打破悖论:在聚合物薄膜中同时恢复光和机械性能

Source: Vy M. Dong and Jan Riedel, Department of Chemistry, University of California, Irvine, CA
Polymers are made from macromolecules, which are composed of repeating units (the so called monomeric units). In our modern world, polymers play an important role. One of the first important polymers was nylon, which is a polyamide. It found widespread application in tooth brushes and...

Presented here is a protocol for the recording of muscle velocity recovery cycles (MVRCs), a new method of examining muscle membrane properties. MVRCs enable in vivo assessment of muscle membrane potential and alterations in muscle ion channel function in relation to pathology, and it enables the demonstration of muscle depolarization in neurogenic...

Photoluminescence is a process where a molecule absorbs light energy and re-emits it in the form of light. This phenomenon occurs when a substance absorbs photons, promoting its electrons to higher energy level excited states, followed by a relaxation process in which the electrons return to their original ground state energy levels and emit light. Photoluminescence is widely observed in various materials, including semiconductors, and organic and inorganic compounds.
A pair of electrons in a...

The radical chain-growth polymerization mechanism consists of three steps: initiation, propagation, and termination of polymerization. The polymerization initiates when a free radical generated from the radical initiator adds to the unsaturated bond in the monomer. The unpaired electron of the free radical and one π electron in the unsaturated bond creates a σ bond between the free radical and the monomer. As a result, the other π electron in the unsaturated bond converts this species into...

The mechanism for anionic chain-growth polymerization involves initiation, propagation, and termination steps. In the initiation step, a nucleophilic anion, such as butyl lithium, initiates the polymerization process by attacking the π bond of the vinylic monomer. As a result, a carbanion, stabilized by the electron‐withdrawing group, is generated. The resulting carbanion acts as a Michael donor in the propagation step and attacks the second vinylic monomer, which acts as a Michael...

The cationic polymerization mechanism consists of three steps: initiation, propagation, and termination. In the initiation step of the polymerization process, the π bond of a monomer gets protonated by the Lewis acid catalyst, which is formed from boron trifluoride and water. The protonation of the π bond generates a carbocation stabilized by the electron‐donating group. In the propagation step, the π bond of the second monomer acts as a nucleophile and attacks the...