The absorbing process in isolating and coating process of α-olefin drag reducing polymer was studied by molecular dynamic simulation method, on basis of coating theory of α-olefin drag reducing polymer particles wit...The absorbing process in isolating and coating process of α-olefin drag reducing polymer was studied by molecular dynamic simulation method, on basis of coating theory of α-olefin drag reducing polymer particles with polyurethane as coating material. The distributions of sodium laurate, sodium dodeeyl sulfate, and sodium dodeeyl benzene sulfonate on the surface of α-olefin drag reducing polymer particles were almost the same, but the bending degrees of them were obviously different. The bending degree of SLA molecules was greater than those of the other two surfactant molecules. Simulation results of absorbing and accumulating structure showed that, though hydrophobie properties of surfactant molecules were almost the same, water density around long chain sulfonate sodium was bigger than that around alkyl sulfate sodium. This property goes against useful absorbing and accumulating on the surface of α-olefin drag reducing polymer particles; simulation results of interactions of different surfactant and multiple hydroxyl compounds on surface of particles showed that, interactions of different surfaetant and one kind of multiple hydroxyl compound were similar to those of one kind of surfaetant and different multiple hydroxyl compounds. These two contrast types of interactions also exhibited the differences of absorbing distribution and closing degrees to surface of particles. The sequence of closing degrees was derived from simulation; control step of addition polymerization interaction in coating process was absorbing mass transfer process, so the more closed to surface of particle the multiple hydroxyl compounds were, the easier interactions With isoeyanate were. Simulation results represented the compatibility relationship between surfactant and multiple hydroxyl compounds. The isolating and coating processes of α-olefin drag reducing polymer were further understood on molecule and atom level through above simulation research, and based on the simulation, a referenced theoretical basis was provided for practical optimal selection and experimental preparation of α-olefin drag reducing polymer particles suspension isolation agent.展开更多
Methyl 2-furoate(FAME2)is a model for the potential renewable biofuel of dimethyl furan-2,5-dicarboxylate,with the development of its new synthesis method.The potential energy surfaces of H-abstractions and OHaddition...Methyl 2-furoate(FAME2)is a model for the potential renewable biofuel of dimethyl furan-2,5-dicarboxylate,with the development of its new synthesis method.The potential energy surfaces of H-abstractions and OHadditions between FAME2 and hydroxyl radical(OH)were studied using CCSD(T)/CBS//M062X/ccpVTZ.The subsequent isomerization and decomposition reactions were also determined for the primary radicals produced.The results showed that H-abstraction on the branched methyl group was the dominant channel and that the OH-addition reactions on the furan ring had a significant pressure dependency.The rate coefficients presented here provide important kinetic data to support future improvement of the combustion mechanism of FAME2,and present a sound basis for further research into practical fuels.展开更多
文摘The absorbing process in isolating and coating process of α-olefin drag reducing polymer was studied by molecular dynamic simulation method, on basis of coating theory of α-olefin drag reducing polymer particles with polyurethane as coating material. The distributions of sodium laurate, sodium dodeeyl sulfate, and sodium dodeeyl benzene sulfonate on the surface of α-olefin drag reducing polymer particles were almost the same, but the bending degrees of them were obviously different. The bending degree of SLA molecules was greater than those of the other two surfactant molecules. Simulation results of absorbing and accumulating structure showed that, though hydrophobie properties of surfactant molecules were almost the same, water density around long chain sulfonate sodium was bigger than that around alkyl sulfate sodium. This property goes against useful absorbing and accumulating on the surface of α-olefin drag reducing polymer particles; simulation results of interactions of different surfactant and multiple hydroxyl compounds on surface of particles showed that, interactions of different surfaetant and one kind of multiple hydroxyl compound were similar to those of one kind of surfaetant and different multiple hydroxyl compounds. These two contrast types of interactions also exhibited the differences of absorbing distribution and closing degrees to surface of particles. The sequence of closing degrees was derived from simulation; control step of addition polymerization interaction in coating process was absorbing mass transfer process, so the more closed to surface of particle the multiple hydroxyl compounds were, the easier interactions With isoeyanate were. Simulation results represented the compatibility relationship between surfactant and multiple hydroxyl compounds. The isolating and coating processes of α-olefin drag reducing polymer were further understood on molecule and atom level through above simulation research, and based on the simulation, a referenced theoretical basis was provided for practical optimal selection and experimental preparation of α-olefin drag reducing polymer particles suspension isolation agent.
基金This work was supported by the National Natural Science Foundation of China(No.51776045,No.51676176 and No.51976207)the Project was also sponsored by the Scientific Research Foundation of Guangxi University(No.XGZ170074)the Foundation of State Key Laboratory of Coal Combustion(No.FSKLCCA1908).The numerical calculations in this work were performed on the supercomputing system in the Supercomputing Center of the University of Science and Technology of China.
文摘Methyl 2-furoate(FAME2)is a model for the potential renewable biofuel of dimethyl furan-2,5-dicarboxylate,with the development of its new synthesis method.The potential energy surfaces of H-abstractions and OHadditions between FAME2 and hydroxyl radical(OH)were studied using CCSD(T)/CBS//M062X/ccpVTZ.The subsequent isomerization and decomposition reactions were also determined for the primary radicals produced.The results showed that H-abstraction on the branched methyl group was the dominant channel and that the OH-addition reactions on the furan ring had a significant pressure dependency.The rate coefficients presented here provide important kinetic data to support future improvement of the combustion mechanism of FAME2,and present a sound basis for further research into practical fuels.
