Search

Abstract Aimed at energy conservation and water saving for the lab, we have designed and constructed one kind of lab-scale small recirculating device of cooling water utilizing a water recirculator coupled to a solar energy system via a self-made multifunctional voltage regulator, which is equipped with an active heat radiator and powered by a solar energy system. It can provide cooling water for 1–3 sets of ordinary refluxing setups in series without additional consumption of water and electricity. The temperature difference between the water in the bucket and the environment is less than 4 °C for eight common solvents in single refluxing set-up or three combined refluxing setups with different solvents in series. In the performance assessment experiments for the refluxing of eight common solvents with different boiling point, the largest solvent loss is less than 6% if the condenser is open to the air in the refluxing time of 8 h, but none obvious solvent loss are found if the condensers were equipped with an oil bubbler. Control experiments indicates that the preparation of bromoethane/ethyl acetate/propyl hexanoate using our water recirculator can achieve almost unanimous yields in relative to those reactions using tap water as cooling water.

Microbial infections due to bacteria, viruses, and molds are a serious threat to both human life and the health of other organisms. To develop inexpensive, easy-to-prepare, efficient, and portable nano-antibacterial materials, as well as to explore the antibacterial prospects of cationic antibacterial agents, in this work, six different membrane materials were prepared by the electrostatic spinning method and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared (FT-IR). The materials were tested for antimicrobial properties using a modified AATCC100-200 test method. Under the most suitable spinning conditions, the doping amount of the cationic antimicrobial agent, CTAB, had the greatest influence on the antimicrobial performance. The antimicrobial performance of PCL/PEO/CS/CTAB0.4 was the highest among the prepared materials, with 83.7% effectiveness against S. aureus and 99.9% against E. coli. The antimicrobial performance was found to be stable. In our study, we determined the most suitable spinning ratio to prepare an inexpensive and efficient cationic antimicrobial agent. Biodegradable, high-antimicrobial-activity antimicrobial materials can be applied as films, and this new nanofiber material has shown great potential in wound dressings and as a mask material due to its remarkable antimicrobial efficiency.