Raman Spectroscopic Observations of the Ion Association between Mg2+ and SO42- in MgSO4-Saturated Droplets at Temperatures of <= 380 degrees C

doi:10.1021/acs.jpca.5b02938

CORC > 深海科学与工程研究所 > 中国科学院深海科学与工程研究所 > 深海科学研究部 > 深海极端环境模拟研究实验室

	Raman Spectroscopic Observations of the Ion Association between Mg2+ and SO42- in MgSO4-Saturated Droplets at Temperatures of <= 380 degrees C
	Wan, Ye 1,3; Chou, I-Ming2 ; Hu, Wenxuan 1,3; Wang, Xiaolin 1,3,4
刊名	JOURNAL OF PHYSICAL CHEMISTRY A
	2015-08-27
卷号	119 期号:34 页码:9027-9036
DOI	10.1021/acs.jpca.5b02938
文献子类	Article
英文摘要	Liquid-liquid phase separation was observed in aqueous MgSO4 solutions with excess H2SO4 at elevated temperatures; the aqueous MgSO4/H2SO4 solutions separated into MgSO4-rich droplets (fluid F1) and a MgSO4-poor phase (fluid F2) during heating. The phase separation temperature increases with SO42-/Mg2+ ratio at a constant MgSO4 concentration. At a MgSO4/H2SO4 ratio of 5, the liquid-liquid phase separation temperature decreases with an increase in MgSO4 concentration up to similar to 1.0 mol/kg and then increases at higher concentrations, showing a typical macroscale property of polymer solutions with a lower critical solution temperature (LCST) of similar to 271.4 degrees C. In situ Raman spectroscopic analyses show that the MgSO4 concentration in fluid Fl increases with an increase in temperature, whereas that in fluid F2 decreases with an increase in temperature. In addition, HSO4-, which does not readily form complexes with Mg2+, tends to accumulate in fluid F2. Analyses of the v(1)(SO42-) bands confirmed the presence of four-sulfate species of unassociated SO42- (similar to 980 cm(-1)), contact ion pairs (CIPs; similar to 995 cm(-1), and triple ion pairs (TIPs; similar to 1005 cm(-1)) in aqueous solution, and more complex ion pair chain structure (similar to 1020 cm-1) in fluid Fl. Comparison of the sulfate species in fluids Fl and F2 at 280 degrees C suggests that SO42- in fluid F2 is less associated with Mg2+. On the basis of in situ visual and Raman spectroscopic observations, we suggest that the formation of the complex Mg2+-SO42- ion association might be responsible for the liquid-liquid phase separation. In addition, Raman spectroscopic analyses of the OH stretching bands indicate that the hydrogen bonding in fluid F1 is stronger than that in fluid F2, which might be ascribed to the increasing probability of collision of H2O with Mg2+ and SO42- in fluid F1.
WOS关键词	LIQUID-LIQUID IMMISCIBILITY ; MAGNESIUM-SULFATE ; FLUID INCLUSIONS ; AB-INITIO ; HYGROSCOPIC PROPERTIES ; AQUEOUS-SOLUTION ; ULTRASONIC-ABSORPTION ; SUPERCRITICAL FLUIDS ; HIGH-PRESSURES ; WATER
语种	英语
WOS记录号	WOS:000360415400007
内容类型	期刊论文
源URL	[http://124.16.218.2:8080/handle/183446/493]
专题	深海科学研究部_深海极端环境模拟研究实验室
作者单位	1.Nanjing Univ, Sch Earth Sci & Engn, Inst Energy Sci, Nanjing 210023, Jiangsu, Peoples R China 2.Chinese Acad Sci, Sanya Inst Deep Sea Sci & Engn, Lab Expt Study Deep Sea Extreme Condit, Sanya 572000, Hainan, Peoples R China 3.Nanjing Univ, Sch Earth Sci & Engn, State Key Lab Mineral Deposit Res, Nanjing 210023, Jiangsu, Peoples R China 4.China Univ Petr, State Key Lab Petr Resources & Prospecting, Beijing 102249, Peoples R China
推荐引用方式 GB/T 7714	Wan, Ye,Chou, I-Ming,Hu, Wenxuan,et al. Raman Spectroscopic Observations of the Ion Association between Mg2+ and SO42- in MgSO4-Saturated Droplets at Temperatures of <= 380 degrees C[J]. JOURNAL OF PHYSICAL CHEMISTRY A,2015,119(34):9027-9036.
APA	Wan, Ye,Chou, I-Ming,Hu, Wenxuan,&Wang, Xiaolin.(2015).Raman Spectroscopic Observations of the Ion Association between Mg2+ and SO42- in MgSO4-Saturated Droplets at Temperatures of <= 380 degrees C.JOURNAL OF PHYSICAL CHEMISTRY A,119(34),9027-9036.
MLA	Wan, Ye,et al."Raman Spectroscopic Observations of the Ion Association between Mg2+ and SO42- in MgSO4-Saturated Droplets at Temperatures of <= 380 degrees C".JOURNAL OF PHYSICAL CHEMISTRY A 119.34(2015):9027-9036.