Antimicrobial Activity of MgB2 Powders Produced via Reactive Liquid Infiltration Method

We report for the first time on the antimicrobial activity of MgB2 powders produced via the Reactive Liquid Infiltration (RLI) process. Samples with MgB2 wt.% ranging from 2% to 99% were obtained and characterized, observing different levels of grain aggregation and of impurity phases. Their antimicrobial activity was tested against Staphylococcus aureus ATCC BAA 1026, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, and Candida albicans ATCC 10231. A general correlation is observed between the antibacterial activity and the MgB2 wt.%, but the sample microstructure also appears to be very important. RLI-MgB2 powders show better performances compared to commercial powders against microbial strains in the planktonic form, and their activity against biofilms is also very similar.

NMR Spectroscopic Study of Chemical Reactions in Mixtures Containing Oleic Acid, Formic Acid, and Formoxystearic Acid

Oleic acid (OA) and formic acid (FA) react to formoxystearic acid (FSA), in the presence of acidic catalysts.This reaction is of interest as OA can be obtained from renewable resources and FSA is a potential precursor for biopolymers.We have recently studied the liquid−liquid equilibrium (LLE) in the uncatalyzed nonreacting system OA + FA + FSA. Thiswork is extended here to the reactive system, in which a reactive liquid−liquid equilibrium (RLLE) exists. The reactionequilibrium is studied by quantitative NMR spectroscopy at temperatures between 333 and 353 K in homogeneous OA-richmixtures. This information is combined with that on the LLE to determine the RLLE. The physicochemical equilibria aremodeled in a thermodynamically consistent way using the associating lattice cluster theory (ALCT). Furthermore, data on thechemical equilibrium of the formation of the OA-isomer elaidic acid (EA) is supplied. Also the decomposition of FA and theformation of estolides (EL), which are oligomers of OA and EA, was observed and quantified.

Novel Hybrid Reactive Distillation with Extraction and Distillation Processes for Furfural Production from an Actual Xylose Solution

Furfural is only derived from lignocellulosic biomass and is an important chemical used in the plastics, agrochemical, and pharmaceutical industries. The existing industrial furfural production process, involving reaction and purification steps, suffers from a low yield and intensive energy use. Hence, major improvements are needed to sustainably upgrade the furfural production process. In this study, the conventional furfural process based on a continuous stirred tank reactor and distillation columns was designed and optimized from an actual aqueous xylose solution via a biomass pretreatment step. Subsequently, a reactive distillation (RD) and extraction/distillation (ED) configuration was proposed for the reaction and purification steps, respectively, to improve the process efficiency. RD can remove furfural instantly from the reactive liquid phase and can separate heavy components from the raw furfural stream, while the ED configuration with toluene and butyl chloride used as extracting solvents can effectively separate furfural from a dilute aqueous stream. The results showed that the hybrid RD-ED process using a butyl chloride solvent saves up to 51.8% and 57.4% of the total investment costs and total annual costs, respectively, compared to the conventional process. Furthermore, environmental impacts were evaluated and compared for all structural alternatives.