Exploring the impact of polyvinylidenefluoride membrane physical properties on the enrichment efficacy of microfluidic electro-membrane extraction of acidic drugs.

Membrane technology has revolutionized various fields with its energy efficiency, versatility, user-friendliness, and adaptability. This study introduces a microfluidic chip, comprised of silicone rubber and polymethylmethacrylate (PMMA) sheets to explore the impacts of polymeric support morphology on electro-membrane extraction efficiency, representing a pioneering exploration in this field. In this research, three polyvinylidenefluoride (PVDF) membranes with distinct pore sizes were fabricated and their characteristics were assessed through field-emission scanning electron microscopy (FESEM), and atomic force microscopy (AFM). This investigation centers on the extraction of three widely prescribed non-steroidal anti-inflammatory drugs: aspirin (ASA), naproxen (NAP), and ibuprofen (IBU). Quantitative parameters in the extraction process including voltage, donor phase flow rate, and acceptor phase composition were optimized, considering the type of membrane as a qualitative factor. To assess the performance of the fabricated PVDF membranes, a comparative analysis with a commercially available Polypropylene (PP) membrane was conducted. Efficient enrichment factors of 30.86, 23.15, and 21.06 were attained for ASA, NAP, and IBU, respectively, from urine samples under optimal conditions using the optimum PVDF membrane. Significantly, the choice of the ideal membrane amplified the purification levels of ASA, NAP, and IBU by factors of 1.6, 7.5, and 40, respectively.

An experimental investigation on the oxidative desulfurization of a mineral lubricant base oil.

In the present study, the oxidative desulfurization (ODS) of Sn 650 base oil with total sulfur content of 10,000 ppmw has been investigated experimentally. The response surface methodology (RSM) considering Box-Behnken design (BBD) was applied to examine the impacts of the oxidation temperature (30-70˚C), hydrogen peroxide to sulfur molar ratio (2-8), and formic acid to sulfur molar ratio (20-60) on the sulfur removal. In the next step, the appropriate values of the independent variables such as stirrer speed (750-1250 rpm), reaction time (60-180 min), and the number of extraction stages (1-4) were determined based on the optimal result obtained from the BBD. The best performance of the ODS process was found at a reaction temperature of 58˚C, an oxidant to sulfur molar ratio of 7.35, a formic acid to sulfur molar ratio of 58.5, a reaction time of 150 min, and a stirrer speed of 1250 rpm for the oxidation reaction. The achieved sulfur removal after oxidation followed by liquid-liquid extraction was 32 %, and 60 % for one extraction and three extraction stages, respectively. The changes in the base oil specifications after the ODS treatment were also investigated.