Microencapsulated n-alkanes as energy- storage materials have promising application prospects. The ndcrocapsules containing 100 - 50 wt% of n - octadecane, 0 -20 wt% of paraffin and 0 - 30 wt% of cyclohexane were synt...Microencapsulated n-alkanes as energy- storage materials have promising application prospects. The ndcrocapsules containing 100 - 50 wt% of n - octadecane, 0 -20 wt% of paraffin and 0 - 30 wt% of cyclohexane were synthesized by in-situ polymerization using melamine- formaldehyde polymer as shell. Cyclohexane was removed after heat-treated the microcapsules at 100℃. The morphologies, cell parameters, phase change properties, thermal stable temperatures of these microcapsules were examined. The diameters of these microcapsules are lower than 5 μm. The effect of paraffin in the microcapsules on the cell parameters of n-octadecane is negligible. The paraff＇m is effectively used as a nucleating agent to decrease the degree of supercooling. The melting enthalpy is decreased from 132 J/g to 111 J/g due to the increase of the cyclohexane contents. The thermal stable temperature is enhanced 6 - 16℃ after heat-treated the microcapsules at 160℃ for 30 min.展开更多
A novel hydroxamic acid,N-hydroxy-9,10-epoxy group-octadecanamide(N-OH-9,10-O-ODA),was synthesised by modifying the structure of oleic acid.The carboxyl group of oleic acid was converted into an N-hydroxy amide group,...A novel hydroxamic acid,N-hydroxy-9,10-epoxy group-octadecanamide(N-OH-9,10-O-ODA),was synthesised by modifying the structure of oleic acid.The carboxyl group of oleic acid was converted into an N-hydroxy amide group,and an epoxy group was introduced into its structure.N-OH-9,10-O-ODA was used as a novel collector in the flotation separation of spodumene from one of its associated gangue minerals,specifically albite.N-OH-9,10-O-ODA exhibits remarkable selectivity,with a stronger affinity for collecting spodumene particles compared to albite particles.Zeta potential measurements and X-ray photoelectron spectroscopic analysis reveal that the adsorption quantity of N-OH-9,10-O-ODA on spodumene surface is comparable to that on albite surface.First-principles calculations demonstrate the diverse adsorption configurations of N-OH-9,10-O-ODA on surfaces of spodumene and albite,leading to its distinct collecting abilities for spodumene and albite particles.展开更多
基金National Natural Science Foundation of China (No.50573058)Specialized Research Foundation for the Doctoral Program of Higher Education (No.20050058004)
文摘Microencapsulated n-alkanes as energy- storage materials have promising application prospects. The ndcrocapsules containing 100 - 50 wt% of n - octadecane, 0 -20 wt% of paraffin and 0 - 30 wt% of cyclohexane were synthesized by in-situ polymerization using melamine- formaldehyde polymer as shell. Cyclohexane was removed after heat-treated the microcapsules at 100℃. The morphologies, cell parameters, phase change properties, thermal stable temperatures of these microcapsules were examined. The diameters of these microcapsules are lower than 5 μm. The effect of paraffin in the microcapsules on the cell parameters of n-octadecane is negligible. The paraff＇m is effectively used as a nucleating agent to decrease the degree of supercooling. The melting enthalpy is decreased from 132 J/g to 111 J/g due to the increase of the cyclohexane contents. The thermal stable temperature is enhanced 6 - 16℃ after heat-treated the microcapsules at 160℃ for 30 min.
基金financial support from the National Natural Science Foundation of China(Nos.91962223,52104287,U2067201)Hubei Key Laboratory for Efficient Utilization and Agglomeration of Metallurgic Mineral Resources and Open Foundation of State Key Laboratory of Mineral Processing,China(No.BGRIMM-KJSKL-2022-14)。
文摘A novel hydroxamic acid,N-hydroxy-9,10-epoxy group-octadecanamide(N-OH-9,10-O-ODA),was synthesised by modifying the structure of oleic acid.The carboxyl group of oleic acid was converted into an N-hydroxy amide group,and an epoxy group was introduced into its structure.N-OH-9,10-O-ODA was used as a novel collector in the flotation separation of spodumene from one of its associated gangue minerals,specifically albite.N-OH-9,10-O-ODA exhibits remarkable selectivity,with a stronger affinity for collecting spodumene particles compared to albite particles.Zeta potential measurements and X-ray photoelectron spectroscopic analysis reveal that the adsorption quantity of N-OH-9,10-O-ODA on spodumene surface is comparable to that on albite surface.First-principles calculations demonstrate the diverse adsorption configurations of N-OH-9,10-O-ODA on surfaces of spodumene and albite,leading to its distinct collecting abilities for spodumene and albite particles.
