Yirong Feng,Mengbo Zhang,Haomiao Zhang,Jingdai Wang,Yongrong Yang
We present a 3D-printed continuous flow platform for controllable synthesis of isobutylaluminoxanes (IBAO), an effective olefin polymerization co-catalyst, via the highly exothermic hydrolytic reaction of triisobutylaluminum (TIBA). This platform encompasses modules of mixing and reaction, in-line separation, and in situ UV–vis characterization. In addition, two NMR protocols are established to validate the results of in-line UV–vis analysis (by 31 P NMR) and reveal product structures (by 1 H NMR). Measured temperature profiles over the reactor indicate essentially fast heat removal, ensuring inherent safety. Co-catalytic activities of IBAO are obtained from ethylene oligomerization experiments using an iron-based catalyst system at atmospheric pressure. Furthermore, we investigate the influence of key operating parameters including temperature, initial molar ratio between water and TIBA, initial TIBA concentration, and residence time. A high IBAO yield over 98% and a superior co-catalytic activity of ~ 5000 kg·(mol Fe) –1 ·h −1 are achieved with optimal parameters in this single-pass platform, demonstrating the advantages of process.
Rapid detection of pesticide residues based on enzyme mimics has recently attracted much interest. However, most nanozymes have low activity. Herein, a “single-atom Ce-N-C nanozyme” (SACe-N-C nanozyme) was rationally devised and verified to mimic peroxidase (POD-like) with superior activity. Based on its high POD-like activities and cascaded catalytic reactions with acetylcholinesterase (AChE), we constructed a bioactive paper for the detection of pesticide residues, which offered a portable approach to monitor fruits and vegetables within 30 min. More importantly, a 3D printed platform was integrated on the basis of SACe-N-C bioactive paper to achieve on-site portable testing of omethoate, methamidophos, carbofuran, and carbosulfan, showing limits of detection (LODs) of 55.83, 71.51, 81.81, and 74.98 ng/mL, respectively. The recovery rates were 84.09–104.68%. This study provided new insight into the design of novel single-atom nanozymes for cascaded catalytic detection and other rapid detection applications with high efficiency and low cost.
危险品化学品经营许可证（带存储）