened a new avenue for a large spectrum of innovative high-tech applications. [ABSTRACT FROM AUTHOR]

polystyrene- b-poly-4-vinypyridine (PS- b-P4VP) diblock copolymer is modified with a gold precursor to obtain an organic-inorganic (hybrid) block copolymer in bulk with gold nanoparticles selectively incorporated in the P4VP block. In the linear viscoelastic regime, temperature sweep tests over a series of these hybrid block copolymer systems revealed consistent shifts (Δ T) in the glass transition temperatures (both T $_{\rm g\text{-}PS}$ and T $_{\rm g\text{-}P4VP}$) of the hybrid materials in comparison to the pristine polymers. Studying different volume fractions of the pyridine block, a level-off point was found for block copolymers with f > 0.26, where the shifts in T $_{\rm g\text{-}P4VP}$ consistently increased up to Δ T = 25°C. By artificially increasing the volume fraction of the pyridine block, the nanoparticles reduce the transition regime determined in master curves. At higher volume fractions of the pyridine block, crossover frequencies were not detected after the entanglement regime, indicating that the material does not relax from topological constraints (entanglements and nanoparticles) into the terminal regime. Above a specific volume fraction of nanoparticles ( Φ = 0.05), the flow behaviour of the hybrid materials becomes increasingly elastic, exhibiting wall-slip from the geometry at lower strain values in comparison to the pristine material. In the non-linear viscoelastic regime, Fourier-transformed rheology was used to analyse the raw signals from strain sweep experiments. It was clearly demonstrated the nanoparticle effect by following the second and third harmonic ( I, I) of the stress response. Comparing the behaviour of the third and second harmonics provided an unambiguous fingerprint for the effect of the nanoparticles. [ABSTRACT FROM AUTHOR]

The preparation of gold nanoparticles in presence of different weak polyampholytes is investigated. As diblock polyampholytes several poly(methacrylic acid)- block-poly((dimethylamino)ethyl methacrylate), PMAA- b-PDMAEMA, have been used, characterized by different molecular weight and block ratio. HAuCl4 is used as gold precursor where LiBH4 is acting as reductive agent to obtain the gold nanoparticles. The addition of gold precursors to aqueous solutions of PMAA- b-PDMAEMA polyampholytes leads to an acidification of the solution resulting in a change of the polyampholyte conformation through protonation of the PDMAEMA blocks. This modification of polyampholyte conformation also allows the tuning of the size and size distribution of the accordingly formed gold nanoparticles. Investigations presented, are performed mainly by AFM of the systems in thin film adsorbed on native oxide-terminated Si substrate. TEM was used to reveal the change in size of the obtained gold nanoparticles. [ABSTRACT FROM AUTHOR]

Herein poly(glycerol sebacate) (PGS) has been synthesized and characterized to identify it’s potential as an active triboelectric layer in implantable and biodegradable TENG devices. The implantable and biodegradable TENG devices require excellent triboelectric properties, as well as the ability to mimic the mechanical properties of the surrounding tissues and exhibiting low cytotoxicity and eventual degradation and removal by bio-absorption. Two-step synthesis of PGS was carried out by using polycondensation between glycerol and sebacic acid in 1:1 molar ratio, followed by film preparation by spray-coating of the prepolymer solution. Crosslinking conditions were elaborated to yield good triboelectric performance together with low cytotoxicity. Triboelectric surface charge density of up to 0.188 nC cm−2 was obtained, exceeding the values of common triboelectric materials such as PDMS and PTFE by 2.89 and 3.76 times, respectively, when tested under identical contact-separation parameters. The mechanical properties of PGS can be tuned by varying the crosslinking degree to mimic soft tissues. In this context, in vitro studies on human skin fibroblasts revealed cell viability up to 78%. Furthermore, the cell viability is found to be strongly related to the crosslinking time of the PGS. The results show significantly lower cytotoxicity as compared to, for example, poly(sorbitol sebacate) and poly(hexanediol-co-citric acid). The flexibility and the confirmed biocompatibility beside the unique mechanical and physio-chemical collective properties of the of the polymer demonstrates the potential use of PGS for the next generation of implantable TENG devices.Graphical abstract: Herein poly(glycerol sebacate) (PGS) has been synthesized and characterized to identify it’s potential as an active triboelectric layer in implantable and biodegradable TENG devices. The implantable and biodegradable TENG devices require excellent triboelectric properties, as well as the ability to mimic the mechanical properties of the surrounding tissues and exhibiting low cytotoxicity and eventual degradation and removal by bio-absorption. Two-step synthesis of PGS was carried out by using polycondensation between glycerol and sebacic acid in 1:1 molar ratio, followed by film preparation by spray-coating of the prepolymer solution. Crosslinking conditions were elaborated to yield good triboelectric performance together with low cytotoxicity. Triboelectric surface charge density of up to 0.188 nC cm−2 was obtained, exceeding the values of common triboelectric materials such as PDMS and PTFE by 2.89 and 3.76 times, respectively, when tested under identical contact-separation parameters. The mechanical properties of PGS can be tuned by varying the crosslinking degree to mimic soft tissues. In this context, in vitro studies on human skin fibroblasts revealed cell viability up to 78%. Furthermore, the cell viability is found to be strongly related to the crosslinking time of the PGS. The results show significantly lower cytotoxicity as compared to, for example, poly(sorbitol sebacate) and poly(hexanediol-co-citric acid). The flexibility and the confirmed biocompatibility beside the unique mechanical and physio-chemical collective properties of the of the polymer demonstrates the potential use of PGS for the next generation of implantable TENG devices. [ABSTRACT FROM AUTHOR]