2024 | Volume 3 | Issue 1

This research delves into the comprehensive exploration of silica nanoparticles (SiO₂-NPs) synthesis via ultrasonic spray pyrolysis. Essential factors investigated encompassed varying concentrations of tetraethyl orthosilicate (TEOS) (0.51 M, 0.25 M, and 0.12 M), furnace temperatures (200°C, 300°C, and 400°C), carrier gases (Ar, N₂, O₂), residence times of reactants in the furnace (0.5 sec, 1.5 sec, 5 sec), and solvents (acetone, ethyl acetate, and ethanol). The influence of incorporating F127 in the synthesis process was scrutinized for its role in producing mesoporous silica nanoparticles. Results indicated that an escalation in TEOS concentration from 0.12M to 0.51M at 400°C resulted in a proportional increase in the average particle diameter of SiO₂ nanoparticles from 7 nm to 40 nm and the specific surface area decreased from 147 to 97 m²/g, revealing a narrow size distribution. Manipulating the nitrogen flow rate during the furnace process from 100 to 300 ml/min exhibited the capability to yield SiO₂ nanoparticles by increasing their particle size to 61nm. Additionally, an extension of the residence time of precursors, achieved through careful regulation of the carrier gas flow rate, yielded a noticeable augmentation in the average particle diameter. Notably, the choice of solvent emerged as a discernible factor, leading to the fabrication of SiO₂-NPs with various morphologies. This multifaceted investigation provides valuable insights into the intricacies of silica nanoparticle synthesis, contributing to the understanding of the nuanced interplay of parameters in achieving desired particle characteristics for diverse applications in nanotechnology and materials science.

In this research, the effects of peroxide and persulfate oxidizing agents such as hydrogen peroxide (H₂O₂), potassium persulfate (K₂S₂O₈), ammonium persulfate ((NH₄)₂S₂O₈) and meta-chloroperoxybenzoic acid (mCPBA) on the texture of graphene oxide (GO) are considered by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and elemental mapping via energy dispersive X-ray spectroscopy (EDX). According to FT-IR results, GO and GO treated by oxidizing agents contain a layer of carbon atoms that decorated by oxygen-containing groups. Based on XRD data, a phase transition from more crystalline graphene oxide to more amorphous state is observed where GO is treated by oxidizing agents. It seems that oxidizing agents can create and enlarge the hole defects in graphene oxide. Significant changes in the morphology of the GO after treatment by oxidizing agents are observed via the FESEM micrographs. The value of the C/O atomic ratio for the GO treated by mCPBA is 1.23. This compound show the higher degree of oxidation than GO and GO treated by other oxidants. The corresponding value for the prepared GO is 1.94.

To use H₂ gas as a common fuel it needs to be in high pressures or cryogenic temperatures to have reasonable density. But, if we have adsorbent materials with high volumetric capacities to store hydrogen at ambient temperature and low pressure without any compressing it is worthwhile to use hydrogen as clean and reversible fuel. Here, we want to report the adsorption and decomposition properties of aluminum and gallium-doped graphene at ambient temperature. We studied the adsorption of H₂O molecule on pure and doped graphene via density functional theory. So, possible interactions between the H₂O molecule from three sides and pure and aluminum and gallium-doped were examined. After adsorption, decomposition of the H₂O molecule has been studied and so on, for receive a reaction pathway, possible intermediates and transition states has been studied. To continue the density of states, interaction energies and thermodynamic parameters have been calculated. The results showed that the adsorbed water on aluminum and/or gallium-doped graphene decompose to OH and H and then adsorb on the surface again at ambient temperature and this process was thermodynamically favorable.

Decreasing reserves of fossil fuels and environmental concerns like greenhouse gases have brought increasing studies into renewable and low-carbon sources of energy. Biodiesel is a renewable and sustainable replacement for crude oil that has become increasingly important as the world’s supply of petroleum decreases, and it is vitally important to research new feedstocks with high efficiency, competitive pricing, and ease of manufacture. Herein we reported nine different biodiesels that were produced from the nine common vegetable oils coconut oil, sesame oil, poppy oil, castor oil, bitter almond oil, olive oil, black seed oil, peanut oil, and pecan oil. The yields of the produced biodiesels are in the range of 50 to 98%, and the density and flashpoints of the produced biodiesels were in the ranges of 0.85 to 0.99 (g/cm³) and 150 to 222°C. Moreover, compositions of the produced biodiesels were analyzed by GC, and the concentrations of the main fatty acid methyl esters (FAME) were reported and compared. Lauric acid methyl ester, oleic acid methyl ester, linoleic acid methyl ester, ricinoleic acid methyl ester, and stearic acid methyl ester are the main components of the produced biodiesels.

The vaginal route offers unique advantages for localized and systemic drug delivery, but efficacy is limited by biological barriers including mucus, epithelium, immune cells, and microbiota. Prevalent microbe-associated infections like bacterial vaginosis, candidiasis, and trichomoniasis often recur due to treatment failures. Drug delivery via nanomaterials and hydrogels provides opportunities to overcome limitations through platforms that modulate drug release kinetics, mucoadhesion, mucus penetration, and intrinsic antimicrobial properties. This review discusses biological barriers, prevalent vaginal infections, and nanoscale delivery systems including nanoparticles, liposomes, hydrogels, and inorganic materials. Surface engineering allows the customization of nanoparticles for mucoadhesive or mucus-penetrating properties. Liposomes can fuse with cell membranes for intracellular delivery. Hydrogels provide sustained drug release. Inorganic nanomaterials exhibit inherent antimicrobial effects. These nanosystems offer targeted, sustained drug delivery to improve treatment outcomes for vaginal infections. Further research is warranted to establish clinical efficacy and safety.

ZnO nanorods with hexagonal structures were synthesized using a hydrothermal method under different conditions. The effect of synthesis parameters on ZnO growth was systematically studied by scanning electron microscopy. The results demonstrated that the morphology and size of ZnO nanorods are influenced by nature of the solvent, zinc acetate concentration, growth temperature and time. Rod-like and needle-shaped ZnO was produced when DI water and ethanol were used as the solvent, respectively. The concentration of precursors can also influence the formation of ZnO nanorods. Increasing growth time leads to rod-like diameter increment. ZnO nanorods with desired diameters were successfully prepared using 2.3 M zinc acetate concentration in DI water with a growing temperature of 80 ºC for 3 h. Next, Au/ZnO nanorod heterostructure was synthesized by a self-assembly of Au salt precursors and subsequent reduction of Au ions on ZnO nanorod surface without any surfactants or additives. Through SEM analysis, it was found that Au nanoparticles were uniformly deposited on the surface of ZnO nanorods. Compared with bare ZnO nanorods, Au/ZnO heterostructures exhibited characteristic surface plasmon absorption at 900 nm.