A photocontrolled reversible addition−fragmentation chain transfer (RAFT) process is developed by initiating polymerization through a 1,3‐diaminopropane‐triethylborane (DAPTB)−diphenyl iodonium salt (Ph2I+) complex (DAPTB/Ph2I+) under ambient temperature and atmospheric conditions. Upon demand, this air‐stable DAPTB/Ph2I+ complex is photolyzed to liberate a reactive triethylborane that consumes atmospheric oxygen and generates ethyl radicals, which initiate and mediate RAFT polymerization. Controlled RAFT polymerization is thus achieved without any prior deoxygenation using a novel RAFT chain transfer agent, BP‐FSBC, which contains both benzophenone and sulfonyl fluoride moieties. Furthermore, the kinetics of polymerization reveal that the reaction process is rapid, and well‐defined polymers are produced by a 61% conversion of 2‐hydroxyethyl acrylate (HEA) within 7 min and 77% conversion of N,N‐dimethylacrylamide (DMA) within 10.5 min. The temporal and spatial control of this photopolymerization is also demonstrated by an “on/off” switch of UV irradiation and a painting‐on‐a‐surface approach, respectively. In addition, active chain ends are demonstrated by preparing block copolymers by chain extension and click sulfur(VI)‐fluoride exchange postreaction using RAFT‐derived macrochain transfer agents.
Flexible strain sensors have been extensively studied for their potential value in monitoring human activity and health. However, it is still challenging to develop multifunctional flexible strain sensors with simultaneously...
Solid base CaO was prepared and characterized, which was used to catalyze depolymerization of lignite in supercritical methanol. Methanolysis products were analyzed by gas chromatography-mass spectrometry (GC-MS) and Fourier transform infrared spectroscopy (FTIR). The results showed that the solubility of methanolysis products in organic solvent increased, the majority species of methanolysis products were aliphatic hydrocarbon and oxygenated compounds such as alkyl substitution phenol. CaO can catalyze selective depolymerization of lignite with the reaction of cleavage of ether bond under given condition.
The hydrodynamics of particles of coarse coal slime and quartz of different sizes in a liquid-solid fluidized bed separator were investigated experimentally, including minimum fluidization velocities, bed expansion ratios, and segregation of mixed particles with two methods. Experimental parameters studied included density and size of particle, superficial water velocity and initial static bed height. The results provide a reference for choice of size scope on coarse coal slime separation by liquid-solid fluidized bed separators.
To understand the distribution of the alkylene bridge bonds which connect aromatic moieties and utilize coal effectively, Shenfu coal (SFC), its solvent extraction fractions and carbon disulfide (CS2)/tetrahydrofuran (THF) inextractable matter (RE) were subject to ruthenium ion-catalyzed oxidation (RICO). The results suggest that the carbon number of the alkylene bridge bonds range from C0 to C30 and that dominant alkylene linkage are C2 and C3 in SFC, a,w-diarylalkanes are soluble in a CS2/THF mixed solvent, whereas highly condensed aromatic species in SFC show poor solubility in the CS2/THF mixed solvent.
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