Green Colloid Chemistry: Characterization of Environmentally Friendly Nonionic Surfactant Systems
(2003)- Abstract
- Phase diagrams of mixed alkylglucoside surfactants, n-nonyl-b-D-glucopyranoside and n-decyl-b-D-glucopyranoside (C9G1 and C10G1) have been examined for the purpose of determining the microstructure surrounding a closed-loop miscibiliyt gap. There are large deuterium isotope effects on the phase diagram. NMR-self diffusion, cryoTEM and TRFQ experiments show the presence of long interconnect networks of rod-like micelles throughout the micellar region, down to quite low concentrations. These networks are present throughout the micellar regions of the ternary C9G1/C10G1/H2O system. However, scale models indicate that the networks in the C9G1 rich region have scissions, whereas those in the C10G1 don't. This likely accounts for the difference... (More)
- Phase diagrams of mixed alkylglucoside surfactants, n-nonyl-b-D-glucopyranoside and n-decyl-b-D-glucopyranoside (C9G1 and C10G1) have been examined for the purpose of determining the microstructure surrounding a closed-loop miscibiliyt gap. There are large deuterium isotope effects on the phase diagram. NMR-self diffusion, cryoTEM and TRFQ experiments show the presence of long interconnect networks of rod-like micelles throughout the micellar region, down to quite low concentrations. These networks are present throughout the micellar regions of the ternary C9G1/C10G1/H2O system. However, scale models indicate that the networks in the C9G1 rich region have scissions, whereas those in the C10G1 don't. This likely accounts for the difference in the phase diagrams of C9G1/H2O and C10G1/H2O. Titration studies were also done to investigate the pKa of a fatty acid probe at the interface of a variety of sugar-based surfactants, C9G1, C10G2, C12G2, C12G3. The average pKa observed for all surfactants and concnetrations investigated was 6.3, indicating that alkylglucoside headgroups are better hydrated than ethylene oxide surfactants, are completely nonionic, and as a result should provide a better pKa(0) reference for calculation of the electric potential at interfaces.. Finally, investigations into the influence of nonionic surfactants on dephosphorylation reactions were conducted, as well as the influence of ethylene oxide and alkylglucoside surfactants on nucleophilic substitution reactions. Results indicate that reactions conducted in the palisade layer of micelles are quite different from reactions in solvent with similar "effective dielectric constants"as the palisade layer, due to the difference in hydration. For nucleophilic substitution reactions, surfactant- substrate ethers are found to be the intermediate product in the reaction. (Less)
- Abstract (Swedish)
- Popular Abstract in Swedish
Tensider är amfifila molekyler, vilket innebär att de består av två delar. En av dessa är hydrofil (”vattenälskande”) och den andra är hydrofob (”vattenhatande”). Detta faktum ger tensider speciella egenskaper av vilken den viktigaste är att de självaggregerar i lösningsmedel (främst vatten), och bildar olika typer av aggregat, varav micellen är den mest kända. Dess speciella egenskaper gör tensider avvändbara både i industriella sammanhang och för personligt bruk: de spelar en viktig roll i kosmetika, i läkemedelsformuleringar, i tvättmedel och livsmedel, oavsett om dessa produkter är tillverkade av människan eller är naturliga. Av miljöskäl måste idag många traditionella tensider bytas ut. För... (More) - Popular Abstract in Swedish
Tensider är amfifila molekyler, vilket innebär att de består av två delar. En av dessa är hydrofil (”vattenälskande”) och den andra är hydrofob (”vattenhatande”). Detta faktum ger tensider speciella egenskaper av vilken den viktigaste är att de självaggregerar i lösningsmedel (främst vatten), och bildar olika typer av aggregat, varav micellen är den mest kända. Dess speciella egenskaper gör tensider avvändbara både i industriella sammanhang och för personligt bruk: de spelar en viktig roll i kosmetika, i läkemedelsformuleringar, i tvättmedel och livsmedel, oavsett om dessa produkter är tillverkade av människan eller är naturliga. Av miljöskäl måste idag många traditionella tensider bytas ut. För närvarande äger därför ett intensivt forskningsarbete rum för att utveckla nya, bättre tensider. En nyligen introducerad klass av tensider är ”sockertensider”, så kallade för att de är baserade på glukos som hydrofil del. Dessa bryts i naturen ner till relativt ofarliga substanser; dessutom kan de produceras från förnyelsebara råvaror. De är därför miljövänligare än traditionellt använda tensider. Innan en ny tensid kan introduceras i någon av de ovan nämnda tillämpningarna, måste man karakterisera dess fasbeteende, dvs dess egenskaper i vatten. I detta arbete har fasbeteendet för rena och blandade sockertensider undersökts. I huvudsak har två tensider undersökts: n-nonyl β-D glucopyranoside (C9G1) och n-decy β-D glucopyranoside (C10G1). Ett nästa steg i introduktionen av en ny tensid är att öka förståelsen för hur tensidens egenskaper kan varieras genom att variera tensidens olika delar, koncentration etc. Detta har undersökts genom att studera hur dessa variabler påverkar egenskaperna för en testmolekyl som har introducerats i de aggregat som tensiderna bildar i vatten. Slutligen har sockertensiders inverkan på en nukleofil substitutionsreaktion som utförs i närvaro av tensider undersökts, och effekterna har jämförts med dem som erhålls när traditionella tensider använts i samma reaktion. Sådana tillämpningar av tensider är viktiga: bland annat används de i destruering av substanser ursprungligen avsedda att användas som kemiska vapen. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/465914
- author
- Whiddon, Christy LU
- supervisor
- opponent
-
- Romsted, Larry
- organization
- publishing date
- 2003
- type
- Thesis
- publication status
- published
- subject
- keywords
- nucleophilic substitution, alkylglucosides, bicontinious micelles, self-diffusion NMR, nonionic surfactants, micellar catalysis, Physical chemistry, pKa, Fysikalisk kemi
- pages
- 152 pages
- publisher
- Physical Chemistry 1, Lund University
- defense location
- Sal B, Kemicentrum
- defense date
- 2003-05-23 10:15:00
- ISBN
- 91-7422-017-9
- language
- English
- LU publication?
- yes
- additional info
- Article: I. CR Whiddon, O Söderman. “Unusually large deuteriumisotope effects in the phase diagram of a mixedalkylglucoside surfactant/water system.” Langmuir 17:1803 (2001).II. CR Whiddon, O Söderman and P Hansson. “Physicalchemicalproperties of a mixed alkylglucosidesurfactant/water system: phase behavior, salt effectsand microstructure around a closed-loop miscibilitygap.” Langmuir 18: 4610 (2002).III. CR Whiddon, J Reimer and O. Söderman. “Diffusionthrough branched micellar networks: A case study.”Manuscript.IV. CR Whiddon, CA Bunton and O Söderman. “Titration offatty acids in sugar-derived (APG) surfactants. A 13CNMR study of the effect of headgroup size, chain lengthand concentration on fatty acid pKa at a non-ionicmicellar interface.” J. Phys. Chem. B. 107:1001 (2003).V. CA Bunton, HJ Foroudian, ND Gillitt, CR Whiddon.“Dephosphorylation and aromatic nucleophilicsubstitution in nonionic micelles. The importance ofsubstrate location.” Can. J. Chem. 76: 946 (1998).VI. CA Bunton, HJ Foroudian, ND Gillitt and CR Whiddon.“Reactions of p-nitrophenyl diphenyl phosphinate withfluoride and hydroxide ion in nonionic micelles: kineticsalt effects.” Journal of Colloid and Interface Science215: 64 (1999).VII. CR Whiddon, CA Bunton and O. Söderman. “AromaticNucleophilic Substitution in Nonionic AlkylglucosideMicelles.” Manuscript.
- id
- 2473d10c-57d9-4955-8d23-2f82f25c4a34 (old id 465914)
- date added to LUP
- 2016-04-04 10:30:24
- date last changed
- 2018-11-21 20:59:09
@phdthesis{2473d10c-57d9-4955-8d23-2f82f25c4a34,
abstract = {{Phase diagrams of mixed alkylglucoside surfactants, n-nonyl-b-D-glucopyranoside and n-decyl-b-D-glucopyranoside (C9G1 and C10G1) have been examined for the purpose of determining the microstructure surrounding a closed-loop miscibiliyt gap. There are large deuterium isotope effects on the phase diagram. NMR-self diffusion, cryoTEM and TRFQ experiments show the presence of long interconnect networks of rod-like micelles throughout the micellar region, down to quite low concentrations. These networks are present throughout the micellar regions of the ternary C9G1/C10G1/H2O system. However, scale models indicate that the networks in the C9G1 rich region have scissions, whereas those in the C10G1 don't. This likely accounts for the difference in the phase diagrams of C9G1/H2O and C10G1/H2O. Titration studies were also done to investigate the pKa of a fatty acid probe at the interface of a variety of sugar-based surfactants, C9G1, C10G2, C12G2, C12G3. The average pKa observed for all surfactants and concnetrations investigated was 6.3, indicating that alkylglucoside headgroups are better hydrated than ethylene oxide surfactants, are completely nonionic, and as a result should provide a better pKa(0) reference for calculation of the electric potential at interfaces.. Finally, investigations into the influence of nonionic surfactants on dephosphorylation reactions were conducted, as well as the influence of ethylene oxide and alkylglucoside surfactants on nucleophilic substitution reactions. Results indicate that reactions conducted in the palisade layer of micelles are quite different from reactions in solvent with similar "effective dielectric constants"as the palisade layer, due to the difference in hydration. For nucleophilic substitution reactions, surfactant- substrate ethers are found to be the intermediate product in the reaction.}},
author = {{Whiddon, Christy}},
isbn = {{91-7422-017-9}},
keywords = {{nucleophilic substitution; alkylglucosides; bicontinious micelles; self-diffusion NMR; nonionic surfactants; micellar catalysis; Physical chemistry; pKa; Fysikalisk kemi}},
language = {{eng}},
publisher = {{Physical Chemistry 1, Lund University}},
school = {{Lund University}},
title = {{Green Colloid Chemistry: Characterization of Environmentally Friendly Nonionic Surfactant Systems}},
year = {{2003}},
}