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The aim of this study is to analyze the properties of a series of polysaccharide composite films, such as apparent density, color, the presence of functional groups, morphology, and thermal stability, as well as the correlation between them and their antimicrobial and optical properties. Natural antioxidants such as anthocyanins (from cranberry; blueberry and pomegranate); betalains (from beetroot and pitaya); resveratrol (from grape); and thymol and carvacrol (from oregano) were added to the films. Few changes in the position and intensity of the FTIR spectra bands were observed despite the low content of extract added to the films. Due to this fact, the antioxidants were extracted and identified by spectroscopic analysis; and they were also quantified using the Folin-Denis method and a gallic acid calibration curve, which confirmed the presence of natural antioxidants in the films. According to the SEM analysis, the presence of natural antioxidants has no influence on the film morphology because the stretch marks and white points that were observed were related to starch presence. On the other hand, the TGA analysis showed that the type of extract influences the total weight loss. The overall interpretation of the results suggests that the use of natural antioxidants as additives for chitosan-starch film preparation has a prominent impact on most of the critical properties that are decisive in making them suitable for food-packing applications.

Natural extracts possess several kinds of antioxidants (anthocyanins, betalains, thymol, carvacrol, and resveratrol) that have also demonstrated antimicrobial properties. In order to study these properties, extracts from cranberry, blueberry, beetroot, pomegranate, oregano, pitaya, and resveratrol (from grapes) were obtained. Growth inhibition tests of mesophilic aerobes, coliforms, and fungi were conducted in films prepared from the extracts in accordance with Mexican Official Norms (NOM). Optical properties such as transparency and opacity, mechanical properties, and pH were also analyzed in these materials. The films with beetroot, cranberry, and blueberry extracts demonstrated the best antimicrobial activity against various bacteria and fungi in comparison with unmodified chitosan–starch film. This study shows that the addition of antioxidants improved the antimicrobial performance of these films. It was also found that antimicrobial properties are inherent to the films. These polymers combined with the extracts effectively inhibit or reduce microorganism growth from human and environmental contact; therefore, previous sterilization could be unnecessary in comparison with traditional plastics. The presence of extracts decreased transmittance percentages at 280 and 400 nm, as well as the transparency values, while increasing their opacity values, providing better UV–VIS light barrier properties. Despite diminished glass transition temperatures (Tg), the values obtained are still adequate for food packaging applications.

Some organic compounds are known to self-assemble into nanotubes in solutions, but the packing of the molecules into the walls of the tubes is known only in a very few cases. Herein, we study two compounds forming nanotubes in alkanes. They bear a secondary alkanamide chain linked to a benzoic acid propyl ester (HUB-3) or to a butyl ester (HUB-4). They gel alkanes for concentrations above 0.2 wt.%. The structures of these gels, studied by freeze fracture electron microscopy, exhibit nanotubes: for HUB-3 their external diameters are polydisperse with a mean value of 33.3 nm; for HUB-4, they are less disperse with a mean value of 25.6 nm. The structure of the gel was investigated by small- and wide-angle X-ray scattering. The evolution of the intensities show that the tubes are metastable and transit slowly toward crystals. The intensities of the tubes of HUB-4 feature up to six oscillations. The shape of the intensities proves the tubular structure of the aggregates, and gives a measurement of 20.6 nm for the outer diameters and 11.0 nm for the inner diameters. It also shows that the electron density in the wall of the tubes is heterogeneous and is well described by a model with three layers.

A family of alkoxybenzoate derivatives was synthesized and were found to selectivity congeal protic/aprotic polar solvents, gasoline, and oils over water; therefore, these organogelators could be used in water remediation as removal agents of fuels and oils. Due to their thermoreversibility, they can be easily separated from the mixtures and be reused; being good candidates for fuel recovery. The π-π stacking interactions were evaluated to establish a relationship between their chemical structure and the gelation process through UV–vis spectroscopy; the three-dimensional network was studied with polarized optical microscopy (POM) and scanning electron microscopy (SEM). It was found that the aromatic ring acts as a stacking unit due to the π-π interactions; the ester group provides a source of dipole–dipole interactions; and the alkyl chains in the ether group showed a significant influence in gelation with the increase of carbon atoms, which increases the effect of nonpolar dispersion interactions.

Chitosan films were used to remove heavy oil from connate water, deionized water, and seawater. In this research, chitosan–starch films were modified with natural extracts from cranberry, blueberry, beetroot, pomegranate, oregano, pitaya, and grape. These biodegradable, low-cost, eco-friendly materials show an important oil sorption capacity from different water conditions. It was observed that the sorption capacity has a clear correlation with the extract type, quantity, and water pH. In order to understand the physical and chemical properties of the films, they were analyzed according to their apparent density, water content, solubility, and swelling degree by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), gas chromatography–mass spectroscopy (GC–MS), and the determination of surface area using the Brunauer Emmett Teller (BET) method. The results indicate that chitosan–starch films modified with natural extracts can be successfully applied for environmental issues such as oil spill remedy.

Ethyl 4-((11-(hexylamino)-11-oxoundecyl)oxy)benzoate was synthesized using 11-bromoundecanoic acid hexylamide and commercially available ethyl 4-hydroxybenzoate through a Williamson etherification synthesis. The structural characterization was performed using UV-Vis, FT-IR, 1H-NMR, 13C-NMR, and HRMS.

The most complex components in heavy crude oils tend to form aggregates that constitute the dispersed phase in these fluids, showing the high viscosity values that characterize them. Water-in-oil (W/O) emulsions are affected by the presence and concentration of this phase in crude oil. In this paper, a theoretical study based on computational chemistry was carried out to determine the molecular interaction energies between paraffin–asphaltenes–water and four surfactant molecules to predict their effect in W/O emulsions and the theoretical influence on the pressure drop behavior for fluids that move through porous media. The mathematical model determined a typical behavior of the fluid when the parameters of the system are changed (pore size, particle size, dispersed phase fraction in the fluid, and stratified fluid) and the viscosity model determined that two of the surfactant molecules are suitable for applications in the destabilization of W/O emulsions. Therefore, an experimental study must be set to determine the feasibility of the methodology and mathematical model displayed in this work.

In order to remedy the environmental pollution caused by oil spills, new materials with gelation capacity of organic solvents and fuels have been synthetized during the recent years. Among them, some of the most promising materials contain amide groups, which are often incorporated into the chemical structure of organogelators due to their effectiveness in gelling organic solvents through hydrogen bonds. A bisamide derivative of hydroxybenzoic acid (Bis-HUB1) was designed and synthesized in two steps and is able to congeal organic solvents. Gelation tests, critical gelation concentrations, and gel-sol transition temperatures were discussed in terms of its supramolecular interactions. Intermolecular hydrogen bonds and π-π stacking were studied through variable-temperature FTIR and UV-visible spectroscopy, while the structural characterization was performed via freeze-fracture TEM. Interestingly, Bis-HUB1 showed the ability to gel gasoline and diesel from monophasic and biphasic systems, which implies its potential use as a remediation agent in fuel spills. The results encourage further research.

The classification models of the states produced by the gelation tests of alkoxy benzoates require designing several corpora of data based on their characteristics. This work studies a series of alkoxybenzoates and 15 solvents characterized by Hansen Solubility Parameters and the number of carbons on the alkyl tail as a distinctive structural feature for the molecules. These properties were evaluated as attributes on the corpora on the kNN algorithm. Different configurations developed were analyzed, with three corpora designed varying their content according to their attributes. From this study, seem the relevance of some attributes over others on the performance prediction of the products class obtained. The significant samples correctly classified on corpora containing HSP and the number of carbons on the alkyl ether tail of alkoxybenzoates denote the influence of these properties on the classification. Also, the more suitable configurations on kNN, metric, k value, attribute weight is founded according to each corpus.

Ethyl 4-((11-(hexylamino)-11-oxoundecyl)oxy)benzoate was synthesized using 11-bromoundecanoic acid hexylamide and commercially available ethyl 4-hydroxybenzoate through a Williamson etherification synthesis. The structural characterization was performed using UV-Vis, FT-IR, [sup.1] H-NMR, [sup.13] C-NMR, and HRMS.