Innovation and Entrepreneurship for Social goals and Sustainability in developing countries

The shift towards a sustainability-driven society includes changes to the educational system, business operations, innovation and entrepreneurial ecosystems as well as policymaking. Moreover, such a shift demands particularly a combination of top-down policy-making initiatives and bottom-up social entrepreneur-driven changes. Social innovation and entrepreneurship are providing solutions for globally recognized social and sustainability challenges such as poverty, education, environmental and climate change, peace support – worldwide yet also in the particularly challenging context of developing economies. We aim to showcase the best practices of social and sustainability-oriented innovation and entrepreneurship in the context of developing economies. In particular, we address the question of how social entrepreneur and innovator with bottom-up ideas could complement the top-down policymaking initiatives. Our design implies qualitative research aiming to disseminate the inspiring story of a social innovative enterprise, which represents a successful example of complementing policy-making efforts. Accordingly, our findings contribute to the literature on social innovation and entrepreneurship in the context of developing economies and simultaneously informs social entrepreneurs and policymakers on potential opportunities for synergy in their efforts

Self-organization of an optomagnetic CoFe2O4-ZnS nanocomposite : preparation and characterization

We report an advanced method for the self-organization of an optomagnetic nanocomposite composed of both fluorescent clusters (ZnS quantum dots, QDs) and magnetic nanoparticles (CoFe2O4). ZnS nanocrystals were prepared via an aqueous method at different temperatures (25, 50, 75, and 100 degrees C). Their structural, optical and chemical properties were comprehensively characterized by X-ray diffraction (XRD), UV-vis, photoluminescence (PL) spectroscopy, scanning electron microscopy (SEM), dynamic light scattering (DLS), transmission electron microscopy (TEM), and infrared spectroscopy (FT-IR). The highest PL intensity was observed for the cubic ZnS nanoparticles synthesized at 75 degrees C which were then stabilized electrosterically using thioglycolic acid. The photophysical analysis of the capped QDs with a particle size in the range 9-25 nm revealed that the emission intensity and the optical band gap increases compared to uncapped nanocrystals (3.88 to 4.02 eV). These band gaps are wider than that of bulk ZnS resulting from the quantum confinement effect. Magnetic nanoparticles were synthesized via a co-precipitation route and a sol-gel process was used to form the functionalized, silica-coated CoFe2O4. Finally, thiol coordination was used for binding the QDs to the surface of the magnetic nanoparticles. The fluorescence intensity and magnetic properties of the nanocomposites are related to the ratio of ZnS and CoFe2O4. An optomagnetic nanocomposite with small size (12-45 nm), acceptable saturation magnetization (about 6.7 emu g(-1)), and satisfactory luminescence characteristics was successfully synthesized. These systems are promising candidates for biological and photocatalytic applications

functionalized multi wall carbon nanotubes tio2 composites as efficient photoanodes for dye sensitized solar cells

The incorporation of functionalized multi-wall carbon nanotubes into TiO2 mesoporous photoanodes for dye-sensitized solar cells leads to 30% enhancement in photoconversion efficiency of the optimized system

Soft-landing electrospray ion beam deposition of sensitive oligoynes on surfaces in vacuum

AbstractAdvances in synthetic chemistry permit the synthesis of large, highly functional, organic molecules. Characterizing the complex structure of such molecules with highly resolving, vacuum-based methods like scanning probe microscopy requires their transfer into the gas phase and further onto an atomically clean surface in ultrahigh vacuum without causing additional contamination. Conventionally this is done via sublimation in vacuum. However, similar to biological molecules, large synthetic compounds can be non-volatile and decompose upon heating. Soft-landing ion beam deposition using soft ionization methods represents an alternative approach to vacuum deposition. Using different oligoyne derivatives of the form of R1(CC)nR2, here we demonstrate that even sensitive molecules can be handled by soft-landing electrospray ion beam deposition. We generate intact molecular ions as well as fragment ions with intact hexayne parts and deposit them on clean metal surfaces. Scanning tunneling microscopy shows that the reactive hexayne segments of the molecules of six conjugated triple bonds are intact. The molecules agglomerate into ribbon-like islands, whose internal structure can be steered by the choice of the substituents. Our results suggest the use of ion beam deposition to arrange reactive precursors for subsequent polymerization reactions

Ambipolar operation of hybrid SiC-carbon nanotube based thin film transistors for logic circuits applications

We report on the ambipolar operation of back-gated thin film field-effect transistors based on hybrid n-type-SiC/p-type-single-walled carbon nanotube networks made with a simple drop casting process. High-performances such an on/off ratio of 105, on-conductance of 20 μS, and a subthreshold swing of less than 165 mV/decades were obtained. The devices are air-stable and maintained their ambipolar operation characteristics in ambient atmosphere for more than two months. Finally, these hybrid transistors were utilized to demonstrate advanced logic NOR-gates. This could be a fundamental step toward realizing stable operating nanoelectronic devices

Fluidic patch antenna based on liquid metal alloy/single-wall carbon-nanotubes operating at the S-band frequency

This letter describes the fabrication and characterization of a fluidic patch antenna operating at the S-band frequency (4GHz). The antenna prototype is composed of a nanocomposite material made by a liquid metal alloy (eutectic gallium indium) blended with single-wall carbon-nanotube (SWNTs). The nanocomposite is then enclosed in a polymeric substrate by employing the UV-assisted direct-writing technology. The fluidic antennas specimens feature excellent performances, in perfect agreement with simulations, showing an increase in the electrical conductivity and reflection coefficient with respect to the SWNTs concentration. The effect of the SWNTs on the long-term stability of antenna’s mechanical properties is also demonstrated

Synthesis of a mesoscale ordered 2D-conjugated polymer with semiconducting properties

2D materials with high charge carrier mobility and tunable electronic band gaps have attracted intense research effort for their potential use as active components in nanoelectronics. 2D-conjugated polymers (2DCP) constitute a promising sub-class due to the fact that the electronic band structure can be manipulated by varying the molecular building blocks, while at the same time preserving the key features of 2D materials such as Dirac cones and high charge mobility. The major challenge for their use in technological applications is to fabricate mesoscale ordered 2DCP networks since current synthetic routes yield only small domains with a high density of defects. Here we demonstrate the synthesis of a mesoscale ordered 2DCP with semiconducting properties and Dirac cone structures via Ullmann coupling on Au(111). This material has been obtained by combining rigid azatriangulene precursors and a hot dosing approach which favours molecular diffusion and reduces the formation of voids in the network. These results open opportunities for the synthesis of 2DCP Dirac cone materials and their integration into devices.Comment: 21 pages, 3 figure

Catalytic Hydrogen Evolution of NaBH4_4 Hydrolysis by Cobalt Nanoparticles Supported on Bagasse-Derived Porous Carbon

As a promising hydrogen storage material, sodium borohydride (NaBH4) exhibits superior stability in alkaline solutions and delivers 10.8 wt.% theoretical hydrogen storage capacity. Nevertheless, its hydrolysis reaction at room temperature must be activated and accelerated by adding an effective catalyst. In this study, we synthesize Co nanoparticles supported on bagasse-derived porous carbon (Co@xPC) for catalytic hydrolytic dehydrogenation of NaBH$_4$. According to the experimental results, Co nanoparticles with uniform particle size and high dispersion are successfully supported on porous carbon to achieve a Co@150PC catalyst. It exhibits particularly high activity of hydrogen generation with the optimal hydrogen production rate of 11086.4 mL$_{H2}$∙min$^{H2}$∙g$_{Co}$$^{H2}$ and low activation energy (E$_{a}$) of 31.25 kJ mol$^{H2}$. The calculation results based on density functional theory (DFT) indicate that the Co@xPC structure is conducive to the dissociation of [BH$_{4}$]$^{-}$, which effectively enhances the hydrolysis efficiency of NaBH$_4$. Moreover, Co@150PC presents an excellent durability, retaining 72.0% of the initial catalyst activity after 15 cycling tests. Moreover, we also explored the degradation mechanism of catalyst performance