Illite mineral is present in shale rocks, and its wettability behavior is significant for the oil and gas industry. In this work, the pH effects on the affinity between the (001) and (010) crystallographic planes of illite K(SiAl)(AlMg)O(OH) and direct and inverse emulsions were studied using molecular dynamics simulations. To develop the simulations, an atomistic model of illite was constructed following Löwenstein's rule.
View Article and Find Full Text PDFSmart water injection is a technology that allows changing the wettability of the oil rock by injecting water at different salinities, in a cheap and environmentally friendly way compared to other traditional methods. In this study, the individual effect of some typical salts on the wettability of the (104) surface of calcite toward non-polar and polar crude oil models was explored by molecular dynamics as a function of the salinity and pH. The results obtained show that the electrical double layer plays a principal role in the detachment of crude oil models.
View Article and Find Full Text PDFBio-oils are precursors for biofuels but are highly corrosive necessitating further upgrading. Furthermore, bio-oil samples are highly complex and represent a broad range of chemistries. They are complex mixtures not simply because of the large number of poly-oxygenated compounds but because each composition can comprise many isomers with multiple functional groups.
View Article and Find Full Text PDFCutaneous leishmaniasis is a skin disease caused by flagellate protozoa of the genus and transmitted by sandflies of the genus . Around 1 million new cases occur in the world annually, with a total of 12 million people affected, mainly in rural areas with low access to health services and adequate treatments. In the area of the Americas, Colombia has one of the highest infection rates after Brazil.
View Article and Find Full Text PDFThe wettability of graphene oxide functionalized with -alkylamines was studied by molecular dynamics simulations. Six different -alkylamines and two functionalization degrees were reviewed. The nucleophilic ring-opening reaction mechanism between the -alkylamines and epoxy functional groups of graphene oxide was considered to generate the atomistic models.
View Article and Find Full Text PDFThis study deals with the laser stereolithography manufacturing feasibility of copper-nickel nanowire-loaded photosensitive resins. The addition of nanowires resulted in a novel resin suitable for additive manufacturing technologies based on layer-by-layer photopolymerization. The pure and nanowire-loaded resin samples were 3D printed in a similar way.
View Article and Find Full Text PDFSix essential oils were analyzed by Fourier transform ion cyclotron resonance mass spectrometry coupled to negative-ion electrospray ionization (ESI(-)/FT-ICR MS). ESI offers selective ionization of a compound's polar functional groups containing nitrogen and oxygen heteroatoms. ESI in negative-ion mode allows the identification of the acidic compounds.
View Article and Find Full Text PDFA new strategy has been developed for characterization of the most challenging complex mixtures to date, using a combination of custom-designed experiments and a new data pre-processing algorithm. In contrast to traditional methods, the approach enables operation of Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) with constant ultrahigh resolution at hitherto inaccessible levels (approximately 3 million FWHM, independent of /). The approach, referred to as OCULAR, makes it possible to analyze samples that were previously too complex, even for high field FT-ICR MS instrumentation.
View Article and Find Full Text PDFGold nanoclusters protected with bovine serum albumin (AuNC) can be used in multiple biomedical applications through functionalization with two new and bioactive peptides. Both cationic peptides sequences of 17 amino acids in length and the cysteine residue at its C-terminus were designed and synthesized. Peptides were obtained by solid phase synthesis using the Fmoc strategy.
View Article and Find Full Text PDFThis study presents the additive manufacture of objects using mass-functionalized photo-resins, which are additively photopolymerized using the laser stereolithography technique. The mass functionalization is based on the incorporation of copper nanowires used as fillers at different concentrations. Cylindrical and tensile test probes are designed and manufactured in a layer-by-layer approach using a low-cost laser stereolithography system working with a layer thickness of 100 µ m .
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