Over the past few years, ionic liquids (ILs) have been widely reported as reaction media for reverse atom transfer radical polymerization (ATRP). In particular, almost all the ILs with the structure [Hmim][RCOO] (R represents an alkyl group) have been used as ligands for a reverse ATRP system. However, the facile, simple and low-cost ILs, 1-alkyl-3-methylimidazole chloride ([Rmim][Cl]), have rarely been employed as ligands for reverse ATRP. In this article, a [Rmim][Cl] was successfully employed as a ligand for the reverse ATRP of methyl methacrylate with Fe(III) as catalyst and 2,2′-azobisisobutyronitrile as initiator. The key to success is to adjust the FeCl3/[Rmim][Cl] molar ratio value to 1 : 1. The results indicated that the polymerization with [Rmim][Cl] as a ligand proceeded in a controlled/“living” fashion, as evidenced by the first-order kinetic plot, low polydispersity index values, and increase in polymer molecular weight with monomer conversion. The effects of various experimental parameters, including different catalysts, reaction temperatures, solvents, and molar ratios of FeCl3/[Rmim][Cl], on the polymerization were investigated in detail. Furthermore, 1H NMR and gel permeation chromatography analyses confirmed the halogen-containing chain-end functionality of the resultant polymer.
Plastic waste has caused severe environmental problems. Some additives in plastics, like organophosphates, enter the environment with plastic waste, causing significant harm to plants and creatures. However, the primary method of recycling phosphorus-containing plastic, especially polycarbonate and acrylonitrile-butadiene-styrene copolymer (PC/ABS), is a mechanical method, which not only does not effectively separate plastics and organophosphates but also tends to cause polymer degradation during recycling. In order to overcome these problems, we proposed an efficient and sustainable approach to recycle of phosphorus-containing plastic. In this method, N, N -dimethylcyclohexylamine (DMCHA), a switchable hydrophilicity solvent (SHS), was used to react with and extract organophosphates in plastic, achieving the goal of complete separation of plastic and organophosphates. PC/ABS can be recovered by precipitation. Dissolved organophosphates can also be easily recovered due to the switching characteristics of SHS. Both of recovered materials were of high purity and were close to virgin materials. This technique is an easy and efficient approach to separate plastic and organophosphates, which has excellent application prospects in recycling phosphorus-containing plastic.
A water-processable blue fluorescent silver nanoparticle@graphene–polymer composite (Ag@G–pNIPAM) consisting of graphene coated with a thermally responsive poly-(N-isopropylacrylamide) (pNIPAM) shell is prepared. The pNIPAM shell swells or collapses as a function of temperature, serving as a means to trap silver nanoparticles in solution and get them sufficiently close to the graphene core to provide fluorescence enhancement based on the local surface plasmon resonance (LSPR) effect. The unique thermoresponsive properties and high enhancement ratio of the material should find application in solution fluorescence enhancers and a variety of biomedical applications, such as cellular uptake, sensing and imaging.
危险品化学品经营许可证（带存储）