Abstract: The heats of sorption of water vapor on the calcium chloride (or lithium bromide)-porous matrix (KSK and KSM silica gels and MSM-41 sorbent) composite sorbents and on pure silica gels were measured by calorimetry. It was shown that samples based on KSK mesoporous silica gel can feature (a) adsorption on the surface of silica gel (pure or modified with salt ions) with a heat effect of Q = 76-84 kJ/mol (at sorption values w < 1.0 wt %), (b) formation of lower crystal hydrates of the salt with Q = 66-72 kJ/mol (at 1 wt % < w < 9-14 wt %), and (c) vapor absorption with Q = 50-54 kJ/mol by a salt solution in pores (at w > 9-14 wt %). Sorption mechanisms (a) and (c) were also observed for samples based on KSM microporous silica gel and MSM-41. The possibility of the formation of solid salt hydrates in micropores was discussed. It was revealed that the heats of sorption measured in the regions of formation of hydrates and solutions are close to those obtained earlier by the sorption method. It was shown that the introduction of a hygroscopic salt into silica gel pores substantially increases the sorption capacity of the composite system compared to the initial host matrix.

Cite: Pankratʹev Y.D. , Tokarev M.M. , Aristov Y.I.
Heats of Water Sorption on Silica Gel Containing CaCl2 and LiBr
Russian Journal of Physical Chemistry A. 2001. V.75. N5. P.806-810. WOS Scopus РИНЦ

Original: Панкратьев Ю.Д. , Токарев М.М. , Аристов Ю.И.
Теплоты сорбции воды на силикагеле, содержащем CaCl2 и LiBr
Журнал физической химии. 2001. Т.75. №5. С.902-906. Scopus РИНЦ ANCAN

Dates:

Submitted:	Mar 22, 2000
Published print:	May 1, 2001

Identifiers:

Web of science:	WOS:000168692800022
Scopus:	2-s2.0-0035343654
Elibrary:	13366871

Citing:

DB	Citing
Web of science	8
Scopus	8
Elibrary	8