Equilibrium Phase Relations and Dissociation Enthalpies of Tri-n-butylalkenylphosphonium Bromide Semiclathrate Hydrates
Equilibrium Phase Relations and Dissociation Enthalpies of Tri-n-butylalkenylphosphonium Bromide Semiclathrate Hydrates
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三正丁基烯基溴化鏻半笼形水合物的平衡相关系和解离焓
DOI：
10.1021/acs.jced.2c00146
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发表时间：
2022
影响因子：
--
通讯作者：
T. Hirai
中科院分区：
文献类型：
--
作者：
S. Azuma;J. Shimada;K. Tsunashima,* T. Sugahara,* A. Tani;T. Hirai
半笼状水合物由于具有较高的平衡温度和较大的分解焓而受到人们的广泛关注。季鎓阳离子的烷基长度显著影响季鎓盐SCHs的平衡温度和离解焓。为了研究鎓阳离子中引入双键的影响，本文研究了三正丁基烯基溴化鏻（P444（烯基）-Br：烯基= 3-丁烯基（3 <$1）或4-戊烯基（4 <$1））SCH的热力学稳定性。平衡温度和解离常数被确定为P444（3 ′ 1）-Br SCH为（277.5 ± 0.1）K和（199 ± 2）J/g，和P444（4 × 1）-Br SCH和P444（4 × 1）-Br SCH的平衡温度分别为（274.8 ± 0.1）K和（188 ± 2）J/g，P444（3 × 1）-Br SCH和P444（4 × 1）-Br SCH的平衡温度分别为（274.8 ± 0.1）K和（188 ± 2）J/g。Br SCH的平衡温度低于相应的正烷基SCH（P4444-Br和P4445-Br），但三正丁基烯丙基溴化鏻 SCH的平衡温度高于P4443-Br SCH。
Semiclathrate hydrates (SCHs) have received attention as thermal storage materials because of their equilibrium temperature and relatively large dissociation enthalpy. The alkyl length of quaternary onium cations significantly affects the equilibrium temperature and dissociation enthalpy of quaternary onium salt SCHs. To investigate the effects of the double bond introduced in onium cations, in the present study, the thermodynamic stability of tri-n-butylalkenylphosphonium bromide (P444(alkenyl)-Br: alkenyl = 3-butenyl (3═1) or 4-pentenyl (4═1)) SCH was investigated. The equilibrium temperatures and the dissociation enthalpies were determined to be (277.5 ± 0.1) K and (199 ± 2) J/g for P444(3═1)-Br SCH, and (274.8 ± 0.1) K and (188 ± 2) J/g for P444(4═1)-Br SCH. The equilibrium temperatures of P444(3═1)-Br SCH and P444(4═1)-Br SCH were lower than those of the corresponding normal alkyl SCHs (P4444-Br and P4445-Br), although the equilibrium temperature of tri-n-butylallylphosphonium bromide SCH was higher than that of the P4443-Br SCH.