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Item type:Publication, Effect of pH and ammonia concentration on the shape and size of fluorapatite nanoparticles obtained by chemical reaction(Elsevier, 2021-11-15)Nanoparticles of fluorapatite (FAp Nps) were prepared by one step chemical reaction in aqueous solutions. The pH of the system was kept constant at 6 and 8. The FAp Nps were characterized with Scanning Electron Microscopy-Energy Dispersive X-Ray Spectroscopy (SEM-EDAX), X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR). The Ca/P calculated from EDAX analysis was 1.69. The results of XRD analysis and FTIR showed the presence of FAp phases. The DRX results confirm the formation of FAp with a hexagonal structure. TEM images show semispherical and elongated nanoparticles with mean diameter of 3.78 nm, 8.63 nm and 10.46 nm, when the pH and ammonia concentrations is varied. Ammonia concentration and pH influence the morphology and size of the FAp Nps. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A generalized Ising-like model for spin crossover nanoparticles(MDPI, 2022-05-01)Cooperative spin crossover (SCO) materials exhibit first‐order phase transitions in the solid state, between the high‐spin (HS) and low‐spin (LS) states. Elastic long‐range interactions are the basic mechanism for this particular behavior and are described well by the Ising‐like model, which allows the reproduction of most of the experimental results in the literature. Until now, this model has been applied with an interaction parameter between the molecules, which is considered to be independent of the states. In this contribution, we extend the Ising‐like model to include interaction energy that depends on the spin states and apply it to study SCO nanoparticles. Our research shows that following this new hypothesis, the equilibrium temperature shifts toward higher values. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Surface modification of ZnO quantum dots coated polylactic acid knitted fabric for photocatalytic application(John Wiley and Sons Inc, 2022-07-05)In this work, ZnO quantum dots (ZnOQD) were synthesized by Sol–gel synthesis and impregnated on polylactic acid (PLA) knitted fabric through self‐assembly of different cycles from layer‐by‐layer (LBL) using cationic agent Poly(diallydimethylammonium chloride) (PDDA). Then, morphological, chemical and photocatalytic properties were studied. The results demonstrate that the synthesis provided 8 nm Wurtzite‐type ZnO nanoparticles. In addition, X‐ray photoelectron spectroscopy (XPS) spectra, X‐ray diffraction (XRD) and scanning electron microscopy (SEM) proved the inclusion of ZnOQD on the surface of PLA matrix, which allowed the evaluation of its photocatalytic properties, therefore, coated PLA with five cycles of ZnOQD obtained the best result for degrading 85% of the dye Rhodamine B (RhB) in 360 min under UV radiation, in addition to its reusability for another five cycles of photocatalytic activity. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Exploring the modelling of gold anisotropic nanoparticles’ optical properties as a promising tool for detection systems design(Multidisciplinary Digital Publishing Institute (MDPI), 2024-12-01)Gold nanoparticles have been a central topic in the last few decades due to their excellent optical properties that can be exploited in many applications, including food analysis, materials science, and biomedicine. The basis of these unique optical properties is the phenomenon known as localized surface plasmon (LSP), which relays in the collective oscillation of the conduction band electrons in the nanoparticle when excited by electromagnetic radiation. The optical properties of the nanoparticles are critical for selecting the best nanomaterials for each application, a key factor for optimum performance, and can be tuned due to their dependence on the geometry and size of the nanoparticles, as well as the polarization of the light beam. Here, we conducted simulations to study the tunable optical properties and local electric field distribution of three types of gold nanoparticles, cubes (AuNC), boxes (AuNB), and triangular prisms (AuNT), which have relatively simple synthetic routes. Finally, we compared these results with experimental data and described possible synthetic routes to discuss the positive and negative aspects of using each type of nanoparticle for potential applications.1 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Surface-Bulk 2D Spin-Crossover Nanoparticles within Ising-Like Model Solved by Using Entropic Sampling Technique(MDPI, 2023-03-01)We model the thermal effects in different 2D spin-crossover (SCO) square lattices within the frame of the Ising-like model using Monte Carlo entropic sampling (MCES) method to enhance the scan of macrostates beyond the most probable thermal ones. In fact, MCES allows access to the metastable states, and it is then well adapted to study thermal hysteresis properties. In this contribution, we distinguish, for the first time, the interaction between molecules located in bulk at the surface and those connecting the bulk and surface regions of an SCO lattice. In addition, an extra ligand field contribution is assigned to surface molecules through an interaction parameter (Formula presented.). In the absence of environmental effects on surface nanoparticles, a single thermal hysteresis loop increasing with the lattice size is simulated with a unique bulk and surface equilibrium temperature (Formula presented.). When environmental effects are accounted for, a two-step behavior associated with two hysteresis loops of widths ΔTS (for the surface) and ΔTB (for the bulk) with an intermediate plateau 14 K wide is obtained in the thermal dependence of the high-spin (HS) fraction for the 6 × 6 lattice. The surface and bulk equilibrium temperatures are then different, both decreasing towards lower values, and the (Formula presented.) parameter controls the three states’ behavior as well as the hysteresis loop interval. Size effects show that the equilibrium temperature is governed by the surface atoms for a small lattice size (5 × 5) and by the bulk atoms for a large lattice size (7 × 7). Moreover, a change in the size of the lattice results in a variation of the order–disorder (or Curie) temperature, TO.D., and the surface equilibrium temperature, Teq, while only TO.D. changes in bulk. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Recent Trends and Notable Advances of Alginate-Based Nano-Particles for Effective Biomedical Materials: Wound Healing and Drug Delivery(Trans Tech Publications Ltd, 2023-01-01)Alginate is natural biodegradable polymers often used for wound treatments and drug delivery purposes. Due to the structural characteristics, alginate polymers are able to form hydrogel. Alginate nanoparticles are obtained by diverse methodologies and the physical and chemical properties can be affected by production techniques and the molecules incorporated. Alginate possesses unique bioactivities such as biocompatibility, biodegradability, hydrophilicity and nontoxicity, so it has great potential for biomedical applications. Alginate based hydrogels and nanoparticles carrying active compounds are able to supply the optimal environments for wound healing and controlled drug administration including targeted or localized drug-delivery systems. In this review, the recent researches about the alginate and alginate-complex nanoparticles as potential tools for wound dressing membrane and drug delivery carriers are studied. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A Comparative Study Between Monte Carlo Entropic Sampling Method and Local Mean Field Investigations of Thermal Properties of Spin-Crossover Nanoparticles Based on Ising-Like Model(OAE Publishing Inc., 2023-12-01)The thermally induced transitions between low-spin (LS) and high-spin (HS) configurations of spin-crossover (SCO) nanoparticles are simulated, focusing on the effects of localized surface and bulk interactions on the average magne-tization of 2D square lattices. The thermal behaviors and hysteresis cycles are investigated within the framework of the Ising model Hamiltonian and are conducted following two approaches: local mean field approximation (LMFA) and Monte Carlo entropic sampling (MCES) techniques. The results obtained by these two methods are compared for the two square lattice sizes, 6 × 6 and 7 × 7. Thus, when the bulk-surface interaction term is set to zero, the two approaches lead to identical values of the surface and bulk transition temperatures separated by a long intermediate plateau in both cases. Although hysteresis curves exhibit a similar shape, LMFA shows slightly larger widths ΔT than MCES. On increasing bulk-surface interaction term, the two methods lead to different shifts in equilibrium temperature values for both bulk and surface components, respectively, to lower and higher values by MCES. In general, it is found that LMFA shifts surface equilibrium temperature differently to lower values and enhances the hysteresis effect, particularly for surface molecules. On the other hand, for the 7 × 7 square lattice, the equilibrium temperatures are slightly higher by 1.5% and 3.2% for bulk and surface molecules, respectively, with a narrower hysteresis width in the surface. Moreover, with the MCES method, an abrupt transition instead of a hysteresis transition is calculated for surface molecules (Formula Presented). - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Monte Carlo Simulations of Thermal Behavior in Two-Block Spin-Crossover Structures(Multidisciplinary Digital Publishing Institute (MDPI), 2026-05-01)Molecular spin-crossover (SCO) compounds constitute prototypical systems exhibiting first-order phase transitions. These transitions involve an abrupt switch between two well-defined states with distinctly different magnetic, optical, and vibrational properties. One state is diamagnetic (low-spin), while the other is paramagnetic (high-spin). Upon heating, the transition occurs at a characteristic temperature, Tup. Upon cooling, it takes place at a lower temperature, Tdown < Tup, thereby giving rise to thermal hysteresis. Accordingly, each SCO compound is defined by a distinct pair of transition temperatures, Tup and Tdown. The investigation of these molecular solids is of great importance, both for elucidating first-order phase transitions—including the potential emergence of re-entrant phases—and for their broad range of prospective applications. The critical temperatures Tup and Tdown are pivotal in defining their practical utility. We present a strategy to modify and tune the transition temperatures of spin-crossover (SCO) compounds to suit different applications. The approach combines a given SCO material with layers of a second SCO system, enabling precise control of the characteristic temperatures of the resulting heterostructure. We illustrate this method with three case studies that span the 100 K–400 K temperature range. All simulations were performed using Monte Carlo methods within the Metropolis algorithm framework.1