Mengbo Zhang,Yirong Feng,Linjin Lou,Haomiao Zhang,Jingdai Wang,Yongrong Yang
We present a flow strategy to characterize reaction enthalpy and showcase the application in synthesis of alkylaluminoxanes from the fast and exothermic alkylaluminum hydrolysis. Our platform mainly encompasses a three-dimensional printed micromixer and a tubular reactor in an adiabatic vacuum box, aided by a thermal imaging camera to record temperature profiles. The temperature increase at steady state is used to calculate the released heat, which is further decoupled to quantify the reaction enthalpy and enthalpy of mixing. We validate the concept with the classic neutralization reaction between sulfuric acid and sodium hydroxide, with less than 2% deviation from theoretical values. In application, we determine the exothermic reaction enthalpy and the endothermic enthalpy of mixing to be −143.13 and +7.66 kJ/mol for triisobutylaluminum hydrolysis and −164.63 and +5.03 kJ/mol for trimethylaluminum hydrolysis, respectively. The presented platform, on the one hand, yields new insights into the microreactor scale-up for alkylaluminoxane synthesis and, on the other hand, can be readily used to measure reaction enthalpies of other reactions.
The development of advanced membranes for the efficient separation of oil-water emulsions and the degradation of soluble pollutants is crucial for environmental protection. This study presents a Janus composite membrane with Co(CO 3 ) 0.5 OH·0.11H 2 O nanoneedle arrays, fabricated through electrospinning, membrane assembly, surface hydrophobization, and chemical bath deposition (CBD). By controlling the amount of carbon nanofiber (CNF) and CBD time, the membrane's morphology can be optimized for improved performance. In dead-end filtration driven by gravity, the membrane effectively separates stabilized oil-in-water emulsions and demonstrates strong anti-fouling capabilities. Furthermore, the membrane exhibits significant catalytic activation for peroxymonosulfate (PMS), enabling complete restoration of water flux of polluted membranes and purifying emulsions with soluble organic pollutants . To further enhance anti-fouling performance, a novel separation strategy integrating pulse current is proposed. Under the influence of a pulsed electric field, the membrane achieves a permeate flux nearly twice as high as that observed without this external stimulus, while maintaining high separation efficiency. This research advances Janus nanofiber membrane development via electrospinning techniques and supports sustainable treatment of oily wastewater.
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