Ionic‐Liquid‐Assisted Sonochemical Synthesis of Carbon‐Nanotube‐Based Nanohybrids: Control in the Structures and Interfacial Characteristics

A versatile, facile, and rapid synthetic method of advanced carbon nanotube (CNT)‐based nanohybrid fabrication, or the so‐called ionic‐liquid‐assisted sonochemical method (ILASM), which combines the supramolecular chemistry between ionic liquids (ILs) and CNTs with sonochemistry for the control in the size and amount of uniformly decorated nanoparticles (NPs) and interfacial engineering, is reported. The excellence in electrocatalysis of hybrid materials with well‐designed nanostructures and favorable interfaces is demonstrated by applying them to electrochemical catalysis. The synthetic method discussed in this report has an important and immediate impact not only on the design and synthesis of functional hybrid nanomaterials by supramolecular chemistry and sonochemistry but also on applications of the same into electrochemical devices such as sensors, fuel cells, solar cells, actuators, batteries, and capacitors.     

Understanding the Antibacterial Mechanism of CuO Nanoparticles: Revealing the Route of Induced Oxidative Stress

To date, there is still a lack of definite knowledge regarding the interaction of CuO nanoparticles with bacteria and the possible permeation of the nanoparticles into bacterial cells. This study was aimed at shedding light on the size‐dependent (from the microscale down to the small nanoscale) antibacterial activity of CuO. The potent antibacterial activity of CuO nanoparticles was found to be due to ROS‐generation by the nanoparticles attached to the bacterial cells, which in turn provoked an enhancement of the intracellular oxidative stress. This paradigm was confirmed by several assays such as lipid peroxidation and reporter strains of oxidative stress. Furthermore, electron microscopy indicated that the small nanoparticles of CuO penetrated the cells. Collectively, the results reported herein may reconcile conflicting concepts in the literature concerning the antibacterial mechanism of CuO nanoparticles, as well as highlight the potential for developing sustainable CuO nanoparticles‐based devices for inhibiting bacterial infections.     

A Zn‐Doped CuO Nanocomposite Shows Enhanced Antibiofilm and Antibacterial Activities Against Streptococcus Mutans Compared to Nanosized CuO

Zinc‐doped copper oxide and copper oxide nanoparticles (NPs) are synthesized and deposited on artificial teeth by sonic irradiation, and the ability of these coatings to restrict biofilm formation by Streptococcus mutans is examined. The CuO and Zn:CuO NP‐coated teeth show significant reductions in biofilm formation of 70% and 88%, respectively, compared to uncoated teeth. The mechanism of the Zn:CuO nanoparticles is investigated, revealing that the nanoparticles attach to and penetrate the bacteria and generate intracellular reactive oxygen species (ROS) that enhance lipid peroxidation and cause cell death. Conversely, the CuO or ZnO NPs do not show this behavior and could not generate intracellular ROS. These results highlight the superior efficacy of Zn:CuO nanocomposites over CuO and ZnO NPs and the role of ROS in their antimicrobial effect.     

超声波在煤浮选中的应用研究

阐述了超声波在煤浮选中的研究与应用现状,介绍了超声化学的作用机理,论述了超声强化浮选的作用机理和应用,阐明了超声辐射对煤浆氧含量、pH值、氧化-还原电位等有积极的影响,同时在优化粒度组成、提高精煤产率、降灰脱硫等方面也具有十分重要的意义。     

声化学法制备格利雅试剂氯化苄基镁的研究

采用声化学法制备出格利雅试剂氯化苄基镁,研究在固定超声功率和频率(500W,25kHz,12个换能器)条件下,溶剂、温度、原料摩尔比、镁粉状态、搅拌对产率的影响,并在此基础上设计正交实验优化各因素。采用气相色谱对产品进行了定性、定量分析,研究表明用声化学法制备格利雅试剂氯化苄基镁的最佳工艺条件为:以新鲜镁粉、氯化苄为原料,THF、乙醚或THF和乙醚的混合液为溶剂,水浴温度约为20℃,不搅拌,产率为81%。     

Facile Ionic Liquid‐Assisted Strategy for Direct Precipitation of Eu2+‐Activated Nanophosphors under Ambient Conditions

This work describes a novel ionic liquid (IL)‐assisted synthesis strategy for a direct and easy production of Eu²⁺‐doped nanoparticles (NPs), where ILs are also used as fluoride sources to avoid the use of elemental fluorine or toxic hydrofluoric acid. Up to now, the direct synthesis of Eu²⁺‐doped nanophosphors consisted of an enormous challenge, due to the oxidation to Eu³⁺ observed in hydrous solution, which is commonly used for the preparation of NPs, generating lattice defects and undesired particle growth or agglomeration by additional reducing steps at high temperatures. In contrast, ILs, unless containing ClO₄ ^– or NO₃ ^– anions, do not present an oxidizing character, allowing the direct precipitation of NPs, e.g., using Eu²⁺ containing starting materials. Here, the undoped and Eu²⁺‐doped BaFCl NPs have been prepared under atmospheric conditions for the first time using ILs as solvents and also as fluoride source, applying sonochemical and microwave‐assisted approaches. In general, this method bears an enormous potential for an easy synthesis of fluoride materials compared to inconvenient solid‐state methods. In addition, the IL plays the role of a strongly attached protecting shell which represents ≈7–8% of the total NPs weight.     

声化学技术在聚合物领域中的研究进展

声化学作为一门新的学科,已经广泛应用于化学及化工领域.本文对声化学及声空化效应进行了简介,并对声化学技术在聚合物领域中(聚合反应、降解反应及聚合物加工过程等)的研究进展进行了综述.     

频率对声致羟自由基形成的影响

本文用声化学效率的概念，报道了频率对声致羟自由基形成的影响，在氮气或空气环境中，高频超声辐照所致ＯＨ的化学产率比低频超声辐照时高。