A hybrid coating made of poly (methyl methacrylate) with SiO2-TiO2 particles (PMMA/SiO2-TiO2) has been developed for use as a coating on nanosatellites, evaluating its resistance to high vacuum by quantifying its weight loss. The coating was applied on an Al 7075 aluminum substrate used for the aerospace sector. PMMA/SiO2-TiO2 hybrid coatings were prepared using sol-gel reaction in situ assisted with sonochemistry.
View Article and Find Full Text PDFSilver nanoparticles (AgNPs) are one of the widely studied nanomaterials for diverse biomedical applications, in particular, as antimicrobial agents to kill bacteria, fungi, and viruses. In this report, AgNPs were synthesized using a geranium ( x ) leaves extract and tested for their antimicrobial and cytotoxic activity and reactive oxygen species (ROS) production. Using green biosynthesis, the leaves extract was employed as a reducing and stabilizing agent.
View Article and Find Full Text PDFIn this work, graphene quantum dots (GQD) were prepared through a hydrothermal process. The photoluminescence (PL) emission spectrum for GQD prepared with high NHOH concentration (sample D1-t) was attained at lower wavelength (406 nm), compared to GQD synthesized with low NHOH concentration (sample D2-t attained at 418 nm). From these results, a smaller particle size for D1-t was deduced; according to TEM images the GQD particles are around 5 nm.
View Article and Find Full Text PDFReclaimed asphalt pavements (RAP) provide economic and environmental benefits. In recent decades, their use has increased, but rheological properties are affected by RAP aging, increasing stiffness, cracking, and susceptibility to water. To counteract these effects, rejuvenating agents are used, but they must be properly dosed to design quality mixtures.
View Article and Find Full Text PDFResearchers in cancer nanomedicine are exploring a revolutionary multifaceted carrier for treatment and diagnosis, resulting in the proposal of various drug cargos or "magic bullets" in this past decade. Even though different nano-based complexes are registered for clinical trials, very few products enter the final stages each year because of various issues. This prevents the formulations from entering the market and being accessible to patients.
View Article and Find Full Text PDFHeparin-based silver nanoparticles (AgHep-NPs) and gold nanoparticles (AuHep-NPs) were produced by a photochemical method using silver nitrate and chloroauric acid as metal precursors and UV light at 254 nm. UV-Vis spectroscopy graphs showed absorption for AgHep-NPs and AuHep-NPs at 420 nm and 530 nm, respectively. TEM revealed a pseudospherical morphology and a small size, corresponding to 10-25 nm for AgHep-NPs and 1.
View Article and Find Full Text PDFBackground: Silica nanoparticles are being developed as a host of biomedical and biotechnological applications. For this reason, there are more studies about biocompatibility of silica with amorphous and crystalline structure. Except hydrated silica (opal), despite is presents directly and indirectly in humans.
View Article and Find Full Text PDFChemotropic proteins guide neuronal projections to their final target during embryo development and are useful to guide axons of neurons used in transplantation therapies. Site-specific delivery of the proteins however is needed for their application in the brain to avoid degradation and pleiotropic affects. In the present study we report the use of Poly (ethylene glycol)-Silica (PEG-Si) nanocomposite gel with thixotropic properties that make it injectable and suitable for delivery of the chemotropic protein semaphorin 3A.
View Article and Find Full Text PDFThe synthesis, characterization and corrosion properties of a novel material, produced by the reaction of silica nanoparticles with a functionalized Phenol-Formaldehyde Resin (PFR), are presented. Carboxylic groups were attached in situ to the PFR skeleton to produce a functionalized resin (PFR-SA), which is then reacted with sol-gel-prepared silica nanoparticles, yielding a novel hybrid (organic/inorganic) material (PFR-SA-nanoSiO2). This hybrid material was characterized by FT-IR, FT-Raman, TGA, DSC, SEM and corrosion tests, whose results showed significant improvement of the thermal properties in comparison with the PFR coating.
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