Solar energy is one of the most common renewables and environment-friendly energy sources that are currently undergoing rapid research and implementation to fulfill rising global energy demand, owing to its relative abundance. Furthermore, the growing usage of solar energy necessitates the advancement of innovative and efficient photovoltaic (PV) technologies with lower production prices and improved power conversion efficiency (PCE). Antimony selenide is the chemical compound with the formula Sb₂Se₃ which crystallizes in an orthorhombic space group. These non-toxic and earth-abundant materials are having a high absorption coefficient (>10⁵ cm^-1) and optimal bandgap (1.2 eV). Sb₂Se₃ is a very promising solar absorber material because of these attractive material, optical and electrical properties and it has become a popular PV absorber, with power conversion efficiency rising gradually compared to other developing compounds. The main objective of this work is to replace the commonly used toxic CdS as buffer layer. Here, a non-toxic buffer layer ZnSe is used and the efficiency of solar cell has be determined by varying the thickness and carrier concentration of buffer and absorber materials and their effect on efficiency is analyzed. A solar cell capacitance simulator in 1 dimension (SCAPS-1D) software has explored of the solar-cell properties of the antimony selenide (Sb₂Se₃).

Volatile organic compounds are recognized

as major contributors to air pollution, either directly through their toxic or malodorous natures or indirectly as ozone precursors. Many

VOCs are health hazards in themselves and can cause cancer or other serious illnesses, even at low concentrations. Industrial processes and transportation activities are mainly responsible

for the VOC emissions. Technologies for tue removal of VOCs from gas streams can be broadly classified into two groups: those that recover the VOCs for possible later reuse and those that destroy the VOCs [1].

In this work gold nanoparticles supported over iron, silver /SBA15 was prepared by deposition-precipitation(DP) method with urea, iron-containing mesoporous materials have been synthesized by hard template method, and characterized by BET, DR X , H2 –TPR, TEM techniques

Silver was until recently considered one of the least catalytically useful metals due to its chemical inertness.

the mesoporous materials containing silver support on SBA15 were synthesized by the method of post-synthesis and direct methode synthesis

We tested our synthesized materials as catalysts in esterification reactions of stearic acid, which is a natural molecule of the fatty acid family. Biodiesel is one of the examples of biofuels intended to combine with or replace conventional fuels and reduce the pollution produced by those of petroleum origin.

The catalytic activity and especially the stability of gold catalysts strongly depend on both the state and structure of the support and the specific interaction between gold and the support.

References

[1] : P. «Les compositions organiques volatiles COV dans l'environnement», Le Cloirec, Lavoisier Tec&Doc, Paris, 1998.

The use of nanostructured materials in the biomedical field aims for diagnostics, drug delivery, therapy activation and monitoring therapeutic responses in real-time, thus maximizing the therapeutic benefits, simultaneously with a minimally invasive effect and low toxicity. Electrochemical analysis and implicitly the development of materials for biosensors have become of vital importance for the monitoring of biomolecules. The conductivity of nanocomposites is usually determined by characteristics related to the concentration, size, and dispersion of the nanoparticles. Generally, graphene's high surface energy and strong interactions moderate their uniform compatibility with different media. In the present paper, we propose the synthesis of yttrium oxide nanoparticles for the development of nanocomposites based on transition oxides and carbon materials for electrochemical applications. The precipitation method was used to obtain nanostructured Y₂O₃. The Hummer method was used for the synthesis of graphene material. After the activation step of the Y₂O₃ surface, the ex-situ method was chosen to obtain the nanocomposites, allowing the insertion of oxide nanoparticles into the sheets of carbon materials. The developed materials were studied from a structural point of view using Raman and FTIR spectroscopy. The surface morphology, particle size and distribution of nanoparticles in the carbon material were studied using a field emission scanning electron microscope. The goniometric studies followed the wetting and percolation capacity of the nanocomposite.

In this work, the effect of the longitudinal magnetic field on the mechanical buckling of single-walled boron nitride nanotube (SWBNNT) integrated in the elastic Kerr medium is investigated. The structure is assumed homogeneous and therefore modeled employing the non-local Euler-Bernoulli theory (NL-EBT). The present model targets thin structures and takes into account the small-scale effect. The elastic matrix is described by the Kerr model, which takes into account the normal pressure and the transverse shear strain. Using the nonlocal elastic theory proposed by Eringen and considering the Lorentz magnetic force obtained from Maxwell relations, the stability equation for buckling analysis of a simply supported single-walled boron nitride nanotube under a longitudinal magnetic field is derived. The governing equations of the system were determined via the virtual work model and resolved by Navier’s method, and the obtained results are compared with those found in literature. Numerical results enable us to observe the effects of the magnetic field on the behavior of single-walled boron nitride nanotube integrated with the various parameters that are: the non-local parameter, the lower spring parameter K_w, the upper spring parameter K_c and the intermediate shear layer parameter K_g are significant and must be taken into account for this kind of analysis.

Current efforts in the field of nanotechnology have led to the orientation of research towards transition metal oxide nanostructures, due to the characteristics it possesses, such as: composition, shape, high surface-to-volume ratio, thermal and chemical stability, low toxicity and the ability to be modified with specific sensitive elements. Among transition oxides, zinc oxide (ZnO) nanostructures are considered materials with applicative potential, which have found their applicability in different scientific fields (e.g. optoelectronic devices, textile industry, food packaging, luminescent materials, drug delivery, bioimaging, medical device, cancer diagnostics, etc). In the case of these materials, it was found that the morphology of ZnO plays an essential role in the development of applications in that regard, being necessary for rigorous control of the main factors that influence the size, shape, agglomeration tendency, and orientation of the nanostructures. Also, depending on the synthesis method approached, ZnO can be obtained in different forms, which determines various physico-chemical properties. In the present paper, the researchers were oriented to synthesize different types of ZnO nanostructures by chemical method, the process variable being optimized (e.g. concentration of precursors, types of solvents, pH, time, temperature, etc.), but also the parameters required for thermal treatment. To obtain the characteristic structural and morphological information, ZnO nanostructures were investigated using Fourier transform infrared spectrometry, scanning electron microscopy, and X-ray diffraction. SEM analysis confirms that the morphology and size of the ZnO nanostructures depend on the process parameters. The XRD results reveal that the synthesized samples have a crystalline structure, and FTIR spectra show the presence of Zn-O bonding. The wetting capacity of continuous ZnO surfaces with different morphologies was studied by measuring the contact angle, indicating the wetting and percolation capacity, depending on the orientation of the synthesized nanostructures.

Fiber reinforced composites are used in increasing quantities in various applications because of their excellent in-plane mechanical properties. However, they suffer from poor out-of-plane properties, which result in delamination in service either from impacts, external loadings, or manufacturing defects. Delamination reduces the strength and stiffness, affecting the overall performance of composite structure and possibly leading to a catastrophic failure. Due to this, recently a lot of interest has been received in developing a modification method to address the delamination problem. These modifications may be of micro- or nanoscale with a possibility of self-diagnostic and in-situ damage monitoring.

In this research, nanoscale modification with industrially available CNT masterbatch is explored to solve the problem of delamination and perform self-diagnostic and monitoring of glass fiber reinforced polymer (GFRP) composite laminate. Compared to conventional methods of introducing CNT into laminate, the application of industrially available masterbatch is scalable, so that it is useful for large composite structures.

Two types of CNT interleaves with a CNT content of 0.6 wt% and 7.5 wt% were produced. The 0.6 wt% interleave has a detrimental effect of ~80% on Mode I initiation and propagation fracture toughness. Whereas, the 7.5 wt% interleave shows an improvement of 27% in initiation and 0.5% in propagation fracture toughness. The R-curves for base and modified laminates will be compared and presented. The addition of CNT interleaves turns unconductive GFRP into a conductive laminate and hence, can be used for self-diagnostics of damage. In-situ damage sensing tests were performed by simultaneously measuring the 2-wire resistance of sample during the double cantilever beam test. The self-diagnostics damage sensing capability of laminates with both kinds of interleaves will be discussed.

Hence, addition of CNT interleaves improves the fracture toughness and adds a new functionality for self-diagnostic of the GFRP laminate.

The temperature coefficient of resistance (TCR) determines the electrical performance of materials in electronics. For a carbon nanotube (CNT) nanocomposite, change of resistivity with temperature depends on changes in CNT intrinsic conductivity, tunnelling thresholds and distances, matrix’ coefficient of thermal expansion, and other factors. In our study, we add one more influencing factor–the degree of cure. Complexities of the curing process cause difficulties to predict, or even measure, the curing state of the polymer matrix while uncertainty in the degree of cure influences TCR measurements leading to biased values. Here we study the influence of the cure state on the TCR of a single-walled CNT/epoxy polymer nanocomposite. For the given degree of cure, TCR measurements are conducted in the temperature range 25–100 ◦C, followed by the next 24 h of post-curing and a new cycle of measurements, 8 cycles in total. We find that contrary to industry practice to expect a high degree of cure after 3 h at 130 ◦C, the curing process is far from reaching the steady state of the material and continues at least for the next 72 h at 120 ◦C, as we observe by changes in the material electrical resistivity. If TCR measurements are conducted in this period, we find them significantly influenced by the post-curing process continuing in parallel, leading in particular to non-monotonic temperature dependence and the appearance of negative values. The unbiased TCR values we observe only when the material reaches the steady state are no longer influenced by the heat input. The dependence becomes steady, monotonically increasing from near zero value at room temperature to 0.001 1/◦C at 100 ◦C.

Propargylamines are interesting intermediates to synthesize built and heterocycled molecules [1] such as pyrrole, oxazoles, pyrazoles [2]. Furthermore, a number of propargylamines derivatives were used to treat Parkinson’s and Alzheimer’s disease such as rasagyline [3]. Their preparation method has drawn the attention of a significant number of researchers. In view of the synthetic procedure, the three coupling component of alkyne, aldehyde and amine (A3) was used in the presence of catalysts[4]

In life science, the recent development of nanotechnology has introduced the potential of inorganic nanomaterials [5, 6]. copper phosphate catalyst have attracted considerable attention of researchers because of their electrochemical properties, compositional and good activity. This material CuPO₄ is known as an electrode which are used as a novel high-capacity cathode [7], there are a wide variety of applications for phosphates of various transition metals including catalysis, environmental remediation, sensors, and electronic materials [8]. Copper phosphate showed excellent performance for oxidation of aromatic benzyl compounds to aromatic ketones.

This work provides a new way to prepare copper phosphate efficient heterogeneous catalysts by hydrothermal route. The catalyst was characterized by FTIR, XRD, and Raman spectroscopy. The nanocatalysts showed a high activity in the propargylamines synthesis via the A3 coupling of aldehyde, amine and alkyne with high a yield [9].

There are many organic molecules having functional properties potentially useful for technological applications in otics, optoelectronics, sensing, etc. However, such organic molecules are frequently thermally and/or photochemically unstable. The dissolution of such molecules un an adequate type of polymer allows at the same time the preparation of a functional materials and the stabilization of the organic molecules. Such stabilization results from the capability of the polymer matrix to absorb photon thermally-induced and to prevent rearrangements. As an example, the rosin, also called colophony is the main component of a very abundant natural substance present in the resin obtained from pines and some other plants. This type of organic compound has interesting fluorescence properties that can be enhanced by mild thermal treatment. However, excessive annealing could degrade the molecule, thus loading to the loss of this useful physical property. Since rosin is highly soluble in organic media like the common thermoplastic polymer it is possible to achieve its stabilization by dissolution in polymers. Here, rosin has been dissolved in poly(methylmethacrilate), which is an optical characterized by high transparency in the visible region. The ability of the polymer-embedding process in the stabilization of this molecules has been verified by thermal analysis (TGA, DSC). In addition, the optical properties of the PMMA-Rosin have been compared with the pure rosin to assess the possibility to exploit these materials in the optical field.

P25 Degussa represents a type of titanium dioxide (TiO2) used as a white pigment in various applications, including coatings, plastics, paper, inks and cosmetics. It is generally considered to be non-toxic, but there have been concerns about the potential skin and inhalation toxicity of TiO2 nanoparticles, as they can cause oxidative stress and other cellular damage in high quantities. A 3D skin barrier system represented by human epidermis reconstructed from highly differentiated keratinocytes cultured at the air-liquid interface (EpiDerm^TM) was used in our study to test the cytotoxicity of P25 Degussa particles. These were characterized from the point of view of structure and morphology, confirming the physico-chemical characteristics of TiO2 particles. A 24-hour exposure of cell culture to a concentration of 10 µg/mL P25 Degussa did not significantly alter cell viability compared to the control as measured by the MTT assay. It also did not induce the release of an appreciable amount of nitric oxide or lactate dehydrogenase in the extracellular environment, the values ​​being close to those of the control. Instead, an increase in the level of the cytokine IL-8 was observed, being suggestive for the initiation of an inflammatory process. Microscopy analysis of cell morphology (through hematoxylin-eosin staining and fluorescent actin labeling) revealed slight changes, especially at the apical surface of the tissue, noting some P25 Degussa particles that remained attached to this surface and were not internalized by cells. Trans-epithelial electrical resistance (TEER) measurement showed that cell barrier integrity was not altered by exposure to TiO2 particles, the tight junctions and normal cell permeability being maintained. In conclusion, our results showed that the toxicity of P25 Degussa particles in small concentration was minimal on the in vitro 3D model of the human skin, not penetrating this biological barrier.