Successful disintegration of Chlorpyrifos pesticide by nearly monodisperse nano-gold photcatalyst (∼10 nm) for remediation of wastewater has been reported in current studies. Nano-Gold dispersion reaction with Chlorpyrifos solutions completes in 45 minutes at ambient temperature under the normal daylight and exhibit systematic variations in the solution color from wine red to pink to light sky blue and finally transforming into a transparent solution with fine precipitates. UV-Vis absorption studies correlates well with the systematic color changes as observed in the nano-gold treated Chlorpyrifos solutions with time. The characteristic localized surface plasmon resonance peak of nanogold dispersion observed at 529 nm red shifts to weak, medium and strong intensity peaks at ∼ 640 nm, 740 nm and 890 nm on increasing chlorpyrifos concentration owing to the aggregation of gold nanoparticles in small to bigger sized clusters. The fine turbidity in final transparent solution further confirms the aggregation of nanogold particles into stable bigger ensembles. IR transmission spectra of final transparent solutions showed disappearance of Chlorpyrifos νC-Cl and phosphorothioate functional group peaks indicating degradation of chlorpyrifos.

Deinking of recycled office (MOW) paper was carried out by using a flotation column and adding separately sodium hydroxide, and the enzyme Cellulase Thricodema Sp., as defibrillators.

The de-inked cellulose fibers were characterized according to the standards of the paper industry, to compare the efficiency of the deinking of each chemical reagent used to hydrolyze the fibers and defibrillate them.

The computational simulation of the molecular coupling between the enzyme and cellulose was performed, to establish the enzyme-cellulose molecular complex and then to identify the principal amino-acids of endo-β-1,4-D-glucanase in this molecular link, which are responsible for the hydrolysis of the cellulose.

Experimental results show the feasibility to replace sodium hydroxide with the enzyme Cellulase Thricodema Sp., by obtaining deinked cellulose with similar optical and physical properties.

The use of the enzyme instead of sodium hydroxide avoids the contamination of the residual water; in addition to that, the column is operated more easily, taking into consideration that the pH of the system goes from alkaline to neutral.

An atmospheric pressure microwave plasma tubular furnace apparatus (MPTF) for the rapid synthesis of carbon nanotubes (CNTs) has been developed. CNTs have been synthesized by an Argon-Hydrogen microwave plasma using ethanol vapor as carbon source with the furnace temperature of 800 °C at the atmospheric pressure. The synthesized CNTs have been analyzed by scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), and are shown to be multi-walled and tangled and chemically connected to form a high-density network with the diameter at the range of 25-70 nm. The measurement of X-ray photoelectron spectroscopy (XPS) indicates that a large number of oxygenated functional groups grown on the surface of CNTs. These properties proved that the CNTs could be utilized as nanoscale templates for various applications.

We present a semi-analytical expression for the dielectric response function of quasi-2D ultrathin films of periodically aligned single-walled carbon nanotubes. We derive the response function in terms of the individual nanotube conductivity, plasma frequency, and the volume fraction of carbon nanotubes in the film. The real part of the dielectric response function is negative for a sufficiently wide range of the incident photon energy, indicating that the film behaves as a hyperbolic metamaterial. Inhomogeneous broadening increases the effect.

An electrostatic and air driven (EStAD) electrospinning device was used to achieve deposition of polymer fiber mats that carry electrical charge. The EStAD device does not require the polymer stream to contact a deposition electrode, thereby allowing enhanced control and processing versatility over production of conductive polymer materials. Direct current (DC) conductivity in the fiber mats was enabled through the use of a composite multi-walled carbon nanotube-polyethylene oxide (MWCNT-PEO) blend for electrospinning (ES). The electrospun fiber mats contained three different concentrations of MWCNTs. Conductivity and resistance were measured for each concentration as an electrospun fiber mat and compared to that of a drop-cast thin film. Results showed that at 7.51 wt% MWCNTs, conductivity in the electrospun fiber mats began to approach that of the drop-cast thin films at 1.76E-01 S/cm. At the lowest weight percent tested (3.37 wt%), conductivity was still measurable at approximately 8.48E-05 S/cm and was comparable to results reported previously using traditional ES methods.

Recently, an experimental study developed an efficient way to obtain sulfur-doped γ-graphdiyne. This study has shown that this new material could have promising applications in lithium-ion batteries, but the complete understanding of how the sulfur atoms are incorporated into the graphdiyne network is still missing. In this work, we have investigated the sulfur doping process through molecular dynamics and density functional theory simulations. Our results suggest that the doped induced distortions of the γ-graphdiyne pores prevent the incorporation of more than two sulfur atoms. The most common configuration is the incorporation of just one sulfur atom per the graphdiyne pore.

Monolayer (ML) molybdenum disulfide (MoS₂) is a novel 2-dimensional (2D) semiconductor whose properties have many applications in devices. Despite its potential, ML MoS₂ is limited in its use due to its degradation under exposure to ambient air. Therefore, studies of possible degradation prevention methods are important. It is well established that air humidity plays a major role in the degradation. In this paper, we investigate the effects of substrate hydrophobicity on the degradation of chemical vapor deposition (CVD) grown ML MoS2. We use optical microscopy, atomic force microscopy (AFM), and Raman mapping to investigate the degradation of ML MoS2 grown on SiO2 and Si3N4 that are hydrophilic and hydrophobic substrates, respectively. Our results show that the degradation of ML MoS₂ on Si3N4 is significantly less than the degradation on SiO2. These results show that using hydrophobic substrates to grow 2D transition metal dichalcogenide ML materials may diminish ambient degradation and enable improved protocols for device manufacturing.

A multiscale Green's function method, based upon a solution of the Dyson equation, is described for modeling the strain field due to a vacancy or any other point defect in graphene and other 2D materials. Numerical results are presented using a fourth-neighbor force-constant model for the purpose of illustration.

Several techniques have been employed for large-scale synthesis of group 10 transition metal dichalcogenides (TMDCs) based on platinum and palladium for nano- and opto-electronic device applications. Nickel Sulphides (NixSy), belonging to group 10 TMDC family, have been widely explored in the field of energy storage devices such as batteries and supercapacitors, etc. and commonly synthesized through the solution process or hydrothermal methods. However, the high-quality thin film growth of NixSy for nanoelectronic applications remains a central challenge. Here, we report the chemical vapor deposition (CVD) growth of NiS2 thin film onto a two-inch SiO2/Si substrate, for the first time. Techniques such as X-ray photoelectron spectroscopy, X-ray Diffraction, Raman Spectroscopy, Scanning Electron Microscopy, have been used to analyse the quality of this CVD grown NiS2 thin film. A high-quality crystalline thin film of thickness up to a few nanometres (~28 nm) of NiS2 has been analysed here. We also fabricated a field-effect device based on NiS2 thin film using interdigitated electrodes by optical lithography. The electrical performance of the fabricated device is characterized at room temperature. On applying the drain voltage from -2 to +2 V, the device shows drain current in the range of 10-9 A before annealing and in the range of 10-6 A after annealing. This, being comparable to that from devices based on MoS2 and other two-dimensional materials, projects CVD grown NiS2 as a good alternative material for nanoelectronic devices.

Many physicochemical processes depend on the diffusion of small molecules through solid materials. While crystallinity in polymers is advantageous with respect to structure performance, diffusion in such materials is difficult to predict. Here, we investigate the impact of crystal morphology and organization on the diffusion of small molecules using a lattice Monte Carlo approach. Interestingly, diffusion determined with this model does not depend on the internal morphology of the semi-crystalline regions. The obtained insight is highly valuable for developing predictive models for all processes in semi-crystalline polymers involving mass transport, like polymer degradation or drug release, and provide design criteria for the time-dependent functional behavior of multifunctional polymer systems.