Detail of "34359-90-5"

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Determination of Krafft point and CMC of hexadecylpyridinium salts in electrolyte solutions

Determination of Krafft point and CMC of hexadecylpyridinium salts in electrolyte solutions. Heckmann, Klaus; Schwarz, Reinhard; Strnad, Jiri (Univ. Regensburg, Regensburg D-8400, Fed. Rep. Ger.). J. Colloid Interface Sci., 120(1), 114-17 (English) 1987. CODEN: JCISA5. ISSN: 0021-9797. DOCUMENT TYPE: Journal CA Section: 66 (Surface Chemistry and Colloids) The Krafft points and the crit. micelle concn. (CMC) were detd. for eight hexadecylpyridinium salts with various counterions. The Krafft points were measured photometrically using a home-made app. The agreement between the CMCs and the Krafft points detd. from the change of the surface tension and from the anal. detd. soly. curve resp. is very good. 34359-90-5 is also in the experiment. Krafft points and CMCs increase and decrease resp. monotonously with increasing electrolyte concn. for the system CPNO3/KNO3 (CP+ = hexadecylpyridinium cation). The same dependencies in the systems CPNO3/HNO3 and CPNO3/LiNO3 show min. at relatively high electrolyte concns. The Krafft points of hexadecylpyridinium salts with various anions in water increase in the order SO42-, H2PO4- < Cl- < NO3- < Tos- < I- < BF4- (Tos- vp-toluenesulfonate). This sequence of anions agrees with the so-called lytropic series, implying the importance of water structure in the Krafft point increase. There seems to be no simple correlation between the Krafft point and the CMC. .