Design of Voltage control Oscillator using Nonlinear Composite Right/Left-Handed Transmission Line

In the present work, we propose a voltage control oscillator (VCO) at high frequency consists of nonlinear composite right/left-handed transmission line (CRLH-TL) loaded with Resonant Tunneling Diode (RTD). We designed three prototype device examples. The first one consists of one cell with short circuit at the beginning of the cell between ground and patch, and 50 Ω load resistance were added at the end of the cell between ground and patch. The second one is similar to the first prototype but with open circuit at the beginning of the cell instated of short circuit. The third prototype consists of one cell with two 50 Ω load resistances added between ground and patch at the beginning and at the end of the cell. The proposed VCO models are capable of generating oscillations at frequencies between 4.87- 14.9 GHz. In our simulations, we used OrCAD and ADS software to analyze the proposed circuit

A shape tailored gold-conductive polymer nanocomposite as a transparent electrode with extraordinary insensitivity to volatile organic compounds (VOCs)

In this study, the transparent conducting polymer of poly (3,4-ethylenendioxythiophene): poly(styrene sulphonate) (PEDOT:PSS) was nanohybridized via inclusion of gold nanofillers including nanospheres (NSs) and nanorods (NRs). Such nanocomposite thin films offer not only more optimum conductivity than the pristine polymer but also excellent resistivity against volatile organic compounds (VOCs). Interestingly, such amazing properties are achieved in the diluted regimes of the nanofillers and depend on the characteristics of the interfacial region of the polymer and nanofillers, i.e. the aspect ratio of the latter component. Accordingly, a shape dependent response is made that is more desirable in case of using the Au nanorods with a much larger aspect ratio than their nanosphere counterparts. This transparent nanocomposite thin film with an optimized conductivity and very low sensitivity to organic gases is undoubtedly a promising candidate material for the touch screen panel production industry. Considering PEDOT as a known material for integrated electrodes in energy saving applications, we believe that our strategy might be an important progress in the field.Peer reviewe

Size-Tailored Physicochemical Properties of Monodisperse Polystyrene Nanoparticles and the Nanocomposites Made Thereof

The latex monodisperse polystyrene (PS) colloids are important for different advanced applications (e.g. in coating, biotechnology etc.). However, the size dependency of their structural properties that impacts the characteristics of the nanocomposites composed thereof is largely unknown. Here, monodisperse PS nanoparticles (MPNPs) are synthesized via emulsion polymerization in five sizes (50, 150, 300, 350, and 450 nm). The size of the PS MPNPs is tailored by controlling the reaction time, temperature, and amount of surfactant and initiator. The correlation between the particle size and structural properties of the PS MPNPs is established by different thermomechanical and optical characterizations. The smaller particles (50 and 150 nm) show a lower glass transition (Tg) and thermal decomposition temperature and a lower Raman peak intensity. Yet, they trigger a higher IR absorption, thanks to a larger surface area. When incorporated in a polyvinyl alcohol (PVA) matrix, the smaller particles impart the resulting nanocomposite a higher tensile strength, and elastic and storage moduli. Whereas, they decline the elongation and loss factor. The very few examples of the MPNPs incorporated polymeric nanocomposites have been unstudied from this perspective. Thus, these tangible knowledge can profit scalable production of this kind of nanocomposite materials for different applications in a cost/energy efficient manner.Peer reviewe

Underwater Leidenfrost nanochemistry for creation of size-tailored zinc peroxide cancer nanotherapeutics

The dynamic underwater chemistry seen in nature is inspiring for the next generation of eco-friendly nanochemistry. In this context, green synthesis of size-tailored nanoparticles in a facile and scalable manner via a dynamic process is an interesting challenge. Simulating the volcano-induced dynamic chemistry of the deep ocean, here we demonstrate the Leidenfrost dynamic chemistry occurring in an underwater overheated confined zone as a new tool for customized creation of nanoclusters of zinc peroxide. The hydrodynamic nature of the phenomenon ensures eruption of the nanoclusters towards a much colder region, giving rise to growth of monodisperse, size-tailored nanoclusters. Such nanoparticles are investigated in terms of their cytotoxicity on suspension and adherent cells to prove their applicability as cancer nanotherapeutics. Our research can pave the way for employment of the dynamic green nanochemistry in facile, scalable fabrication of size-tailored nanoparticles for biomedical applications.Peer reviewe

Thickness dependence of dielectric properties in sub-nanometric Al2O3/ZnO laminates

International audienceIn recent years, laminates consisting of alternating layers of two binary oxides with layer thicknesses below 1 nm have attracted attention for their high dielectric constant values, reaching values of about 1000 in the case of Al2O3/TiO2 sub-nanometric laminates. This excellent dielectric performance of the sub-nanometric laminates relies on the Maxwell Wagner (MW) relaxation, exploiting the blocking of the mobile charge carriers of the semiconducting TiO2 at the interface with Al2O3. In this work, we explore the possibilities of enhancing the dielectric constant by MW relaxation in amorphous sub-nanometric laminates of Al2O3/ZnO. We demonstrate that the sublayer thickness and the interface of individual layers define the apparent dielectric constant of the laminates. In addition or further understanding, simulations and equivalent circuit analysis of the sub-nanometric laminates were conducted