Silica Nanoparticles Loaded with Curcumin—Encapsulation Efficiency

Curcumin is a natural compound, being a well-known ingredient in different foods. There are [...

Synthesis and Morphological Investigation of Flower-Like ZnO Nanostructures

In recent years, ZnO nanostructures have attracted great interest due to their significantpotential applications. [...

Novel Formulations of PEG–Silica Phase-Changing Materials (PCMs) with Applications in Passive Storage of Thermal Energy

The aim of the present study is to design new PEG–silica hybrids (PEGx–Si) as phase changing [...

Mesoporous Silica Nanoreservoirs Loaded with 1-H Benzotriazole for Active Anticorrosion Protection

In recent years, scientists are paying increased attention to the development of intelligent nanocontainers in applications such as biomedical, catalysis, and anticorrosion [1]. Preparation of anticorrosion coatings containing smart nanocontainers loaded with corrosion inhibitors, which can be initiated when the barrier coatings are damaged, favor the long-term function, as uncontrolled loss by leaching is inhibited [2]. The aim of the present study is to optimize the amount of an organic inhibitor (1-H benzotriazole (BTA)) that can be in situ encapsulated in a mesoporous silica nanocontainer, prepared by an original sol-gel formulation. Materials and methods: For the synthesis of silica mesoporous, nanoparticles loaded with BTA were used with three silica co-precursors: tetraethylorthosilicate (TEOS), phenyltriethoxysilane (PTES), and octyltriethoxysilane (OTES), at a 5/1/1 gravimetric ratio. The synthesis was carried out in the presence of a solvent (ethanol) and of a surfactant (Igepal CA-630). The pH of the sol–gel system was adjusted to ~9 by dripping an aqueous solution of NH4OH (25%). Prior to the addition to the sol–gel reaction system, BTA was completely dissolved in ethanol. Various amounts of BTA were loaded to the sol–gel systems: 0.25; 0.5; 0.75; 1; 1.25; 1.5; and 2 g (corresponding to 0.09; 0.18; 0.27; 0.35; 0.44; 0.53; and 0.70% grav. of the total amount of sol–gel mixture, respectively). Furthermore, a similar set of samples was prepared in the presence of a constant amount of rhodamine B, dissolved in ethanol. This second set was obtained in order to perform a visual evaluation of the encapsulation efficiency. Particles dimensions, size distributions, and particles charging in the final dispersions were evaluated by the dynamic light scattering (DLS) technique and Zeta potential measurements. Surface morphology was observed by SEM. The structural characteristics of the silica mesoporous particles were investigated by N2 adsorption–desorption analysis on the calcined samples. Results: During the in situ synthesis of silica nanoparticles, the aromatic molecules of the corrosion inhibitor BTA were linked via a hydrophobic interaction with the phenyl groups from the silica pores formed by the hydrophobic functions of silica co-precursors, i.e., PTES and OTES. In addition, the corrosion inhibitor was trapped inside the surfactant micelles of Igepal and encapsulated together inside the silica pores formed by the surfactant. Moreover, it was observed that only a small amount of BTA can be encapsulated in the absence of the surfactant. Conclusions: An optimized method was developed to obtain mesoporous silica nanoparticles loaded with 1-H Benzotriazole (BTA) as a corrosion inhibitor. The optimal range of the BTA concentration was found to be between 0.18 and 0.35%

Preliminary Studies on Silica Nanoparticles Preparation as Transport Vectors for Curcumin

Mesoporous silica nanoparticles (MSN) are currently central to studies in different scientific areas [...

The Effect of Different Coupling Agents on Nano-ZnO Materials Obtained via the Sol–Gel Process

Hybrid nanomaterials based on zinc oxide were synthesized via the sol–gel method, using different silane coupling agents: (3-glycidyloxypropyl)trimethoxysilane (GPTMS), phenyltriethoxysilane (PhTES), octyltriethoxysilane (OTES), and octadecyltriethoxysilane (ODTES). Morphological properties and the silane precursor type effect on the particle size were investigated using dynamic light scattering (DLS), environmental scanning electron microscopy (ESEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and X-ray diffraction (XRD). The bonding characteristics of modified ZnO materials were investigated using Fourier transform infrared spectroscopy (FTIR). The final solutions were deposited on metallic substrate (aluminum) in order to realize coatings with various wettability and roughness. The morphological studies, obtained by ESEM and TEM analysis, showed that the sizes of the ZnO nanoparticles are changed as function of silane precursor used in synthesis. The thermal stability of modified ZnO materials showed that the degradation of the alkyl groups takes place in the 300–500 °C range. Water wettability study revealed a contact angle of 142 ± 5° for the surface covered with ZnO material modified with ODTES and showed that the water contact angle increases as the alkyl chain from the silica precursor increases. These modified ZnO materials, therefore, can be easily incorporated in coatings for various applications such as anti-corrosion and anti-icing