Fabrication and biofunctionalization of selenium-polypyrrole core-shell nanoparticles for targeting and imaging of cancer cells

Selenium-polypyrrole core-shell nanoparticles are fabricated by an in-situ polymerization process and functionalized with transferrin for targeting and imaging of human cervical cancer cells. The shell thickness and chemical composition of the as-synthesized particles can be manipulated by controlling the precursor concentration. The presence of the polymer layer can greatly increase the thermal stability of the selenium nanoparticles. The presence of transferrin molecules on the surface of the core-shell nanoparticles can significantly enhance their cellular uptake. The tranferrin-conjugated core-shell nanoparticles can be potentially used for the targeting and imaging of cancer cells.

A three-dimensional highly interconnected composite oxygen reduction reaction electrocatalyst prepared from a core-shell precursor

Getting intimate: A 3D interconnected Bi_0.5Sr _0.5FeO_3-ð (BSF)-Ag electrocatalyst is prepared from a BSF-AgNO₃ core-shell precursor in one step. The nanometer-sized Ag enhances the sintering process, enabling an optimum cathode microstructure and good cathode-to-electrolyte attachment upon firing at 850°C. A solid-oxide fuel cell based on this cathode shows a near 100% peak power density enhancement at 550°C.

One-dimensional polyelectrolyte/polymeric semiconductor core/shell structure : sulfonated poly(arylene ether ketone)/polyaniline nanofibers for organic field-effect transistors

A polyelectrolyte/polymeric semiconductor core/shell structure is developed for organic field-effect transistors (OFETs) based on sulfonated poly(arylene ether ketone)/polyaniline core/shell nanofibers via electrospinning and solution-phase selective polymerization. The polyelectrolyte does not work as a gate dielectric, but can provide an internal modulation from the nanointerface of the 1D core/shell nanostructure. The transistor devices display very high mobilities.

Au-doped polyacrylonitrile-polyaniline core-shell electrospun nanofibers having high field-effect mobilities

Au-doped polyacrylonitrile–polyaniline core–shell nanofibers are fabricated via electrospinning and subsequent gas-phase polymerization, providing a very high field-effect mobility of up to 11.6 cm² V⁻¹ s⁻¹. This method is also suitable for other conducting polymers and may eventually lead to a new and simplified fabrication of high-performance polymer organic field-effect transistors.

Reinforcement of natural rubber with core-shell structure silica-poly(Methyl Methacrylate) nanoparticles

A highly performing natural rubber/silica (NR/SiO2) nanocomposite with a SiO2 loading of 2 wt% was prepared by combining similar dissolve mutually theory with latex compounding techniques. Before polymerization, double bonds were introduced onto the surface of the SiO2 particles with the silane-coupling agent. The core-shell structure silica-poly(methyl methacrylate), SiO2-PMMA, nanoparticles were formed by grafting polymerization of MMA on the surface of the modified SiO2 particles via in situ emulsion, and then NR/SiO2 nanocomposite was prepared by blending SiO2-PMMA and PMMA-modified NR (NR-PMMA). The Fourier transform infrared spectroscopy results show that PMMA has been successfully introduced onto the surface of SiO2, which can be well dispersed in NR matrix and present good interfacial adhesion with NR phase. Compared with those of pure NR, the thermal resistance and tensile properties of NR/SiO2 nanocomposite are significantly improved.

Synthesis and characterization of tin dioxide core-shell structure nanowires

In this study, one-dimensional and quasi-one-dimensional tin dioxide nanowires and nan-owalls were fabricated by the use of the chemical vapor deposition technique. It was demonstrated that the growth and nanostructure of tin oxide can be controlled by varying the thickness of gold layer and the partial pressure of vapor at growing sites. Nanowires with a core-shell structure, i.e., pure tin core and tin oxide shell, were synthesized from C-S_nO₂ powders at a mol ratio of C/S_nO₂=3/5 on both silicon and Lanthanum Strontium Co-balt Ferrite ceramic wafers through the vapor-solid mechanism. The conditions that are favorable to the growth of core-shell structure nanowires are investigated.

Synthesis of LiFePO4@carbon nanotube core-shell nanowires with a high-energy efficient method for superior lithium ion battery cathodes

A high-energy efficient method is developed for the synthesis of LiFePO4@CNT core-shell nanowire structures. The method consists of two steps: liquid deposition approach to prepare FePO4@CNT core-shell nanowires and solvothermal lithiation to obtain the LiFePO4@CNT core-shell nanowires at a low temperature. The solution phase method can be easily scaled up for commercial application. The performance of the materials produced by this method is evaluated in Li ion batteries. The one-dimensional LiFePO4@CNT nanowires offer a stable and efficient backbone for electron transport. The LiFePO4@CNT core-shell nanowires exhibit a high capacity of 132.8 mAh g^-1 at a rate of 0.2C, as well as high rate capability (64.4 mAh g^-1 at 20C) for Li ion storage.

Fabrication of core-shell structured natural rubber based microfibres for artificial blood vessel tissue engineering scaffolds

A successful trial on preparing natural rubber based core-shell structured fibres by co-axial electrospinning and fabrication of artificial blood vessel scaffolds from crosslinked fibres.

Fabrication of ZnO/SiO2 composite nanospheres with high core-loading levels

Monodispersed silica shell / zinc oxide core composite nanospheres were prepared in an oil-in-water microemulsion system. By using cyclohexane as the oil phase and Triton X-100 as the surfactant, nanospheres with a high core loading level and high monodispersity were obtained. The silica coating greatly reduced the photoactivity of ZnO nanoparticles, offering safe and durable applications of ZnO as UV screening agents.

Superhydrophobic fabrics prepared by silica coating

In this work, a silica sol prepared by co-hydrolysis and co-condensation of TEGS (Tetraethylrthosilicate) and alkyl silane under alkaline condition was applied to polyester, wool, and cotton fabrics. The water contact angle measurement indicated considerable increase in the surface hydrophobicity of the sol-treated fabrics. Five different alky silanes were used, namely methyltritthoxysilane (MTES), pheryl triethoxysilane (PTES), n-octyltricthoxysilane (OTES), hexadecyl trimethoxysilan (HDTMS), and tridecafluorooctyl triethoxysilane (FAS), and the water contact anglc (CA) for the coated fabrics ranged between 1300 and 174°. The alkyl silane used influenced the CA valuc, and the silica coating from FAS, HDTMS and PTES snowed CA value greater than ISO', indicating the formation of superhydrophobicity. The fabric coated by the fluorinated silica (TEOS/FAS) has a water contact angle as high as 174°. The treated polyester fabric showed a slightly higher CA value than the wool and cotton fabrics, under the same coating condition.
The coating surface was characterized by SEM, EDX, TEM, FTlR, XPS and AFM. The results showed that silica nanoparticles with thc sizc in the range of 50-ISOnm werc formed in the cohydrolyzed silica sol, and these particles had a core-shell structure with many alkyl groups gathering on the surface region. The formation of superhydrophobic surface was attributed to the nano-structured surface coating with a low surface energy.

Self-assembled natural rubber/silica nanocomposites : its preparation and characterization

A novel natural rubber/silica (NR/SiO2) nanocomposite is developed by combining self-assembly and latex-compounding techniques. The results show that the SiO2 nanoparticles are homogenously distributed throughout NR matrix as nano-clusters with an average size ranged from 60 to 150 nm when the SiO2 loading is less than 6.5 wt%. At low SiO2 contents (less-than-or-equals, slant4.0 wt%), the NR latex (NRL) and SiO2 particles are assembled as a core-shell structure by employing poly (diallyldimethylammonium chloride) (PDDA) as an inter-medium, and only primary aggregations of SiO2 are observed. When more SiO2 is loaded, secondary aggregations of SiO2 nanoparticles are gradually generated, and the size of SiO2 cluster dramatically increases. The thermal/thermooxidative resistance and mechanical properties of NR/SiO2 nanocomposites are compared to the NR host. The nanocomposites, particularly when the SiO2 nanoparticles are uniformly dispersed, possess significantly enhanced thermal resistance and mechanical properties, which are strongly depended on the morphology of nanocomposites. The NR/SiO2 has great potential to manufacture medical protective products with high performances.

Super water repellent fabrics produced by silica nanoparticle-containing coating

In this paper, we report on superhydrophobic fabrics (polyester, wool and cotton) produced by a wet-chemical coating technique. The coating solutions were synthesized by the co-hydrolysis of two silane precursors, tetraethyl orthosilicate (TEOS) and an alkylsilane, in an alkaline condition. Without any purification, the as-hydrolyzed solutions were directly used to treat fabrics, and the treated fabrics had water contact angles (CA) as high as 170º and sliding angles (SA) as low as 5º. Three alkylsilanes have been used for the synthesis of the coating solutions, and all contain three hydrolysable alkoxyl groups and one non-hydrolysable alkyl, but with different chain lengths (C1, C8 and C16). It was found that the CA value increased with an increase in the alkyl chain length, while the SA showed a reverse trend. When the functional group had a C16 alkyl, the treated fabric surfaces were highly superhydrophobic, with the CA not being affected much by the fabric type, while the SA values were slightly affected by the original wettability of the fabric substrates. The superhydrophobic feature was attributed to a highly rough surface formed by the particulate coating. Aside from the superhydrophobicity, the influence of the coating on the fabric softness was also examined.

In situ synchrotron SAXS study of polymerizable microemulsions

We present for the first time a real-time small-angle X-ray scattering (SAXS) study of the structural transition of fluid microemulsion to solid polymerized material in a silicone polymerizable microemulsion system. A reactive methacrylate-terminated siloxane macromonomer (MTSM, Mn ∼ 1000 g/mol) was synthesized and used for microemulsion formulations comprising MTSM (oil phase), water, and a mixture of nonionic surfactant (Teric G9A8) with isopropanol. In situ synchrotron SAXS was used to investigate time-dependent nanostructure evolution during the polymerization reaction, which was directly initiated by X-ray radiation. The SAXS data were analyzed using both the Teubner-Strey model and the core-shell model. The results obtained by the Teubner-Strey model showed that the domain size (d) decreased while the correlation length (ξ) increased upon polymerization. The analysis in terms of the core-shell model displayed that adding water to the precursor microemulsion caused the water droplets to start swelling, which resulted in the discontinuity of water in oil microemulsion. There exhibited large differences in morphologies of polymerized materials from the microemulsion formulations with different water and surfactant contents. The core and shell sizes of water droplets decreased during the course of polymerization when there was 15 wt % or more water in the microemulsion formulation; the polymerized material thus exhibited increasingly discrete granular morphology. When there was 10 wt % or less water content in the precursor microemulsion, the rearrangement of water domains could be minimized during the course of polymerization and transparent polymerized material was obtained.