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- W2001048975 abstract "Eight bolaform amphiphiles were synthesised and characterised; 4 α,ω-hydroxy-alkane trialkyl (and pyridyl) ammonium bromides and 4 α,ω-carboxy-alkane trialkyl (and pyridyl) ammonium bromides where the alkyl groups were methyl, ethyl and propyl. Four of these represented new compounds. Overall the Krafft temperatures (TK) of the eight amphiphiles were high, with 6 of the eight possessing TKs greater than 45 °C. Thus most of the amphiphiles could only expect to find applications at raised temperatures limiting their potential utility. However in addition to the previously reported α,ω-hydroxy-hexadecyl triethylammonium bromide (2b) with a TK of 19.1 °C, another amphiphile, α,ω-carboxy-hexadecyl tripropylammonium bromide (2c) has been identified with a TK near ambient temperatures (TK of 22.1 °C). This provides an acid functional ammonium bolaform amphiphile that micellises at ambient temperatures to complement the hydroxyl derivative. A correlation between TK and the product of the enthalpies and Tms of the compounds was observed for 7 of the eight compounds. No correlation between the amphiphile critical micelle concentrations (cmc) and TKs was observed confirming previous reports that TK values are predominantly determined by crystalline stability rather than solubility. Considerable differences were observed between the various amphiphile TKs at different pHs but no clear trend was apparent for the various compounds (despite the degree to which the compounds’ carboxylic acid and hydroxyl functionalities were likely to be ionised). The cmcs for the amphiphiles were an order of magnitude larger than those for analogous mono-ammonium amphiphiles with little difference in between the hydroxyl- and carboxy-functionalised compounds. The aggregation numbers (Nagg) obtained for all compounds were very low (Nagg < 7) and the apparent micellar diameters for the hydroxyl-bolaforms were in the range 1.0–1.4 nm whereas those for the carboxy-compounds were in the range 2.1–2.4 nm. These results strongly suggest a difference in the packing of the two sets of amphiphiles with loose low density aggregates or ‘molecular clusters’ for the carboxy compounds and denser classical micellar type aggregates for the hydroxyl-compounds. In both cases however the sizes and the low aggregation numbers point suggest that these aggregates are more characteristic of the pre-micellar aggregates observed for many amphiphiles but in particular gemini surfactants." @default.
- W2001048975 created "2016-06-24" @default.
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- W2001048975 date "2012-02-01" @default.
- W2001048975 modified "2023-10-11" @default.
- W2001048975 title "Headgroup effects on the krafft temperatures and self-assembly of ω-hydroxy and ω-carboxy hexadecyl quaternary ammonium bromide bolaform amphiphiles: Micelles versus molecular clusters?" @default.
- W2001048975 cites W1491785144 @default.
- W2001048975 cites W1597081070 @default.
- W2001048975 cites W1878969881 @default.
- W2001048975 cites W187995005 @default.
- W2001048975 cites W1964086751 @default.
- W2001048975 cites W1965306364 @default.
- W2001048975 cites W1970254734 @default.
- W2001048975 cites W1972000386 @default.
- W2001048975 cites W1976350222 @default.
- W2001048975 cites W1978696707 @default.
- W2001048975 cites W1978749641 @default.
- W2001048975 cites W1979700083 @default.
- W2001048975 cites W1983441733 @default.
- W2001048975 cites W1987247223 @default.
- W2001048975 cites W1992566921 @default.
- W2001048975 cites W1993180195 @default.
- W2001048975 cites W1993237789 @default.
- W2001048975 cites W1995149071 @default.
- W2001048975 cites W1996254008 @default.
- W2001048975 cites W1997462116 @default.
- W2001048975 cites W1997988238 @default.
- W2001048975 cites W1999942481 @default.
- W2001048975 cites W2001533794 @default.
- W2001048975 cites W2002951878 @default.
- W2001048975 cites W2003177825 @default.
- W2001048975 cites W2007564889 @default.
- W2001048975 cites W2013347876 @default.
- W2001048975 cites W2015538332 @default.
- W2001048975 cites W2016678220 @default.
- W2001048975 cites W2017049918 @default.
- W2001048975 cites W2018619293 @default.
- W2001048975 cites W2021065073 @default.
- W2001048975 cites W2021214982 @default.
- W2001048975 cites W2025561938 @default.
- W2001048975 cites W2031632765 @default.
- W2001048975 cites W2034611491 @default.
- W2001048975 cites W2042329681 @default.
- W2001048975 cites W2044048957 @default.
- W2001048975 cites W2044579101 @default.
- W2001048975 cites W2044902521 @default.
- W2001048975 cites W2045289695 @default.
- W2001048975 cites W2047603324 @default.
- W2001048975 cites W2051137105 @default.
- W2001048975 cites W2052194192 @default.
- W2001048975 cites W2054416435 @default.
- W2001048975 cites W2054699668 @default.
- W2001048975 cites W2054725754 @default.
- W2001048975 cites W2057387078 @default.
- W2001048975 cites W2060051777 @default.
- W2001048975 cites W2068305995 @default.
- W2001048975 cites W2068960135 @default.
- W2001048975 cites W2071342496 @default.
- W2001048975 cites W2075438810 @default.
- W2001048975 cites W2080778237 @default.
- W2001048975 cites W2082276903 @default.
- W2001048975 cites W2082894304 @default.
- W2001048975 cites W2086934375 @default.
- W2001048975 cites W2089334264 @default.
- W2001048975 cites W2092704399 @default.
- W2001048975 cites W2094442148 @default.
- W2001048975 cites W2106463378 @default.
- W2001048975 cites W2116339366 @default.
- W2001048975 cites W2119280206 @default.
- W2001048975 cites W2130882681 @default.
- W2001048975 cites W2140559383 @default.
- W2001048975 cites W2143303707 @default.
- W2001048975 cites W2165142112 @default.
- W2001048975 cites W2316877181 @default.
- W2001048975 cites W2331319842 @default.
- W2001048975 cites W2335571082 @default.
- W2001048975 cites W2753449827 @default.
- W2001048975 cites W3102550750 @default.
- W2001048975 cites W314524984 @default.
- W2001048975 cites W4211017567 @default.
- W2001048975 doi "https://doi.org/10.1016/j.jcis.2011.10.017" @default.
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